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Zhuang Y, Wu J, Dong B, Wang F, Hu D, Zhang Y, Bo Y, Peng L. Evidences for the influence from key chemical structures of per- and polyfluoroalkyl substances on their environmental behaviors. JOURNAL OF HAZARDOUS MATERIALS 2024; 471:134383. [PMID: 38669930 DOI: 10.1016/j.jhazmat.2024.134383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 02/03/2024] [Accepted: 04/20/2024] [Indexed: 04/28/2024]
Abstract
This study carried out the atmospheric and precipitation observation in Beijing for nearly one year, and firstly simultaneously observed the pollution characteristics of PFASs and their main isomers, focusing on their gas-particle partitioning mechanism and dry and wet deposition characteristics. After deducting PFASs in the aqueous phase of particulate matter, the gas-particle partitioning coefficients (-7.04 to -5.49) were about 3-4 units smaller than before (-2.77 to -1.51), and all were smaller than 0, which indicated that each PFAS and isomer were more distributed in the gas phase. Dry deposition was dominant in the atmospheric deposition of each PFAS and isomer with relative contribution of 66 ± 17%, but the relative contribution of dry deposition was significantly different. It was found that the gas-particle partitioning coefficient can be influenced by key chemical structures such as carbon chain length, functional group type, and isomer structure. Furthermore, the gas-particle partitioning can influence the dry and wet deposition of PFASs. Specifically, PFASs with longer carbon chains, carboxylic acid functional group (compared to sulfonic acid functional group) or PFOA branched chain structures had larger gas-particle partitioning coefficients and can be more distributed in the hydrophobic phase of particulate matter, and their relative contributions of dry deposition were smaller.
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Affiliation(s)
- Yiru Zhuang
- The MOE Key Laboratory of Resource and Environmental System Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, PR China
| | - Jing Wu
- The MOE Key Laboratory of Resource and Environmental System Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, PR China; Institute of Transport Energy and Environment, Beijing Jiaotong University, Beijing 100044, PR China; School of Environment, Beijing Jiaotong University, Beijing 100044, PR China.
| | - Bingqi Dong
- The MOE Key Laboratory of Resource and Environmental System Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, PR China
| | - Fan Wang
- The MOE Key Laboratory of Resource and Environmental System Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, PR China
| | - Dongmei Hu
- The MOE Key Laboratory of Resource and Environmental System Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, PR China
| | - Yueling Zhang
- The MOE Key Laboratory of Resource and Environmental System Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, PR China
| | - Yu Bo
- CAS Key Laboratory of Regional Climate and Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, PR China
| | - Lin Peng
- The MOE Key Laboratory of Resource and Environmental System Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, PR China; Institute of Transport Energy and Environment, Beijing Jiaotong University, Beijing 100044, PR China; School of Environment, Beijing Jiaotong University, Beijing 100044, PR China.
