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Middleton A, Hedin BC, Hsu-Kim H. Recovery of Rare Earth Elements from Acid Mine Drainage with Supported Liquid Membranes: Impacts of Feedstock Composition for Extraction Performance. Environ Sci Technol 2024; 58:2998-3006. [PMID: 38287223 PMCID: PMC10868582 DOI: 10.1021/acs.est.3c06445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 01/01/2024] [Accepted: 01/10/2024] [Indexed: 01/31/2024]
Abstract
Acid mine drainage (AMD) from inactive coal mines can be enriched in rare earth elements (REEs) and has gained much attention as an alternative source for these technology-critical metals. However, AMD is a relatively low-grade REE resource in which the abundance of impurities and the composition variability of the feedstock create major uncertainties for the performance of REE extraction technologies. This study sought to identify AMD feedstock variables that influence the extraction efficiency of REEs by supported liquid membranes (SLMs). SLM separation is a process involving a hydrophobic membrane embedded with an extracting solvent that facilitates the selective extraction of REE ions. The major aims were to (1) assess the effectiveness of SLM-based REE separation from several AMD samples representing a spectrum of aqueous composition, (2) determine the effects of AMD storage and holding time on extraction performance, and (3) assess the impact of AMD pretreatment (e.g., filtration and pH adjustment) on REE recovery. The results showed that relative extraction fluxes of REE correlated with AMD characteristics such as pH and major ions such as Fe, Ca, and Mn. The purity of the acid strippant product, expressed as the REE dry weight content, depended on the initial REE concentrations in the AMD source rather than the flux of individual REEs across the membrane. For AMD samples stored for 3 months prior to extraction, REE recovery by SLM separations was substantially decreased if oxidation of Fe(II) to Fe(III) was observed during sample storage. Pretreatment of AMD feedstocks by pH adjustment did not substantially improve the separation performance. Overall, this study establishes primary water quality parameters of AMD that influence the SLM separation flux and product purity. Such insights contribute to a mechanistic understanding of critical metals extractions by SLM for complex and nontraditional feedstocks such as AMD wastes.
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Affiliation(s)
- Andrew Middleton
- Department
of Civil & Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States
| | - Benjamin C. Hedin
- Hedin
Environmental, 195 Castle
Shannon Blvd., Pittsburgh, Pennsylvania 15228, United States
| | - Heileen Hsu-Kim
- Department
of Civil & Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States
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2
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Wadle A, Neal-Walthall N, Ndu U, Hsu-Kim H. Distribution and Homogenization of Multiple Mercury Species Inputs to Freshwater Wetland Mesocosms. Environ Sci Technol 2024; 58:1709-1720. [PMID: 38181227 PMCID: PMC10810159 DOI: 10.1021/acs.est.3c07169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 12/17/2023] [Accepted: 12/18/2023] [Indexed: 01/07/2024]
Abstract
Mercury (Hg)-impaired aquatic ecosystems often receive multiple inputs of different Hg species with varying potentials for transformation and bioaccumulation. Over time, these distinct input pools of Hg homogenize in their relative distributions and bioaccumulation potentials as a result of biogeochemical processes and other aging processes within the ecosystem. This study sought to evaluate the relative time scale for homogenization of multiple Hg inputs to wetlands, information that is relevant for ecosystem management strategies that consider Hg source apportionment. We performed experiments in simulated freshwater wetland mesocosms that were dosed with four isotopically labeled mercury forms: two dissolved forms (Hg2+ and Hg-humic acid) and two particulate forms (nano-HgS and Hg adsorbed to FeS). Over the course of one year, we monitored the four Hg isotope endmembers for their relative distribution between surface water, sediment, and fish in the mesocosms, partitioning between soluble and particulate forms, and conversion to methylated mercury (MeHg). We also evaluated the reactivity and mobility of Hg through sequential selective extractions of sediment and the uptake flux of aqueous Hg in a diffusive gradient in thin-film (DGT) passive samplers. We observed that the four isotope spikes were relatively similar in surface water concentration (ca. 3000 ng/L) immediately after spike addition. At 1-3 months after dosing, Hg concentrations were 1-50 ng/L and were greater for the initially dissolved isotope endmembers than the initially particulate endmembers. In contrast, the Hg isotope endmembers in surface sediments were similar in relative concentration within 2 months after spike addition. However, the uptake fluxes of Hg in DGT samplers, deployed in both the water column and surface sediment, were generally greater for initially dissolved Hg endmembers and lower for initially particulate endmembers. At one year postdosing, the DGT-uptake fluxes were converging toward similar values between the Hg isotope endmembers. However, the relative distribution of isotope endmembers was still significantly different in both the water column and sediment (p < 0.01 according to one-way ANOVA analysis). In contrast, selective sequential extractions resulted in a homogeneous distribution, with >90% of each endmember extracted in the KOH fraction, suggesting that Hg species were associated with sediment organic matter. For MeHg concentrations in surface sediment and fish, the relative contributions from each endmember were significantly different at all sampling time points. Altogether, these results provide insights into the time scales of distribution for different Hg species that enter a wetland ecosystem. While these inputs attain homogeneity in concentration in primary storage compartments (i.e., sediments) within weeks after addition, these input pools remain differentiated for more than one year in terms of reactivity for passive samplers, MeHg concentration, and bioaccumulation.
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Affiliation(s)
- Austin Wadle
- Department
of Civil and Environmental Engineering, Duke University, P.O. Box 90287, Durham, North Carolina 27708, United States
| | - Natalia Neal-Walthall
- Department
of Civil and Environmental Engineering, Duke University, P.O. Box 90287, Durham, North Carolina 27708, United States
| | - Udonna Ndu
- Department
of Civil and Environmental Engineering, Duke University, P.O. Box 90287, Durham, North Carolina 27708, United States
- Harte
Research Institute for Gulf of Mexico Studies, Texas A&M Corpus
Christi, Corpus Christi, Texas 78412, United States
| | - Heileen Hsu-Kim
- Department
of Civil and Environmental Engineering, Duke University, P.O. Box 90287, Durham, North Carolina 27708, United States
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Lalwani P, King DE, Morton KS, Rivera NA, Huayta J, Hsu-Kim H, Meyer JN. Increased cytotoxicity of Pb 2+ with co-exposures to a mitochondrial uncoupler and mitochondrial calcium uniporter inhibitor. Environ Sci Process Impacts 2023; 25:1743-1751. [PMID: 37503664 PMCID: PMC10681630 DOI: 10.1039/d3em00188a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Lead (Pb2+) is an important developmental toxicant. The mitochondrial calcium uniporter (MCU) imports calcium ions using the mitochondrial membrane potential (MMP), and also appears to mediate the influx of Pb2+ into the mitochondria. Since our environment contains mixtures of toxic agents, it is important to consider multi-chemical exposures. To begin to develop generalizable, predictive models of interactive toxicity, we developed mechanism-based hypotheses about interactive effects of Pb2+ with other chemicals. To test these hypotheses, we exposed HepG2 (human liver) cells to Pb2+ alone and in mixtures with other mitochondria-damaging chemicals: carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP), a mitochondrial uncoupler that reduces MMP, and Ruthenium Red (RuRed), a dye that inhibits the MCU. After 24 hours, Pb2+ alone, the mixture of Pb2+ and RuRed, and the mixture of Pb2+ and FCCP caused no decrease in cell viability. However, the combination of all three exposures led to a significant decrease in cell viability at higher Pb2+ concentrations. After 48 hours, the co-exposure to elevated Pb2+ concentrations and FCCP caused a significant decrease in cell viability, and the mixture of all three showed a clear dose-response curve with significant decreases in cell viability across a range of Pb2+ concentrations. We performed ICP-MS analyses on isolated mitochondrial and cytosolic fractions and found no differences in Pb2+ uptake across exposure groups, ruling out altered cellular uptake as the mechanism for interactive toxicity. We assessed MMP following exposure and observed a decrease in membrane potential that corresponds to loss of cell viability but is likely not sufficient to be the causative mechanistic driver of cell death. This research provides a mechanistically-based framework for understanding Pb2+ toxicity in mixtures with mitochondrial toxicants.
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Affiliation(s)
- Pooja Lalwani
- Nicholas School of Environment, Duke University, 308 Research Drive, A354 LSRC Building, Durham, NC 27708, USA.
| | - Dillon E King
- Nicholas School of Environment, Duke University, 308 Research Drive, A354 LSRC Building, Durham, NC 27708, USA.
| | - Katherine S Morton
- Nicholas School of Environment, Duke University, 308 Research Drive, A354 LSRC Building, Durham, NC 27708, USA.
| | | | - Javier Huayta
- Nicholas School of Environment, Duke University, 308 Research Drive, A354 LSRC Building, Durham, NC 27708, USA.
| | | | - Joel N Meyer
- Nicholas School of Environment, Duke University, 308 Research Drive, A354 LSRC Building, Durham, NC 27708, USA.
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Dai Y, Zhou Z, Kim K, Rivera N, Mohammed J, Hsu-Kim H, Chilkoti A, You L. Global control of cellular physiology by biomolecular condensates through modulation of electrochemical equilibria. bioRxiv 2023:2023.10.19.563018. [PMID: 37904914 PMCID: PMC10614965 DOI: 10.1101/2023.10.19.563018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2023]
Abstract
Control of the electrochemical environment in living cells is typically attributed to ion channels. Here we show that the formation of biomolecular condensates can modulate the electrochemical environment in cells, which affects processes globally within the cell and interactions of the cell with its environment. Condensate formation results in the depletion or enrichment of certain ions, generating intracellular ion gradients. These gradients directly affect the electrochemical properties of a cell, including the cytoplasmic pH and hyperpolarization of the membrane potential. The modulation of the electrochemical equilibria between the intra- and extra-cellular environments by biomolecular condensates governs charge-dependent uptake of small molecules by cells, and thereby directly influences bacterial survival under antibiotic stress. The shift of the intracellular electrochemical equilibria by condensate formation also drives a global change of the gene expression profile. The control of the cytoplasmic environment by condensates is correlated with their volume fraction, which can be highly variable between cells due to the stochastic nature of gene expression at the single cell level. Thus, condensate formation can amplify cell-cell variability of the environmental effects induced by the shift of cellular electrochemical equilibria. Our work reveals new biochemical functions of condensates, which extend beyond the biomolecules driving and participating in condensate formation, and uncovers a new role of biomolecular condensates in cellular regulation.
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Affiliation(s)
- Yifan Dai
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708
- Department of Biomedical Engineering, Center for Biomolecular Condensates, Washington University in St. Louis, Saint Louis, MO, 63130
| | - Zhengqing Zhou
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708
| | - Kyeri Kim
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708
| | - Nelson Rivera
- Department of Civil and Environmental Engineering, Duke University, Durham, NC, 27708
| | - Javid Mohammed
- Department of Immunology, Duke University, Durham, NC, 27705
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Duke University, Durham, NC, 27708
| | - Ashutosh Chilkoti
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708
- Center for Quantitative Biodesign, Duke University, Durham, NC 27708
| | - Lingchong You
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708
- Center for Quantitative Biodesign, Duke University, Durham, NC 27708
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710
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Berky AJ, Weinhouse C, Vissoci J, Rivera N, Ortiz EJ, Navio S, Miranda JJ, Mallipudi A, Fixen E, Hsu-Kim H, Pan WK. In Utero Exposure to Metals and Birth Outcomes in an Artisanal and Small-Scale Gold Mining Birth Cohort in Madre de Dios, Peru. Environ Health Perspect 2023; 131:97008. [PMID: 37747404 PMCID: PMC10519195 DOI: 10.1289/ehp10557] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 08/03/2023] [Accepted: 08/09/2023] [Indexed: 09/26/2023]
Abstract
BACKGROUND Few birth cohorts in South America evaluate the joint effect of minerals and toxic metals on neonatal health. In Madre de Dios, Peru, mercury exposure is prevalent owing to artisanal gold mining, yet its effect on neonatal health is unknown. OBJECTIVES We aimed to determine whether toxic metals are associated with lower birth weight and shorter gestational age independently of antenatal care and other maternal well-being factors. METHODS Data are from the COhorte de NAcimiento de MAdre de Dios (CONAMAD) birth cohort, which enrolled pregnant women in Madre de Dios prior to their third trimester and obtained maternal and cord blood samples at birth. We use structural equation models (SEMs) to construct latent variables for the maternal metals environment (ME) and the fetal environment (FE) using concentrations of calcium, iron, selenium, zinc, magnesium, mercury, lead, and arsenic measured in maternal and cord blood, respectively. We then assessed the relationship between the latent variables ME and FE, toxic metals, prenatal visits, hypertension, and their effect on gestational age and birth weight. RESULTS Among 198 mothers successfully enrolled and followed at birth, 29% had blood mercury levels that exceeded the U.S. Centers for Disease Control and Prevention threshold of 5.8 μ g / L and 2 mothers surpassed the former 5 - μ g / dL threshold for blood lead. The current threshold value is 3.5 μ g / dL . Minerals and toxic metals loaded onto ME and FE latent variables. ME was associated with FE (β = 0.24; 95% CI: 0.05, 0.45). FE was associated with longer gestational age (β = 2.31; 95% CI: - 0.3 , 4.51) and heavier birth weight. Mercury exposure was not directly associated with health outcomes. A 1% increase in maternal blood lead shortened gestational age by 0.05 d (β = - 0.75 ; 95% CI: - 1.51 , - 0.13 ), which at the 5 - μ g / dL threshold resulted in a loss of 3.6 gestational days and 76.5 g in birth weight for newborns. Prenatal care visits were associated with improved birth outcomes, with a doubling of visits from 6 to 12 associated with 5.5 more gestational days (95% CI: 1.6, 9.4) and 319 g of birth weight (95% CI: 287.6, 350.7). DISCUSSION Maternal lead, even at low exposures, was associated with shorter gestation and lower birth weight. Studies that focus only on harmful exposures or nutrition may mischaracterize the dynamic maternal ME and FE. SEMs provide a framework to evaluate these complex relationships during pregnancy and reduce overcontrolling that can occur with linear regression. https://doi.org/10.1289/EHP10557.
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Affiliation(s)
- Axel J Berky
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
| | - Caren Weinhouse
- Oregon Institute of Occupational Health Sciences, Oregon Health & Sciences University, Portland, Oregon, USA
| | - Joao Vissoci
- Division of Emergency Medicine, Department of Surgery, Duke University School of Medicine, Durham, North Carolina, USA
| | - Nelson Rivera
- Department of Civil and Environmental Engineering, Pratt School of Engineering, Duke University, Durham, North Carolina, USA
| | - Ernesto J Ortiz
- Duke Global Health Institute, Duke University, Durham, North Carolina, USA
| | - Susy Navio
- Dirección Regional de Salud, Ministerio de Salud del Perú, Madre de Dios, Perú
| | - J Jaime Miranda
- CRONICAS Center of Excellence in Chronic Diseases, Universidad Peruana Cayetano Heredia, Lima, Peru
- School of Medicine, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Andres Mallipudi
- Bellevue Hospital Center/Ronald O. Perelman Department of Emergency Medicine, New York University Grossman School of Medicine, New York, New York, USA
| | - Emma Fixen
- Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Pratt School of Engineering, Duke University, Durham, North Carolina, USA
| | - William K Pan
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
- Duke Global Health Institute, Duke University, Durham, North Carolina, USA
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Koenigsmark F, Rivera NA, Pierce EM, Hsu-Kim H. Dissolution Potential of Elemental Mercury in the Presence of Bisulfide and Implications for Mobilization. Environ Sci Technol 2023; 57:12388-12397. [PMID: 37561589 DOI: 10.1021/acs.est.3c00694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Liquid elemental mercury (Hg0L) pollution can remain in soils for decades and, over time, will undergo corrosion, a process in which the droplet surface oxidizes soil constituents to form more reactive phases, such as mercury oxide (HgO). While these reactive coatings may enhance Hg migration in the subsurface, little is known about the transformation potential of corroded Hg0L in the presence of reduced inorganic sulfur species to form sparingly soluble HgS particles, a process that enables the long-term sequestration of mercury in soils and generally reduces its mobility and bioavailability. In this study, we investigated the dissolution of corroded Hg0L in the presence of sulfide by quantifying rates of aqueous Hg release from corroded Hg0L droplets under different sulfide concentrations (expressed as the S:Hg molar ratio). For droplets corroded in ambient air, no differences in soluble Hg release were observed among all sulfide exposure levels (S:Hg mole ratios ranging from 10-4 to 10). However, for droplets oxidized in the presence of a more reactive oxidant (hydrogen peroxide, H2O2), we observed a 10- to 25-fold increase in dissolved Hg when the oxidized droplets were exposed to low sulfide concentrations (S:Hg ratios from 10-4 to 10-1) relative to droplets exposed to high sulfide concentrations. These results suggest two critical factors that dictate the release of soluble Hg from Hg0L in the presence of sulfide: the extent of surface corrosion of the Hg0L droplet and sufficient sulfide concentration for the formation of HgS solids. The mobilization of Hg0L in porous media, therefore, largely depends on aging conditions in the subsurface and chemical reactivity at the Hg0L droplet interface.
