1
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Huang G, Li Y, Liu J, Jiang D, Jiang K. Interference of the gas chromatography- mass spectrometry instrumental background on the determination of trace cyclic volatile methylsiloxanes and exclusion of it by delayed injection. J Chromatogr A 2024; 1726:464894. [PMID: 38733926 DOI: 10.1016/j.chroma.2024.464894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Revised: 04/04/2024] [Accepted: 04/08/2024] [Indexed: 05/13/2024]
Abstract
Cyclic volatile methylsiloxanes (cVMS) have been widely found in various types of environmental media and attracted increasing attention as new pollutants. However, there is still a great challenge in the accurate quantification of trace cVMS, due to their volatility, and the high background originating from GC/MS accessories and surroundings. In this work, the main sources of the high background were investigated in detail for octamethylcyclotetrasiloxane (D4), decmethylcyclopentasiloxane (D5) and dodecmethylcyclohexosiloxane (D6). Several effective measures were employed to minimize these backgrounds, including the delayed injection method to minimize the interference from the injection septum. Then, a GC-MS method was developed for the accurate determination of D4, D5 and D6, with a linear range of 2 - 200 μg/L. The coefficient of determination was 0.9982-0.9986, the limit of detection (LOD) was 0.40-0.52 μg/L, and the quantitative range was 1.88-190 μg/L. Good reproducibility and recovery were obtained, indicating the reliability of the established analytical method.
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Affiliation(s)
- Guoliang Huang
- College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, Yuhangtang Road 2318, Yuhang District, Hangzhou, China
| | - Yunna Li
- College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, Yuhangtang Road 2318, Yuhang District, Hangzhou, China
| | - Jinsong Liu
- Zhejiang Key Laboratory of Ecological and Environmental Monitoring, Forewarning and Quality Control, Zhejiang Ecological and Environmental Monitoring Center, Xueyuan Road 117, Xihu District, Hangzhou, China.
| | - Duohao Jiang
- College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, Yuhangtang Road 2318, Yuhang District, Hangzhou, China
| | - Kezhi Jiang
- College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, Yuhangtang Road 2318, Yuhang District, Hangzhou, China.
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2
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Brunet C, Marek RF, Stanier CO, Hornbuckle KC. Concentrations of Volatile Methyl Siloxanes in New York City Reflect Emissions from Personal Care and Industrial Use. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:8835-8845. [PMID: 38722766 PMCID: PMC11112754 DOI: 10.1021/acs.est.3c10752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/22/2024]
Abstract
Volatile methyl siloxanes (VMS) are a group of organosilicon compounds of interest because of their potential health effects, their ability to form secondary organic aerosols, and their use as tracer compounds. VMS are emitted in the gas-phase from using consumer and personal care products, including deodorants, lotions, and hair conditioners. Because of this emission route, airborne concentrations are expected to increase with population density, although there are few studies in large urban centers. Here, we report summertime concentrations and daily variations of VMS congeners measured in New York City. Median concentrations of the 6 studied congeners, D3 (20 ng m-3), D4 (57 ng m-3), D5 (230 ng m-3), D6 (11 ng m-3), L5 (2.5 ng m-3), and L7 (1.3 ng m-3) are among the highest reported outdoor concentrations in the literature to date. Average congener ratios of D5:D4 and D5:D6 were consistent with previously reported emissions ratios, suggesting that concentrations were dominated by local emissions. Measured concentrations agree with previously published results from a Community Multiscale Air Quality model and support commonly accepted emissions rates for D4, D5, and D6 of 32.8, 135, and 6.1 mg per capita per day. Concentrations of D4, D5, D6, L5, and L7 and total VMS were significantly lower during the day than during the night, consistent with daytime oxidation reactivity. Concentrations of D3 did not show the same diurnal trend but exhibited a strong directional dependence, suggesting that it may be emitted by industrial point sources in the area rather than personal care product use. Concentrations of all congeners had large temporal variations but showed relatively weak relationships with wind speed, temperature, and mixing height.
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Affiliation(s)
- Christopher
E. Brunet
- Department
of Civil and Environmental Engineering, IIHR-Hydroscience & Engineering, University of Iowa, Iowa City Iowa 52242, United States
| | - Rachel F. Marek
- Department
of Civil and Environmental Engineering, IIHR-Hydroscience & Engineering, University of Iowa, Iowa City Iowa 52242, United States
| | - Charles O. Stanier
- Department
of Chemical and Biochemical Engineering, IIHR-Hydroscience and Engineering, The University of Iowa, Iowa City Iowa 52242, United States
| | - Keri C. Hornbuckle
- Department
of Civil and Environmental Engineering, IIHR-Hydroscience & Engineering, University of Iowa, Iowa City Iowa 52242, United States
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3
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Meepage J, Welker JK, Meyer CM, Mohammadi S, Stanier CO, Stone EA. Advances in the Separation and Detection of Secondary Organic Aerosol Produced by Decamethylcyclopentasiloxane (D 5) in Laboratory-Generated and Ambient Aerosol. ACS ES&T AIR 2024; 1:365-375. [PMID: 38751609 PMCID: PMC11091883 DOI: 10.1021/acsestair.3c00073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 05/18/2024]
Abstract
Decamethylcyclopentasiloxane (D5), a common ingredient in many personal care products (PCPs), undergoes oxidation in the atmosphere, leading to the formation of secondary organic aerosol (SOA). Yet, the specific contributions of D5-derived SOA on ambient fine particulate matter (PM2.5) have not been characterized. This study addresses this knowledge gap by introducing a new analytical method to advance the molecular characterization of oxidized D5 and its detection in ambient aerosol. The newly developed reversed phase liquid chromatography method, in conjunction with high-resolution mass spectrometry, separates and detects D5 oxidation products, enabling new insights into their molecular and isomeric composition. Application of this method to laboratory-generated SOA and urban PM2.5 in New York City expands the number of D5 oxidation products observed in ambient aerosol and informs a list of molecular candidates to track D5-derived SOA in the atmosphere. An oxidation series was observed in which one or more methyl groups in D5 (C10H30O5Si5) is replaced by a hydroxyl group, which indicates the presence of multistep oxidation products in ambient PM2.5. Because of their specificity to PCPs and demonstrated detectability in ambient PM2.5, several oxidation products are proposed as molecular tracers for D5-derived SOA and may prove useful in assessing the impact of PCPs-derived SOA in the atmosphere.
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Affiliation(s)
- Jeewani
N. Meepage
- Department
of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Josie K. Welker
- Department
of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Claire M. Meyer
- Department
of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Saeideh Mohammadi
- Department
of Chemical and Biochemical Engineering, University of Iowa, Iowa City, Iowa 52242, United States
| | - Charles O. Stanier
- Department
of Chemical and Biochemical Engineering, University of Iowa, Iowa City, Iowa 52242, United States
| | - Elizabeth A. Stone
- Department
of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
- Department
of Chemical and Biochemical Engineering, University of Iowa, Iowa City, Iowa 52242, United States
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4
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Xing Y, Ge Y, Lu S, Yang T, Peng X. Dimethylcyclosiloxanes in Mobile Smart Terminal Devices: Concentrations, Distributions, Profiles, and Environmental Emissions. TOXICS 2024; 12:287. [PMID: 38668510 PMCID: PMC11053745 DOI: 10.3390/toxics12040287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 04/10/2024] [Accepted: 04/11/2024] [Indexed: 04/29/2024]
Abstract
Dimethylcyclosiloxanes (DMCs) are utilized as vital monomers in the synthesis of organosilicon compounds, integral to the manufacture of mobile smart terminal devices. Toxicological studies have revealed potential endocrine-disrupting activity, reproductive toxicity, neurotoxicity, and other toxicities of the DMCs. This study investigated the concentrations and composition profiles of seven DMCs, including hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), and tetradecamethylcycloheptasiloxane (D7), hexadecamethylcyclooctasiloxane (D8), and octadecamethylcyclononasiloxane (D9) in three types of mobile smart terminal device components (silicone rubber, adhesive, and plastics). Environmental emissions of DMCs from silicone rubber materials were also estimated to improve the recognition of their potential fate within the environment. D5-D9 were widely present in silicone rubber and adhesives with detection rates ranging from 91-95.5% and 50-100%, respectively, while D3 and D4 were more frequently detected in plastics, both showing a detection rate of 61.1%. Silicone rubber had the highest total DMCs (∑7DMCs) and a concentration of 802.2 mg/kg, which were dominated by D7, D8, and D9. DMCs detected in adhesives were dominated by D4, D5, and D6. The estimated emission of ∑DMCs released into the environment in China from silicone rubber used in mobile smart terminal devices exceeds 5000 tons per year. Further studies are needed on the presence of DMCs in various commodities and environmental media to assess their ecological and human health impacts, as well as the toxicological effects of D7-D9 for the appropriate regulation of these chemicals.
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Affiliation(s)
- Yuanna Xing
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; (Y.X.); (T.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiming Ge
- School of Public Health (Shenzhen), Shenzhen Campus of SunYat-sen University, Shenzhen 518107, China; (Y.G.); (S.L.)
| | - Shaoyou Lu
- School of Public Health (Shenzhen), Shenzhen Campus of SunYat-sen University, Shenzhen 518107, China; (Y.G.); (S.L.)
| | - Tao Yang
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; (Y.X.); (T.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xianzhi Peng
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; (Y.X.); (T.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
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5
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Xu S, Courtemanche MA, Miller J. Volatilization of dimethylsilanediol (DMSD) under environmentally relevant conditions: Sampling method and impact of water and soil materials. CHEMOSPHERE 2024; 354:141681. [PMID: 38467199 DOI: 10.1016/j.chemosphere.2024.141681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/06/2024] [Accepted: 03/08/2024] [Indexed: 03/13/2024]
Abstract
Dimethylsilanediol (DMSD) is the common breakdown product of methylsiloxanes such as polydimethylsiloxane (PDMS) and volatile methylsiloxanes (VMS) in soil. In this work, we first present a sorbent selection experiment aiming to identify a sorbent that can trap gas-phase DMSD without causing DMSD condensation and VMS hydrolysis at environmentally relevant humidities. With a proper sorbent (Tenax) identified, the volatilization of DMSD from water and various wet soil and soil materials were measured in a controlled environment. It was demonstrated that DMSD underwent volatilization after soil water was completely evaporated. Various types of soil constituents show drastic differences in preventing DMSD from volatilization. Analysis of the sorbent-captured products provides further insight, most notably that virtually no cyclic methylsiloxanes are formed during the volatilization of DMSD from water or soil materials, except in one extreme case where only traces are detected.
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Affiliation(s)
- Shihe Xu
- Toxicology, Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48642, USA; Currently at Tridge Environmental Consulting LLC, Midland, MI, 48642, USA.
| | | | - Julie Miller
- Toxicology, Environmental Research and Consulting, The Dow Chemical Company, Midland, MI, 48642, USA; Currently at Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
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6
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Li WL, Shunthirasingham C, Wong F, Smyth SA, Pajda A, Alexandrou N, Hung H, Huo CY, Bisbicos T, Alaee M, Pacepavicius G, Marvin C. Assessing Contributions of Synthetic Musk Compounds from Wastewater Treatment Plants to Atmospheric and Aquatic Environments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:5524-5533. [PMID: 38466636 DOI: 10.1021/acs.est.4c00840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
The high environmental concentrations, persistence, and toxicity of synthetic musk compounds (SMCs) necessitate a better grasp of their fate in wastewater treatment plants (WWTPs). To investigate the importance of WWTPs as pathways of SMCs to the environment, air and wastewater samples were collected at four WWTPs in Ontario, Canada. Polycyclic musks (PCMs) were present at higher concentrations than nitro musks (NMs) and macrocyclic musks (MCMs). Three PCMs [galaxolide (HHCB), tonalide (AHTN), and iso-E super (OTNE)] were the most abundant compounds (0.30-680 ng/m3 in air, 0.40-15 μg/L in influent, and 0.007-6.0 μg/L in effluent). Analyses of multiyear data suggest that risk management measures put in place have been effective in reducing the release of many SMCs into the environment. The highest removal efficiency, up to almost 100% of some SMCs, was observed for the plant with the longest solid retention time. A fugacity-based model was established to simulate the transport and fate of SMCs in the WWTP, and good agreement was obtained between the measured and modeled values. These findings indicate that the levels of certain SMCs discharged into the atmospheric and aquatic environments were substantial, potentially resulting in exposure to both humans and wildlife.