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Optimization of haloacid dehalogenase production by recombinant E. coli BL21 (DE3)/pET-hakp1 containing haloacid dehalogenase gene from Klebsiella pneumoniae ITB1 using Response Surface Methodology (RSM). Heliyon 2022; 8:e11546. [DOI: 10.1016/j.heliyon.2022.e11546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 02/04/2022] [Accepted: 11/04/2022] [Indexed: 11/11/2022] Open
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Björnsdotter MK, Hartz WF, Kallenborn R, Ericson Jogsten I, Humby JD, Kärrman A, Yeung LWY. Levels and Seasonal Trends of C 1-C 4 Perfluoroalkyl Acids and the Discovery of Trifluoromethane Sulfonic Acid in Surface Snow in the Arctic. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:15853-15861. [PMID: 34779623 PMCID: PMC8655978 DOI: 10.1021/acs.est.1c04776] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 10/23/2021] [Accepted: 11/07/2021] [Indexed: 05/31/2023]
Abstract
C1-C4 perfluoroalkyl acids (PFAAs) are highly persistent chemicals that have been found in the environment. To date, much uncertainty still exists about their sources and fate. The importance of the atmospheric degradation of volatile precursors to C1-C4 PFAAs were investigated by studying their distribution and seasonal variation in remote Arctic locations. C1-C4 PFAAs were measured in surface snow on the island of Spitsbergen in the Norwegian Arctic during January-August 2019. Trifluoroacetic acid (TFA), perfluoropropanoic acid (PFPrA), perfluorobutanoic acid (PFBA), and trifluoromethane sulfonic acid (TFMS) were detected in most samples, including samples collected at locations presumably receiving PFAA input solely from long-range processes. The flux of TFA, PFPrA, PFBA, and TFMS per precipitation event was in the ranges of 22-1800, 0.79-16, 0.19-170, and 1.5-57 ng/m2, respectively. A positive correlation between the flux of TFA, PFPrA, and PFBA with downward short-wave solar radiation was observed. No correlation was observed between the flux of TFMS and solar radiation. These findings suggest that atmospheric transport of volatile precursors and their subsequent degradation plays a major role in the global distribution of C2-C4 perfluoroalkyl carboxylic acids and their consequential deposition in Arctic environments. The discovery of TFMS in surface snow at these remote Arctic locations suggests that TFMS is globally distributed. However, the transport mechanism to the Arctic environment remains unknown.
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Affiliation(s)
- Maria K. Björnsdotter
- Man-Technology-Environment
Research Centre (MTM), Örebro University, Örebro SE-701 82, Sweden
| | - William F. Hartz
- Department
of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, United Kingdom
- Department
of Arctic Geology, University Centre in
Svalbard (UNIS), Longyearbyen, Svalbard NO-9171, Norway
| | - Roland Kallenborn
- Faculty
of Chemistry, Biotechnology and Food Sciences (KBM), Norwegian University of Life Sciences (NMBU), Ås NO-1432, Norway
- Department
of Arctic Technology, University Centre
in Svalbard (UNIS), Longyearbyen, Svalbard NO-9171, Norway
| | - Ingrid Ericson Jogsten
- Man-Technology-Environment
Research Centre (MTM), Örebro University, Örebro SE-701 82, Sweden
| | - Jack D. Humby
- Ice Dynamics
and Paleoclimate, British Antarctic Survey, High Cross, Cambridge CB3 0ET, United
Kingdom
| | - Anna Kärrman
- Man-Technology-Environment
Research Centre (MTM), Örebro University, Örebro SE-701 82, Sweden
| | - Leo W. Y. Yeung
- Man-Technology-Environment
Research Centre (MTM), Örebro University, Örebro SE-701 82, Sweden
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Chen G, Jiang N, Villalobos Solis MI, Kara Murdoch F, Murdoch RW, Xie Y, Swift CM, Hettich RL, Löffler FE. Anaerobic Microbial Metabolism of Dichloroacetate. mBio 2021; 12:e00537-21. [PMID: 33906923 PMCID: PMC8092247 DOI: 10.1128/mbio.00537-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 03/17/2021] [Indexed: 12/23/2022] Open
Abstract
Dichloroacetate (DCA) commonly occurs in the environment due to natural production and anthropogenic releases, but its fate under anoxic conditions is uncertain. Mixed culture RM comprising "Candidatus Dichloromethanomonas elyunquensis" strain RM utilizes DCA as an energy source, and the transient formation of formate, H2, and carbon monoxide (CO) was observed during growth. Only about half of the DCA was recovered as acetate, suggesting a fermentative catabolic route rather than a reductive dechlorination pathway. Sequencing of 16S rRNA gene amplicons and 16S rRNA gene-targeted quantitative real-time PCR (qPCR) implicated "Candidatus Dichloromethanomonas elyunquensis" strain RM in DCA degradation. An (S)-2-haloacid dehalogenase (HAD) encoded on the genome of strain RM was heterologously expressed, and the purified HAD demonstrated the cofactor-independent stoichiometric conversion of DCA to glyoxylate at a rate of 90 ± 4.6 nkat mg-1 protein. Differential protein expression analysis