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Affiliation(s)
- Faye Koenigsmark
- Civil and Environmental Engineering, Duke University ,118A Hudson Hall, Box 90287,Durham, North Carolina 27708, United States
| | - Nelson A Rivera
- Civil and Environmental Engineering, Duke University ,118A Hudson Hall, Box 90287,Durham, North Carolina 27708, United States
| | - Eric M Pierce
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Heileen Hsu-Kim
- Civil and Environmental Engineering, Duke University ,118A Hudson Hall, Box 90287,Durham, North Carolina 27708, United States
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Rivera NA, Ling FT, Jin Z, Pattammattel A, Yan H, Chu YS, Peters CA, Hsu-Kim H. Nanoscale heterogeneity of arsenic and selenium species in coal fly ash particles: analysis using enhanced spectroscopic imaging and speciation techniques. Environ Sci Nano 2023; 10:1768-1777. [PMID: 37457049 PMCID: PMC10339362 DOI: 10.1039/d2en01056a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 05/19/2023] [Indexed: 07/18/2023]
Abstract
Coal combustion byproducts are known to be enriched in arsenic (As) and selenium (Se). This enrichment is a concern during the handling, disposal, and reuse of the ash as both elements can be harmful to wildlife and humans if mobilized into water and soils. The leaching potential and bioaccessibility of As and Se in coal fly ash depends on the chemical forms of these elements and their association with the large variety of particles that comprise coal fly ash. The overall goal of this research was to determine nanoscale and microscale solid phase mineral associations and oxidation states of As and Se in fly ash. We utilized nanoscale 2D imaging (30-50 nm spot size) with the Hard X-ray Nanoprobe (HXN) in combination with microprobe X-ray capabilities (∼5 μm resolution) to determine the As and Se elemental associations. Speciation of As and Se was also measured at the nano- to microscale with X-ray absorption spectroscopy. The enhanced resolution of HXN showed As and Se as either diffusely located around or comingled with Ca- and Fe-rich particles. The results also showed nanoparticles of Se attached to the surface of fly ash grains. Overall, a comparison of As and Se species across scales highlights the heterogeneity and complexity of chemical associations for these trace elements of concern in coal fly ash.
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Affiliation(s)
- Nelson A Rivera
- Department of Civil and Environmental Engineering, Duke University Box 90287 Durham North Carolina 27708 USA
| | - Florence T Ling
- Department of Civil and Environmental Engineering, Princeton University Princeton New Jersey 08544 USA
- Environmental Science Program, Department of Chemistry and Biochemistry, La Salle University Philadelphia PA 19141 USA
| | - Zehao Jin
- Department of Civil and Environmental Engineering, Duke University Box 90287 Durham North Carolina 27708 USA
| | - Ajith Pattammattel
- National Synchrotron Light Source II, Brookhaven National Laboratory Upton NY 11973 USA
| | - Hanfei Yan
- National Synchrotron Light Source II, Brookhaven National Laboratory Upton NY 11973 USA
| | - Yong S Chu
- National Synchrotron Light Source II, Brookhaven National Laboratory Upton NY 11973 USA
| | - Catherine A Peters
- Department of Civil and Environmental Engineering, Princeton University Princeton New Jersey 08544 USA
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Duke University Box 90287 Durham North Carolina 27708 USA
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Koenigsmark F, Chiu M, Rivera N, Johs A, Eskelsen J, Leonard D, Robertson BK, Szynkiewicz A, Derolph C, Zhao L, Gu B, Hsu-Kim H, Pierce EM. Crystal lattice defects in nanocrystalline metacinnabar in contaminated streambank soils suggest a role for biogenic sulfides in the formation of mercury sulfide phases. Environ Sci Process Impacts 2023; 25:445-460. [PMID: 36692344 DOI: 10.1039/d1em00549a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
At mercury (Hg)-contaminated sites, streambank erosion can act as a main mobilizer of Hg into nearby waterbodies. Once deposited into the waters, mercury from these soils can be transformed to MeHg by microorganisms. It is therefore important to understand the solid-phase speciation of Hg in streambanks as differences in Hg speciation will have implications for Hg transport and bioavailability. In this study, we characterized Hg solid phases in Hg-contaminated soils (100-1100 mg per kg Hg) collected from the incised bank of the East Fork Poplar Creek (EFPC) in Oak Ridge, TN (USA). The analysis of the soil samples by scanning electron microscopy-energy dispersive spectroscopy indicated numerous microenvironments where Hg and sulfur (S) are co-located. According to bulk soil analyses by extended X-ray absorption fine structure spectroscopy (EXAFS), the near-neighbor Hg molecular coordination in the soils closely resembled freshly precipitated Hg sulfide (metacinnabar, HgS); however, EXAFS fits indicated the Hg in the HgS structure was undercoordinated with respect to crystalline metacinnabar. This undercoordination of Hg-S observed by spectroscopy is consistent with transmission electron microspy images showing the presence of nanocrystallites with structural defects (twinning, stacking faults, dislocations) in individual HgS-bearing particles. Although the soils were collected from exposed parts of the stream bank (i.e., open to the atmosphere), the presence of reduced forms of S and sulfate-reducing microbes suggests that biogenic sulfides promote the formation of HgS nanoparticles in these soils. Altogether, these data demonstrate the predominance of nanoparticulate HgS with crystal lattice defects in the bank soils of an industrially impacted stream. Efforts to predict the mobilization and bioavailability of Hg associated with nano-HgS forms should consider the impact of nanocrystalline lattice defects on particle surface reactivity, including Hg dissolution rates and bioavailability on Hg fate and transformations.
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Affiliation(s)
- Faye Koenigsmark
- Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA
| | - Michelle Chiu
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
| | - Nelson Rivera
- Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA
| | - Alexander Johs
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
| | - Jeremy Eskelsen
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
| | - Donovan Leonard
- Manufacturing Demonstration Facility Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Boakai K Robertson
- Department of Biological Sciences, Alabama State University, Montgomery, AL 36104, USA
| | - Anna Szynkiewicz
- Department of Earth and Planetary Sciences, University of Tennessee at Knoxville, Knoxville, TN 37996, USA
| | - Christopher Derolph
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
| | - Linduo Zhao
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
| | - Baohua Gu
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
| | - Heileen Hsu-Kim
- Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA
| | - Eric M Pierce
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
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Berky AJ, Robie E, Chipa SN, Ortiz EJ, Palmer EJ, Rivera NA, Avalos AMM, Meyer JN, Hsu-Kim H, Pan WK. Risk of lead exposure from wild game consumption from cross-sectional studies in Madre de Dios, Peru. The Lancet Regional Health - Americas 2022; 12. [PMID: 36237535 PMCID: PMC9555248 DOI: 10.1016/j.lana.2022.100266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Background Methods Findings Interpretation
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Affiliation(s)
- Axel J. Berky
- Nicholas School of the Environment, Duke University, Grainger Hall, 9 Circuit Drive, Box 90328, Durham, NC 27708, USA
- Corresponding author.
| | - Emily Robie
- Duke Global Health Institute, Duke University, NC 27080, USA
| | | | - Ernesto J. Ortiz
- Duke Global Health Innovations Centre, Duke University, NC 27080, USA
| | - Emma J. Palmer
- Civil Architectural and Environmental Engineering, University of Texas at Austin, TX 78712, USA
| | - Nelson A. Rivera
- Department of Civil and Environmental Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA
| | - Ana Maria Morales Avalos
- Dirección Ejecutiva de Medicina Alternativa y Complementaria, Instituto Nacional de Salud, Lima, Peru
| | - Joel N. Meyer
- Nicholas School of the Environment, Duke University, Grainger Hall, 9 Circuit Drive, Box 90328, Durham, NC 27708, USA
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA
| | - William K. Pan
- Nicholas School of the Environment, Duke University, Grainger Hall, 9 Circuit Drive, Box 90328, Durham, NC 27708, USA
- Duke Global Health Institute, Duke University, NC 27080, USA
- Corresponding author at: Dirección Regional de Salud, Madre de Dios, Peru.
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10
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Kose-Mutlu B, Hsu-Kim H, Wiesner MR. Separation of rare earth elements from mixed-metal feedstocks by micelle enhanced ultrafiltration with sodium dodecyl sulfate. Environ Technol 2022; 43:1013-1025. [PMID: 32812520 DOI: 10.1080/09593330.2020.1812732] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 08/06/2020] [Indexed: 06/11/2023]
Abstract
Micelle enhanced ultrafiltration (MEUF) is a surfactant-based membrane separation process that may be used to separate target ions from mixed metal aqueous solutions, such as leachates of coal ash and other geological wastewaters. The ability of MEUF to separate rare earth elements (REEs) was evaluated using sodium dodecyl sulfate (SDS) as the sorbent in surfactant micelle phase, which was subsequently separated using ultrafiltration, acidification, and ferricyanide precipitation. Separation experiments were performed with a synthetic coal ash leachate feedstock as an example mixed-metal feedstock. Experiments tested the influence of surfactant concentration, pH, and co-existing competitive ions on REE recoveries, and also tested methods for SDS recovery and reuse. Membrane rejection efficiencies of REEs were 97% and 71% respectively for synthetic and real leachate under optimized operating conditions. A two-step process of precipitation with CaCl2 and Na2CO3 following membrane separation was the best for recovering SDS with a yield of 99.7%.
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Affiliation(s)
- Borte Kose-Mutlu
- Department of Civil Engineering, Yeditepe University, Istanbul, Turkey
- Department of Civil and Environmental Engineering, Pratt School of Engineering, Duke University, Durham, NC, USA
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Pratt School of Engineering, Duke University, Durham, NC, USA
| | - Mark R Wiesner
- Department of Civil and Environmental Engineering, Pratt School of Engineering, Duke University, Durham, NC, USA
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11
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Neal-Walthall N, Ndu U, Rivera NA, Elias DA, Hsu-Kim H. Utility of Diffusive Gradient in Thin-Film Passive Samplers for Predicting Mercury Methylation Potential and Bioaccumulation in Freshwater Wetlands. Environ Sci Technol 2022; 56:1743-1752. [PMID: 35044747 PMCID: PMC9630924 DOI: 10.1021/acs.est.1c06796] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Mercury is a risk in aquatic ecosystems when the metal is converted to methylmercury (MeHg) and subsequently bioaccumulates in aquatic food webs. This risk can be difficult to manage because of the complexity of biogeochemical processes for mercury and the need for accessible techniques to navigate this complexity. Here, we explored the use of diffusive gradient in thin-film (DGT) passive samplers as a tool to simultaneously quantify the methylation potential of inorganic Hg (IHg) and the bioaccumulation potential of MeHg in freshwater wetlands. Outdoor freshwater wetland mesocosms were amended with four isotopically labeled and geochemically relevant IHg forms that represent a range of methylation potentials (202Hg2+, 201Hg-humic acid, 199Hg-sorbed to FeS, and 200HgS nanoparticles). Six weeks after the spikes, we deployed DGT samplers in the mesocosm water and sediments, evaluated DGT-uptake rates of total Hg, MeHg, and IHg (calculated by difference) for the Hg isotope spikes, and examined correlations with total Hg, MeHg, and IHg concentrations in sediment, water, and micro and macrofauna in the ecosystem. In the sediments, we observed greater relative MeHg concentrations from the initially dissolved IHg isotope spikes and lower MeHg levels from the initially particulate IHg spikes. These trends were consistent with uptake flux of IHg into DGTs deployed in surface sediments. Moreover, we observed correlations between total Hg-DGT uptake flux and MeHg levels in periphyton biofilms, submergent plant stems, snails, and mosquitofish in the ecosystem. These correlations were better for DGTs deployed in the water column compared to DGTs in the sediments, suggesting the importance of vertical distribution of bioavailable MeHg in relation to food sources for macrofauna. Overall, these results demonstrate that DGT passive samplers are a relatively simple and efficient tool for predicting IHg methylation and MeHg bioaccumulation potentials without the need to explicitly delineate IHg and MeHg speciation and partitioning in complex ecosystems.
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Affiliation(s)
- Natalia Neal-Walthall
- Department of Civil and Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States
| | - Udonna Ndu
- Department of Civil and Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States
- Harte Research Institute for Gulf of Mexico Studies, Texas A&M Corpus Christi, Corpus Christi, TX, 78412, United States
| | - Nelson A. Rivera
- Department of Civil and Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States
| | - Dwayne A. Elias
- Elias Consulting, LLC, Knoxville, Tennessee 37934, United States
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States
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12
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Gerson JR, Szponar N, Zambrano AA, Bergquist B, Broadbent E, Driscoll CT, Erkenswick G, Evers DC, Fernandez LE, Hsu-Kim H, Inga G, Lansdale KN, Marchese MJ, Martinez A, Moore C, Pan WK, Purizaca RP, Sánchez V, Silman M, Ury EA, Vega C, Watsa M, Bernhardt ES. Amazon forests capture high levels of atmospheric mercury pollution from artisanal gold mining. Nat Commun 2022; 13:559. [PMID: 35091543 PMCID: PMC8799693 DOI: 10.1038/s41467-022-27997-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 12/16/2021] [Indexed: 11/10/2022] Open
Abstract
Mercury emissions from artisanal and small-scale gold mining throughout the Global South exceed coal combustion as the largest global source of mercury. We examined mercury deposition and storage in an area of the Peruvian Amazon heavily impacted by artisanal gold mining. Intact forests in the Peruvian Amazon near gold mining receive extremely high inputs of mercury and experience elevated total mercury and methylmercury in the atmosphere, canopy foliage, and soils. Here we show for the first time that an intact forest canopy near artisanal gold mining intercepts large amounts of particulate and gaseous mercury, at a rate proportional with total leaf area. We document substantial mercury accumulation in soils, biomass, and resident songbirds in some of the Amazon's most protected and biodiverse areas, raising important questions about how mercury pollution may constrain modern and future conservation efforts in these tropical ecosystems.
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Affiliation(s)
- Jacqueline R Gerson
- Department of Biology, Duke University, Durham, NC, 27708, USA.