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Affiliation(s)
- Wen-Long Li
- Air Quality Processes Research Section, Environment and Climate Change Canada, 4905 Dufferin St, Toronto, ON M3H 5T4, Canada
- College of the Environment and Ecology, Xiamen University, Xiamen 361005, China
| | - Chubashini Shunthirasingham
- Air Quality Processes Research Section, Environment and Climate Change Canada, 4905 Dufferin St, Toronto, ON M3H 5T4, Canada
| | - Fiona Wong
- Air Quality Processes Research Section, Environment and Climate Change Canada, 4905 Dufferin St, Toronto, ON M3H 5T4, Canada
| | - Shirley Anne Smyth
- Science and Risk Assessment Directorate, Environment and Climate Change Canada, Burlington, ON L7S 1A1, Canada
| | - Artur Pajda
- Air Quality Processes Research Section, Environment and Climate Change Canada, 4905 Dufferin St, Toronto, ON M3H 5T4, Canada
| | - Nick Alexandrou
- Air Quality Processes Research Section, Environment and Climate Change Canada, 4905 Dufferin St, Toronto, ON M3H 5T4, Canada
| | - Hayley Hung
- Air Quality Processes Research Section, Environment and Climate Change Canada, 4905 Dufferin St, Toronto, ON M3H 5T4, Canada
| | - Chun-Yan Huo
- Air Quality Processes Research Section, Environment and Climate Change Canada, 4905 Dufferin St, Toronto, ON M3H 5T4, Canada
- College of the Environment and Ecology, Xiamen University, Xiamen 361005, China
| | - Tommy Bisbicos
- Water Science and Technology Directorate, Environment and Climate Change Canada, Burlington, ON L7S 1A1, Canada
| | - Mehran Alaee
- Water Science and Technology Directorate, Environment and Climate Change Canada, Burlington, ON L7S 1A1, Canada
| | - Grazina Pacepavicius
- Water Science and Technology Directorate, Environment and Climate Change Canada, Burlington, ON L7S 1A1, Canada
| | - Chris Marvin
- Water Science and Technology Directorate, Environment and Climate Change Canada, Burlington, ON L7S 1A1, Canada
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7
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Xu S, Courtemanche MA, Miller J. Fate of dimethylsilanediol (DMSD) in outdoor bare surface soil and its relation to soil water loss. CHEMOSPHERE 2024; 352:141478. [PMID: 38364924 DOI: 10.1016/j.chemosphere.2024.141478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/21/2024] [Accepted: 02/14/2024] [Indexed: 02/18/2024]
Abstract
Dimethylsilanediol (DMSD) is a primary degradation product of silicone materials in the environment. Due to its low air/water partition coefficient and low soil/water distribution coefficient, this compound is not expected to undergo sorption and volatilization in wet soil. In an accompanying paper, we confirm that under controlled indoor conditions in test tubes, there is little to no volatilization of DMSD from soil and soil constituents if soil is wet. However, a significant amount of DMSD was volatilized when the soil substrates became air dried. Given the importance of water on the partition and fate of DMSD, we now report a continuation of this study focusing on the relation between DMSD removal and water loss in re-constituted soil columns under outdoor conditions. Consistent with predictions based on its partition properties and reconciling this evidence with previously reported field and laboratory studies, DMSD distribution was found to be largely dependent on water partitioning. The results suggested that DMSD moved upward in soil profile as soil water was evaporated from topmost layers with little DMSD retention by the soil matrix. As soil dried, a fraction of DMSD was sorbed by the soil matrix in the topmost layer, while most of the spiked radio-labeled DMSD was removed from soil through volatilization.
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Affiliation(s)
- Shihe Xu
- Toxicology, Environmental Research and Consulting, the Dow Chemical Company, Midland, MI, 48642, USA; Currently at Tridge Environmental Consulting LLC, Midland, MI, 48642, USA.
| | | | - Julie Miller
- Toxicology, Environmental Research and Consulting, the Dow Chemical Company, Midland, MI, 48642, USA; Currently at Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
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8
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Zhang L, Chen X, Luo G, Liu S, Guo P, Ye Y, Jiang R. Unraveling the distribution characteristic of cyclic volatile methylsiloxanes in various environmental media of a wastewater treatment plant. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169106. [PMID: 38065489 DOI: 10.1016/j.scitotenv.2023.169106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/27/2023] [Accepted: 12/02/2023] [Indexed: 12/17/2023]
Abstract
Cyclic volatile methylsiloxane (cVMS) is extensively used in consumer products and frequently detected in various environmental media, including water and air. In this study, we developed reliable and convenient methods to sample three cVMS compounds: octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in water and air samples collected from different tanks within a wastewater treatment plant (WWTP). The concentrations of D4, D5, and D6 in the water samples ranged from 0.40 to 8.0 μg L-1, 0.35 to 91 μg L-1, and 0.54 to 17 μg L-1, respectively. In the air samples, these concentrations varied from 0.34 to 20 μg m-3, 0.34 to 128 μg m-3, and 0.08 to 12 μg m-3, respectively. It is worth noting that the air-water distribution coefficient (Kaw) for these three cVMS exhibited a strong correlation with their water solubility. Moreover, fugacity fractions indicated a net evaporation process from water to the atmosphere. Furthermore, we investigated the distribution of cVMS between the gaseous and particulate phases. The results revealed a significant fraction, exceeding 72 %, of cVMS resided in the gas phase. D4 and D5 predominate in the gaseous phase, while D5 and D6 are the principal constituents within the particulate phase. The distribution coefficient characterizing the partitioning of cVMS compounds between the gaseous and particulate (Kp) exhibited a strong correlation with their corresponding octanol-air partitioning coefficients (Koa). These findings contribute to a better understanding of the distribution of cVMS in diverse environmental media and the underlying mechanism governing their dispersion.
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Affiliation(s)
- Lifang Zhang
- Guangdong Provincial Key Laboratory of Chemical Measurement and Emergency Test Technology, Guangdong Provincial Engineering Research Center for Ambient Mass Spectrometry, Institute of Analysis, Guangdong Academy of Sciences (China National Analytical Center, Guangzhou), Guangzhou 510070, China
| | - Xinlv Chen
- Guangdong Provincial Key Laboratory of Chemical Measurement and Emergency Test Technology, Guangdong Provincial Engineering Research Center for Ambient Mass Spectrometry, Institute of Analysis, Guangdong Academy of Sciences (China National Analytical Center, Guangzhou), Guangzhou 510070, China
| | - Gan Luo
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China
| | - Shuqin Liu
- Guangdong Provincial Key Laboratory of Chemical Measurement and Emergency Test Technology, Guangdong Provincial Engineering Research Center for Ambient Mass Spectrometry, Institute of Analysis, Guangdong Academy of Sciences (China National Analytical Center, Guangzhou), Guangzhou 510070, China
| | - Pengran Guo
- Guangdong Provincial Key Laboratory of Chemical Measurement and Emergency Test Technology, Guangdong Provincial Engineering Research Center for Ambient Mass Spectrometry, Institute of Analysis, Guangdong Academy of Sciences (China National Analytical Center, Guangzhou), Guangzhou 510070, China
| | - Yuanjian Ye
- Guangzhou Quality Supervision and Testing Institute, Guangzhou 511400, China
| | - Ruifen Jiang
- Guangdong Provincial Key Laboratory of Chemical Measurement and Emergency Test Technology, Guangdong Provincial Engineering Research Center for Ambient Mass Spectrometry, Institute of Analysis, Guangdong Academy of Sciences (China National Analytical Center, Guangzhou), Guangzhou 510070, China; Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China.
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9
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Sarai NS, Fulton TJ, O'Meara RL, Johnston KE, Brinkmann-Chen S, Maar RR, Tecklenburg RE, Roberts JM, Reddel JCT, Katsoulis DE, Arnold FH. Directed evolution of enzymatic silicon-carbon bond cleavage in siloxanes. Science 2024; 383:438-443. [PMID: 38271505 DOI: 10.1126/science.adi5554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 12/18/2023] [Indexed: 01/27/2024]
Abstract
Volatile methylsiloxanes (VMS) are man-made, nonbiodegradable chemicals produced at a megaton-per-year scale, which leads to concern over their potential for environmental persistence, long-range transport, and bioaccumulation. We used directed evolution to engineer a variant of bacterial cytochrome P450BM3 to break silicon-carbon bonds in linear and cyclic VMS. To accomplish silicon-carbon bond cleavage, the enzyme catalyzes two tandem oxidations of a siloxane methyl group, which is followed by putative [1,2]-Brook rearrangement and hydrolysis. Discovery of this so-called siloxane oxidase opens possibilities for the eventual biodegradation of VMS.
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Affiliation(s)
- Nicholas S Sarai
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Tyler J Fulton
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Ryen L O'Meara
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Kadina E Johnston
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Sabine Brinkmann-Chen
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | | | | | | | | | | | - Frances H Arnold
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
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10
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Fulton TJ, Sarai NS, O'Meara RL, Arnold FH. Directed evolution for Si-C bond cleavage of volatile siloxanes in glass bioreactors. Methods Enzymol 2023; 693:375-403. [PMID: 37977737 DOI: 10.1016/bs.mie.2023.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
Volatile methylsiloxanes (VMS) are a class of non-biodegradable anthropogenic compounds with propensity for long-range transport and potential for bioaccumulation in the environment. As a proof-of-principle for biological degradation of these compounds, we engineered P450 enzymes to oxidatively cleave Si-C bonds in linear and cyclic VMS. Enzymatic reactions with VMS are challenging to screen with conventional tools, however, due to their volatility, poor aqueous solubility, and tendency to extract polypropylene from standard 96-well deep-well plates. To address these challenges, we developed a new biocatalytic reactor consisting of individual 2-mL glass shells assembled in conventional 96-well plate format. In this chapter, we provide a detailed account of the assembly and use of the 96-well glass shell reactors for screening biocatalytic reactions. Additionally, we discuss the application of GC/MS analysis techniques for VMS oxidase reactions and modified procedures for validating improved variants. This protocol can be adopted broadly for biocatalytic reactions with substrates that are volatile or not suitable for polypropylene plates.
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Affiliation(s)
- Tyler J Fulton
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Nicholas S Sarai
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Ryen L O'Meara
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Frances H Arnold
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, United States.
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11
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Yao P, Holzinger R, Materić D, Oyama BS, de Fátima Andrade M, Paul D, Ni H, Noto H, Huang RJ, Dusek U. Methylsiloxanes from Vehicle Emissions Detected in Aerosol Particles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:14269-14279. [PMID: 37698874 PMCID: PMC10537456 DOI: 10.1021/acs.est.3c03797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/13/2023]
Abstract
Methylsiloxanes have gained growing attention as emerging pollutants due to their toxicity to organisms. As man-made chemicals with no natural source, most research to date has focused on volatile methylsiloxanes from personal care or household products and industrial processes. Here, we show that methylsiloxanes can be found in primary aerosol particles emitted by vehicles based on aerosol samples collected in two tunnels in São Paulo, Brazil. The aerosol samples were analyzed with thermal desorption-proton transfer reaction-mass spectrometry (TD-PTR-MS), and methylsiloxanes were identified and quantified in the mass spectra based on the natural abundance of silicon isotopes. Various methylsiloxanes and derivatives were found in aerosol particles from both tunnels. The concentrations of methylsiloxanes and derivatives ranged 37.7-377 ng m-3, and the relative fractions in organic aerosols were 0.78-1.9%. The concentrations of methylsiloxanes exhibited a significant correlation with both unburned lubricating oils and organic aerosol mass. The emission factors of methylsiloxanes averaged 1.16 ± 0.59 mg kg-1 of burned fuel for light-duty vehicles and 1.53 ± 0.37 mg kg-1 for heavy-duty vehicles. Global annual emissions of methylsiloxanes in vehicle-emitted aerosols were estimated to range from 0.0035 to 0.0060 Tg, underscoring the significant yet largely unknown potential for health and climate impacts.
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Affiliation(s)
- Peng Yao
- Centre for Isotope Research (CIO), Energy and Sustainability Research Institute Groningen (ESRIG), University of Groningen, Groningen 9747 AG, The Netherlands
| | - Rupert Holzinger
- Institute for Marine and Atmospheric Research, IMAU, Utrecht University, Princetonplein 5, Utrecht 3584 CC, The Netherlands
| | - Dušan Materić
- Institute for Marine and Atmospheric Research, IMAU, Utrecht University, Princetonplein 5, Utrecht 3584 CC, The Netherlands
- Department of Analytical Chemistry, Helmholtz Centre for Environmental Research─UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Beatriz Sayuri Oyama
- Institute for Marine and Atmospheric Research, IMAU, Utrecht University, Princetonplein 5, Utrecht 3584 CC, The Netherlands
- Institute of Astronomy, Geophysics and Atmospheric Sciences, University of São Paulo, São Paulo 05508-090, Brazil
| | - Maria de Fátima Andrade
- Institute of Astronomy, Geophysics and Atmospheric Sciences, University of São Paulo, São Paulo 05508-090, Brazil
| | - Dipayan Paul
- Centre for Isotope Research (CIO), Energy and Sustainability Research Institute Groningen (ESRIG), University of Groningen, Groningen 9747 AG, The Netherlands
| | - Haiyan Ni
- Centre for Isotope Research (CIO), Energy and Sustainability Research Institute Groningen (ESRIG), University of Groningen, Groningen 9747 AG, The Netherlands
- State Key Laboratory of Loess and Quaternary Geology, Center for Excellence in Quaternary Science and Global Change, Key Laboratory of Aerosol Chemistry & Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Hanne Noto
- Institute for Marine and Atmospheric Research, IMAU, Utrecht University, Princetonplein 5, Utrecht 3584 CC, The Netherlands
| | - Ru-Jin Huang
- State Key Laboratory of Loess and Quaternary Geology, Center for Excellence in Quaternary Science and Global Change, Key Laboratory of Aerosol Chemistry & Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Ulrike Dusek
- Centre for Isotope Research (CIO), Energy and Sustainability Research Institute Groningen (ESRIG), University of Groningen, Groningen 9747 AG, The Netherlands
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12
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Wang WL, Zhang Y, Sun DM, Chen ZY, Qian M, Zhou Y, Feng XS, Zhang XY. Volatile Methylsiloxanes in Complex Samples: Recent Updates on Pretreatment and Analysis Methods. Crit Rev Anal Chem 2023:1-21. [PMID: 37603425 DOI: 10.1080/10408347.2023.2245050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
Volatile methylsiloxanes (VMSs) are massively produced chemicals having applications in industry and home because of their physical and chemical characteristics. They are used in personal care products such as cosmetics, household coatings, cleaners, skin care products, and others. Resultantly, large number of VMSs are discharged into air where they can be subjected to atmospheric migrations over long distances causing toxic and estrogenic effects, persistence, and bioaccumulations. Many institutions have taken measures to control VMSs. They require accurate, rapid, and sensitive pretreatment and analysis methods for diverse samples. Herein, the pretreatment and determination methods of VMSs as reported in recent years are reviewed and summarized. Pretreatments include commonly methods such as membrane-assisted solvent extraction, liquid-liquid extraction, and others, while novel methods are solid phase extraction, solid phase microextraction, diverse liquid phase microextraction and others. Analyses are made through gas chromatography-based methods. In addition, the advantages, and disadvantages of techniques are compared, and the prospects of pretreatment and analysis methods are discussed.