- Duke Global Health Institute, Duke University, Durham, NC, 27708, USA.
| | - Natalie Szponar
- Department of Earth Sciences, University of Toronto, Toronto, ON, M5S 3B1, Canada
| | | | - Bridget Bergquist
- Department of Earth Sciences, University of Toronto, Toronto, ON, M5S 3B1, Canada
| | - Eben Broadbent
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL, 32611, USA
| | - Charles T Driscoll
- Department of Civil and Environmental Engineering, Syracuse University, Syracuse, NY, 13244, USA
| | - Gideon Erkenswick
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Field Projects International, Escondido, CA, 92029, USA
| | - David C Evers
- Biodiversity Research Institute, Portland, ME, 04103, USA
| | - Luis E Fernandez
- Centro de Innovación Científica Amazónica (CINCIA), Puerto Maldonado, Peru
- Center for Energy, Environment, and Sustainability (CEES), Wake Forest University, Winston-Salem, NC, 27109, USA
- Department of Biology, Wake Forest University, Winston-Salem, NC, 27109, USA
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Duke University, Durham, NC, 27708, USA
| | - Giancarlo Inga
- San Diego Zoo Wildlife Alliance, San Diego, CA, 92101, USA
| | - Kelsey N Lansdale
- Environmental Science Program, Duke University, Durham, NC, 27708, USA
| | - Melissa J Marchese
- Duke Global Health Institute, Duke University, Durham, NC, 27708, USA
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Ari Martinez
- Department of Biological Sciences, California State University, Long Beach, CA, 90840, USA
| | - Caroline Moore
- San Diego Zoo Wildlife Alliance, San Diego, CA, 92101, USA
| | - William K Pan
- Duke Global Health Institute, Duke University, Durham, NC, 27708, USA
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | | | - Victor Sánchez
- Instituto de Investigación en Ecología y Conservación (IIECOO), La Libertad, Peru
| | - Miles Silman
- Centro de Innovación Científica Amazónica (CINCIA), Puerto Maldonado, Peru
- Center for Energy, Environment, and Sustainability (CEES), Wake Forest University, Winston-Salem, NC, 27109, USA
- Department of Biology, Wake Forest University, Winston-Salem, NC, 27109, USA
| | - Emily A Ury
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - Claudia Vega
- Centro de Innovación Científica Amazónica (CINCIA), Puerto Maldonado, Peru
- Center for Energy, Environment, and Sustainability (CEES), Wake Forest University, Winston-Salem, NC, 27109, USA
- Department of Biology, Wake Forest University, Winston-Salem, NC, 27109, USA
| | - Mrinalini Watsa
- Field Projects International, Escondido, CA, 92029, USA
- San Diego Zoo Wildlife Alliance, San Diego, CA, 92101, USA
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13
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Mello DF, Maurer LL, Ryde IT, Song DH, Marinakos SM, Jiang C, Wiesner MR, Hsu-Kim H, Meyer JN. In Vivo Effects of Silver Nanoparticles on Development, Behavior, and Mitochondrial Function are Altered by Genetic Defects in Mitochondrial Dynamics. Environ Sci Technol 2022; 56:1113-1124. [PMID: 35038872 PMCID: PMC8802983 DOI: 10.1021/acs.est.1c05915] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Silver nanoparticles (AgNPs) are extensively used in consumer products and biomedical applications, thus guaranteeing both environmental and human exposures. Despite extensive research addressing AgNP safety, there are still major knowledge gaps regarding AgNP toxicity mechanisms, particularly in whole organisms. Mitochondrial dysfunction is frequently described as an important cytotoxicity mechanism for AgNPs; however, it is still unclear if mitochondria are the direct targets of AgNPs. To test this, we exposed the nematodeCaenorhabditis elegans to sublethal concentrations of AgNPs and assessed specific mitochondrial parameters as well as organismal-level endpoints that are highly reliant on mitochondrial function, such as development and chemotaxis behavior. All AgNPs tested significantly delayed nematode development, disrupted mitochondrial bioenergetics, and blocked chemotaxis. However, silver was not preferentially accumulated in mitochondria, indicating that these effects are likely not due to direct mitochondria-AgNP interactions. Mutant nematodes with deficiencies in mitochondrial dynamics displayed both greater and decreased susceptibility to AgNPs compared to wild-type nematodes, which was dependent on the assay and AgNP type. Our study suggests that AgNPs indirectly promote mitochondrial dysfunction, leading to adverse outcomes at the organismal level, and reveals a role of gene-environment interactions in the susceptibility to AgNPs. Finally, we propose a novel hypothetical adverse outcome pathway for AgNP effects to guide future research.
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Affiliation(s)
- Danielle F. Mello
- Center for the Environmental Implications of Nanotechnology, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
- To whom correspondence should be addressed: and
| | - Laura L. Maurer
- Center for the Environmental Implications of Nanotechnology, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
| | - Ian T. Ryde
- Center for the Environmental Implications of Nanotechnology, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
| | - Dong Hoon Song
- Simulation Group, Samsung SDI, Suwon-si, Gyeonggi-do, Republic of Korea
| | - Stella M. Marinakos
- Center for the Environmental Implications of Nanotechnology, Department of Civil & Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Chuanjia Jiang
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin 300350, P. R. China
| | - Mark R. Wiesner
- Center for the Environmental Implications of Nanotechnology, Department of Civil & Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Heileen Hsu-Kim
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin 300350, P. R. China
| | - Joel N. Meyer
- Center for the Environmental Implications of Nanotechnology, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
- To whom correspondence should be addressed: and
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Koenigsmark F, Weinhouse C, Berky AJ, Morales AM, Ortiz EJ, Pierce EM, Pan WK, Hsu-Kim H. Efficacy of Hair Total Mercury Content as a Biomarker of Methylmercury Exposure to Communities in the Area of Artisanal and Small-Scale Gold Mining in Madre de Dios, Peru. Int J Environ Res Public Health 2021; 18:13350. [PMID: 34948962 PMCID: PMC8707462 DOI: 10.3390/ijerph182413350] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/06/2021] [Accepted: 12/08/2021] [Indexed: 12/05/2022]
Abstract
Total mercury content (THg) in hair is an accepted biomarker for chronic dietary methylmercury (MeHg) exposure. In artisanal and small-scale gold mining (ASGM) communities, the validity of this biomarker is questioned because of the potential for contamination from inorganic mercury. As mining communities may have both inorganic and organic mercury exposures, the efficacy of the hair-THg biomarker needs to be evaluated, particularly as nations begin population exposure assessments under their commitments to the Minamata Convention. We sought to validate the efficacy of hair THg for public health monitoring of MeHg exposures for populations living in ASGM communities. We quantified both THg and MeHg contents in hair from a representative subset of participants (N = 287) in a large, population-level mercury exposure assessment in the ASGM region in Madre de Dios (MDD), Peru. We compared population MeHg-THg correlations and %MeHg values with demographic variables including community location, sex, occupation, and nativity. We observed that hair MeHg-THg correlations were high (r > 0.7) for all communities, regardless of location or nativity. Specifically, for individuals within ASGM communities, 81% (121 of 150 total) had hair THg predominantly in the form of MeHg (i.e., >66% of THg) and reflective of dietary exposure to mercury. Furthermore, for individuals with hair THg exceeding the U.S. EPA threshold (1.0 μg/g), 88 out of 106 (83%) had MeHg as the predominant form. As a result, had urine THg solely been used for mercury exposure monitoring, approximately 59% of the ASGM population would have been misclassified as having low mercury exposure. Our results support the use of hair THg for monitoring of MeHg exposure of populations in ASGM settings where alternative biomarkers of MeHg exposure are not feasible.
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Affiliation(s)
- Faye Koenigsmark
- Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA;
| | - Caren Weinhouse
- Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA;
| | - Axel J. Berky
- Nicholas School of the Environment, Duke University, 9 Circuit Drive, Durham, NC 27710, USA;
| | - Ana Maria Morales
- Centro Nacional de Salud Intercultural, Instituto Nacional de Salud, Ministerio de Salud, Cápac Yupanqui 1400-Jesus María, Lima 15027, Peru;
| | - Ernesto J. Ortiz
- Duke Global Health Innovation Center, Duke University, 310 Blackwell Street, Durham, NC 27701, USA;
| | - Eric M. Pierce
- Environmental Sciences Division, Oak Ridge National Laboratory, 1 Bethel Valley, Oak Ridge, TN 37831, USA;
| | - William K. Pan
- Nicholas School of the Environment, Duke University, 9 Circuit Drive, Durham, NC 27710, USA;
- Duke Global Health Institute, Duke University, 310 Trent Drive, Durham, NC 27710, USA
| | - Heileen Hsu-Kim
- Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA;
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15
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Wang L, Mello DF, Zucker RM, Rivera NA, Rogers NMK, Geitner NK, Boyes WK, Wiesner MR, Hsu-Kim H, Meyer JN. Lack of Detectable Direct Effects of Silver and Silver Nanoparticles on Mitochondria in Mouse Hepatocytes. Environ Sci Technol 2021; 55:10.1021/acs.est.1c02295. [PMID: 34346225 PMCID: PMC8814061 DOI: 10.1021/acs.est.1c02295] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Silver nanoparticles (AgNPs) are well-proven antimicrobial nanomaterials, yet little is elucidated regarding the mechanism underlying cytotoxicity induced by these nanoparticles. Here, we tested the hypothesis that mitochondria are primary intracellular targets of two AgNPs and silver ions in mouse hepatocytes (AML12) cultured in glucose- and galactose-based media. AML12 cells were more sensitive to mitochondrial uncoupling when grown with galactose rather than glucose. However, 24 h treatments with 15 nm AgNPs and 6 nm GA-AgNPs (5 and 10 μg/mL) and AgNO3 (1 and 3 μg/mL), concentrations that resulted in either 10 or 30% cytotoxicity, failed to cause more toxicity to AML12 cells grown on galactose than glucose. Furthermore, colocalization analysis and subcellular Ag quantification did not show any enrichment of silver content in mitochondria in either medium. Finally, the effects of the same exposures on mitochondrial respiration were mild or undetectable, a result inconsistent with mitochondrial toxicity causing cell death. Our results suggest that neither ionic Ag nor the AgNPs that we tested specifically target mitochondria and are inconsistent with mitochondrial dysfunction being the primary cause of cell death after Ag exposure under these conditions.
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Affiliation(s)
- Lu Wang
- Department of Nicholas School of the Environment, Duke University, Durham, NC, 27708
- Department of Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, No. 174 Shazheng Road, Chongqing 400044, China
| | - Danielle F. Mello
- Department of Nicholas School of the Environment, Duke University, Durham, NC, 27708
| | - Robert M. Zucker
- Department of U.S. Environmental Protection Agency, Office of Research and Development, Center for Public Health and Environmental Assessment, Public Health and Integrated Toxicology Division, Reproductive and Developmental Toxicology Branch, Research Triangle Park, Durham, NC, 27709
| | - Nelson A. Rivera
- Department of Civil & Environmental Engineering, Duke University, Durham, NC, 27708
| | - Nicholas M K Rogers
- Department of Civil & Environmental Engineering, Duke University, Durham, NC, 27708
| | - Nicholas K. Geitner
- Department of U.S. Environmental Protection Agency, Office of Research and Development, Center for Public Health and Environmental Assessment, Public Health and Integrated Toxicology Division, Reproductive and Developmental Toxicology Branch, Research Triangle Park, Durham, NC, 27709
| | - William K. Boyes
- Department of U.S. Environmental Protection Agency, Office of Research and Development, Center for Public Health and Environmental Assessment, Public Health and Integrated Toxicology Division, Reproductive and Developmental Toxicology Branch, Research Triangle Park, Durham, NC, 27709
| | - Mark R. Wiesner
- Department of Civil & Environmental Engineering, Duke University, Durham, NC, 27708
| | - Heileen Hsu-Kim
- Department of Civil & Environmental Engineering, Duke University, Durham, NC, 27708
| | - Joel N. Meyer
- Department of Nicholas School of the Environment, Duke University, Durham, NC, 27708
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16
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McMillan HM, Rogers N, Wadle A, Hsu-Kim H, Wiesner MR, Kuehn MJ, Hendren CO. Microbial vesicle-mediated communication: convergence to understand interactions within and between domains of life. Environ Sci Process Impacts 2021; 23:664-677. [PMID: 33899070 DOI: 10.1039/d1em00022e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
All cells produce extracellular vesicles (EVs). These biological packages contain complex mixtures of molecular cargo and have a variety of functions, including interkingdom communication. Recent discoveries highlight the roles microbial EVs may play in the environment with respect to interactions with plants as well as nutrient cycling. These studies have also identified molecules present within EVs and associated with EV surfaces that contribute to these functions. In parallel, studies of engineered nanomaterials have developed methods to track and model small particle behavior in complex systems and measure the relative importance of various surface features on transport and function. While studies of EV behavior in complex environmental conditions have not yet employed transdisciplinary approaches, it is increasingly clear that expertise from disparate fields will be critical to understand the role of EVs in these systems. Here, we outline how the convergence of biology, soil geochemistry, and colloid science can both develop and address questions surrounding the basic principles governing EV-mediated interkingdom interactions.
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Affiliation(s)
- Hannah M McMillan
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Nicholas Rogers
- Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA
| | - Austin Wadle
- Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA
| | - Mark R Wiesner
- Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA
| | - Meta J Kuehn
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA and Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Christine Ogilvie Hendren
- Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA and Department of Geological and Environmental Sciences, Appalachian State University, Boone, NC 28608, USA.
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17
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Dong Z, Deblonde G, Middleton A, Hu D, Dohnalkova A, Kovarik L, Qafoku O, Shutthanandan V, Jin H, Hsu-Kim H, Theaker N, Jiao Y, Park D. Microbe-Encapsulated Silica Gel Biosorbents for Selective Extraction of Scandium from Coal Byproducts. Environ Sci Technol 2021; 55:6320-6328. [PMID: 33797230 DOI: 10.1021/acs.est.0c08632] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Scandium (Sc) has great potential for use in aerospace and clean energy applications, but its supply is currently limited by a lack of commercially viable deposits and the environmental burden of its production. In this work, a biosorption-based flow-through process was developed for extraction of Sc from low-grade feedstocks. A microbe-encapsulated silica gel (MESG) biosorbent was synthesized through sol-gel encapsulation of Arthrobacter nicotianae, a bacterium that selectively adsorbs Sc. Microscopic imaging revealed a high cell loading and macroporous structure, which enabled rapid mass transport and adsorption/desorption of metal ions. The biosorbent displayed high Sc selectivity against lanthanides and major base metals, with the exception of Fe(III). Following pH adjustment to remove Fe(III) from an acid leachate prepared from lignite coal, a packed-bed column loaded with the MESG biosorbent exhibited near-complete Sc separation from lanthanides; the column eluate had a Sc enrichment factor of 10.9, with Sc constituting 96.4% of the total rare earth elements. The MESG biosorbent exhibited no significant degradation with regard to both adsorption capacity and physical structure after 10 adsorption/desorption cycles. Overall, our results suggest that the MESG biosorbent offers an effective and green alternative to conventional liquid-liquid extraction for Sc recovery.
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Affiliation(s)
- Ziye Dong
- Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Gauthier Deblonde
- Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Andrew Middleton
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Dehong Hu
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Alice Dohnalkova
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Libor Kovarik
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Odeta Qafoku
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Vaithiyalingam Shutthanandan
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Hongyue Jin
- Department of System and Industrial Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Nolan Theaker
- Institute for Energy Studies, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Yongqin Jiao
- Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Dan Park
- Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
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18
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Weinhouse C, Gallis JA, Ortiz E, Berky AJ, Morales AM, Diringer SE, Harrington J, Bullins P, Rogers L, Hare-Grogg J, Hsu-Kim H, Pan WK. A population-based mercury exposure assessment near an artisanal and small-scale gold mining site in the Peruvian Amazon. J Expo Sci Environ Epidemiol 2021; 31:126-136. [PMID: 32467625 PMCID: PMC8281380 DOI: 10.1038/s41370-020-0234-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 02/14/2020] [Accepted: 03/01/2020] [Indexed: 05/04/2023]
Abstract
Human exposure to mercury is a leading public health problem. Artisanal and small-scale gold mining (ASGM) is a major source of global mercury emissions. Although occupational mercury exposure to miners (via mercury vapor inhalation) is known, chronic mercury exposure to nearby residents that are not miners (via mercury-contaminated fish consumption) is poorly characterized. We conducted a population-based mercury exposure assessment in 23 communities (19 rural, 4 urban) around the Amarakaeri Communal Reserve, which is bordered on the east by heavy ASGM activity. We measured total mercury in hair (N = 2083) and blood (N = 476) from March-June 2015 and performed follow-up measurements (N = 723 hair and N = 290 blood) from February-April 2016. Mercury exposure risk was highest in communities classified as indigenous, or native, regardless of proximity to mining activity. Residence in a native community (vs. non-native) was associated with mercury levels 1.9 times higher in hair (median native 3.5 ppm vs. median non-native 1.4 ppm total mercury) and 1.6 times higher in blood (median native 7.4 ng/mL vs median non-native 3.2 ng/mL total mercury). Unexpectedly, proximity to mining was not associated with exposure risk. These findings challenge common assumptions about mercury exposure patterns and emphasize the importance of population-representative studies to identify high risk sub-populations.