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Affiliation(s)
- Wei-Lai Wang
- School of Pharmacy, China Medical University, Shenyang, China
| | - Yuan Zhang
- School of Pharmacy, China Medical University, Shenyang, China
| | - De-Mei Sun
- School of Pharmacy, China Medical University, Shenyang, China
| | - Zu-Yi Chen
- School of Pharmacy, China Medical University, Shenyang, China
| | - Min Qian
- School of Pharmacy, China Medical University, Shenyang, China
| | - Yu Zhou
- Department of Pharmacy, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xue-Song Feng
- School of Pharmacy, China Medical University, Shenyang, China
| | - Xin-Yuan Zhang
- School of Forensic Medicine, China Medical University, Shenyang, China
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13
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Liu YQ, Wang ZW, Hu CY. Progress in research on the safety of silicone rubber products in food processing. Compr Rev Food Sci Food Saf 2023; 22:2887-2909. [PMID: 37183940 DOI: 10.1111/1541-4337.13165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 03/24/2023] [Accepted: 04/15/2023] [Indexed: 05/16/2023]
Abstract
Silicone rubber (SR) is widely used in the food processing industry due to its excellent physical and chemical properties. However, due to the differences in SR product production formulas and processes, the quality of commercially available SR products varies greatly, with chemical and biological hazard potentials. Residual chemicals in SR, such as siloxane oligomers and 2,4-dichlorobenzoic acid, are non-intentionally added substances, which may migrate into food during processing so the safe use of SR must be guaranteed. Simultaneously, SR in contact with food is susceptible to pathogenic bacteria growing and biofilm formation, like Cronobacter sakazakii, Staphylococcus aureus, Salmonella enteritidis, and Listeria monocytogenes, posing a food safety risk. Under severe usage scenarios such as high-temperature, high-pressure, microwave, and freezing environments with long-term use, SR products are more prone to aging, and their degradation products may pose potential food safety hazards. Based on the goal of ensuring food quality and safety to the greatest extent possible, this review suggests that enterprises need to prepare high-quality food-contact SR products by optimizing the manufacturing formula and production process, and developing products with antibacterial and antiaging properties. The government departments should establish quality standards for food-contact SR products and conduct effective supervision. Besides, the reusable SR products should be cleaned by consumers immediately after use, and the deteriorated products should be replaced as soon as possible.
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Affiliation(s)
- Yi-Qi Liu
- Department of Food Science & Engineering, Jinan University, Guangzhou, Guangdong, China
| | - Zhi-Wei Wang
- Packaging Engineering Institute, Jinan University, Zhuhai, Guangdong, China
| | - Chang-Ying Hu
- Department of Food Science & Engineering, Jinan University, Guangzhou, Guangdong, China
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14
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Muir DCG, Getzinger GJ, McBride M, Ferguson PL. How Many Chemicals in Commerce Have Been Analyzed in Environmental Media? A 50 Year Bibliometric Analysis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023. [PMID: 37319372 DOI: 10.1021/acs.est.2c09353] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Over the past 50 years, there has been a tremendous expansion in the measurement of chemical contaminants in environmental media. But how many chemicals have actually been determined, and do they represent a significant fraction of substances in commerce or of chemicals of concern? To address these questions, we conducted a bibliometric survey to identify what individual chemicals have been determined in environmental media and their trends over the past 50 years. The CAplus database of CAS, a Division of the American Chemical Society, was searched for indexing roles "analytical study" and "pollutant" yielding a final list of 19,776 CAS Registry Numbers (CASRNs). That list was then used to link the CASRNs to biological studies, yielding a data set of 9.251 × 106 total counts of the CASRNs over a 55 year period. About 14,150 CASRNs were substances on various priority lists or their close analogs and transformation products. The top 100 most reported CASRNs accounted for 34% of the data set, confirming previous studies showing a significant bias toward repeated measurements of the same substances due to regulatory needs and the challenges of determining new, previously unmeasured, compounds. Substances listed in the industrial chemical inventories of Europe, China, and the United States accounted for only about 5% of measured substances. However, pharmaceuticals and current use pesticides were widely measured accounting for 50-60% of total CASRN counts for the period 2000-2015.
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Affiliation(s)
- Derek C G Muir
- Environment & Climate Change Canada, Burlington, Ontario L7S1A1, Canada
- School of Environmental Sciences, University of Guelph, Guelph, Ontario N1G2W1, Canada
| | - Gordon J Getzinger
- School of Environmental Sustainability, Loyola University Chicago, Chicago, Illinois 60660, United States
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Matt McBride
- CAS IP Services, CAS, Columbus, Ohio 43202, United States
| | - P Lee Ferguson
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
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15
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Saini A, Chinnadurai S, Schuster JK, Eng A, Harner T. Per- and polyfluoroalkyl substances and volatile methyl siloxanes in global air: Spatial and temporal trends. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 323:121291. [PMID: 36796663 DOI: 10.1016/j.envpol.2023.121291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/20/2023] [Accepted: 02/12/2023] [Indexed: 06/18/2023]
Abstract
The study reports on the atmospheric concentrations of per- and polyfluoroalkyl substances (PFAS) and volatile methyl siloxanes (VMS) measured using sorbent-impregnated polyurethane foam disks (SIPs) passive air samplers. New results are reported for samples collected in 2017, which extends temporal trend information to the period 2009-2017, for 21 sites where SIPs have been deployed since 2009. Among neutral PFAS, fluorotelomer alcohols (FTOHs) had higher concentrations than perfluoroalkane sulfonamides (FOSAs) and perfluoroalkane sulfonamido ethanols (FOSEs) with levels of ND‒228, ND‒15.8, ND‒10.4 pg/m3, respectively. Among ionizable PFAS, the sum of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) in air were 0.128-781 and 6.85-124 pg/m3, respectively. Longer-chain i.e. C9-C14 PFAS, which are relevant to the recent proposal by Canada for a listing of long-chain (C9-C21) PFCAs to the Stockholm Convention, were also detected in the environment at all site categories including Arctic sites. Cyclic and linear VMS ranged between 1.34‒452 and 0.01-12.1 ng/m3, respectively, showing dominance in urban areas. Despite the wide range of levels observed across different site categories, geometric means of the PFAS and VMS groups were fairly similar when grouped according to the five United Nations regions. Variable temporal trends in air (2009-2017) were observed for both PFAS and VMS. PFOS, which has been listed in the Stockholm Convention since 2009, is still showing increasing tendencies at several sites, indicating constant input from direct and/or indirect sources. These new data inform international chemicals management for PFAS and VMS.
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Affiliation(s)
- Amandeep Saini
- Air Quality Processes Research Section, Environment and Climate Change Canada, Toronto, Ontario, M3H 5T4, Canada.
| | - Sita Chinnadurai
- Air Quality Processes Research Section, Environment and Climate Change Canada, Toronto, Ontario, M3H 5T4, Canada
| | - Jasmin K Schuster
- Air Quality Processes Research Section, Environment and Climate Change Canada, Toronto, Ontario, M3H 5T4, Canada
| | - Anita Eng
- Air Quality Processes Research Section, Environment and Climate Change Canada, Toronto, Ontario, M3H 5T4, Canada
| | - Tom Harner
- Air Quality Processes Research Section, Environment and Climate Change Canada, Toronto, Ontario, M3H 5T4, Canada
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16
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Lee J, Kim K, Park SM, Kwon JS, Jeung EB. Effects of Decamethylcyclopentasiloxane on Reproductive Systems in Female Rats. TOXICS 2023; 11:302. [PMID: 37112528 PMCID: PMC10143965 DOI: 10.3390/toxics11040302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 03/20/2023] [Accepted: 03/23/2023] [Indexed: 06/19/2023]
Abstract
The female reproductive system becomes fertile through the action of hormones involved in the hypothalamic-pituitary-ovarian axis. On the other hand, estrogen-like endocrine disruptors released into the environment come into contact with humans by various routes and affect the reproductive system. Exposure to these chemicals can cause problems with the reproductive process, from egg ovulation to implantation, or cause female reproductive diseases. These reproductive problems cause infertility. Decamethylcyclopentasiloxane (D5) is used for lubrication in silicone polymers, households, and personal care products. In the case of D5, it is discharged through factory wastewater and can bioaccumulate. Therefore, it accumulates in the human body. In this study, D5 was administered orally for four weeks to determine the effects of D5 on the reproductive process. As a result, D5 increases the number of follicles in the ovary and suppresses the expression of genes related to the growth of follicles. In addition, it increases the gonadotropin hormone, inducing estradiol enhancement and progesterone reduction. Because of these changes in the reproductive system when exposed to D5, the industry should reconsider using D5.
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Affiliation(s)
- Jimin Lee
- College of Veterinary Medicine, Chungbuk National University, Chengju 28644, Republic of Korea
| | - Kangmin Kim
- College of Veterinary Medicine, Chungbuk National University, Chengju 28644, Republic of Korea
| | - Seon-Mi Park
- College of Veterinary Medicine, Chungbuk National University, Chengju 28644, Republic of Korea
| | | | - Eui-Bae Jeung
- College of Veterinary Medicine, Chungbuk National University, Chengju 28644, Republic of Korea
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17
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Kumari K, Singh A, Marathe D. Cyclic volatile methyl siloxanes (D4, D5, and D6) as the emerging pollutants in environment: environmental distribution, fate, and toxicological assessments. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-25568-7. [PMID: 36809612 DOI: 10.1007/s11356-023-25568-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 01/18/2023] [Indexed: 06/18/2023]
Abstract
Cyclic volatile methyl siloxanes (cVMS) have now become a subject of environmental contamination and risk assessment due to their widespread use and occurrence in different environmental matrices. Due to their exceptional physio-chemical properties, these compounds are diversely used for formulations of consumer products and others implying their continuous and significant release to environmental compartments. This has captured the major attention of the concerned communities on the grounds of potential health hazards to human and biota. The present study aims at comprehensively reviewing its occurrence in air, water, soil, sediments, sludge, dusts, biogas, biosolids, and biota and their environmental behavior as well. Concentrations of cVMS in indoor air and biosolids were higher; however, no significant concentrations were observed in water, soil, and sediments except for wastewaters. No threat to the aquatic organisms has been identified as their concentrations do not exceed the NOEC (maximum no observed effect concentration) thresholds. Mammalian (rodents) toxicity hazards were not very evident except for the occurrence of uterine tumors in very rare cases under long-term chronic and repeated dose exposures in laboratory conditions. Human relevancy to rodents were also not strongly enough established. Therefore, more careful examinations are required to develop stringent weight of evidences in scientific domain and ease the policy making with respect to their production and use so as to combat any environmental consequences.
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Affiliation(s)
- Kanchan Kumari
- CSIR-National Environmental Engineering Research Institute (NEERI), Kolkata Zonal Centre, 700 107, Kolkata, West Bengal, India.
- Academy of Scientific and Innovative Research (AcSIR), Uttar Pradesh, Ghaziabad, 201 002, India.
| | - Anshika Singh
- Academy of Scientific and Innovative Research (AcSIR), Uttar Pradesh, Ghaziabad, 201 002, India
- CSIR-National Environmental Engineering Research Institute (NEERI), Nagpur, 440020, Maharashtra, India
| | - Deepak Marathe
- Academy of Scientific and Innovative Research (AcSIR), Uttar Pradesh, Ghaziabad, 201 002, India
- CSIR-National Environmental Engineering Research Institute (NEERI), Nagpur, 440020, Maharashtra, India
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18
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Oxidation decomposition mechanism of hexamethyldisiloxane. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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19
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Zhu Y, Tang Z, He Y, Wang F, Lyu Y. Occurrence of methylsiloxanes in indoor store dust in China and potential human exposure. ENVIRONMENTAL RESEARCH 2023; 218:114969. [PMID: 36455627 DOI: 10.1016/j.envres.2022.114969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 11/23/2022] [Accepted: 11/27/2022] [Indexed: 06/17/2023]
Abstract
Methylsiloxanes are synthetic molecules with versatile and extensive applications. Because of their volatile properties, they are easily released from manufactured products and contaminate indoor environments, causing high human exposure. However, available information on their presence in specific microenvironments, and on the related potential risks for human health, is limited. We conducted a survey of sixteen methylsiloxanes species, including three cyclic (D4-D6) and thirteen linear (L4-L16) chemicals, in indoor dust samples from twenty-eight stores representative of six store categories in Beijing, China. Total methylsiloxane concentrations in store dust were 176-54,825 ng/g, depending on the store, with a median of 2196 ng/g. Linear chemicals represented a median proportion of 90.8% of total methylsiloxanes. The measured methylsiloxane concentrations in this study were marginally higher than those reported previously for standard living and working environments. The highest linear and total methylsiloxane concentrations were measured in electronic stores, while the highest cyclic methylsiloxane concentrations were measured in department stores. The presence of methylsiloxanes in the store dust samples was attributed mainly to their release from chemical additives in marketed products. Estimated median total exposure doses under normal and worst-case exposure scenarios were 0.237 and 0.888 ng/kg bw/d, respectively. Further investigation is needed to characterize methylsiloxane distribution in other microenvironments and to evaluate the associated health risks.
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Affiliation(s)
- Yanhuan Zhu
- Key Laboratory of Ecology and Environment in Minority Areas, Minzu University of China, National Ethnic Affairs Commission, Beijing, 100081, China; College of Life and Environmental Sciences, Minzu University of China, Beijing, 100081, China.
| | - Zhenwu Tang
- Key Laboratory of Ecology and Environment in Minority Areas, Minzu University of China, National Ethnic Affairs Commission, Beijing, 100081, China; College of Life and Environmental Sciences, Minzu University of China, Beijing, 100081, China.
| | - Ying He
- Key Laboratory of Ecology and Environment in Minority Areas, Minzu University of China, National Ethnic Affairs Commission, Beijing, 100081, China; College of Life and Environmental Sciences, Minzu University of China, Beijing, 100081, China.
| | - Fei Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
| | - Yang Lyu
- Key Laboratory of Ecology and Environment in Minority Areas, Minzu University of China, National Ethnic Affairs Commission, Beijing, 100081, China; College of Life and Environmental Sciences, Minzu University of China, Beijing, 100081, China.
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20
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Chen W, Kang YJ, Lee HK, Lee M, Moon HB. Nationwide monitoring of cyclic and linear siloxanes in sediment and bivalves from Korean coastal waters: Occurrence, geographical distribution, and bioaccumulation potential. MARINE POLLUTION BULLETIN 2022; 185:114201. [PMID: 36257246 DOI: 10.1016/j.marpolbul.2022.114201] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 06/16/2023]
Abstract
Contamination of coastal environments by siloxanes is of growing concern. Sediment and bivalves were collected from 50 locations along the Korean coast to assess the geographical distribution, sources, and bioaccumulation potential of siloxanes. Cyclic and linear siloxanes were detectable in all sediment and bivalve samples. The highest siloxane concentrations were detected in sediment (656 ng/g dw) and bivalves (3273 ng/g dw) from highly industrialized bays and harbor-zones, suggesting that industrial and shipping activities are major sources of siloxanes in coastal environment. The geographical distribution of siloxanes was similar in sediment and bivalves. Sedimentary siloxanes were dominated by cyclic siloxanes, while linear siloxanes were predominant in bivalves. Bioaccumulation of linear siloxanes in bivalves originated mainly from the sedimentary environment. Mean biota-sediment accumulation factors (BSAFs) of seven siloxanes ranged from 1.26 to 6.03, indicating potential for bioaccumulation. This is the first report on the nationwide survey on siloxanes in Korean coastal waters.
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Affiliation(s)
- Wenming Chen
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea; College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, PR China
| | - Yu-Jin Kang
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea
| | - Hyun-Kyung Lee
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea
| | - Moonjin Lee
- Maritime Safety and Environmental Research Division, Korea Research Institute of Ships and Ocean Engineering, Daejeon 34103, Republic of Korea
| | - Hyo-Bang Moon
- Department of Marine Science and Convergence Engineering, College of Science and Convergence Technology, Hanyang University, Ansan 15588, Republic of Korea.
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21
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Fernandes AS, Azevedo T, Rocha F, Nunes E, Homem V. Plant uptake potential and soil persistence of volatile methylsiloxanes in sewage sludge amended soils. CHEMOSPHERE 2022; 308:136314. [PMID: 36067813 DOI: 10.1016/j.chemosphere.2022.136314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 06/15/2023]
Abstract
Volatile methylsiloxanes (VMSs) are organosilicon compounds, ubiquitous in modern life. Due to their high use in consumer products, large amounts of these compounds are released into sewer systems, reaching wastewater treatment plants (WWTPs). Its frequent detection in sewage sludge can be of concern when considering its land application, not only due to potential negative impacts on the environment, but also on human health. In this work, the effects of sewage sludge application on plant development and crop productivity were studied, as well as VMSs persistence in the soil and their plant uptake. This study focused on 7 VMSs (D3, D4, D5, D6, L3, L4 and L5) and consisted of a 12-week greenhouse pot experiment, where sewage sludge-amended soils were used to cultivate Pisum sativum (peas). Sewage sludge application to soils had no negative effects on plant development and was tied to crop productivity improvements. Most of the VMSs were still present in soils at the end of the experiment and plant uptake and translocation of the 4 cyclic VMSs (D3, D4, D5, D6) occurred. VMSs were detected in plant tissues up to 161 ± 27 ng g-1 dw (samples of stems, leaves and tendrils), but did not exceed 50 ± 19 ng g-1 dw in peas, which did not translate into a human exposure risk due to ingestion, according to an intake risk assessment. However, soil risk assessments showed that for L5 the hazardous ratios were higher than the threshold value of 1. This means a potential environmental risk despite the low levels of this compound in soils (up to 7.3 ± 0.7 ng g-1 dw). Considering these results, sewage sludge monitoring plans should be defined for VMSs, namely when its final destination is land application, thus allowing a safer management of this residue, taking advantage of its valorization potential.
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Affiliation(s)
- Ana Sofia Fernandes
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal; ALiCE - Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
| | - Tomé Azevedo
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
| | - Filipe Rocha
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal; ALiCE - Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
| | - Eugénia Nunes
- GreenUPorto, Sustainable Agrifood Production, Campus de Vairão, Rua da Agrária 747, 4485-646, Portugal
| | - Vera Homem
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal; ALiCE - Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal.
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22
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Molinier B, Arata C, Katz EF, Lunderberg DM, Liu Y, Misztal PK, Nazaroff WW, Goldstein AH. Volatile Methyl Siloxanes and Other Organosilicon Compounds in Residential Air. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:15427-15436. [PMID: 36327170 PMCID: PMC9670844 DOI: 10.1021/acs.est.2c05438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 10/22/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
Volatile methyl siloxanes (VMS) are ubiquitous in indoor environments due to their use in personal care products. This paper builds on previous work identifying sources of VMS by synthesizing time-resolved proton-transfer reaction time-of-flight mass spectrometer VMS concentration measurements from four multiweek indoor air campaigns to elucidate emission sources and removal processes. Temporal patterns of VMS emissions display both continuous and episodic behavior, with the relative importance varying among species. We find that the cyclic siloxane D5 is consistently the most abundant VMS species, mainly attributable to personal care product use. Two other cyclic siloxanes, D3 and D4, are emitted from oven and personal care product use, with continuous sources also apparent. Two linear siloxanes, L4 and L5, are also emitted from personal care product use, with apparent additional continuous sources. We report measurements for three other organosilicon compounds found in personal care products. The primary air removal pathway of the species examined in this paper is ventilation to the outdoors, which has implications for atmospheric chemistry. The net removal rate is slower for linear siloxanes, which persist for days indoors after episodic release events. This work highlights the diversity in sources of organosilicon species and their persistence indoors.
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Affiliation(s)
- Betty Molinier
- Department
of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - Caleb Arata
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Department
of Environmental Science, Policy and Management, University of California, Berkeley, California 94720, United States
| | - Erin F. Katz
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Department
of Environmental Science, Policy and Management, University of California, Berkeley, California 94720, United States
| | - David M. Lunderberg
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Department
of Environmental Science, Policy and Management, University of California, Berkeley, California 94720, United States
| | - Yingjun Liu
- Department
of Environmental Science, Policy and Management, University of California, Berkeley, California 94720, United States
- College
of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Pawel K. Misztal
- Department
of Environmental Science, Policy and Management, University of California, Berkeley, California 94720, United States
- Civil,
Architectural, and Environmental Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - William W Nazaroff
- Department
of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - Allen H. Goldstein
- Department
of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
- Department
of Environmental Science, Policy and Management, University of California, Berkeley, California 94720, United States
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23
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Horii Y, Ohtsuka N, Nishino T, Kuroda K, Imaizumi Y, Sakurai T. Spatial distribution and benthic risk assessment of cyclic, linear, and modified methylsiloxanes in sediments from Tokyo Bay catchment basin, Japan: Si-based mass profiles in extractable organosilicon. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:155956. [PMID: 35580679 DOI: 10.1016/j.scitotenv.2022.155956] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 06/15/2023]
Abstract
We investigated the spatial distribution, mass profiles, and benthic risk assessment of a wide range of methylsiloxanes (MSs), including 7 cyclic MSs (CMSs; D3-D9; the number refers to the number of SiO bonds), 13 linear MSs (LMSs; L3-L15), and 15 modified and other MSs (MMSs) in sediments from the Tokyo Bay catchment basin, Japan. We observed widespread distribution of MSs (ΣCMS, ΣLMS, and ΣMMS) in the sediment samples, with concentrations of 1.0-6180 ng/g dry weight (dw), 1.8-10,100 ng/g dw, and < 0.31-210 ng/g dw, respectively. Our study is the first to measure various MMSs modified with hydrogen, vinyl, or phenyl groups; however, only methyltris(trimethylsiloxy)silane and phenyltris(trimethylsiloxy)silane were detected with high occurrence frequency. Notably, no elevated concentrations of MSs were observed downstream of silicone manufacturers, whereas the sediment was characterized by a specific D4/D5 ratio. With the Si-based mass profiles in extractable organosilicon (EOSi), the measured CMSs, LMSs, and MMSs accounted for 5.4%, 7.8%, and 0.2%, respectively. Unidentified EOSi (unknown fraction) constituted a major proportion of the EOSi in the sediment, with a mean of 87%, suggesting that the organosilicon environmental emissions were more than the measured MSs. In risk assessment of the adverse effects of D4, D5, and D6 in sediment on benthic organisms, the respective distributions indicated no overlap between the 95th percentile field sediment concentration and the 5th percentile chronic sediment no-effect concentration in organic carbon-normalized concentration. Although the hazard quotient compared with the predicted no-effect concentration for D5 and D6 exceeded the threshold level (hazard quotient ≥1), the results of probabilistic risk assessment for the three CMSs were not high enough to indicate a threat to benthic organisms in the study area.
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Affiliation(s)
- Yuichi Horii
- Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama 347-0115, Japan.
| | - Nobutoshi Ohtsuka
- Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama 347-0115, Japan
| | - Takahiro Nishino
- Tokyo Metropolitan Research Institute for Environmental Protection, 1-7-5 Shinsuna, Koto, Tokyo 136-0075, Japan
| | - Keisuke Kuroda
- Department of Environmental and Civil Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Yoshitaka Imaizumi
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Takeo Sakurai
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
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Zhang J, Liu N, Ren J, Xu L, Cai Y. Vinylmethylsiloxanes in Municipal Wastewater Treatment Plant and Biosolid-Amended Soils: Their Distribution and Backbone/Vinyl Branch Degradation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:10691-10698. [PMID: 35833964 DOI: 10.1021/acs.est.2c01400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
This study is the first to investigate the emission and environmental fate of one type of modified methylsiloxane with double-bond (vinyl) groups. During 2018-2020, 2,4,6-trimethyl-2,4,6-trivinylcyclotrisiloxane (V3), 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (V4), and 2,4,6,8,10-pentavinyl-2,4,6,8,10-pentamethylcyclopentasiloxane (V5) were found in aqueous (<LOD-72.9 ng/L) and solid [13.0-371 ng/g dw (dry weight)] phases of wastewater samples from one Chinese municipal wastewater treatment plant (WWTP) as well as the corresponding biosolid-amended soils [<LOD-36.9 ng/g dw, df (detection frequency) = 37.5-41.7%, n = 48]. Based on the measure of environmental samples, simulated experiment, and product analysis by ESI-FT-ICR-MS, it was found that (1) in addition to sorption to sludge, abiotic degradation of vinylmethylsiloxanes (especially V3, t1/2 = 0.5-1.9 h at pH = 5.2-9.2) should have an important contribution to their sufficient removal in WWTP; (2) different from siloxane analogues with saturated branches and aromatic branches, abiotic degradation pathways of vinylmethylsiloxane might include both the hydrolysis of Si-O backbone and the oxidation/addition reactions of vinyl branches; (3) although vinylmethylsiloxanes in wastewater could be transferred to soil by biosolids application, these compounds had no accumulation in soil, which should arise from their fast elimination, such as volatilization (t1/2 = 3.2 h-20.9 days) and degradation (t1/2 =9.1 h-96.3 days); and (4) degradation of the Si-O backbone and vinyl branches had slowing trends with the increase in the soil organic matter.
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Affiliation(s)
- Jie Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Nannan Liu
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China
| | - Juntao Ren
- Dongying Eco-Environment Monitoring Center of Shandong Province, Dongying 257091, China
| | - Lin Xu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 330106, China
| | - Yaqi Cai
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Hubei Key Laboratory of Environmental and Health Effects of Persistence Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan 430056, China
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25
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Jessup WH, Wiegand J, Delbridge-Perry M, MacAvoy SE, Connaughton VP. Developmental effects of siloxane exposure in zebrafish: a comparison study using laboratory-mixed and environmental water samples. J Appl Toxicol 2022; 42:1986-2004. [PMID: 35863877 DOI: 10.1002/jat.4369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/14/2022] [Accepted: 07/19/2022] [Indexed: 11/08/2022]
Abstract
Siloxanes are used in personal care, biomedical, and industrial products. Their worldwide use and persistence in the environment cause consistent exposure for both humans and aquatic animals. Two siloxane congeners, decamethylcyclopentasiloxane (D5; CAS 541-02-6) and octamethylcyclotetrasiloxane (D4; CAS 556-67-2), are among the most prevalent, with measurable levels in air, sediment, water, and biological samples. However, few studies have examined the impact of developmental (embryo/larva) exposure. To address this gap, we performed parallel experiments using wildtype zebrafish (Danio rerio). One set of experiments used laboratory-mixed individual solutions containing either D4, D5, or 2,4,6,8-tetramethylcyclotetrasiloxane (D4 H ; CAS 2370-88-9); the other used environmental water samples containing a mixture of siloxanes, including D4 and D5. These samples were collected from Bladensburg Waterfront Park (BWP) a site along the Anacostia River, Washington, DC. In both experiments, zebrafish (24-48 hours postfertilization, hpf) were exposed until 7 or 14 days (d)pf. Chronic exposure to D4, D5, or BWP water until 7 dpf caused stress-like behaviors and reduced swim velocities; anatomical differences were noted only in BWP-exposed larvae. At 14 dpf, BWP-treated larvae still showed slower swimming velocities and increased immobility; anatomical differences were no longer evident and thigmotactic behavior was reduced. D4 and D5-exposed larvae did not survive after 10 dpf. Larvae exposed to D4 H showed no decreases in behavior or growth at either age. These results suggest early developmental sensitivity to siloxane exposure and point to the need to consider embryonic/larval endpoints when assessing aquatic contaminants.