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Affiliation(s)
- Caren Weinhouse
- Duke Global Health Institute, Duke University, 310 Trent Drive, Durham, North Carolina 27710
| | - John A. Gallis
- Duke Global Health Institute, Duke University, 310 Trent Drive, Durham, North Carolina 27710
- Department of Biostatistics and Bioinformatics, Duke University Medical Center, 2424 Erwin Road, Suite 1102 Hock Plaza, Durham, North Carolina 27710
| | - Ernesto Ortiz
- Duke Global Health Institute, Duke University, 310 Trent Drive, Durham, North Carolina 27710
| | - Axel J. Berky
- Nicholas School of the Environment, Duke University, 9 Circuit Drive, Durham, North Carolina 27710
| | | | - Sarah E. Diringer
- Pacific Institute, 654 13 Street, Preservation Park, Oakland, California 94612
| | - James Harrington
- Research Triangle Institute, 3040 East Cornwallis Road, Research Triangle Park, North Carolina 27709
| | - Paige Bullins
- Duke Global Health Institute, Duke University, 310 Trent Drive, Durham, North Carolina 27710
| | - Laura Rogers
- Civil and Environmental Engineering, Pratt School of Engineering, Duke University, 121 Hudson Hall, Durham, North Carolina 27708
| | - John Hare-Grogg
- Civil and Environmental Engineering, Pratt School of Engineering, Duke University, 121 Hudson Hall, Durham, North Carolina 27708
| | - Heileen Hsu-Kim
- Nicholas School of the Environment, Duke University, 9 Circuit Drive, Durham, North Carolina 27710
- Civil and Environmental Engineering, Pratt School of Engineering, Duke University, 121 Hudson Hall, Durham, North Carolina 27708
| | - William K. Pan
- Duke Global Health Institute, Duke University, 310 Trent Drive, Durham, North Carolina 27710
- Nicholas School of the Environment, Duke University, 9 Circuit Drive, Durham, North Carolina 27710
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19
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Park D, Middleton A, Smith R, Deblonde G, Laudal D, Theaker N, Hsu-Kim H, Jiao Y. A biosorption-based approach for selective extraction of rare earth elements from coal byproducts. Sep Purif Technol 2020. [DOI: 10.1016/j.seppur.2020.116726] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Diana Z, Sawickij N, Rivera NA, Hsu-Kim H, Rittschof D. Plastic pellets trigger feeding responses in sea anemones. Aquat Toxicol 2020; 222:105447. [PMID: 32145485 DOI: 10.1016/j.aquatox.2020.105447] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 02/08/2020] [Accepted: 02/11/2020] [Indexed: 06/10/2023]
Abstract
Multiple mechanisms for plastic consumption by marine animals have been proposed based on the feeding cues and behavior of the animal studied. We investigated plastic consumption in sea anemones. We found that anemones readily consumed pristine National Institute of Standards and Technology low-density polyethylene and high-density polyethylene II and III pre-production pellets. Anemone weight, crown area, and number of tentacles were measured before and after 12 days of daily pellet consumption. Crown area significantly increased for control anemones only. Fresh anemones were then sequentially fed consumed and egested pellets from two of the earlier daily trials to measure feeding retention time, which decreased over three to four feedings. The concentrations of elements in anemones (zinc, iron, arsenic, manganese, chromium, copper, vanadium, selenium, nickel, cadmium, and cobalt) were similar to control anemones that were not exposed to pellets. Lead concentrations were significantly higher in anemones fed HDPE III pellets as compared to control. Plastic consumption by marine animals might be reduced by reducing the amount of plastic that enters the ocean and understanding the chemical triggers underlying plastic consumption.
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Affiliation(s)
- Zoie Diana
- Duke Marine Laboratory, Nicholas School of the Environment, Duke University, Beaufort, NC, 28516, United States.
| | - Natasha Sawickij
- Duke Marine Laboratory, Nicholas School of the Environment, Duke University, Beaufort, NC, 28516, United States.
| | - Nelson A Rivera
- Duke University, Department of Civil & Environmental Engineering, 121 Hudson Hall, Durham, NC, 27708, United States.
| | - Heileen Hsu-Kim
- Duke University, Department of Civil & Environmental Engineering, 121 Hudson Hall, Durham, NC, 27708, United States.
| | - Daniel Rittschof
- Duke Marine Laboratory, Nicholas School of the Environment, Duke University, Beaufort, NC, 28516, United States.
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21
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Feingold BJ, Berky A, Hsu-Kim H, Rojas Jurado E, Pan WK. Population-based dietary exposure to mercury through fish consumption in the Southern Peruvian Amazon. Environ Res 2020; 183:108720. [PMID: 31627842 PMCID: PMC8299663 DOI: 10.1016/j.envres.2019.108720] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 09/02/2019] [Accepted: 09/03/2019] [Indexed: 05/06/2023]
Abstract
BACKGROUND Mercury exposure related to artisanal and small-scale gold mining (ASGM) has raised environmental and public health concerns globally. Exposure to mercury, a potent neurotoxin that bioaccumulates in fish, is especially of concern to women of childbearing age (WCBA) and children in high-fish consuming populations. In Madre de Dios (MDD), Peru, an Amazon region with naturally occurring mercury and high ASGM activity, there is significant exposure concern among the mainly riverine, fish-consuming communities. The objective of this study was to conduct the first assessment of mercury exposure in a population-based sample of MDD, identify factors associated with elevated levels and compare the relationship between fish consumption and hair total mercury (H-THg) among persons living in ASGM affected and non-ASGM affected watersheds. METHODS Hair samples and household demographic surveys, including a module on fish consumption, were collected from 723 participants across 46 communities within 10 km of the Interoceanic Highway in MDD, who were previously enrolled in the first population-based study in MDD spanning areas affected and unaffected by ASGM. H-THg concentration (natural log transformed) was evaluated for association with independent demographic variables through multilevel multivariate regression models accounting for clustering among households and communities. Samples from canned fish available at local stores were also tested for total mercury. RESULTS Fish consumption (diversity and total consumed) varied spatially along the highway. 269 participants (37.2%) had elevated H-THg (>2.2 μg/g; median 1.60 μg/g; mean 2.24 μg/g), including 42.7% of WCBA and 20.0% of children under 5. Overall, H-THg was higher among people living in ASGM-affected areas. H-THg concentrations were strongly associated with fish consumption; however, in the multivariate models, household consumption of high trophic level fish was associated with elevated H-THg only in communities located in the ASGM-impacted watersheds. Similarly, the relationship between living in a household engaged in economic activities of fishing or Brazil nut harvesting was associated with higher H-THg, but only among households in the ASGM-affected area. In the non-ASGM affected areas, we observed a positive relationship between household daily fruit consumption and H-THg that was not observed in ASGM-affected areas. CONCLUSION Diet, residential location, and occupation are strong predictors of mercury exposure in Madre de Dios, Peru. Canned fish may represent a previously overlooked source of dietary Hg exposure in the region. In accordance with the Minamata Convention on Mercury, the significant environmental health concern of mercury exposure in ASGM areas demands policy and programmatic attention.
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Affiliation(s)
- Beth J Feingold
- University at Albany School of Public Health, State University of New York, 1 University Place, Rensselaer, NY, USA; Institute for Health and the Environment, University at Albany, State University of New York, 5 University Place, Albany, NY, USA.
| | - Axel Berky
- Nicholas School of the Environment, Duke University, Durham, NC, USA.
| | - Heileen Hsu-Kim
- Civil and Environmental Engineering, Duke University, Durham, NC, USA.
| | | | - William K Pan
- Nicholas School of the Environment, Duke University, Durham, NC, USA; Duke Global Health Institute, Duke University, Durham, NC, USA.
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22
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Avellan A, Simonin M, Anderson SM, Geitner NK, Bossa N, Spielman-Sun E, Bernhardt ES, Castellon BT, Colman BP, Cooper JL, Ho M, Hochella MF, Hsu-Kim H, Inoue S, King RS, Laughton S, Matson CW, Perrotta BG, Richardson CJ, Unrine JM, Wiesner MR, Lowry GV. Differential Reactivity of Copper- and Gold-Based Nanomaterials Controls Their Seasonal Biogeochemical Cycling and Fate in a Freshwater Wetland Mesocosm. Environ Sci Technol 2020; 54:1533-1544. [PMID: 31951397 DOI: 10.1021/acs.est.9b05097] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Reliable predictions of the environmental fate and risk of engineered nanomaterials (ENMs) require a better understanding of ENM reactivity in complex, biologically active systems for chronic low-concentration exposure scenarios. Here, simulated freshwater wetland mesocosms were dosed with ENMs to assess how their reactivity and seasonal changes in environmental parameters influence ENM fate in aquatic systems. Copper-based ENMs (Kocide), known to dissolve in water, and gold nanoparticles (AuNPs), stable against dissolution in the absence of specific ligands, were added weekly to mesocosm waters for 9 months. Metal accumulation and speciation changes in the different environmental compartments were assessed over time. Copper from Kocide rapidly dissolved likely associating with organic matter in the water column, transported to terrestrial soils and deeper sediment where it became associated with organic or sulfide phases. In contrast, Au accumulated on/in the macrophytes where it oxidized and transferred over time to surficial sediment. A dynamic seasonal accumulation and metal redox cycling were found between the macrophyte and the surficial sediment for AuNPs. These results demonstrate the need for experimental quantification of how the biological and chemical complexity of the environment, combined with their seasonal variations, drive the fate of metastable ENMs.
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Affiliation(s)
- Astrid Avellan
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Civil & Environmental Engineering , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213 , United States
| | - Marie Simonin
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Department of Biology , Duke University , Durham , North Carolina 27708 , United States
| | - Steven M Anderson
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Department of Biology , Duke University , Durham , North Carolina 27708 , United States
- Forestry & Environmental Resources , North Carolina State University , Raleigh , North Carolina 27695 , United States
| | - Nicholas K Geitner
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Department of Civil and Environmental Engineering , Duke University , Durham , North Carolina 27708 , United States
| | - Nathan Bossa
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Department of Civil and Environmental Engineering , Duke University , Durham , North Carolina 27708 , United States
- LEITAT Technological Center , C/de la Innovació 2 , 08225 Terrassa , Barcelona , Spain
| | - Eleanor Spielman-Sun
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Civil & Environmental Engineering , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213 , United States
| | - Emily S Bernhardt
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Department of Biology , Duke University , Durham , North Carolina 27708 , United States
| | - Benjamin T Castellon
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Department of Environmental Science , Baylor University , Waco , Texas 76706 , United States
| | - Benjamin P Colman
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Department of Ecosystem and Conservation Sciences , University of Montana , Missoula , Montana 59812 , United States
| | - Jane L Cooper
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Department of Civil and Environmental Engineering , Duke University , Durham , North Carolina 27708 , United States
| | - Mengchi Ho
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Duke University Wetland Center , Nicholas School of the Environment , Durham , North Carolina 27708 , United States
| | - Michael F Hochella
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Department of Geosciences , Virginia Polytechnic Institute and State University , Blacksburg , Virginia 24061 , United States
- Pacific Northwest National Laboratory , Richland , Washington 99354 , United States
| | - Heileen Hsu-Kim
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Department of Civil and Environmental Engineering , Duke University , Durham , North Carolina 27708 , United States
| | - Sayako Inoue
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Department of Geosciences , Virginia Polytechnic Institute and State University , Blacksburg , Virginia 24061 , United States
| | - Ryan S King
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Department of Biology , Baylor University , Waco , Texas 76706 , United States
| | - Stephanie Laughton
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Civil & Environmental Engineering , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213 , United States
| | - Cole W Matson
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Department of Environmental Science , Baylor University , Waco , Texas 76706 , United States
| | - Brittany G Perrotta
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Department of Biology , Baylor University , Waco , Texas 76706 , United States
| | - Curtis J Richardson
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Duke University Wetland Center , Nicholas School of the Environment , Durham , North Carolina 27708 , United States
| | - Jason M Unrine
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Department of Plant and Soil Sciences , University of Kentucky , Lexington , Kentucky 40506 , United States
| | - Mark R Wiesner
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Department of Civil and Environmental Engineering , Duke University , Durham , North Carolina 27708 , United States
| | - Gregory V Lowry
- Center for the Environmental Implications of Nanotechnology , Duke University, Durham , North Carolina 27708 , United States
- Civil & Environmental Engineering , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213 , United States
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23
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Diringer SE, Berky AJ, Marani M, Ortiz EJ, Karatum O, Plata DL, Pan WK, Hsu-Kim H. Deforestation Due to Artisanal and Small-Scale Gold Mining Exacerbates Soil and Mercury Mobilization in Madre de Dios, Peru. Environ Sci Technol 2020; 54:286-296. [PMID: 31825606 PMCID: PMC7244384 DOI: 10.1021/acs.est.9b06620] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Artisanal and small-scale gold mining (ASGM) is a significant contributor of mercury (Hg) contamination and deforestation across the globe. In the Colorado River watershed in Madre de Dios, Peru, mining and deforestation have increased exponentially since the 1980s, resulting in major socioeconomic shifts in the region and two national state of emergency (2016 and 2019) in response to concerns for wide-scale mercury poisoning by these activities. This research employed a watershed-scale soil particle detachment model and environmental field sampling to estimate the role of land cover change and soil erosion on river transport of Hg in a heavily ASGM-impacted watershed. The model estimated that observed decreases in forest cover increased soil mobilization by a factor of two in the Colorado River watershed during the 18 year period and by 4-fold in the Puquiri subwatershed (the area of most concentrated ASGM activity). If deforestation continues to increase at its current exponential rate through 2030, the annual mobilization of soil and Hg may increase by an additional 20-25% relative to 2014 levels. While, the estimated total mass of Hg transported by rivers is substantially less than the estimated tons of Hg used with ASGM in Peru, this research shows that deforestation associated with ASGM is an additional mechanism for mobilizing naturally occurring and anthropogenic Hg from terrestrial landscapes to aquatic environments in the region, potentially leading to bioaccumulation in fish and exposure to communities downstream.
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Affiliation(s)
- Sarah E. Diringer
- Department of Civil and Environmental Engineering, Pratt School of Engineering, Duke University, Durham, NC 27710, USA
| | - Axel J. Berky
- Nicholas School of the Environment, Duke University, Durham, NC 27710 USA
- Duke Global Health Institute, Duke University, Durham, NC 27710, USA
| | - Marco Marani
- Nicholas School of the Environment, Duke University, Durham, NC 27710 USA
- Department of Civil, Environmental, and Architectural Engineering, University of Padova, 35131 Padova, Italy
| | - Ernesto J. Ortiz
- Nicholas School of the Environment, Duke University, Durham, NC 27710 USA
| | - Osman Karatum
- Department of Civil and Environmental Engineering, Pratt School of Engineering, Duke University, Durham, NC 27710, USA
| | - Desiree L. Plata
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - William K. Pan
- Nicholas School of the Environment, Duke University, Durham, NC 27710 USA
- Duke Global Health Institute, Duke University, Durham, NC 27710, USA
- co-corresponding authors: W.K. Pan: , (919) 684-4108; H. Hsu-Kim: , (919) 660-5109
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Pratt School of Engineering, Duke University, Durham, NC 27710, USA
- co-corresponding authors: W.K. Pan: , (919) 684-4108; H. Hsu-Kim: , (919) 660-5109
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24
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Volkoff SJ, Osterberg JS, Jayasundara N, Cooper E, Hsu-Kim H, Rogers L, Gehrke GE, Jayaraman S, Di Giulio RT. Embryonic Fundulus heteroclitus responses to sediment extracts from differentially contaminated sites in the Elizabeth River, VA. Ecotoxicology 2019; 28:1126-1135. [PMID: 31620948 PMCID: PMC7768634 DOI: 10.1007/s10646-019-02116-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/27/2019] [Indexed: 05/27/2023]
Abstract
Sites along the Elizabeth River are contaminated with polycyclic aromatic hydrocarbons (PAHs) from historical creosote production and other industrial processes. Previous studies have demonstrated that Atlantic killifish collected from sites throughout the Elizabeth River display resistance to the teratogenic effects of PAH-exposure in a manner commensurate with sediment PAH concentrations. The current study characterized various chemical pollutants in sediment and investigated the effects of aqueous sediment extracts from sites along the Elizabeth River to the cardiac development of Atlantic killifish embryos from fish collected from an uncontaminated reference site. Embryonic cardiac deformities were more prevalent after exposure to extracts from sites with high PAH loads. However, activation of cytochrome P4501A, a gene up-regulated by PAH-induction of the aryl hydrocarbon receptor and measured using an in ovo EROD assay, did not consistently increase with PAH concentrations. This work further characterizes sediments in the Elizabeth River, as well as provides insight into the evolutionary pressures at each ER site.