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Affiliation(s)
| | - Jenna Wiegand
- Departments of Environmental Science, American University, Washington, DC
| | | | - Stephen E MacAvoy
- Departments of Environmental Science, American University, Washington, DC
| | - Victoria P Connaughton
- Departments of Biology, American University, Washington, DC.,Center for Neuroscience and Behavior, American University, Washington, DC
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Feng D, Zhang X, Yuan H, Li X, Fan X. Identification, migration, and childhood exposure of methylsiloxanes in silicone infant bottle nipples marketed in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 829:154449. [PMID: 35276138 DOI: 10.1016/j.scitotenv.2022.154449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 02/06/2022] [Accepted: 03/06/2022] [Indexed: 06/14/2023]
Abstract
The analysis, migration, and childhood exposure of methylsiloxanes (MSs) in 32 silicone infant bottle nipples marketed in China were studied. Thirty types of MSs in two families, which included 11 linear MSs (LMSs, L4-L14) and 19 cyclic MSs (CMSs, D4-D22), were identified using gas chromatography-mass spectrometry (GC-MS) associated with standards, retention index, and carbon number rule. In 32 nipples, MSs with molecular weight < 1000 Da and CMSs were predominant. Considering the actual daily use of bottle nipples, the migration tests of MSs from nipples to artificial saliva and reconstituted powdered formula were performed. In particular, the orthogonal test design-QuEChERS-GC/MS was employed to detect MSs in formula. The median migration level of ΣMSs (MW < 1000 Da) in formula was 950.9 ng/mL, which was much higher than that in artificial saliva (98.1 ng/mL). If formula is fed to children aged 3-36 months using bottle nipples according to product instructions, the daily oral exposure to ΣMSs (MW < 1000) for children ranged from 52 to 146 μg/kg bw-day, which were two to five orders of magnitude higher than those of other exposure pathways. In sum, oral intake (especially through formula) may be the predominant pathway of exposure of MSs in children. This research enhances our understanding of the oral exposure risks of MSs and provides useful information that could aid the development of risk management strategies.
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Affiliation(s)
- Di Feng
- School of Light Industry, Beijing Technology and Business University, Beijing, China.
| | - XiRong Zhang
- School of Light Industry, Beijing Technology and Business University, Beijing, China
| | - Hang Yuan
- School of Light Industry, Beijing Technology and Business University, Beijing, China
| | - XueYan Li
- School of Light Industry, Beijing Technology and Business University, Beijing, China
| | - XiaoJie Fan
- School of Light Industry, Beijing Technology and Business University, Beijing, China
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27
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Yao P, Chianese E, Kairys N, Holzinger R, Materić D, Sirignano C, Riccio A, Ni H, Huang RJ, Dusek U. A large contribution of methylsiloxanes to particulate matter from ship emissions. ENVIRONMENT INTERNATIONAL 2022; 165:107324. [PMID: 35689851 DOI: 10.1016/j.envint.2022.107324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 05/24/2022] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
The chemical and stable carbon isotopic composition of the organic aerosol particles (OA) emitted by a shuttle passenger ship between mainland Naples and island Capri in Italy were investigated. Various methylsiloxanes and derivatives were found in particulate ship emissions for the first time, as identified in the mass spectra of a thermal desorption - proton transfer reaction - mass spectrometer (TD-PTR-MS) based on the natural abundance of silicon isotopes. Large contributions of methylsiloxanes to OA (up to 59.3%) were found under inefficient combustion conditions, and considerably lower methylsiloxane emissions were observed under cruise conditions (1.2% of OA). Furthermore, the stable carbon isotopic composition can provide a fingerprint for methylsiloxanes, as they have low δ13C values in the range of -44.91‰ ± 4.29‰. The occurrence of methylsiloxanes was therefore further supported by low δ13C values of particulate organic carbon (OC), ranging from -34.7‰ to -39.4‰, when carbon fractions of methylsiloxanes in OC were high. The δ13C values of OC increased up to around -26.7‰ under cruise conditions, when carbon fractions of methylsiloxanes in OC were low. Overall, the δ13C value of OC decreased linearly with increasing carbon fraction of methylsiloxanes in OC, and the slope is consistent with a mixture of methylsiloxanes and fuel combustion products. The methylsiloxanes in ship emissions may come from engine lubricants.
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Affiliation(s)
- Peng Yao
- Centre for Isotope Research (CIO), Energy and Sustainability Research Institute Groningen (ESRIG), University of Groningen, Groningen 9747AG, The Netherlands.
| | - Elena Chianese
- Department of Science and Technology, University of Naples, 'Parthenope' Centro Direzionale, Isola C4 80143, Napoli, Italy
| | - Norbertas Kairys
- Centre for Isotope Research (CIO), Energy and Sustainability Research Institute Groningen (ESRIG), University of Groningen, Groningen 9747AG, The Netherlands
| | - Rupert Holzinger
- Institute for Marine and Atmospheric Research, IMAU, Utrecht University, Princetonplein 5, 3584 CC, Utrecht, The Netherlands
| | - Dušan Materić
- Institute for Marine and Atmospheric Research, IMAU, Utrecht University, Princetonplein 5, 3584 CC, Utrecht, The Netherlands
| | - Carmina Sirignano
- Department of Mathematics and Physics, University of Campania "Luigi Vanvitelli", Viale Lincoln, 5-81100, Caserta, Italy
| | - Angelo Riccio
- Department of Science and Technology, University of Naples, 'Parthenope' Centro Direzionale, Isola C4 80143, Napoli, Italy
| | - Haiyan Ni
- Centre for Isotope Research (CIO), Energy and Sustainability Research Institute Groningen (ESRIG), University of Groningen, Groningen 9747AG, The Netherlands; State Key Laboratory of Loess and Quaternary Geology, Center for Excellence in Quaternary Science and Global Change, Key Laboratory of Aerosol Chemistry & Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Ru-Jin Huang
- State Key Laboratory of Loess and Quaternary Geology, Center for Excellence in Quaternary Science and Global Change, Key Laboratory of Aerosol Chemistry & Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Ulrike Dusek
- Centre for Isotope Research (CIO), Energy and Sustainability Research Institute Groningen (ESRIG), University of Groningen, Groningen 9747AG, The Netherlands.
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28
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Bernardo F, Alves A, Homem V. A review of bioaccumulation of volatile methylsiloxanes in aquatic ecosystems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 824:153821. [PMID: 35167889 DOI: 10.1016/j.scitotenv.2022.153821] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 02/07/2022] [Accepted: 02/08/2022] [Indexed: 06/14/2023]
Abstract
Volatile methylsiloxanes (VMSs) are found in a broad range of industrial and consumer products. They are categorized as "high production volume chemicals" by the U.S. Environmental Protection Agency and listed as candidates of substances of very high concern in 2018, by the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH). Industrial wastewater and treated effluents may contain VMSs in different amounts, which can be discharged in the receptor media and may lead to environmental contamination. This can result in direct exposure to aquatic receptors in the water column or to benthic invertebrates from contact and/or ingestion of sediments, and indirect exposures through the aquatic food chain. The possible toxicological effects of VMSs for the aquatic biota and human ecology are not very well known since published information regarding this topic is scarce. VMSs have been subjected to regulatory scrutiny for environmental concerns and have already been screened to determine their environmental risk and ecological harm. This paper aims to assess VMSs bioaccumulation and potential biomagnification on food webs, using several bioaccumulation metrics. The result is a high-level overview of all the collected data, comparing the findings and the experimental conditions applied during the assessments. Several studies present conflicting results regarding the bioaccumulation categorization. Some aquatic organisms demonstrated a high bioconcentration and bioaccumulation of these contaminants. Trophic magnification factors (TMFs) have been suggested as the most reliable tool to assess a chemical behaviour in food webs. However, bioaccumulation studies in food webs provided mixed information, with some studies indicating trophic dilution and others presenting a potential of trophic biomagnification of VMSs. Efforts should be directed to obtain field-based levels of VMSs at different trophic levels and a wider range of linear VMSs should be analysed, since most studies focused on D4, D5 and D6.
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Affiliation(s)
- Fábio Bernardo
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; ALiCE-Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Arminda Alves
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; ALiCE-Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Vera Homem
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; ALiCE-Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
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29
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Bio-based alternatives to volatile silicones: Relationships between chemical structure, physicochemical properties and functional performances. Adv Colloid Interface Sci 2022; 304:102679. [PMID: 35512559 DOI: 10.1016/j.cis.2022.102679] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 04/08/2022] [Accepted: 04/13/2022] [Indexed: 11/23/2022]
Abstract
Emollient oils are ubiquitous ingredients of personal care products, especially skin care and hair care formulations. They offer excellent spreading properties and give end-use products a soft, pleasant and non-sticky after-feel. Emollients belong to various petro- or bio-based chemical families among which silicone oils, hydrocarbons and esters are the most prominent. Silicones have exceptional physicochemical and sensory properties but their high chemical stability results in very low biodegradability and a high bioaccumulation potential. Nowadays, consumers are increasingly responsive to environmental issues and demand more environmentally friendly products. This awareness strongly encourages cosmetics industries to develop bio-based alternatives to silicone oils. Finding effective silicon-free emollients requires understanding the molecular origin of emollience. This review details the relationships between the molecular structures of emollients and their physicochemical properties as well as the resulting functional performances in order to facilitate the design of alternative oils with suitable physicochemical and sensory properties. The molecular profile of an ideal emollient in terms of chemical function (alkane, ether, ester, carbonate, alcohol), optimal number of carbons and branching is established to obtain an odourless oil with good spreading on the skin. Since none of the carbon-based emollients alone can imitate the non-sticky and dry feel of silicone oils, it is judicious to blend alkanes and esters to significantly improve both the sensory properties and the solubilizing properties of the synergistic mixture towards polar ingredients (sun filters, antioxidants, fragrances). Finally, it is shown how modelling tools (QSPR, COSMO-RS and neural networks) can predict in silico the key properties of hundreds of virtual candidate molecules in order to synthesize only the most promising whose predicted properties are close to the specifications.
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Whelan MJ, Kim J. Application of multimedia models for understanding the environmental behavior of volatile methylsiloxanes: Fate, transport, and bioaccumulation. INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2022; 18:599-621. [PMID: 34375022 PMCID: PMC9293016 DOI: 10.1002/ieam.4507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/11/2021] [Accepted: 07/26/2021] [Indexed: 06/13/2023]
Abstract
Multimedia fate and transport models (MFTMs) describe how chemicals behave in the environment based on their inherent properties and the characteristics of receiving systems. We critically review the use of MFTMs for understanding the behavior of volatile methylsiloxanes (VMS). MFTMs have been used to predict the fate of VMS in wastewater treatment, rivers, lakes, marine systems, and the atmosphere, and to assess bioaccumulation and trophic transfers. More widely, they have been used to assess the overall persistence, long-range transport potential (LRTP), and the propensity for atmosphere-surface exchange. The application of MFTMs for VMS requires particularly careful selection of model inputs because the properties of VMS differ from those of most organic compounds. For example, although n-octanol/water partition coefficient (KOW ) values are high, air:water partition coefficient (KAW ) values are also high and n-octanol/air partition coefficient (KOA ) values are relatively low. In addition, organic carbon/water partition coefficient (KOC ) values are substantially lower than expectations based on KOW . This means that most empirical relationships between KOC and KOW are not appropriate. Good agreement between modeled and measured concentrations in air, sediment, and biota indicates that our understanding of environmental fate is reasonable. VMS compounds are "fliers" that principally partition to the atmosphere, implying high LRTP, although they have low redeposition potential. They are degraded in air (half-lives 3-10 days) and, thus, have low overall persistence. In water, exposure can be limited by hydrolysis, volatilization, and partitioning to sediments (where degradation half-lives are likely to be high). In food webs, they are influenced by metabolism in biota, which tends to drive trophic dilution (i.e., trophic magnification factors are often but not always <1). Key remaining uncertainties include the following: (i) the strength and direction of the temperature dependence for KOC ; (ii) the fate of atmospheric reaction products; and (iii) the magnitude of emissions to wastewater. Integr Environ Assess Manag 2022;18:599-621. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
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Affiliation(s)
- Michael J. Whelan
- Centre for Landscape and Climate Research, School of Geography, Geology and the EnvironmentUniversity of LeicesterLeicesterUK
| | - Jaeshin Kim
- Toxicology and Environmental Research and ConsultingThe Dow Chemical CompanyMidlandMichiganUSA
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Iacomi P, Gulcay-Ozcan E, Pires Conti P, Biswas S, Steunou N, Maurin G, Rioland G, Devautour-Vinot S. MIL-101(Cr) MOF as an Effective Siloxane Sensor. ACS APPLIED MATERIALS & INTERFACES 2022; 14:17531-17538. [PMID: 35380791 DOI: 10.1021/acsami.2c02607] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Volatile methylsiloxanes (VMSs) are common silicone degradation byproducts that cause serious concern for the contamination of sensitive electronics and optics, among others. With the goal of fast, online detection of VMS, we herein highlight the mesoporous MIL-101(Cr) MOF as a promising mass sensing layer for integration with a quartz crystal microbalance (QCM), using an in-house modified gravimetric adsorption system capable of achieving extremely low concentrations of siloxane D4 (down to 0.04 ppm), targeting applications for monitoring in indoor spaces and spacecraft. Our developed MIL-101(Cr)@QCM sensor achieves near-perfect reversibility with no hysteresis alongside excellent repeatability over cycling and fast response/recovery times under 1 min. We attribute this capability to optimum host/guest interactions as uncovered through molecular simulations.
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Affiliation(s)
- Paul Iacomi
- ICGM, Univ. Montpellier, CNRS, ENSCM, F-34095 Montpellier, France
| | | | | | - Subharanjan Biswas
- Institut Lavoisier de Versailles, UMR CNRS 8180, Université de Versailles St Quentin en Yvelines, Université Paris-Saclay, 78035 Versailles, France
| | - Nathalie Steunou
- Institut Lavoisier de Versailles, UMR CNRS 8180, Université de Versailles St Quentin en Yvelines, Université Paris-Saclay, 78035 Versailles, France
| | - Guillaume Maurin
- ICGM, Univ. Montpellier, CNRS, ENSCM, F-34095 Montpellier, France
| | - Guillaume Rioland
- Centre National d'Etudes Spatiales, DTN/QE/LE, 18 Avenue Edouard Belin, 31401 Toulouse, Cedex 09, France
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32
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Nguyen HMN, Khieu HT, Le HQ, Duong TT, Do TQ, Minh TB, Tran TM. Assessment of distributional characteristics and ecological risks of cyclic volatile methylsiloxanes in sediments from urban rivers in northern Vietnam. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:29917-29926. [PMID: 34994938 DOI: 10.1007/s11356-021-18487-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 12/30/2021] [Indexed: 06/14/2023]
Abstract
In this report, four cVMSs including hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) were determined in 85 sediment samples collected from three rivers in northern Vietnam during the period from May to November 2020. Total mean concentrations of cVMSs ranged from 75.4 to 15,000 ng/g-dw. The highest levels of cVMS were found in sediment samples collected from the To Lich River (range, 260-15,000 ng/g-dw; median, 2840 ng/g-dw), followed by the Nhue River (range, 188-6800 ng/g-dw; median, 1370 ng/g-dw), and the Day River (range, 75.4-4600 ng/g-dw; median, 666 ng/g-dw). Among cVMSs, decamethylcyclopentasiloxane (D5) was found at the highest levels in all samples and ranged from 9.00 to 11,000 ng/g-dw. Significant correlations exist between the concentrations of D4/D6 and D5/D6 pairs in river sediment samples. Although the calculated ecological risk was not high, the presence of cVMSs in the sediment raises concerns about the impact on aquatic life because of their long-term accumulation capacity.
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Affiliation(s)
- Ha My Nu Nguyen
- Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, 19 Le Thanh Tong, Hanoi, 10000, Vietnam
- Ha Tinh University, Cam Vinh Commune, Cam Xuyen District, Ha Tinh, Vietnam
| | - Hanh Thi Khieu
- Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, 19 Le Thanh Tong, Hanoi, 10000, Vietnam
| | - Huong Quang Le
- Center for Research and Technology Transfer, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, 10000, Vietnam
| | - Thi Thuy Duong
- Institute of Environmental Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, 10000, Vietnam
| | - Trung Quang Do
- Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, 19 Le Thanh Tong, Hanoi, 10000, Vietnam
| | - Tu Binh Minh
- Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, 19 Le Thanh Tong, Hanoi, 10000, Vietnam
| | - Tri Manh Tran
- Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, 19 Le Thanh Tong, Hanoi, 10000, Vietnam.
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Kim D, Cho HE, Won EJ, Kim HJ, Lee S, An KG, Moon HB, Shin KH. Environmental fate and trophic transfer of synthetic musk compounds and siloxanes in Geum River, Korea: Compound-specific nitrogen isotope analysis of amino acids for accurate trophic position estimation. ENVIRONMENT INTERNATIONAL 2022; 161:107123. [PMID: 35147083 DOI: 10.1016/j.envint.2022.107123] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 01/23/2022] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
Despite the extensive usage of synthetic musk compounds (SMCs) and siloxanes in various personal care products (PCPs), trophic magnification of such chemicals in aquatic environments remains unexplored. In June and September 2020, eleven SMCs and nineteen siloxanes were measured in water, sediments, and biota. Samples were collected from two sites where levels were expected to be influenced by the distance from the wastewater treatment plant (WWTP) in the Geum River, Republic of Korea, were expected. High concentrations of SMCs and siloxanes entered through WWTP were measured in water, sediment, and biota at the both sites and both seasons. The δ15N of amino acids provided a high-resolution food web and accurate trophic position (TP), which is an important factor for determining the trophic magnification factor (TMF). Among 24 TMFs, 19 of them were <1, ranging 0.7-0.8 for 1,3,4,6,7,8‑hexahydro‑4,6,6,7,8,8‑hexamethyl‑cyclopenta‑γ‑2‑benzopyran (HHCB), 0.6-0.8 for 6-Acetyl-1,1,2,4,4,7-hexamethyltetralin (AHTN), 0.7-0.8 for 4-tert-Butyl-3,5-dinitro-2,6-dimethylacetophenone (MK), 0.7-0.9 for octamethylcyclotetrasiloxane (D4), 0.1-0.4 for decamethylcyclopentasiloxane (D5), and 0.04-0.8 for dodecamethylcyclohexasiloxane (D6), and the remaining ones including HHCB, AHTN, MK, and D4 showed values close to 1 or slightly higher (TMF range: 1.0-2.3) indicating no or a little trophic magnification. The TMFs of these compounds were constant across sites and seasons. The TMF values of PCPs might be affected by species specificity and food web structure rather than by chemical properties such as log Kow, which describes a wide range of TMF values in various environments. This study presents valuable implications for assessing risk and managing environmental fate and trophic transfer of SMCs and siloxanes in freshwater environments.
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Affiliation(s)
- Dokyun Kim
- Department of Marine Sciences and Convergent Technology, Hanyang University, Ansan 15588, Republic of Korea
| | - Ha-Eun Cho
- Department of Marine Sciences and Convergent Technology, Hanyang University, Ansan 15588, Republic of Korea
| | - Eun-Ji Won
- Department of Marine Sciences and Convergent Technology, Hanyang University, Ansan 15588, Republic of Korea; Institute of Marine and Atmospheric Sciences, Hanyang University, Ansan 15588, Republic of Korea
| | - Hye-Jin Kim
- Department of Bioscience and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Sunggyu Lee
- Department of Marine Sciences and Convergent Technology, Hanyang University, Ansan 15588, Republic of Korea; Institute of Marine and Atmospheric Sciences, Hanyang University, Ansan 15588, Republic of Korea
| | - Kwang-Guk An
- Department of Bioscience and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Hyo-Bang Moon
- Department of Marine Sciences and Convergent Technology, Hanyang University, Ansan 15588, Republic of Korea; Institute of Marine and Atmospheric Sciences, Hanyang University, Ansan 15588, Republic of Korea
| | - Kyung-Hoon Shin
- Department of Marine Sciences and Convergent Technology, Hanyang University, Ansan 15588, Republic of Korea; Institute of Marine and Atmospheric Sciences, Hanyang University, Ansan 15588, Republic of Korea.
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Microalgal Cultures for the Bioremediation of Urban Wastewaters in the Presence of Siloxanes. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19052634. [PMID: 35270319 PMCID: PMC8909507 DOI: 10.3390/ijerph19052634] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/20/2022] [Accepted: 02/23/2022] [Indexed: 11/25/2022]
Abstract
Microalgae are widely used in the bioremediation of wastewaters due to their efficient removal of pollutants such as nitrogen, phosphorus, and contaminants of emerging concern (CECs). Siloxanes are CECs that reach wastewater treatment plants (WWTPs), leading to the production of biogas enriched with these compounds, associated with the breakdown of cogeneration equipment. The biological removal of siloxanes from wastewaters could be a sustainable alternative to the costly existing technologies, but no investigation has been performed using microalgal cultures for this purpose. This study evaluated the ability of Chlorella vulgaris to bioremediate primary (PE) and secondary (SE) urban effluents and remove volatile methylsiloxanes (VMSs). C. vulgaris grew successfully in both effluents, and approximately 86% of nitrogen and 80% of phosphorus were efficiently removed from the PE, while 52% of nitrogen and 87% of phosphorus were removed from the SE, and the presence of VMSs does not seem to have a negative influence on nutrient removal. Three out of the seven of the analysed VMSs were detected in the microalgal biomass at the end of the PE assay. However, dodecamethylcyclohexasiloxane (D6) was the one that accumulated to a greater extent, since 48% of the initial mass of D6 was detected in the biomass samples. D6 is one of the most lipophilic VMSs, which might contribute to the higher adsorption onto the surface of microalgae. Overall, the results indicate C. vulgaris’ potential to remove specific VMSs from effluents.
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Pelletier M, Isabel L, Armellin A, McDaniel T, Martin P, McGoldrick D, Clark M, Moore S. Influence of wastewater effluents on the bioaccumulation of volatile methylsiloxanes in the St. Lawrence River. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:151267. [PMID: 34715227 DOI: 10.1016/j.scitotenv.2021.151267] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 10/13/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
The bioaccumulation of cyclic volatile methylsiloxanes (D3 to D6) as well as linear siloxanes (L3 to L5) was studied in a food web in the St. Lawrence River downstream of the effluent of the municipal wastewater treatment plant in Montreal, Canada. For most species, differences in δ15N in fish and prey showed a clear separation of individual fish feeding in food webs influenced by the wastewater plume from those feeding outside the plume. Cyclic siloxanes were detected in all biotic samples from the individuals identified as feeding in the effluent plume. Siloxane D5 accounted for more than 80% of the total siloxanes. Linear siloxane L5 was also abundant in walleye and gull eggs. Total siloxane concentrations in suspended sediments were 17.3 times higher than in surface sediments in the region of the river in the effluent plume. Caged freshwater mussels (Elliptio sp.), placed in the effluent plume, bioaccumulated 43 times more total siloxanes than PBDEs in 30 days, demonstrating how readily siloxanes are taken up in biota and what a significant component of the contaminant body burden they can account for. The sediment-biota accumulation factors (BSAF) for total siloxanes (∑ D3 to D6 and L3 to L5) showed values of 65.4, 27.8, 9.9 and 6.4 for walleye, northern pike, yellow perch and round goby respectively.
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Affiliation(s)
- Magella Pelletier
- Environment and Climate Change Canada, Water Quality Monitoring and Surveillance, 105 McGill Street, 7th Floor, Montreal, Quebec H2Y 2E7, Canada
| | - Laurie Isabel
- Fisheries and Oceans Canada, Maurice Lamontagne Institute, 850, route de la Mer, P.O. Box 1000, Mont-Joli, QC G5H 3Z4, Canada
| | - Alain Armellin
- Environment and Climate Change Canada, Water Quality Monitoring and Surveillance, 105 McGill Street, 7th Floor, Montreal, Quebec H2Y 2E7, Canada
| | - Tana McDaniel
- Environment and Climate Change Canada, Water Quality Monitoring and Surveillance, 867 Lakeshore Road, Burlington, ON L7S 1A1, Canada.
| | - Pamela Martin
- Environment and Climate Change Canada, Wildlife and Landscape Science Directorate, 867 Lakeshore Road, Burlington, ON L7R 4A6, Canada
| | - Daryl McGoldrick
- Environment and Climate Change Canada, Water Quality Monitoring and Surveillance, 867 Lakeshore Road, Burlington, ON L7S 1A1, Canada
| | - Mandi Clark
- Environment and Climate Change Canada, Water Quality Monitoring and Surveillance, 867 Lakeshore Road, Burlington, ON L7S 1A1, Canada
| | - Serge Moore
- Environment and Climate Change Canada, Quebec Laboratory for Environmental Testing, 105 McGill Street, 7th Floor, Montreal, Quebec H2Y 2E7, Canada
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Liu N, Zhao X, Xu L, Cai Y. Temporal and spatial variation, input fluxes and risk assessment of cyclic methylsiloxanes in Rivers-Bohai Sea System. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 231:113169. [PMID: 35032727 DOI: 10.1016/j.ecoenv.2022.113169] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 12/23/2021] [Accepted: 01/03/2022] [Indexed: 06/14/2023]
Abstract
In the present study, the total concentrations of three cyclic methylsiloxanes (ΣCMSs), including octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6), in surface water and sediment samples of five main rivers draining into the Bohai Sea were in the range of 1.62-1.39 × 103 ng/L and 1.92-1.69 × 103 ng/g dw, respectively. Riverine input had great influence on the coastal distribution of siloxanes in the Bohai Sea. The concentrations of ΣCMSs in coastal sediments farthest away (40-50 Km) from the estuaries were only 4-33% of those close to the estuaries. But surprisingly, compared with those in coastal sediments (1.03-1.44 × 103 ng/g dw), the concentrations of CMSs (1.56-2.67 × 103 ng/g dw) in some deep-sea sediments were higher, and certain positive correlation existed between sediment ΣCMSs in this area with the total petroleum hydrocarbons concentration (R2 = 0.92, p < 0.05) suggested offshore oil exploitation as one important emission source of siloxanes. Overall, calculated based on their sediment concentrations, D4-D6 had negligible ecological risks to the benthic organisms in river-Bohai Sea system, i.e. HQs < 1. However, sediment-accumulation of siloxanes should be paid attention, especially for some deep-sea sediments nearby drilling platforms, where it will take only less than 1 year for D4 to reach its threshold.
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Affiliation(s)
- Nannan Liu
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China
| | - Xuesheng Zhao
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China; Joint Research Centre for Protective Infrastructure Technology and Environmental Green Bioprocess, Tianjin 300384, China
| | - Lin Xu
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 330106, China.
| | - Yaqi Cai
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 330106, China; University of Chinese Academy of Sciences, Beijing 100049, China
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Xu J, Harrison RM, Song C, Hou S, Wei L, Fu P, Li H, Li W, Shi Z. PM 2.5-bound silicon-containing secondary organic aerosols (Si-SOA) in Beijing ambient air. CHEMOSPHERE 2022; 288:132377. [PMID: 34600012 DOI: 10.1016/j.chemosphere.2021.132377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 09/15/2021] [Accepted: 09/25/2021] [Indexed: 06/13/2023]
Abstract
Volatile methyl siloxanes (VMS) have been widely used in personal care products and industrial applications, and are an important component of VOCs (volatile organic compounds) indoors. They have sufficiently long lifetimes to undergo long-range transport and to form secondary aerosols through atmospheric oxidation. To investigate these silicon-containing secondary organic aerosols (Si-SOA), we collected PM2.5 samples during 8th-21st August 2018 (summer) and 3rd-23rd January 2019 (winter) at an urban site of Beijing. As the oxidation of VMS mainly results in hydrophilic polar semi-volatile and non-volatile oxidation products, the differences between total water-soluble Si and total water-soluble inorganic Si were used to estimate water-soluble organic Si, considered to be secondary organic Si (SO-Si). The average concentrations of SO-Si during the summer and winter campaigns were 4.6 ± 3.7 and 13.2 ± 8.6 ng m-3, accounting for approximately 80.1 ± 10.1% and 80.2 ± 8.7% of the total water-soluble Si, and 1.2 ± 1.2% and 5.0 ± 6.9% of total Si in PM2.5, respectively. The estimated Si-SOA concentrations were 12.7 ± 10.2 ng m-3 and 36.6 ± 23.9 ng m-3 on average in summer and winter, which accounted for 0.06 ± 0.07% and 0.16 ± 0.22% of PM2.5 mass, but increased to 0.26% and 0.92% on certain days. We found that net solar radiation is positively correlated with SO-Si levels in the summer but not in winter, suggesting seasonally different formation mechanisms.