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Affiliation(s)
| | | | - Nishad Jayasundara
- Nicholas School of the Environment, Duke University, Durham, NC, USA
- School of Marine Sciences, University of Maine, Orono, ME, USA
| | - Ellen Cooper
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Heileen Hsu-Kim
- Pratt School of Engineering, Duke University, Durham, NC, USA
| | - Laura Rogers
- Pratt School of Engineering, Duke University, Durham, NC, USA
| | | | - Saro Jayaraman
- United States Environmental Protection Agency, Narragansett, RI, USA
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25
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Mello DF, Trevisan R, Rivera N, Geitner NK, Di Giulio RT, Wiesner MR, Hsu-Kim H, Meyer JN. Caveats to the use of MTT, neutral red, Hoechst and Resazurin to measure silver nanoparticle cytotoxicity. Chem Biol Interact 2019; 315:108868. [PMID: 31669321 DOI: 10.1016/j.cbi.2019.108868] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 10/09/2019] [Accepted: 10/21/2019] [Indexed: 10/25/2022]
Abstract
The extensive use of silver nanoparticles (AgNPs) in manufactured products will inevitably increase environmental exposure, highlighting the importance of accurate toxicity assessments. A frequent strategy to estimate AgNP cytotoxicity is to use absorbance or fluorescent-based assays. In this study we report that AgNPs - with or without surface functionalizations (polyvinyl pyrrolidone or gum arabic), and of different sizes (2-15 nm) - can interfere with the spectrometric quantification of different dyes commonly used in cytotoxicity assays, such as 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), neutral red (NR), Hoechst, and Resazurin. Some AgNP types caused more interference than others, which was dependent on the assay. Overall most AgNPs caused the direct reduction of MTT, as well as Hoechst and NR fluorescence quenching, and absorbed light at the same wavelength as NR. None of the AgNPs tested caused the direct reduction of Resazurin; however, depending on AgNP characteristics and concentration, they may still promote fluorescence quenching of this dye. Our results show that AgNPs with different size and coatings can interfere with spectroscopy-based assays to different degrees, suggesting that their cytotoxicity may be underestimated or overestimated. We suggest that when using any spectroscopy-based assay it is essential that each individual nanoparticle formulation be tested first for potential interferences at all intended concentrations.
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Affiliation(s)
- Danielle F Mello
- Nicholas School of the Environment, Duke University, Box 90328, Durham, NC, 27708- 0328, USA.
| | - Rafael Trevisan
- Nicholas School of the Environment, Duke University, Box 90328, Durham, NC, 27708- 0328, USA.
| | - Nelson Rivera
- Department of Civil & Environmental Engineering, Duke University, Box 90287, Durham, NC, 27708-0287, USA.
| | - Nicholas K Geitner
- Department of Civil & Environmental Engineering, Duke University, Box 90287, Durham, NC, 27708-0287, USA.
| | - Richard T Di Giulio
- Nicholas School of the Environment, Duke University, Box 90328, Durham, NC, 27708- 0328, USA.
| | - Mark R Wiesner
- Department of Civil & Environmental Engineering, Duke University, Box 90287, Durham, NC, 27708-0287, USA.
| | - Heileen Hsu-Kim
- Department of Civil & Environmental Engineering, Duke University, Box 90287, Durham, NC, 27708-0287, USA.
| | - Joel N Meyer
- Nicholas School of the Environment, Duke University, Box 90328, Durham, NC, 27708- 0328, USA.
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26
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Rivera NA, Bippus PM, Hsu-Kim H. Relative Reactivity and Bioavailability of Mercury Sorbed to or Coprecipitated with Aged Iron Sulfides. Environ Sci Technol 2019; 53:7391-7399. [PMID: 31173690 PMCID: PMC8412064 DOI: 10.1021/acs.est.9b00768] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The potential for inorganic mercury (Hg) to be converted to methylmercury depends, in part, on the chemical form of Hg and its bioavailability to anaerobic microorganisms that can methylate Hg. In anaerobic settings, Hg can be associated with sulfide phases, including ferrous iron sulfide (FeS), which can sorb or be coprecipitated with Hg. The objective of this study was to determine if the aging state of FeS alters the Hg coordination environment as well as the reactivity and bioavailability of sorbed and coprecipitated Hg species. FeS particles were synthesized with and without Hg2+ and aged in anaerobic conditions for multiple time frames spanning from 1 h to 1 month. For FeS particles synthesized without Hg, Hg2+ was subsequently sorbed to the FeS for 1 day. Analysis of Hg speciation of these materials by X-ray absorption near edge spectroscopy revealed a predominance of four-coordinate Hg-S species in the sorbed Hg-FeS solids and a mixture of two- and four-coordinate Hg-S in the coprecipitated Hg-FeS. The leaching potential of the Hg was assessed by exposing the particles to a solution of dissolved glutathione (a thiolate-based Hg chelator). As expected, the sorbed Hg-FeS released more soluble Hg compared to the coprecipitated Hg-FeS. However, when these particles were exposed to Desulfovibrio desulfuricans ND132 (a known Hg methylator), more Hg was methylated from the coprecipitated Hg-FeS than the sorbed Hg-FeS, consistent with expectations from the Hg-S coordination state and inconsistent with the selective leaching results. Overall, these results suggest that the bioavailability of particulate Hg cannot be easily discerned by its leaching potential into bulk solution. Rather, bioavailability entails more subtle interactions at particle-cell interfaces and perhaps correlates with the local Hg-S coordination state in the particles.
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Affiliation(s)
- Nelson A. Rivera
- Department of Civil and Environmental Engineering, Box 90287, Duke University, Durham, North Carolina 27708, USA
| | - Paige M. Bippus
- Department of Civil and Environmental Engineering, Box 90287, Duke University, Durham, North Carolina 27708, USA
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Box 90287, Duke University, Durham, North Carolina 27708, USA
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27
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Smith RC, Taggart RK, Hower JC, Wiesner MR, Hsu-Kim H. Selective Recovery of Rare Earth Elements from Coal Fly Ash Leachates Using Liquid Membrane Processes. Environ Sci Technol 2019; 53:4490-4499. [PMID: 30907587 DOI: 10.1021/acs.est.9b00539] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Coal combustion residues and other geological waste materials have been proposed as a resource for rare earth elements (REEs, herein defined as the 14 stable lanthanides, yttrium, and scandium). The extraction of REEs from residues often generate acidified leachates that require highly selective separation methods to recover the REEs from other major soluble ions in the leachates. Here, we studied two liquid membrane processes (liquid emulsion membranes, LEM, and supported liquid membranes, SLM) and compared them to standard solvent extraction techniques for selective recovery and concentration of REEs from a leachate of coal fly ash. All separation methods involved an organic solution of di(2-ethylhexyl)phosphoric acid dissolved in kerosene or mineral oil and an acid strippant solution of 5 M nitric acid for the liquid-based separations. The LEM configuration, which separated REEs by immersing an acid-in-oil emulsion in the ash leachate, resulted in similar recovery percentages of individual REEs as the conventional solvent extraction approach. The recovery of REEs in the SLM configuration, which involved the impregnation of the solvent in a hydrophobic membrane, was slower than the LEM process. However, the SLM process was notably more selective for the heavy (and higher value) REEs, while the conventional extraction and LEM processes were more selective for the light REEs. A flux-based model of the extraction processes suggested that recovery rates were limited by REE affinity for the solvent chelator in the SLM, while the rates of REEs separation via LEM were limited by diffusive mass transfer across the liquid membrane. Altogether, these results help to identify specific steps in the recovery process that future work should target in the development of scalable liquid membrane separations for REE recovery.
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Affiliation(s)
- Ryan C Smith
- Department of Civil and Environmental Engineering , Duke University , Durham , North Carolina 27708 , United States
| | - Ross K Taggart
- Department of Civil and Environmental Engineering , Duke University , Durham , North Carolina 27708 , United States
| | - James C Hower
- Center for Applied Energy Research , University of Kentucky , Lexington , Kentucky 40511 , United States
| | - Mark R Wiesner
- Department of Civil and Environmental Engineering , Duke University , Durham , North Carolina 27708 , United States
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering , Duke University , Durham , North Carolina 27708 , United States
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28
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Berky AJ, Ryde IT, Feingold B, Ortiz EJ, Wyatt LH, Weinhouse C, Hsu-Kim H, Meyer JN, Pan WK. Predictors of mitochondrial DNA copy number and damage in a mercury-exposed rural Peruvian population near artisanal and small-scale gold mining: An exploratory study. Environ Mol Mutagen 2019; 60:197-210. [PMID: 30289587 PMCID: PMC6452630 DOI: 10.1002/em.22244] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 07/22/2018] [Accepted: 07/31/2018] [Indexed: 05/22/2023]
Abstract
Mitochondrial DNA (mtDNA) copy number (CN) and damage in circulating white blood cells have been proposed as effect biomarkers for pollutant exposures. Studies have shown that mercury accumulates in mitochondria and affects mitochondrial function and integrity; however, these data are derived largely from experiments in model systems, rather than human population studies that evaluate the potential utility of mitochondrial exposure biomarkers. We measured mtDNA CN and damage in white blood cells (WBCs) from 83 residents of nine communities in the Madre de Dios region of the Peruvian Amazon that vary in proximity to artisanal and small-scale gold mining. Prior research from this region reported high levels of mercury in fish and a significant association between food consumption and human total hair mercury level of residents. We observed that mtDNA CN and damage were both associated with consumption of fruit and vegetables, higher diversity of fruit consumed, residential location, and health characteristics, suggesting common environmental drivers. Surprisingly, we observed negative associations of mtDNA damage with both obesity and age. We did not observe any association between total hair mercury or, in contrast to previous results, age, with either mtDNA damage or CN. The results of this exploratory study highlight the importance of combining epidemiological and laboratory research in studying the effects of stressors on mitochondria, suggesting that future work should incorporate nutritional and social characteristics, and caution should be taken when applying conclusions from epidemiological studies conducted in the developed world to other regions, as results may not be easily translated. Environ. Mol. Mutagen. 60: 197-210, 2019. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Axel J. Berky
- Nicholas School of the Environment, Box 90328, Duke University, Durham, NC 27708, USA
| | - Ian T. Ryde
- Nicholas School of the Environment, Box 90328, Duke University, Durham, NC 27708, USA
| | - Beth Feingold
- University of Albany, School of Public Health, Rensselaer, NY 12144, USA
| | - Ernesto J. Ortiz
- Duke Global Health Institute, Duke University, 310 Trent Dr, Durham, NC 27710, USA
| | - Lauren H. Wyatt
- Nicholas School of the Environment, Box 90328, Duke University, Durham, NC 27708, USA
| | - Caren Weinhouse
- Duke Global Health Institute, Duke University, 310 Trent Dr, Durham, NC 27710, USA
| | - Heileen Hsu-Kim
- Department of Civil and Engineering, Box 90287, Duke University, Durham, NC 27708, USA
| | - Joel N. Meyer
- Nicholas School of the Environment, Box 90328, Duke University, Durham, NC 27708, USA
- Corresponding authors: William Pan, Duke Global Health Institute, 310 Trent Drive, Campus Box 90519, Durham, NC 27708, fax 681-7748, , Joel N. Meyer, Nicholas School of the Environment, Box 90328, Duke University, Durham, NC 27708, USA,
| | - William K. Pan
- Nicholas School of the Environment, Box 90328, Duke University, Durham, NC 27708, USA
- Duke Global Health Institute, Duke University, 310 Trent Dr, Durham, NC 27710, USA
- Corresponding authors: William Pan, Duke Global Health Institute, 310 Trent Drive, Campus Box 90519, Durham, NC 27708, fax 681-7748, , Joel N. Meyer, Nicholas School of the Environment, Box 90328, Duke University, Durham, NC 27708, USA,
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Wyatt L, Permar SR, Ortiz E, Berky A, Woods CW, Amouou GF, Itell H, Hsu-Kim H, Pan W. Mercury Exposure and Poor Nutritional Status Reduce Response to Six Expanded Program on Immunization Vaccines in Children: An Observational Cohort Study of Communities Affected by Gold Mining in the Peruvian Amazon. Int J Environ Res Public Health 2019; 16:ijerph16040638. [PMID: 30795575 PMCID: PMC6406457 DOI: 10.3390/ijerph16040638] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/09/2019] [Accepted: 02/15/2019] [Indexed: 01/02/2023]
Abstract
Background: Poor nutritional status combined with mercury exposure can generate adverse child health outcomes. Diet is a mediator of mercury exposure and evidence suggests that nutritional status modifies aspects of mercury toxicity. However, health impacts beyond the nervous system are poorly understood. This study evaluates antibody responses to six vaccines from the expanded program on immunization (EPI), including hepatitis B, Haemophilus influenzae type B, measles, pertussis, tetanus, and diphtheria in children with variable hair mercury and malnutrition indicators. Methods: An observational cohort study (n = 98) was conducted in native and non-native communities in Madre de Dios, Peru, a region with elevated mercury exposure from artisanal and small-scale gold mining. Adaptive immune responses in young (3–48 months) and older children (4–8 year olds) were evaluated by vaccine type (live attenuated, protein subunits, toxoids) to account for differences in response by antigen, and measured by total IgG concentration and antibody (IgG) concentrations of each EPI vaccine. Mercury was measured from hair samples and malnutrition determined using anthropometry and hemoglobin levels in blood. Generalized linear mixed models were used to evaluate associations with each antibody type. Results: Changes in child antibodies and protection levels were associated with malnutrition indicators, mercury exposure, and their interaction. Malnutrition was associated with decreased measles and diphtheria-specific IgG. A one-unit decrease in hemoglobin was associated with a 0.17 IU/mL (95% CI: 0.04–0.30) decline in measles-specific IgG in younger children and 2.56 (95% CI: 1.01–6.25) higher odds of being unprotected against diphtheria in older children. Associations between mercury exposure and immune responses were also dependent on child age. In younger children, one-unit increase in log10 child hair mercury content was associated with 0.68 IU/mL (95% CI: 0.18–1.17) higher pertussis and 0.79 IU/mL (95% CI: 0.18–1.70) higher diphtheria-specific IgG levels. In older children, child hair mercury content exceeding 1.2 µg/g was associated with 73.7 higher odds (95% CI: 2.7–1984.3) of being a non-responder against measles and hair mercury content exceeding 2.0 µg/g with 0.32 IU/mL (95% CI: 0.10–0.69) lower measles-specific antibodies. Log10 hair mercury significantly interacted with weight-for-height z-score, indicating a multiplicative effect of higher mercury and lower nutrition on measles response. Specifically, among older children with poor nutrition (WHZ = −1), log10 measles antibody is reduced from 1.40 to 0.43 for low (<1.2 µg/g) vs. high mercury exposure, whereas for children with good nutritional status (WHZ = 1), log10 measles antibody is minimally changed for low vs. high mercury exposure (0.72 vs. 0.81, respectively). Conclusions: Child immune response to EPI vaccines may be attenuated in regions with elevated mercury exposure risk and exacerbated by concurrent malnutrition.
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Affiliation(s)
- Lauren Wyatt
- Nicholas School of the Environment, Duke University, Durham, NC 27710, USA.
| | - Sallie Robey Permar
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA.
| | - Ernesto Ortiz
- Global Health Institute, Duke University, Durham, NC 27710, USA.
| | - Axel Berky
- Nicholas School of the Environment, Duke University, Durham, NC 27710, USA.
| | - Christopher W Woods
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA.
| | | | - Hannah Itell
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA.
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Duke University, Durham, NC 27710, USA.
| | - William Pan
- Nicholas School of the Environment, Duke University, Durham, NC 27710, USA.
- Global Health Institute, Duke University, Durham, NC 27710, USA.
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30
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Taggart RK, Rivera NA, Levard C, Ambrosi JP, Borschneck D, Hower JC, Hsu-Kim H. Differences in bulk and microscale yttrium speciation in coal combustion fly ash. Environ Sci Process Impacts 2018; 20:1390-1403. [PMID: 30264835 DOI: 10.1039/c8em00264a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Coal combustion ash is a promising alternative source of rare earth elements (REE; herein defined as the 14 stable lanthanides, yttrium, and scandium). Efforts to extract REE from coal ash will depend heavily on the location and speciation of these elements in the ash. This study sought to identify the major chemical forms of yttrium (Y), as a representative REE in coal fly ash samples selected from major coal sources in the United States. Y speciation was evaluated using both bulk scale analyses (sequential extractions, Y K-edge X-ray absorption near-edge spectroscopy - XANES) and complementary analyses at the micron scale (micro-focus X-ray fluorescence and micro-XANES). Sequential selective extractions revealed that the REE were primarily in the residual (unextracted fraction) of coal fly ash samples. Extraction patterns for yttrium resembled those of the lanthanides, indicating that these elements were collectively dispersed throughout the aluminosilicate glass in fly ash. Bulk XANES analysis indicated that Y coordination states resembled a combination of Y-oxides, Y-carbonate, and Y-doped glass, regardless of ash origin. However, in the microprobe analysis, we observed "hotspots" of Y (∼10-50 μm) in some samples that included different Y forms (e.g., Y-phosphate) not observed in bulk measurements. Overall, this study demonstrated that yttrium (and potentially other REEs) are entrained in the glass phase of fly ash and that microscale investigations of individual high-REE regions in fly ash samples do not necessarily capture the dominant speciation.
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Affiliation(s)
- Ross K Taggart
- Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA.
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31
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Geitner NK, Cooper JL, Avellan A, Castellon BT, Perrotta BG, Bossa N, Simonin M, Anderson SM, Inoue S, Hochella MF, Richardson CJ, Bernhardt ES, Lowry GV, Ferguson PL, Matson CW, King RS, Unrine JM, Wiesner MR, Hsu-Kim H. Size-Based Differential Transport, Uptake, and Mass Distribution of Ceria (CeO 2) Nanoparticles in Wetland Mesocosms. Environ Sci Technol 2018; 52:9768-9776. [PMID: 30067347 DOI: 10.1021/acs.est.8b02040] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Trace metals associated with nanoparticles are known to possess reactivities that are different from their larger-size counterparts. However, the relative importance of small relative to large particles for the overall distribution and biouptake of these metals is not as well studied in complex environmental systems. Here, we have examined differences in the long term fate and transport of ceria (CeO2) nanoparticles of two different sizes (3.8 vs 185 nm), dosed weekly to freshwater wetland mesocosms over 9 months. While the majority of CeO2 particles were detected in soils and sediments at the end of nine months, there were significant differences observed in fate, distribution, and transport mechanisms between the two materials. Small nanoparticles were removed from the water column primarily through heteroaggregation with suspended solids and plants, while large nanoparticles were removed primarily by sedimentation. A greater fraction of small particles remained in the upper floc layers of sediment relative to the large particles (31% vs 7%). Cerium from the small particles were also significantly more bioavailable to aquatic plants (2% vs 0.5%), snails (44 vs 2.6 ng), and insects (8 vs 0.07 μg). Small CeO2 particles were also significantly reduced from Ce(IV) to Ce(III), while aquatic sediments were a sink for untransformed large nanoparticles. These results demonstrate that trace metals originating from nanoscale materials have much greater potential than their larger counterparts to distribute throughout multiple compartments of a complex aquatic ecosystem and contribute to the overall bioavailable pool of the metal for biouptake and trophic transfer.
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Affiliation(s)
- Nicholas K Geitner
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Civil and Environmental Engineering Department , Duke University , Durham , North Carolina 27708 , United States
| | - Jane L Cooper
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Civil and Environmental Engineering Department , Duke University , Durham , North Carolina 27708 , United States
| | - Astrid Avellan
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Civil & Environmental Engineering , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213 , United States
| | - Benjamin T Castellon
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Environmental Science , Baylor University , Waco , Texas 76706 , United States
| | - Brittany G Perrotta
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Biology , Baylor University , Waco , Texas 76706 , United States
| | - Nathan Bossa
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Civil and Environmental Engineering Department , Duke University , Durham , North Carolina 27708 , United States
| | - Marie Simonin
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Biology , Duke University , Durham , North Carolina 27708 , United States
| | - Steven M Anderson
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Biology , Duke University , Durham , North Carolina 27708 , United States
| | - Sayako Inoue
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Geosciences , Virginia Polytechnic Institute and State University , Blacksburg , Virginia 24061 , United States
| | - Michael F Hochella
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Geosciences , Virginia Polytechnic Institute and State University , Blacksburg , Virginia 24061 , United States
- Energy and Environment Directorate Pacific Northwest National Laboratory Richland , Washington 99354 , United States
| | - Curtis J Richardson
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Nicholas School of the Environment , Duke University , Durham , North Carolina 27708 , United States
| | - Emily S Bernhardt
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Biology , Duke University , Durham , North Carolina 27708 , United States
| | - Gregory V Lowry
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Civil & Environmental Engineering , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213 , United States
| | - P Lee Ferguson
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Civil and Environmental Engineering Department , Duke University , Durham , North Carolina 27708 , United States
| | - Cole W Matson
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Environmental Science , Baylor University , Waco , Texas 76706 , United States
| | - Ryan S King
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Biology , Baylor University , Waco , Texas 76706 , United States
| | - Jason M Unrine
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Plant and Soil Sciences , University of Kentucky , Lexington , Kentucky 40506 , United States
| | - Mark R Wiesner
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Civil and Environmental Engineering Department , Duke University , Durham , North Carolina 27708 , United States
| | - Heileen Hsu-Kim
- Center for the Environmental Implications of Nanotechnology , Duke University , Durham , North Carolina 27708 , United States
- Civil and Environmental Engineering Department , Duke University , Durham , North Carolina 27708 , United States
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Chen CY, Driscoll CT, Eagles-Smith CA, Eckley CS, Gay DA, Hsu-Kim H, Keane SE, Kirk JL, Mason RP, Obrist D, Selin H, Selin NE, Thompson MR. A Critical Time for Mercury Science to Inform Global Policy. Environ Sci Technol 2018; 52:9556-9561. [PMID: 30067020 PMCID: PMC6200401 DOI: 10.1021/acs.est.8b02286] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Mercury is a global pollutant released into the biosphere by varied human activities including coal combustion, mining, artisanal gold mining, cement production, and chemical production. Once released to air, land and water, the addition of carbon atoms to mercury by bacteria results in the production of methylmercury, the toxic form that bioaccumulates in aquatic and terrestrial food chains resulting in elevated exposure to humans and wildlife. Global recognition of the mercury contamination problem has resulted in the Minamata Convention on Mercury, which came into force in 2017. The treaty aims to protect human health and the environment from human-generated releases of mercury curtailing its movement and transformations in the biosphere. Coincident with the treaty's coming into force, the 13th International Conference of Mercury as a Global Pollutant (ICMGP-13) was held in Providence, Rhode Island USA. At ICMGP-13, cutting edge research was summarized and presented to address questions relating to global and regional sources and cycling of mercury, how that mercury is methylated, the effects of mercury exposure on humans and wildlife, and the science needed for successful implementation of the Minamata Convention. Human activities have the potential to enhance mercury methylation by remobilizing previously released mercury, and increasing methylation efficiency. This synthesis concluded that many of the most important factors influencing the fate and effects of mercury and its more toxic form, methylmercury, stem from environmental changes that are much broader in scope than mercury releases alone. Alterations of mercury cycling, methylmercury bioavailability and trophic transfer due to climate and land use changes remain critical uncertainties in effective implementation of the Minamata Convention. In the face of these uncertainties, important policy and management actions are needed over the short-term to support the control of mercury releases to land, water and air. These include adequate monitoring and communication on risk from exposure to various forms of inorganic mercury as well as methylmercury from fish and rice consumption. Successful management of global and local mercury pollution will require integration of mercury research and policy in a changing world.
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Affiliation(s)
- Celia Y Chen
- Dartmouth College , Department of Biological Sciences , Hanover , New Hampshire 03755 United States
| | - Charles T Driscoll
- Syracuse University , Department of Civil and Environmental Engineering , Syracuse , New York 13244 United States
| | | | - Chris S Eckley
- U.S. Environmental Protection Agency , Region-10 , Seattle , Washington 98101 United States
| | - David A Gay
- University of Wisconsin , Madison , Wisconsin 53706 United States
| | - Heileen Hsu-Kim
- Duke University , Department of Civil & Environmental Engineering , Durham , North Carolina 27708 United States
| | - Susan E Keane
- Natural Resources Defense Council , Washington , D.C. 20005 United States
| | - Jane L Kirk
- Environment and Climate Change, Canada , Burlington , ON L7P2X3 Canada
| | - Robert P Mason
- University of Connecticut , Department of Marine Sciences , Groton , Connecticut 06340 United States
| | - Daniel Obrist
- University of Massachusetts, Lowell , Department of Environmental, Earth and Atmospheric Sciences , Lowell , Massachusetts 01854 United States
| | - Henrik Selin
- Boston University , Frederick S. Pardee School of Global Studies , Boston , Massachusetts 02215 United States
| | - Noelle E Selin
- Massachusetts Institute of Technology, Institute for Data, Systems, and Society , Department of Earth, Atmospheric and Planetary Sciences , Boston , Massachusetts 02139 United States
| | - Marcella R Thompson
- University of Rhode Island , College of Nursing , Providence , Rhode Island 02903 United States
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33
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Ndu U, Christensen GA, Rivera NA, Gionfriddo CM, Deshusses MA, Elias DA, Hsu-Kim H. Quantification of Mercury Bioavailability for Methylation Using Diffusive Gradient in Thin-Film Samplers. Environ Sci Technol 2018; 52:8521-8529. [PMID: 29920204 PMCID: PMC6085726 DOI: 10.1021/acs.est.8b00647] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 05/03/2018] [Accepted: 06/19/2018] [Indexed: 05/25/2023]
Abstract
Mercury-contaminated sediment and water contain various Hg species, with a small fraction available for microbial conversion to the bioaccumulative neurotoxin monomethylmercury (MeHg). Quantification of this available Hg pool is needed to prioritize sites for risk management. This study compared the efficacy of diffusive gradient in thin-film (DGT) passive samplers to a thiol-based selective extraction method with glutathione (GSH) and conventional filtration (<0.2 μm) as indicators of Hg bioavailability. Anaerobic sediment slurry microcosms were amended with isotopically labeled inorganic Hg "endmembers" (dissolved Hg2+, Hg-humic acid, Hg-sorbed to FeS, HgS nanoparticles) with a known range of bioavailability and methylation potentials. Net MeHg production (expressed as percent of total Hg as MeHg) over 1 week correlated with mass accumulation of Hg endmembers on the DGTs and only sometimes correlated with the 0.2 μm filter passing Hg fraction and the GSH-extractable Hg fraction. These results suggest for the first time that inorganic Hg uptake in DGTs may indicate bioavailability for methylating microbes. Moreover, the methylating microbial community assessed by hgcA gene abundance was not always consistent with methylation rates between the experiments, indicating that knowledge of the methylating community should target the transcript or protein level. Altogether, these results suggest that DGTs could be used to quantify the bioavailable Hg fraction as part of a method to assess net MeHg production potential in the environment.
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Affiliation(s)
- Udonna Ndu
- Department
of Civil and Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States
| | - Geoff A. Christensen
- Biosciences
Division, Oak Ridge National Laboratory, P.O. Box 2008, MS-6036, Oak Ridge, Tennessee 37831-6036, United States
| | - Nelson A. Rivera
- Department
of Civil and Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States
| | - Caitlin M. Gionfriddo
- Biosciences
Division, Oak Ridge National Laboratory, P.O. Box 2008, MS-6036, Oak Ridge, Tennessee 37831-6036, United States
| | - Marc A. Deshusses
- Department
of Civil and Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States
| | - Dwayne A. Elias
- Biosciences
Division, Oak Ridge National Laboratory, P.O. Box 2008, MS-6036, Oak Ridge, Tennessee 37831-6036, United States
| | - Heileen Hsu-Kim
- Department
of Civil and Environmental Engineering, Duke University, Box 90287, Durham, North Carolina 27708, United States
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34
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Schwartz GE, Hower JC, Phillips AL, Rivera N, Vengosh A, Hsu-Kim H. Ranking Coal Ash Materials for Their Potential to Leach Arsenic and Selenium: Relative Importance of Ash Chemistry and Site Biogeochemistry. Environ Eng Sci 2018; 35:728-738. [PMID: 29983540 PMCID: PMC6034393 DOI: 10.1089/ees.2017.0347] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 12/15/2017] [Indexed: 05/29/2023]
Abstract
The chemical composition of coal ash is highly heterogeneous and dependent on the origin of the source coal, combustion parameters, and type and configuration of air pollution control devices. This heterogeneity results in uncertainty in the evaluation of leaching potential of contaminants from coal ash. The goal of this work was to identify whether a single leaching protocol could roughly group high-leaching potential coal ash from low-leaching potential coal ash, with respect to arsenic (As) and selenium (Se). We used four different leaching tests, including the Toxicity Characteristic Leaching Protocol (TCLP), natural pH, aerobic sediment microcosms, and anaerobic sediment microcosms on 10 different coal ash materials, including fly ash, lime-treated ash, and flue gas desulfurization materials. Leaching tests showed promise in categorizing high and low-leaching potential ash materials, indicating that a single point test could act as a first screening measure to identify high-risk ash materials. However, the amount of contaminant leached varied widely across tests, reflecting the importance of ambient conditions (pH, redox state) on leaching. These results demonstrate that on-site geochemical conditions play a critical role in As and Se mobilization from coal ash, underscoring the need to develop a situation-based risk assessment framework for contamination by coal ash pollutants.
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Affiliation(s)
- Grace E. Schwartz
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina
| | - James C. Hower
- Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky
| | - Allison L. Phillips
- Levine Science Research Center, Nicholas School of the Environment, Duke University, Durham, North Carolina
| | - Nelson Rivera
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina
| | - Avner Vengosh
- Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, North Carolina
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina
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35
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Hsu-Kim H, Eckley CS, Selin NE. Modern science of a legacy problem: mercury biogeochemical research after the Minamata Convention. Environ Sci Process Impacts 2018; 20:582-583. [PMID: 29658559 PMCID: PMC6681803 DOI: 10.1039/c8em90016g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Guest editors Heileen Hsu-Kim, Chris Eckley, and Noelle Selin introduce the Mercury Biogeochemistry, Exposure, and Impacts themed issue of Environmental Science: Processes & Impacts.
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Affiliation(s)
- Heileen Hsu-Kim
- Department of Civil & Environmental Engineering, Duke University, Durham, North Carolina, USA.
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36
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Hsu-Kim H, Eckley CS, Achá D, Feng X, Gilmour CC, Jonsson S, Mitchell CPJ. Challenges and opportunities for managing aquatic mercury pollution in altered landscapes. Ambio 2018; 47:141-169. [PMID: 29388127 PMCID: PMC5794684 DOI: 10.1007/s13280-017-1006-7] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The environmental cycling of mercury (Hg) can be affected by natural and anthropogenic perturbations. Of particular concern is how these disruptions increase mobilization of Hg from sites and alter the formation of monomethylmercury (MeHg), a bioaccumulative form of Hg for humans and wildlife. The scientific community has made significant advances in recent years in understanding the processes contributing to the risk of MeHg in the environment. The objective of this paper is to synthesize the scientific understanding of how Hg cycling in the aquatic environment is influenced by landscape perturbations at the local scale, perturbations that include watershed loadings, deforestation, reservoir and wetland creation, rice production, urbanization, mining and industrial point source pollution, and remediation. We focus on the major challenges associated with each type of alteration, as well as management opportunities that could lessen both MeHg levels in biota and exposure to humans. For example, our understanding of approximate response times to changes in Hg inputs from various sources or landscape alterations could lead to policies that prioritize the avoidance of certain activities in the most vulnerable systems and sequestration of Hg in deep soil and sediment pools. The remediation of Hg pollution from historical mining and other industries is shifting towards in situ technologies that could be less disruptive and less costly than conventional approaches. Contemporary artisanal gold mining has well-documented impacts with respect to Hg; however, significant social and political challenges remain in implementing effective policies to minimize Hg use. Much remains to be learned as we strive towards the meaningful application of our understanding for stakeholders, including communities living near Hg-polluted sites, environmental policy makers, and scientists and engineers tasked with developing watershed management solutions. Site-specific assessments of MeHg exposure risk will require new methods to predict the impacts of anthropogenic perturbations and an understanding of the complexity of Hg cycling at the local scale.
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Affiliation(s)
- Heileen Hsu-Kim
- Department of Civil & Environmental Engineering, Duke University, 121 Hudson Hall, Box 90287, Durham, NC 27708 USA
| | - Chris S. Eckley
- U.S. Environmental Protection Agency, Region-10, 1200 6th Ave, Seattle, WA 98101 USA
| | - Dario Achá
- Unidad de Calidad Ambiental, Instituto de Ecología, Carrera de Biología, Universidad Mayor de San Andrés, P.O. Box 10077, La Paz, Bolivia
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002 China
| | - Cynthia C. Gilmour
- Smithsonian Environmental Research Center, 647 Contees Wharf Rd, Edgewater, MD 21037-0028 USA
| | - Sofi Jonsson
- Department of Environmental Science and Analytical Chemistry, Stockholm University, Svante Arrhenius väg 8, 11418 Stockholm, Sweden
| | - Carl P. J. Mitchell
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4 Canada
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Avellan A, Stegemeier JP, Gai K, Dale J, Hsu-Kim H, Levard C, O'Rear D, Hoelen TP, Lowry GV. Speciation of Mercury in Selected Areas of the Petroleum Value Chain. Environ Sci Technol 2018; 52:1655-1664. [PMID: 29224346 DOI: 10.1021/acs.est.7b05066] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Petroleum, natural gas, and natural gas condensate can contain low levels of mercury (Hg). The speciation of Hg can affect its behavior during processing, transport, and storage so efficient and safe management of Hg requires an understanding of its chemical form in oil, gas and byproducts. Here, X-ray absorption spectroscopy was used to determine the Hg speciation in samples of solid residues collected throughout the petroleum value chain including stabilized crude oil residues, sediments from separation tanks and condensate glycol dehydrators, distillation column pipe scale, and biosludge from wastewater treatment. In all samples except glycol dehydrators, metacinnabar (β-HgS) was the primary form of Hg. Electron microscopy on particles from a crude sediment showed nanosized (<100 nm) particles forming larger aggregates, and confirmed the colocalization of Hg and sulfur. In sediments from glycol dehydrators, organic Hg(SR)2 accounted for ∼60% of the Hg, with ∼20% present as β-HgS and/or Hg(SR)4 species. β-HgS was the predominant Hg species in refinery biosludge and pipe scale samples. However, the balance of Hg species present in these samples depended on the nature of the crude oil being processed, i.e. sweet (low sulfur crudes) vs sour (higher sulfur crudes). This information on Hg speciation in the petroleum value chain will inform development of better engineering controls and management practices for Hg.