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Affiliation(s)
- Jingsha Xu
- School of Geography Earth and Environmental Science, University of Birmingham, Birmingham, B15 2TT, UK; Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK.
| | - Roy M Harrison
- School of Geography Earth and Environmental Science, University of Birmingham, Birmingham, B15 2TT, UK; Department of Environmental Sciences/Center of Excellence in Environmental Studies, King Abdulaziz University, P.O. Box 80203, Jeddah, 21589, Saudi Arabia
| | - Congbo Song
- School of Geography Earth and Environmental Science, University of Birmingham, Birmingham, B15 2TT, UK
| | - Siqi Hou
- School of Geography Earth and Environmental Science, University of Birmingham, Birmingham, B15 2TT, UK
| | - Lianfang Wei
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China
| | - Pingqing Fu
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China
| | - Hong Li
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Weijun Li
- Department of Earth and Atmospheric Sciences, Zhejiang University, Hangzhou, 310027, China
| | - Zongbo Shi
- School of Geography Earth and Environmental Science, University of Birmingham, Birmingham, B15 2TT, UK.
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Horii Y, Minomo K, Lam JCW, Yamashita N. Spatial distribution and accumulation profiles of volatile methylsiloxanes in Tokyo Bay, Japan: Mass loadings and historical trends. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150821. [PMID: 34627924 DOI: 10.1016/j.scitotenv.2021.150821] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/01/2021] [Accepted: 10/01/2021] [Indexed: 06/13/2023]
Abstract
We investigated mass loading and the spatial distribution of volatile methylsiloxanes (VMSs) including four cyclic VMSs (D3-D6; cVMSs, the number refers to the number of SiO bonds) and three linear VMSs (L3-L5; lVMSs) in Tokyo Bay, Japan, which is one of the most industrialized, urbanized, and populated areas in the world. Based on the VMS concentrations determined in eight main inflow rivers to the bay, the mass loading of VMSs via inflow rivers and sewage treatment plants located in Tokyo Bay was estimated at 2500 kg/y for total VMSs. Elevated mass loadings of VMSs were found in three of the rivers, inflowing to the inner west of Tokyo Bay. The distribution and deposition characteristics of VMSs were observed depending on the estuarine condition. Estuarine sediments were found to be efficient and effective traps for VMSs and the salting-out effect is one possible mechanism to explain this phenomenon. The overall profiles of D4, D5, and D6 in surface water and sediment were observed across Tokyo Bay; elevated concentrations were identified in the inner west bay with dispersed low concentrations in the outer bay, except for one hotspot of D4 in the sediment, indicating a major emission route of VMSs via inflow rivers. Additionally, the historical pollution profiles of VMSs in Tokyo Bay were reconstructed based on the VMS concentrations determined in a dated sediment core. VMSs were identified throughout the upper 40 cm of the sediment core (representing the mid 1980s); the profiles correspond with the historical use of VMSs in wash-off personal care-products. The noted decreasing trend of D4 might be a reflection of the early 2000s replacement of D4 with D5 in such products. The elevated VMS concentrations in the estuarine sediment raise concerns about the impact on the aquatic environment.
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Affiliation(s)
- Yuichi Horii
- Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama 347-0115, Japan.
| | - Kotaro Minomo
- Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama 347-0115, Japan
| | - James C W Lam
- Department of Science and Environmental Studies, The Education University of Hong Kong, Hong Kong Special administrative Region
| | - Nobuyoshi Yamashita
- National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan
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Yang Y, Lin Y, Yang J, Su Y, Li Y, Deng Y, Zheng C. 3D printed miniature atomic emission detector coupling with gas chromatography: A sensitive and cost-effective strategy for the determination of volatile methylsiloxanes in municipal sewage. Anal Chim Acta 2022; 1191:339288. [PMID: 35033261 DOI: 10.1016/j.aca.2021.339288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 11/05/2021] [Accepted: 11/15/2021] [Indexed: 12/01/2022]
Abstract
The determination of volatile methylsiloxanes (VMSs) in municipal sewage has attracted great attention. Gas chromatography-mass spectrometry (GC-MS) is the most mature detection technique for VMSs, however, its instrumentation and operation cost are unfavorable in low- and middle-income countries. Herein, a novel and cost-effective strategy by using a 3D printed miniature microplasma optical emission detector (μAED) as an alternative to MS detector, was developed to detect VMSs in municipal sewage by GC after preconcentration by a laboratory-built automatic purge and trap (P&T) system. Two types of μAEDs have been fabricated and their analytical performances were compared. The one using two tungsten rods as electrodes shows better performance and was thus selected as the detecting system for real sample analysis. Under the optimized conditions, the P&T-GC-μAED system provided limits of detection of 3.6 ng L-1 to 15.5 ng L-1 of Si for tested VMSs. Relative standard deviations were better than 3.0% and good recoveries ranging from 82.4% to 102.8% were obtained for all analytes. The applicability of this system was demonstrated via the measurement of VMSs in the influents and effluents from 10 wastewater treatment plants (WWTPs) in Chengdu, China.
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Affiliation(s)
- Yuan Yang
- Key Laboratory of Green Chemistry & Technology of MOE, College of Chemistry, Sichuan University, Chengdu, Sichuan, 610064, China
| | - Yao Lin
- West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, Sichuan, 610064, China
| | - Jiahui Yang
- Key Laboratory of Green Chemistry & Technology of MOE, College of Chemistry, Sichuan University, Chengdu, Sichuan, 610064, China
| | - Yubin Su
- Key Laboratory of Green Chemistry & Technology of MOE, College of Chemistry, Sichuan University, Chengdu, Sichuan, 610064, China
| | - Yuanyuan Li
- Key Laboratory of Green Chemistry & Technology of MOE, College of Chemistry, Sichuan University, Chengdu, Sichuan, 610064, China
| | - Yurong Deng
- Key Laboratory of Green Chemistry & Technology of MOE, College of Chemistry, Sichuan University, Chengdu, Sichuan, 610064, China
| | - Chengbin Zheng
- Key Laboratory of Green Chemistry & Technology of MOE, College of Chemistry, Sichuan University, Chengdu, Sichuan, 610064, China.
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Considerations on the Analysis of E-900 Food Additive: An NMR Perspective. Foods 2022; 11:foods11030297. [PMID: 35159449 PMCID: PMC8833973 DOI: 10.3390/foods11030297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 01/17/2022] [Accepted: 01/20/2022] [Indexed: 12/07/2022] Open
Abstract
Food additives are in widespread use in the food industry to extend the shelf life of food, improve its organoleptic characteristics or facilitate industrial processing. Their use is not without controversy, which makes regulation and control crucial for food safety and public health. Among food additives, silicone-based antifoaming agents (polysiloxanes or E900) are difficult to analyze and quantify due to their polymeric nature. Currently, there is no official method of quantifying this additive in foods. In this context, nuclear magnetic resonance (NMR) is a quantitative method for speciation analysis of silicon compounds almost without known interferents. In this work, we describe the evolution of the regulation of the E900 additive, discuss different analytic methods quantifying polydimethylsiloxanes (PDMS), and propose a new method based on NMR suitable for analyzing the content of E900 in the form of PDMS in various types of food from dietary oils to marmalades and jellies, among others. The proposed method consists of a previous quantitative concentration of PDMS by liquid–liquid extraction and the monitoring of the quantification using a bis(trimethylsilyl)benzene (BTMSB) standard to control the variability, ranging within 2–7%, depending on the food. This simple, direct, and reproducible procedure for aqueous and lipidic foods may help to monitor and fill a gap in regulatory legislation regarding the E900 additive.
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Pennington EA, Seltzer KM, Murphy BN, Qin M, Seinfeld JH, Pye HO. Modeling secondary organic aerosol formation from volatile chemical products. ATMOSPHERIC CHEMISTRY AND PHYSICS 2021; 21:18247-18261. [PMID: 35087576 PMCID: PMC8788583 DOI: 10.5194/acp-21-18247-2021] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Volatile chemical products (VCPs) are commonly-used consumer and industrial items that are an important source of anthropogenic emissions. Organic compounds from VCPs evaporate on atmospherically relevant time scales and include many species that are secondary organic aerosol (SOA) precursors. However, the chemistry leading to SOA, particularly that of intermediate volatility organic compounds (IVOCs), has not been fully represented in regional-scale models such as the Community Multiscale Air Quality (CMAQ) model, which tend to underpredict SOA concentrations in urban areas. Here we develop a model to represent SOA formation from VCP emissions. The model incorporates a new VCP emissions inventory and employs three new classes of emissions: siloxanes, oxygenated IVOCs, and nonoxygenated IVOCs. VCPs are estimated to produce 1.67 μg m-3 of noontime SOA, doubling the current model predictions and reducing the SOA mass concentration bias from -75% to -58% when compared to observations in Los Angeles in 2010. While oxygenated and nonoxygenated intermediate volatility VCP species are emitted in similar quantities, SOA formation is dominated by the nonoxygenated IVOCs. Formaldehyde and SOA show similar relationships to temperature and bias signatures indicating common sources and/or chemistry. This work suggests that VCPs contribute up to half of anthropogenic SOA in Los Angeles and models must better represent SOA precursors from VCPs to predict the urban enhancement of SOA.
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Affiliation(s)
- Elyse A. Pennington
- Oak Ridge Institute for Science and Education Fellow in the Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711
- Department of Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Karl M. Seltzer
- Oak Ridge Institute for Science and Education Fellow in the Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711
| | - Benjamin N. Murphy
- Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711
| | - Momei Qin
- Oak Ridge Institute for Science and Education Fellow in the Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing, China
| | - John H. Seinfeld
- Department of Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Havala O.T. Pye
- Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711
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He Y, Su S, Lyu Y, Tang Z. Occurrence of methylsiloxanes in sediments from a subtropical river-lake system in eastern China and its implication for ecological risks. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 223:112627. [PMID: 34390983 DOI: 10.1016/j.ecoenv.2021.112627] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 07/24/2021] [Accepted: 08/08/2021] [Indexed: 06/13/2023]
Abstract
Distribution of methylsiloxanes in environment is still far from being well studied. Little is known about the concentrations and associated risks of these chemicals in river-lake systems. This study investigated the occurrence of twelve methylsiloxanes (D4-D6, L5-L13) in the sediments from Lake Chaohu and its inflowing rivers, China, and found the total concentrations (ng/g dry weight) were in the range of 47.1-496 and 239-3593, respectively. Linear congeners were dominant, representing a median of 62.8% and 58.7% of the total concentrations found in the lake and its inflowing rivers, respectively. In general, the concentrations of sediment methylsiloxanes in the investigated river-lake system were low to moderate, compared with the results reported previously in other waters. Source assessment indicated that the emissions from industrial activities and the use of silicone-containing products were the main contributors of sediment methylsiloxanes in the investigated waters. D4 and D5 in 18.5% and 11.1% of river sediment samples might pose ecological risks to fish. The risks from the linear congeners in sediments in the area were not estimated due to no related benchmarks available. More studies are needed to investigate the occurrence of these chemicals and associated risks in aquatic environment.
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Affiliation(s)
- Ying He
- Key Laboratory of Ecology and Environment in Minority Areas (Minzu University of China), National Ethnic Affairs Commission, Beijing 100081, China; College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China.
| | - Shuai Su
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China.
| | - Yang Lyu
- Key Laboratory of Ecology and Environment in Minority Areas (Minzu University of China), National Ethnic Affairs Commission, Beijing 100081, China; College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China.
| | - Zhenwu Tang
- Key Laboratory of Ecology and Environment in Minority Areas (Minzu University of China), National Ethnic Affairs Commission, Beijing 100081, China; College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China; College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China.
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Tang Z, Cheng J, Yin H, Meng T, Sun J. Methylsiloxane occurrence and distribution in free-range poultry eggs near a rural industrial park: Indicators of potential risks to birds. JOURNAL OF HAZARDOUS MATERIALS 2021; 415:125683. [PMID: 33773252 DOI: 10.1016/j.jhazmat.2021.125683] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 03/11/2021] [Accepted: 03/15/2021] [Indexed: 06/12/2023]
Abstract
The ecological harm from methylsiloxanes has drawn worldwide attention. This study investigated three cyclic (D4-D6) and four linear siloxanes (L7-L10) in the eggs of free-range poultry collected near a rural industrial park in China and found total concentrations in the range of 19.2-1204 (median, 268) ng/g dry weight. Higher concentrations of methylsiloxanes were observed in chicken eggs than duck eggs. Cyclic siloxanes represented a median of 62.2% of the total methylsiloxane concentrations. A source assessment indicated that local soils and outdoor dust were more important sources of egg methylsiloxanes than poultry food. The partitioning of methylsiloxanes between egg yolk and egg albumen was investigated, and preferential distributions of the chemicals in the yolk were observed. This study confirmed that methylsiloxanes were highly prevalent in the study poultry eggs. The results suggested that the potential risks to some wild birds inhabiting this area should be of concern, as their physiologies and feeding ecologies are similar to those of the studied poultry, although available ecotoxicological data of the chemicals to birds remains scarce. Additional research is needed to characterize the accumulation of methylsiloxanes in different bird species and its associated adverse effects on their offspring.
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Affiliation(s)
- Zhenwu Tang
- College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China.
| | - Jiali Cheng
- Key Laboratory of Trace Element Nutrition of the National Health Commission, National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
| | - Hongmin Yin
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China.
| | - Tong Meng
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China.
| | - Jiazheng Sun
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China.