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Affiliation(s)
- Astrid Avellan
- Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
- Center for Environmental Implications of Nanotechnology , Pittsburgh, Pennsylvania 15213, United States
| | - John P Stegemeier
- Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
- Center for Environmental Implications of Nanotechnology , Pittsburgh, Pennsylvania 15213, United States
| | - Ke Gai
- Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
- Center for Environmental Implications of Nanotechnology , Pittsburgh, Pennsylvania 15213, United States
| | - James Dale
- Center for Environmental Implications of Nanotechnology , Pittsburgh, Pennsylvania 15213, United States
- Geological and Environmental Science, Virginia Tech , Blacksburg, Virginia 24061, United States
| | - Heileen Hsu-Kim
- Center for Environmental Implications of Nanotechnology , Pittsburgh, Pennsylvania 15213, United States
- Civil & Environmental Engineering, Duke University , Durham, North Carolina 27708-0287, United States
| | - Clément Levard
- Center for Environmental Implications of Nanotechnology , Pittsburgh, Pennsylvania 15213, United States
- Aix Marseille Univ., CNRS, IRD, Coll. France, CEREGE , Aix en Provence, France
| | - Dennis O'Rear
- Chevron Energy Technology Company , Richmond, California 94802, United States
| | - Thomas P Hoelen
- Chevron Energy Technology Company , Richmond, California 94802, United States
| | - Gregory V Lowry
- Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
- Center for Environmental Implications of Nanotechnology , Pittsburgh, Pennsylvania 15213, United States
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Lefèvre E, Bossa N, Gardner CM, Gehrke GE, Cooper EM, Stapleton HM, Hsu-Kim H, Gunsch CK. Biochar and activated carbon act as promising amendments for promoting the microbial debromination of tetrabromobisphenol A. Water Res 2018; 128:102-110. [PMID: 29091801 PMCID: PMC5796758 DOI: 10.1016/j.watres.2017.09.047] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 09/25/2017] [Accepted: 09/26/2017] [Indexed: 05/13/2023]
Abstract
The increasing occurrence of tetrabromobisphenol A (TBBPA) in the environment is raising questions about its potential environmental health impacts as it has been shown to cause various deleterious effects in humans. The fact that the highest concentrations of TBBPA have been reported in wastewater sludge is concerning as effluent discharge and biosolids land application are likely a route by which TBBPA can be further disbursed to the environment. Our objectives in this study were to evaluate the effect of biochar (BC) and activated carbon (AC) in promoting the biodegradation of TBBPA, and characterize the response of anaerobic sludge microbial communities following amendments. Both carbonaceous amendments were found to promote the reductive debromination of TBBPA. Nearly complete transformation of TBBPA to BPA was observed in the amended reactors ∼20 days earlier than in the control reactors. In particular, the transformation of diBBPA to monoBBPA, which appears to be the rate-limiting step, was accelerated in the presence of either amendment. Overall, microbial taxa responding to the amendments, i.e., 'sensitive responders', represented a small proportion of the community (i.e., 7.2%), and responded positively. However, although both amendments had a similar effect on TBBPA degradation, the taxonomic profile of the sensitive responders differed greatly from one amendment to the other. BC had a taxonomically broader and slightly more pronounced effect than AC. This work suggests that BC and AC show great potential to promote the biodegradation of TBBPA in anaerobic sludge, and their integration into wastewater treatment processes may be helpful for removing TBBPA and possibly other emerging hydrophobic contaminants.
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Affiliation(s)
- Emilie Lefèvre
- Department of Civil and Environmental Engineering, Duke University, Hudson Hall, Durham, NC 27708, USA.
| | - Nathan Bossa
- Department of Civil and Environmental Engineering, Duke University, Hudson Hall, Durham, NC 27708, USA.
| | - Courtney M Gardner
- Department of Civil and Environmental Engineering, Duke University, Hudson Hall, Durham, NC 27708, USA.
| | - Gretchen E Gehrke
- Department of Civil and Environmental Engineering, Duke University, Hudson Hall, Durham, NC 27708, USA.
| | - Ellen M Cooper
- Nicholas School of the Environment, Duke University, 9 Circuit Drive, Durham, NC 27710, USA.
| | - Heather M Stapleton
- Nicholas School of the Environment, Duke University, 9 Circuit Drive, Durham, NC 27710, USA.
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Duke University, Hudson Hall, Durham, NC 27708, USA.
| | - Claudia K Gunsch
- Department of Civil and Environmental Engineering, Duke University, Hudson Hall, Durham, NC 27708, USA.
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Weinhouse C, Ortiz EJ, Berky AJ, Bullins P, Hare-Grogg J, Rogers L, Morales AM, Hsu-Kim H, Pan WK. Hair Mercury Level is Associated with Anemia and Micronutrient Status in Children Living Near Artisanal and Small-Scale Gold Mining in the Peruvian Amazon. Am J Trop Med Hyg 2017; 97:1886-1897. [PMID: 29016304 DOI: 10.4269/ajtmh.17-0269] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Anemia has been widely studied in global health contexts because of severe nutritional deficiency, and more recently, inflammatory status, but chemical exposures are rarely considered. Until recently, "anemia" was used synonymously with "iron deficiency anemia (IDA)" in global health settings. However, only 50% of anemia cases worldwide are IDA. Environmental toxicology studies of anemia risk have generally focused on populations in developed countries, albeit with high exposure to environmental toxicants, such as lead or cadmium. In the developing world, toxicant exposures commonly coexist with other risk factors for anemia. In particular, artisanal and small-scale gold mining (ASGM) communities are at risk for dietary methylmercury exposure through contaminated fish consumption, and for anemia due to food insecurity and infectious and chronic diseases. Here, we report analysis of total hair mercury content, hemoglobin, and serum micronutrient levels in children < 12 years of age (N = 83) near ASGM in the Peruvian Amazon. Forty-nine percent (N = 29/59) of those aged < 5 years were anemic (< 11 g/dL) and 52% (N = 12/23) of those aged 5-11 years (< 11.5 g/dL). Few children were stunted, wasted, or micronutrient deficient. Median total hair mercury was 1.18 μg/g (range: 0.06-9.70 μg/g). We found an inverse association between total mercury and hemoglobin (β = -0.12 g/dL, P = 0.06) that persisted (β = -0.14 g/dL, P = 0.04) after adjusting for age, sex, anthropometrics, and vitamin B12 in multivariate regression. This study provides preliminary evidence that methylmercury exposure is associated with anemia, which is especially relevant to children living near ASGM.
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Affiliation(s)
- Caren Weinhouse
- Duke Global Health Institute, Duke University, Durham, North Carolina
| | - Ernesto J Ortiz
- Duke Global Health Institute, Duke University, Durham, North Carolina
| | - Axel J Berky
- Duke Global Health Institute, Duke University, Durham, North Carolina
| | - Paige Bullins
- Duke Global Health Institute, Duke University, Durham, North Carolina
| | - John Hare-Grogg
- Civil and Environmental Engineering, Duke University, Durham, North Carolina
| | - Laura Rogers
- Civil and Environmental Engineering, Duke University, Durham, North Carolina
| | - Ana-Maria Morales
- Centro de Estudios, Investigación y Servicios en Salud Publica, Lima, Peru
| | - Heileen Hsu-Kim
- Nicholas School of the Environment, Duke University, Durham, North Carolina.,Civil and Environmental Engineering, Duke University, Durham, North Carolina
| | - William K Pan
- Duke Global Health Institute, Duke University, Durham, North Carolina.,Nicholas School of the Environment, Duke University, Durham, North Carolina
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Jiang C, Castellon BT, Matson CW, Aiken GR, Hsu-Kim H. Relative Contributions of Copper Oxide Nanoparticles and Dissolved Copper to Cu Uptake Kinetics of Gulf Killifish (Fundulus grandis) Embryos. Environ Sci Technol 2017; 51:1395-1404. [PMID: 28081364 DOI: 10.1021/acs.est.6b04672] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The toxicity of soluble metal-based nanomaterials may be due to the uptake of metals in both dissolved and nanoparticulate forms, but the relative contributions of these different forms to overall metal uptake rates under environmental conditions are not quantitatively defined. Here, we investigated the linkage between the dissolution rates of copper(II) oxide (CuO) nanoparticles (NPs) and their bioavailability to Gulf killifish (Fundulus grandis) embryos, with the aim of quantitatively delineating the relative contributions of nanoparticulate and dissolved species for Cu uptake. Gulf killifish embryos were exposed to dissolved Cu and CuO NP mixtures comprising a range of pH values (6.3-7.5) and three types of natural organic matter (NOM) isolates at various concentrations (0.1-10 mg-C L-1), resulting in a wide range of CuO NP dissolution rates that subsequently influenced Cu uptake. First-order dissolution rate constants of CuO NPs increased with increasing NOM concentration and for NOM isolates with higher aromaticity, as indicated by specific ultraviolet absorbance (SUVA), while Cu uptake rate constants of both dissolved Cu and CuO NP decreased with NOM concentration and aromaticity. As a result, the relative contribution of dissolved Cu and nanoparticulate CuO species for the overall Cu uptake rate was insensitive to NOM type or concentration but largely determined by the percentage of CuO that dissolved. These findings highlight SUVA and aromaticity as key NOM properties affecting the dissolution kinetics and bioavailability of soluble metal-based nanomaterials in organic-rich waters. These properties could be used in the incorporation of dissolution kinetics into predictive models for environmental risks of nanomaterials.
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Affiliation(s)
| | - Benjamin T Castellon
- Department of Environmental Science, Institute of Biomedical Studies, Center for Reservoir and Aquatic Systems Research (CRASR), Baylor University , Waco, Texas 76798, United States
| | - Cole W Matson
- Department of Environmental Science, Institute of Biomedical Studies, Center for Reservoir and Aquatic Systems Research (CRASR), Baylor University , Waco, Texas 76798, United States
| | - George R Aiken
- U.S. Geological Survey, Boulder, Colorado 80303, United States
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Hood MM, Taggart RK, Smith RC, Hsu-Kim H, Henke KR, Graham U, Groppo JG, Unrine JM, Hower JC. Rare Earth Element Distribution in Fly Ash Derived from the Fire Clay Coal, Kentucky. ACTA ACUST UNITED AC 2017. [DOI: 10.4177/ccgp-d-17-00002.1] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Schwartz GE, Redfern LK, Ikuma K, Gunsch CK, Ruhl LS, Vengosh A, Hsu-Kim H. Impacts of coal ash on methylmercury production and the methylating microbial community in anaerobic sediment slurries. Environ Sci Process Impacts 2016; 18:1427-1439. [PMID: 27722355 DOI: 10.1039/c6em00458j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Mercury (Hg) associated with coal ash is an environmental concern, particularly if the release of coal ash to the environment is associated with the conversion of inorganic Hg to methylmercury (MeHg), a bioaccumulative form of Hg that is produced by anaerobic microorganisms. In this study, sediment slurry microcosm experiments were performed to understand how spilled coal ash might influence MeHg production in anaerobic sediments of an aquatic ecosystem. Two coal ash types were used: (1) a weathered coal ash; and (2) a freshly collected, unweathered fly ash that was relatively enriched in sulfate and Hg compared to the weathered ash. These ash samples were added to anaerobic sediment slurries constructed with a relatively pristine sediment (containing 0.03 mg kg-1 Hg) and a Hg-contaminated sediment (containing 0.29 mg kg-1 Hg). The results of these experiments showed negligible net production of MeHg in microcosms with no ash and in microcosms amended with the low sulfate/low Hg ash. In contrast, slurry microcosms amended with high sulfate/high Hg ash showed increases in total MeHg content that was 2 to 3 times greater than control microcosms without ash (p < 0.001). 16S amplicon sequencing of microbial communities in the slurries indicated that the coal ash addition generally increased the relative abundance of the methylating microbial community, including sulfate-reducing bacteria and iron-reducing bacteria species that are known to be efficient methylators of Hg. The stimulation of these microorganisms was likely caused by the release of substrates (sulfate and Fe) originating from the ash. Overall, the results highlight the need to incorporate both environmental parameters and coal ash characteristics into risk assessments that guide coal ash management and disposal.
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Affiliation(s)
- Grace E Schwartz
- Duke University, Department of Civil & Environmental Engineering, 121 Hudson Hall, Durham, North Carolina 27708, USA.
| | - Lauren K Redfern
- Duke University, Department of Civil & Environmental Engineering, 121 Hudson Hall, Durham, North Carolina 27708, USA.
| | - Kaoru Ikuma
- Iowa State University, Department of Civil, Construction, and Environmental Engineering, Ames, Iowa 50011, USA
| | - Claudia K Gunsch
- Duke University, Department of Civil & Environmental Engineering, 121 Hudson Hall, Durham, North Carolina 27708, USA.
| | - Laura S Ruhl
- University of Arkansas-Little Rock, Department of Earth Sciences, Little Rock, Arkansas 72204, USA
| | - Avner Vengosh
- Duke University, Division of Earth and Ocean Sciences, Nicholas School of the Environment, Durham, North Carolina, USA
| | - Heileen Hsu-Kim
- Duke University, Department of Civil & Environmental Engineering, 121 Hudson Hall, Durham, North Carolina 27708, USA.
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McEwen AR, Hsu-Kim H, Robins NA, Hagan NA, Halabi S, Barras O, Richter DD, Vandenberg JJ. Residential metal contamination and potential health risks of exposure in adobe brick houses in Potosí, Bolivia. Sci Total Environ 2016; 562:237-246. [PMID: 27100004 DOI: 10.1016/j.scitotenv.2016.03.152] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 03/16/2016] [Accepted: 03/19/2016] [Indexed: 06/05/2023]
Abstract
Potosí, Bolivia, is the site of centuries of historic and present-day mining of the Cerro Rico, a mountain known for its rich polymetallic deposits, and was the site of large-scale Colonial era silver refining operations. In this study, the concentrations of several metal and metalloid elements were quantified in adobe brick, dirt floor, and surface dust samples from 49 houses in Potosí. Median concentrations of total mercury (Hg), lead (Pb), and arsenic (As) were significantly greater than concentrations measured in Sucre, Bolivia, a non-mining town, and exceeded US-based soil screening levels. Adobe brick samples were further analyzed for bioaccessible concentrations of trace elements using a simulated gastric fluid (GF) extraction. Median GF extractable concentrations of Hg, As, and Pb were 0.085, 13.9, and 32.2% of the total element concentration, respectively. Total and GF extractable concentrations of Hg, As, and Pb were used to estimate exposure and potential health risks to children following incidental ingestion of adobe brick particles. Risks were assessed using a range of potential ingestion rates (50-1000mg/day). Overall, the results of the risk assessment show that the majority of households sampled contained concentrations of bioaccessible Pb and As, but not Hg, that represent a potential health risk. Even at the lowest ingestion rate considered, the majority of households exceeded the risk threshold for Pb, indicating that the concentrations of this metal are of particular concern. To our knowledge, this is the first study to quantify key trace elements in building materials in adobe brick houses and the results indicate that these houses are a potential source of exposure to metals and metalloids in South American mining communities. Additional studies are needed to fully characterize personal exposure and to understand potential adverse health outcomes within the community.
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Affiliation(s)
- Abigail R McEwen
- Nicholas School of the Environment, Duke University, Box 90328, LSRC, Durham, NC 27708, USA.
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Duke University, Box 90287, Durham, NC 27708, USA.
| | - Nicholas A Robins
- Department of History, North Carolina State University, 467 Withers Hall, Raleigh, NC 27695, USA.
| | - Nicole A Hagan
- Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, 109 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA.
| | - Susan Halabi
- Department of Biostatistics and Bioinformatics, Duke University, Box 2717, Medical Center, Durham, NC 27710, USA.
| | | | - Daniel deB Richter
- Nicholas School of the Environment, Duke University, Box 90328, LSRC, Durham, NC 27708, USA.
| | - John J Vandenberg
- Office of Research and Development, U.S. Environmental Protection Agency, 109 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA.
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Matson CW, Bone AJ, Auffan M, Lindberg TT, Arnold MC, Hsu-Kim H, Wiesner MR, Di Giulio RT. Silver toxicity across salinity gradients: the role of dissolved silver chloride species (AgCl x ) in Atlantic killifish (Fundulus heteroclitus) and medaka (Oryzias latipes) early life-stage toxicity. Ecotoxicology 2016; 25:1105-1118. [PMID: 27170044 DOI: 10.1007/s10646-016-1665-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/27/2016] [Indexed: 06/05/2023]
Abstract
The influence of salinity on Ag toxicity was investigated in Atlantic killifish (Fundulus heteroclitus) early life-stages. Embryo mortality was significantly reduced as salinity increased and Ag(+) was converted to AgCl(solid). However, as salinity continued to rise (>5 ‰), toxicity increased to a level at least as high as observed for Ag(+) in deionized water. Rather than correlating with Ag(+), Fundulus embryo toxicity was better explained (R(2) = 0.96) by total dissolved Ag (Ag(+), AgCl2 (-), AgCl3 (2-), AgCl4 (3-)). Complementary experiments were conducted with medaka (Oryzias latipes) embryos to determine if this pattern was consistent among evolutionarily divergent euryhaline species. Contrary to Fundulus data, medaka toxicity data were best explained by Ag(+) concentrations (R(2) = 0.94), suggesting that differing ionoregulatory physiology may drive observed differences. Fundulus larvae were also tested, and toxicity did increase at higher salinities, but did not track predicted silver speciation. Alternatively, toxicity began to increase only at salinities above the isosmotic point, suggesting that shifts in osmoregulatory strategy at higher salinities might be an important factor. Na(+) dysregulation was confirmed as the mechanism of toxicity in Ag-exposed Fundulus larvae at both low and high salinities. While Ag uptake was highest at low salinities for both Fundulus embryos and larvae, uptake was not predictive of toxicity.
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Affiliation(s)
- Cole W Matson
- Department of Environmental Science, Center for Reservoir and Aquatic Systems Research, Baylor University, Waco, TX, 76798, USA.
- Center for the Environmental Implications of NanoTechnology (CEINT), Duke University, Durham, NC, 27708, USA.
| | - Audrey J Bone
- Center for the Environmental Implications of NanoTechnology (CEINT), Duke University, Durham, NC, 27708, USA
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Mélanie Auffan
- Center for the Environmental Implications of NanoTechnology (CEINT), Duke University, Durham, NC, 27708, USA
- Aix-Marseille Université, CNRS, IRD, CEREGE UM34, UMR 7330, 13545, Aix en Provence, France
- GDRi iCEINT, International Consortium for the Environmental Implication of Nanotechnology, Paris, France
| | - T Ty Lindberg
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
- National Ecological Observatory Network, Boulder, CO, 80301, USA
| | - Mariah C Arnold
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Heileen Hsu-Kim
- Center for the Environmental Implications of NanoTechnology (CEINT), Duke University, Durham, NC, 27708, USA
- Civil and Environmental Engineering, Duke University, Durham, NC, 27708, USA
| | - Mark R Wiesner
- Center for the Environmental Implications of NanoTechnology (CEINT), Duke University, Durham, NC, 27708, USA
- Civil and Environmental Engineering, Duke University, Durham, NC, 27708, USA
| | - Richard T Di Giulio
- Center for the Environmental Implications of NanoTechnology (CEINT), Duke University, Durham, NC, 27708, USA
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
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45
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Taggart RK, Hower JC, Dwyer GS, Hsu-Kim H. Trends in the Rare Earth Element Content of U.S.-Based Coal Combustion Fly Ashes. Environ Sci Technol 2016; 50:5919-26. [PMID: 27228215 DOI: 10.1021/acs.est.6b00085] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Rare earth elements (REEs) are critical and strategic materials in the defense, energy, electronics, and automotive industries. The reclamation of REEs from coal combustion fly ash has been proposed as a way to supplement REE mining. However, the typical REE contents in coal fly ash, particularly in the United States, have not been comprehensively documented or compared among the major types of coal feedstocks that determine fly ash composition. The objective of this study was to characterize a broad selection of U.S. fly ashes of varied geological origin in order to rank their potential for REE recovery. The total and nitric acid-extractable REE content for more than 100 ash samples were correlated with characteristics such as the major element content and coal basin to elucidate trends in REE enrichment. Average total REE content (defined as the sum of the lanthanides, yttrium, and scandium) for ashes derived from Appalachian sources was 591 mg kg(-1) and significantly greater than in ashes from Illinois and Powder River basin coals (403 and 337 mg kg(-1), respectively). The fraction of critical REEs (Nd, Eu, Tb, Dy, Y, and Er) in the fly ashes was 34-38% of the total and considerably higher than in conventional ores (typically less than 15%). Powder River Basin ashes had the highest extractable REE content, with 70% of the total REE recovered by heated nitric acid digestion. This is likely due to the higher calcium content of Powder River Basin ashes, which enhances their solubility in nitric acid. Sc, Nd, and Dy were the major contributors to the total REE value in fly ash, based on their contents and recent market prices. Overall, this study shows that coal fly ash production could provide a substantial domestic supply of REEs, but the feasibility of recovery depends on the development of extraction technologies that could be tailored to the major mineral content and origins of the feed coal for the ash.
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Affiliation(s)
| | - James C Hower
- Center for Applied Energy Research, University of Kentucky , Lexington, Kentucky 40511, United States
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Abstract
Mercury (Hg) occurs as a myriad of species in environmental media, each with different physicochemical properties. The influence of Hg speciation on its transport in unsaturated soils is not well studied. Transport of four Hg species (dissolved inorganic Hg (II) species, a prepared Hg(II) and dissolved organic matter (DOM) complex, Hg(0), and HgS nanoparticles) was measured in sand and soil packed columns with partial water saturation under simulated rainfall (low ionic strength solution without DOM) and landfill leachate (high DOM content and high ionic strength) influent conditions. The Hg(II)-DOM species had the highest mobility among the four Hg species evaluated, and HgS particles (∼230 nm hydrodynamic diameter) had the poorest mobility, for all soil and influent conditions tested. The addition of 2 wt % clay particles to sand greatly retarded the transport of all Hg species, especially under simulated rainfall. DOM in the column influent facilitated the transport of all four Hg species in model and natural soils. For simulated rainfall, the transport trends observed in model sands were consistent with those measured in a sandy soil, except that the mobility of dissolved inorganic Hg(II) species was significantly lower in natural soils. For simulated rainfall, Hg transport was negligible in a high organic content (∼3.72 wt %) soil for all species except Hg-DOM. This work suggests that the Hg-DOM species presents the greatest potential for vertical migration to groundwater, especially with DOM in the influent solution.
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Affiliation(s)
- Ke Gai
- Civil & Environmental Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Thomas P Hoelen
- Chevron Energy Technology Company , San Ramon, California 94583, United States
| | | | - Gregory V Lowry
- Civil & Environmental Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
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Wyatt LH, Diringer SE, Rogers LA, Hsu-Kim H, Pan WK, Meyer JN. Antagonistic Growth Effects of Mercury and Selenium in Caenorhabditis elegans Are Chemical-Species-Dependent and Do Not Depend on Internal Hg/Se Ratios. Environ Sci Technol 2016; 50:3256-64. [PMID: 26938845 PMCID: PMC4964607 DOI: 10.1021/acs.est.5b06044] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The relationship between mercury (Hg) and selenium (Se) toxicity is complex, with coexposure reported to reduce, increase, and have no effect on toxicity. Different interactions may be related to chemical compound, but this has not been systematically examined. Our goal was to assess the interactive effects between the two elements on growth in the nematode Caenorhabditis elegans, focusing on inorganic and organic Hg (HgCl2 and MeHgCl) and Se (selenomethionine, sodium selenite, and sodium selenate) compounds. We utilized aqueous Hg/Se dosing molar ratios that were either above, below, or equal to 1 and measured the internal nematode total Hg and Se concentrations for the highest concentrations of each Se compound. Observed interactions were complicated, differed between Se and Hg compounds, and included greater-than-additive, additive, and less-than-additive growth impacts. Biologically significant interactions were only observed when the dosing Se solution concentration was 100-25,000 times greater than the dosing Hg concentration. Mitigation of growth impacts was not predictable on the basis of internal Hg/Se molar ratio; improved growth was observed at some internal Hg/Se molar ratios both above and below 1. These findings suggest that future assessments of the Hg and Se relationship should incorporate chemical compound into the evaluation.
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Affiliation(s)
- Lauren H. Wyatt
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
| | - Sarah E. Diringer
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Laura A. Rogers
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
| | - William K. Pan
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
- Global Health Institute, Duke University, Durham, North Carolina 27708, United States
| | - Joel N. Meyer
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
- Corresponding Author. Phone: 919-613-8109;
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Lee SW, Lowry GV, Hsu-Kim H. Biogeochemical transformations of mercury in solid waste landfills and pathways for release. Environ Sci Process Impacts 2016; 18:176-189. [PMID: 26745831 DOI: 10.1039/c5em00561b] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Mercury (Hg) is present in a variety of solid wastes including industrial wastes, household products, consumer electronics, and medical wastes, some of which can be disposed in conventional landfills. The presence of this neurotoxic metal in landfills is a concern due to the potential for it to leach or volatilize from the landfill and impact local ecosystems. The objective of this review is to describe general practices for the disposal of mercury-bearing solid wastes, summarize previous studies on the release of mercury from landfills, and delineate the expected transformations of Hg within landfill environments that would influence transport of Hg via landfill gas and leachate. A few studies have documented the emissions of Hg as landfill gas, primarily as gaseous elemental Hg(0) and smaller amounts as methylated Hg species. Much less is known regarding the release of Hg in leachate. Landfill conditions are unique from other subsurface environments in that they can contain water with very high conductivity and organic carbon concentration. Landfills also experience large changes in redox potential (and the associated microbial community) that greatly influence Hg speciation, transformations, and mobilization potential. Generally, Hg is not likely to persist in large quantities as dissolved species, since Hg(0) tends to evolve in the gas phase and divalent Hg(ii) sorbs strongly to particulate phases including organic carbon and sulfides. However, Hg(ii) has the potential to associate with or form colloidal particles that can be mobilized in porous media under high organic carbon conditions. Moreover, the anaerobic conditions within landfills can foster the growth of microorganisms that produced monomethyl- and dimethyl-Hg species, the forms of mercury with high potential for bioaccumulation. Much advancement has recently been made in the mercury biogeochemistry research field, and this study seeks to incorporate these findings for landfill settings.
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Affiliation(s)
- Sung-Woo Lee
- Department of Civil & Environmental Engineering, Duke University, Durham, North Carolina 27708, USA.
| | - Gregory V Lowry
- Department of Civil & Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Heileen Hsu-Kim
- Department of Civil & Environmental Engineering, Duke University, Durham, North Carolina 27708, USA.
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49
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Maurer LL, Yang X, Schindler AJ, Taggart RK, Jiang C, Hsu-Kim H, Sherwood DR, Meyer JN. Intracellular trafficking pathways in silver nanoparticle uptake and toxicity in Caenorhabditis elegans. Nanotoxicology 2015; 10:831-5. [PMID: 26559224 DOI: 10.3109/17435390.2015.1110759] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We used the nematode Caenorhabditis elegans to study the roles of endocytosis and lysosomal function in uptake and subsequent toxicity of silver nanoparticles (AgNP) in vivo. To focus on AgNP uptake and effects rather than silver ion (AgNO3) effects, we used a minimally dissolvable AgNP, citrate-coated AgNPs (CIT-AgNPs). We found that the clathrin-mediated endocytosis inhibitor chlorpromazine reduced the toxicity of CIT-AgNPs but not AgNO3. We also tested the sensitivity of three endocytosis-deficient mutants (rme-1, rme-6 and rme-8) and two lysosomal function deficient mutants (cup-5 and glo-1) as compared to wild-type (N2 strain). One of the endocytosis-deficient mutants (rme-6) took up less silver and was resistant to the acute toxicity of CIT-AgNPs compared to N2s. None of those mutants showed altered sensitivity to AgNO3. Lysosome and lysosome-related organelle mutants were more sensitive to the growth-inhibiting effects of both CIT-AgNPs and AgNO3. Our study provides mechanistic evidence suggesting that early endosome formation is necessary for AgNP-induced toxicity in vivo, as rme-6 mutants were less sensitive to the toxic effects of AgNPs than C. elegans with mutations involved in later steps in the endocytic process.
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Affiliation(s)
- Laura L Maurer
- a Nicholas School of the Environment, Duke University , Durham , NC , USA .,b Center for the Environmental Implications of Nanotechnology, Duke University , Durham , NC , USA
| | - Xinyu Yang
- a Nicholas School of the Environment, Duke University , Durham , NC , USA .,b Center for the Environmental Implications of Nanotechnology, Duke University , Durham , NC , USA
| | | | - Ross K Taggart
- b Center for the Environmental Implications of Nanotechnology, Duke University , Durham , NC , USA .,d Department of Civil & Environmental Engineering , Duke University , Durham , NC , USA
| | - Chuanjia Jiang
- b Center for the Environmental Implications of Nanotechnology, Duke University , Durham , NC , USA .,d Department of Civil & Environmental Engineering , Duke University , Durham , NC , USA
| | - Heileen Hsu-Kim
- b Center for the Environmental Implications of Nanotechnology, Duke University , Durham , NC , USA .,d Department of Civil & Environmental Engineering , Duke University , Durham , NC , USA
| | | | - Joel N Meyer
- a Nicholas School of the Environment, Duke University , Durham , NC , USA .,b Center for the Environmental Implications of Nanotechnology, Duke University , Durham , NC , USA
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Pham ALT, Johnson C, Manley D, Hsu-Kim H. Influence of Sulfide Nanoparticles on Dissolved Mercury and Zinc Quantification by Diffusive Gradient in Thin-Film Passive Samplers. Environ Sci Technol 2015; 49:12897-903. [PMID: 26414810 PMCID: PMC4782790 DOI: 10.1021/acs.est.5b02774] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Diffusive gradient in thin-film (DGT) passive samplers are frequently used to monitor the concentrations of metals such as mercury and zinc in sediments and other aquatic environments. The application of these samplers generally presumes that they quantify only the dissolved fraction and not particle-bound metal species that are too large to migrate into the sampler. However, metals associated with very small nanoparticles (smaller than the pore size of DGT samplers) can be abundant in certain environments, yet the implications of these nanoparticles for DGT measurements are unclear. The objective of this study was to determine how the performance of the DGT sampler is affected by the presence of nanoparticulate species of Hg and Zn. DGT samplers were exposed to solutions containing known amounts of dissolved Hg(II) and nanoparticulate HgS (or dissolved Zn(II) and nanoparticulate ZnS). The amounts of Hg and Zn accumulated onto the DGT samplers were quantified over hours to days, and the rates of diffusion of the dissolved metal (i.e., the effective diffusion coefficient D) into the sampler's diffusion layer were calculated and compared for solutions containing varying concentrations of nanoparticles. The results suggested that the nanoparticles deposited on the surface of the samplers might have acted as sorbents, slowing the migration of the dissolved species into the samplers. The consequence was that the DGT sampler data underestimated the dissolved metal concentration in the solution. In addition, X-ray absorption spectroscopy was employed to determine the speciation of the Hg accumulated on the sampler binding layer, and the results indicated that HgS nanoparticles did not appear to directly contribute to the DGT measurement. Overall, our findings suggest that the deployment of DGT samplers in settings where nanoparticles are relevant (e.g., sediments) may result in DGT data that incorrectly estimated the dissolved metal concentrations. Models for metal uptake into the sampler may need to be reconsidered.
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Affiliation(s)
- Anh Le-Tuan Pham
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27503, United States
| | - Carol Johnson
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27503, United States
| | - Devon Manley
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27503, United States
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27503, United States
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