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Ortiz-Ardila AE, Díez B, Celis C, Jenicek P, Labatut R. Microaerobic conditions in anaerobic sludge promote changes in bacterial composition favouring biodegradation of polymeric siloxanes. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2021; 23:1182-1197. [PMID: 34302159 DOI: 10.1039/d1em00143d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Volatile organic silicon compounds (VOSiC) are harmful pollutants to the biota and ecological dynamics as well as biogas-based energy conversion systems. However, there is a lack of understanding regarding the source of VOSiCs in biogas, especially arising from the biochemical conversion of siloxane polymers such as polydimethylsiloxanes (PDMS). The biodegradation of PDMS was evaluated under anaerobic/microaerobic conditions (PO2 = 0, 1, 3, 5%), using wastewater treatment plant (WWTP) sludge as an inoculum and PDMS as a co-substrate (0, 50, 100, 500 ppm). On average, strictly anaerobic treatments produced significantly less methane than the 3 and 5% microaerated ones, which show the highest PMDS biodegradation at 50 ppm. Thauera sp. and Rhodococcus sp. related phylotypes were identified as the most abundant bacterial groups in microaerated treatments, and siloxane-related molecules were identified as remnants of PDMS catabolism. Our study demonstrates that microaeration promotes changes to the native bacterial community which favour the biological degradation of PDMS. This confirms that the presence of VOSiC (e.g., D4-D6) in biogas is not only due to its direct input in wastewaters, but also to the PDMS microbial catabolism. Microaerobic conditions enhance both PDMS and (subsequent) VOSiC degradation in the liquid phase, increasing the concentrations of D4 and D5 in biogas, and the production of less toxic siloxane-based derivatives in the liquid phase. This study suggests that microaeration of the anaerobic sludge can significantly decrease the concentration of PDMSs in the WWTP effluent. However, for WWTPs to become effective barriers for the emission of these ecotoxic contaminants to the environment, such a strategy needs to be coupled with an efficient biodegradation of VOSiCs from the biogas.
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Affiliation(s)
- A E Ortiz-Ardila
- Department of Hydraulic and Environmental Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile.
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Liu N, Sun H, Xu L, Cai Y. Methylsiloxanes in petroleum refinery facility: Their sources, emissions, environmental distributions and occupational exposure. ENVIRONMENT INTERNATIONAL 2021; 152:106471. [PMID: 33676090 DOI: 10.1016/j.envint.2021.106471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 02/13/2021] [Accepted: 02/15/2021] [Indexed: 06/12/2023]
Abstract
High concentrations (1.08 ng/g-3.61 mg/g) of methylsiloxanes, including cyclic analogs [octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6)], and linear analogs with 3-14 silicon atoms (L3-L14), have been detected in crude oil, additives and petroleum products from one petroleum refinery facility in China. Overall, the total mass load of Σmethylsiloxanes (1320 kg/day) in crude oil and additives was 1.5 times higher than that in petroleum products (857 kg/day), indicating their potential emissions in this facility, which were further confirmed by the find of their obvious emission through exhaust-gas (89.4 kg/day) and wastewater (4.70 kg/day). Σmethylsiloxanes emission from exhaust-gas discharge outlets of deep catalytic cracking units (60.6 kg/day) took up 68% of their total emission from all gas outlets. Overall, Σmethylsiloxanes in air (17.1-743 μg/m3) and soil samples [311 ng/g dw (dry weight) - 34.2 μg/g dw] from this facility were up to four orders of magnitude greater than those from surrounding areas, and plasma concentrations of Σmethylsiloxanes in current workers from this facility (7.4-609 ng/mL) were up to two orders of magnitude larger than those from reference group (<LOQ-21.2 ng/mL). Furthermore, concentration ratios (0.09-0.58) of total cyclic methylsiloxanes to their hepatic metabolites for workers were 2.3-17 times lower than those (1.32-1.56) for reference group, indicating that refinery workers may be exposed to more unknown methylsiloxane analogs than general population.
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Affiliation(s)
- Nannan Liu
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China
| | - Hongyu Sun
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China; Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin 300350, China; Joint Research Centre for Protective Infrastructure Technology and Environmental Green Bioprocess, Tianjin 300384, China
| | - Lin Xu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China.
| | - Yaqi Cai
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
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Järlskog I, Strömvall AM, Magnusson K, Galfi H, Björklund K, Polukarova M, Garção R, Markiewicz A, Aronsson M, Gustafsson M, Norin M, Blom L, Andersson-Sköld Y. Traffic-related microplastic particles, metals, and organic pollutants in an urban area under reconstruction. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 774:145503. [PMID: 33609838 DOI: 10.1016/j.scitotenv.2021.145503] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/18/2021] [Accepted: 01/25/2021] [Indexed: 05/14/2023]
Abstract
In urban environments, particularly areas under reconstruction, metals, organic pollutants (OP), and microplastics (MP), are released in large amounts due to heavy traffic. Road runoff, a major transport route for urban pollutants, contributes significantly to a deteriorated water quality in receiving waters. This study was conducted in Gothenburg, Sweden, and is unique because it simultaneously investigates the occurrence of OP, metals, and MP on roads and in stormwater from an urban area under reconstruction. Correlations between the various pollutants were also explored. The study was carried out by collecting washwater and sweepsand generated from street sweeping, road surface sampling, and flow-proportional stormwater sampling on several occasions. The liquid and solid samples were analyzed for metals, polycyclic aromatic hydrocarbons (PAH), oxy-PAH, aliphatics, aromatics, phthalates, and MP. The occurrence of OP was also analyzed with a non-target screening method of selected samples. Microplastics, i.e. plastic fragments/fibers, paint fragments, tire wear particles (TWP) and bitumen, were analyzed with a method based on density separation with sodium iodide and identification with a stereo microscope, melt-tests, and tactile identification. MP concentrations amounted to 1500 particles/L in stormwater, 51,000 particles/L in washwater, and 2.6 × 106 particles/kg dw in sweepsand. In stormwater, washwater and sweepsand, MP ≥20 μm were found to be dominated by TWP (38%, 83% and 78%, respectively). The results confirm traffic as an important source to MP, OP, and metal emissions. Concentrations exceeding water and sediment quality guidelines for metals (e.g. Cu and Zn), PAH, phthalates, and aliphatic hydrocarbons in the C16-C35 fraction were found in most samples. The results show that the street sweeper collects large amounts of polluted materials and thereby prevents further spread of the pollutants to the receiving stormwater.
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Affiliation(s)
- Ida Järlskog
- VTI, Swedish National Road and Transport Research Institute, SE-581 95 Linköping, Sweden; Geology and Geotechnics, Department of Architecture and Civil Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
| | - Ann-Margret Strömvall
- Water Environment Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Kerstin Magnusson
- IVL, Swedish Environmental Research Institute, Kristineberg, SE-451 78 Fiskebäckskil, Sweden
| | - Helén Galfi
- Sustainable Waste and Water, City of Gothenburg, SE-424 23 Gothenburg, Sweden
| | - Karin Björklund
- Kerr Wood Leidal Associates Ltd., 200 - 4185A Still Creek Drive Burnaby, British Columbia V5C 6G9, Canada
| | - Maria Polukarova
- VTI, Swedish National Road and Transport Research Institute, SE-581 95 Linköping, Sweden
| | - Rita Garção
- Engineering and Sustainability, NCC Infrastructure, NCC, SE-405 14 Gothenburg, Sweden
| | - Anna Markiewicz
- Water Environment Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Maria Aronsson
- Urban Transport Administration, City of Gothenburg, SE-403 16 Gothenburg, Sweden
| | - Mats Gustafsson
- VTI, Swedish National Road and Transport Research Institute, SE-581 95 Linköping, Sweden
| | - Malin Norin
- Engineering and Sustainability, NCC Infrastructure, NCC, SE-405 14 Gothenburg, Sweden
| | - Lena Blom
- Water Environment Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden; Sustainable Waste and Water, City of Gothenburg, SE-424 23 Gothenburg, Sweden
| | - Yvonne Andersson-Sköld
- VTI, Swedish National Road and Transport Research Institute, SE-581 95 Linköping, Sweden; Geology and Geotechnics, Department of Architecture and Civil Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
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47
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Fonseca CR, Paterno GB, Guadagnin DL, Venticinque EM, Overbeck GE, Ganade G, Metzger JP, Kollmann J, Sauer J, Cardoso MZ, Lopes PF, Oliveira RS, Pillar VD, Weisser WW. Conservation biology: four decades of problem- and solution-based research. Perspect Ecol Conserv 2021. [DOI: 10.1016/j.pecon.2021.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Exposure to Dodecamethylcyclohexasiloxane (D6) Affects the Antioxidant Response and Gene Expression of Procambarus clarkii. SUSTAINABILITY 2021. [DOI: 10.3390/su13063495] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Dodecamethylcyclohexasiloxane (D6) is widely used daily in the chemical industry and exists in the environment; however, its eco-toxicity is not well documented. A hydroponic experiment was performed to investigate the effects of D6 exposure (10–1000 mg L−1) on oxidative stress induction and gene expression changes in crayfish (Procambarus clarkii). The results showed that superoxide dismutase (SOD) activity was enhanced by 20–32% at low D6 exposure (10 mg L−1) in muscle but reduced in gill tissue at high D6 exposure (1000 mg L−1). High D6 (1000 mg L−1) also increased catalase (CAT) and peroxidase (POD) activities in muscle tissue by 14–37% and 14–45%, respectively, and the same trend was observed in the carapace and gill tissue of crayfish. The Malondialdehyde (MDA), ascorbate (AsA), and glutathione (GSH) contents were increased by 16–31%, 19–31%, and 21–28% in the muscle of crayfish under D6 exposure. Additionally, silicon (Si) content increased in three organs (gill, carapace, and muscle) of crayfish. Related genes involved in enzyme and nonenzyme activities were detected, and when crayfish was exposed to D6, genes such as Sod3, Cat3, Pod3, and Gsh3 were up-regulated, while Asa3 and Oxido3 were significantly down-regulated in the muscle. The research results help us to understand the toxicity of D6 in crayfish and provide a basis for further research on the mechanism of D6-induced stress in crayfish and other aquatic organisms.
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Cheng Z, Qiu X, Shi X, Zhu T. Identification of organosiloxanes in ambient fine particulate matters using an untargeted strategy via gas chromatography and time-of-flight mass spectrometry. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 271:116128. [PMID: 33421844 DOI: 10.1016/j.envpol.2020.116128] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/11/2020] [Accepted: 11/13/2020] [Indexed: 06/12/2023]
Abstract
Organosilicons are widely used in consumer products and are ubiquitous in living environments. However, there is little systemic information on this group of pollutants in ambient particles. This study proposes a novel untargeted strategy based mainly on the mass difference of three silicon isotopes to screen organosilicon compounds from 2-year PM2.5 samples of Beijing using gas chromatography and high-resolution time-of-flight mass spectrometry. 61 organosilicons were filtered from 1019 peaks, and 35 ones were identified as organosiloxanes including 17 methylsiloxanes and 18 phenylmethylsiloxanes, of which 6 and 3 species were confirmed using reference standards, respectively. These organosiloxanes could be clustered into three groups: low-silicon-number methylsiloxanes, high-silicon-number methylsiloxanes, and phenylmethylsiloxanes. Low-silicon-number methylsiloxanes showed high abundance in the heating season but low abundance in the non-heating season, whereas high-silicon-number methylsiloxanes showed the opposite seasonal variation. This study provides a promising strategy for screening organosilicon compounds through an untargeted approach and gives insights for further investigation of the sources and health risks of organosiloxanes.
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Affiliation(s)
- Zhen Cheng
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, And Center for Environment and Health, Peking University, Beijing, 100871, PR China
| | - Xinghua Qiu
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, And Center for Environment and Health, Peking University, Beijing, 100871, PR China.
| | - Xiaodi Shi
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, And Center for Environment and Health, Peking University, Beijing, 100871, PR China
| | - Tong Zhu
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, And Center for Environment and Health, Peking University, Beijing, 100871, PR China
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Horii Y, Ohtsuka N, Minomo K, Takemine S, Motegi M, Hara M. Distribution characteristics of methylsiloxanes in atmospheric environment of Saitama, Japan: Diurnal and seasonal variations and emission source apportionment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 754:142399. [PMID: 33254939 DOI: 10.1016/j.scitotenv.2020.142399] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/27/2020] [Accepted: 09/13/2020] [Indexed: 06/12/2023]
Abstract
The large production volume of methylsiloxanes (MSs), combined with their high mobility/volatility and persistence, is a matter of concern from the atmospheric pollution perspective. Therefore, we evaluated of the concentrations and emission sources of MSs, including 7 cyclic methylsiloxanes (D3-D9; CMSs, the number refers to the number of Si-O bonds) and 13 linear methylsiloxanes (L3-L15; LMSs) in ambient air collected from Saitama, Japan. This is a first study regarding the evaluation of 20 methylsiloxanes in the Japanese atmosphere. We improved the air sampling methodology by determination the stability of D5 during a 7-d air sampling and arbitrary sample storage period using polystyrene-divinyl benzene copolymer sorbent (Sep-Pak plus PS-2). We analyzed air samples for MSs seasonally collected from nine locations in Saitama, including urban, suburban, rural, and mountainous areas. The mean CMS and LMS concentrations were 358 ng m-3 and 13.4 ng m-3, respectively. The D5 concentrations were distributed widely, with high concentrations in urban/suburban populous areas and dispersed at low concentrations in surrounding areas (north and mountainous areas). We analyzed 7-d air samples collected every week over a year and found apparent seasonal and periodic trends in the CMS concentrations. In the diurnal sampling campaign, we observed periodic fluctuations in ambient CMSs, with an inverse relationship with the atmospheric boundary layer development during the day. Backward trajectories and the prevailing wind direction during the sampling period indicated that the specific profiles of D4 observed in fall/winter weeks and north of Saitama could be ascribed to northwestward air-mass advection. We employed a novel approach in estimating CMSs emission sources and source apportionment by using non-negative matrix factorization (NMF). The concentration matrix was divided successfully into two factors (emission sources) namely, personal care and household products and industrial activities.
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Affiliation(s)
- Yuichi Horii
- Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama 347-0115, Japan.
| | - Nobutoshi Ohtsuka
- Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama 347-0115, Japan
| | - Kotaro Minomo
- Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama 347-0115, Japan
| | - Shusuke Takemine
- Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama 347-0115, Japan
| | - Mamoru Motegi
- Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama 347-0115, Japan
| | - Masayuki Hara
- Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama 347-0115, Japan
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