identified enzymes catalyzing the conversion of DCA to acetyl coenzyme A (acetyl-CoA) via glyoxylate as well as enzymes of the Wood-Ljungdahl pathway. Glyoxylate carboligase, which catalyzes the condensation of two molecules of glyoxylate to form tartronate semialdehyde, was highly abundant in DCA-grown cells. The physiological, biochemical, and proteogenomic data demonstrate the involvement of an HAD and the Wood-Ljungdahl pathway in the anaerobic fermentation of DCA, which has implications for DCA turnover in natural and engineered environments, as well as the metabolism of the cancer drug DCA by gut microbiota.IMPORTANCE Dichloroacetate (DCA) is ubiquitous in the environment due to natural formation via biological and abiotic chlorination processes and the turnover of chlorinated organic materials (e.g., humic substances). Additional sources include DCA usage as a chemical feedstock and cancer drug and its unintentional formation during drinking water disinfection by chlorination. Despite the ubiquitous presence of DCA, its fate under anoxic conditions has remained obscure. We discovered an anaerobic bacterium capable of metabolizing DCA, identified the enzyme responsible for DCA dehalogenation, and elucidated a novel DCA fermentation pathway. The findings have implications for the turnover of DCA and the carbon and electron flow in electron acceptor-depleted environments and the human gastrointestinal tract.
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Affiliation(s)
- Gao Chen
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, USA
| | - Nannan Jiang
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
- Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, Tennessee, USA
- University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | | | - Fadime Kara Murdoch
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
- University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Robert Waller Murdoch
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
| | - Yongchao Xie
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, USA
| | - Cynthia M Swift
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
| | - Robert L Hettich
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Frank E Löffler
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, USA
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
- Department of Biosystems Engineering & Soil Science, University of Tennessee, Knoxville, Tennessee, USA
- Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, Tennessee, USA
- Genome Science and Technology, University of Tennessee, Knoxville, Tennessee, USA
- University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
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Pike KA, Edmiston PL, Morrison JJ, Faust JA. Correlation Analysis of Perfluoroalkyl Substances in Regional U.S. Precipitation Events. WATER RESEARCH 2021; 190:116685. [PMID: 33279752 DOI: 10.1016/j.watres.2020.116685] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/21/2020] [Accepted: 11/25/2020] [Indexed: 05/28/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are transported in the atmosphere, leading to both wet and dry deposition to the surface. The concentrations of 15 PFAS were measured at six locations in the Ohio-Indiana region of the U.S. during the summer of 2019 and compared to samples collected at a distant site in NW Wyoming. ΣPFAS concentrations ranged from 50-850 ng L-1, with trifluoroacetic acid (TFA) being the dominant compound (~90%). Concentrations of perfluorooctanoic acid (PFOA) and perfluorosulfonic acid (PFOS) were similar to amounts observed over the past 20 years, indicating persistence in the atmosphere despite regulatory action, and the newer species HFPO-DA (GenX) was also widely detected in rainwater. ANOVA modeling and correlation matrices were used to determine association of PFAS concentrations, location, and functional group and chain length. Statistically significant differences (p < 0.05) in PFAS profiles across sites separated by 10-100 km indicate that local point sources strongly contribute to wet deposition. This work introduces correlation plots for PFAS that allow rapid visual comparison of multi-analyte and multi-site data sets.
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Affiliation(s)
- Kyndal A Pike
- Department of Chemistry, College of Wooster, 943 College Mall, Wooster, Ohio 44691, United States; Department of Mathematical and Computational Sciences, College of Wooster, 308 E. University, Wooster, Ohio 44691, United States
| | - Paul L Edmiston
- Department of Chemistry, College of Wooster, 943 College Mall, Wooster, Ohio 44691, United States
| | - Jillian J Morrison
- Department of Mathematical and Computational Sciences, College of Wooster, 308 E. University, Wooster, Ohio 44691, United States
| | - Jennifer A Faust
- Department of Chemistry, College of Wooster, 943 College Mall, Wooster, Ohio 44691, United States.
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Freeling F, Behringer D, Heydel F, Scheurer M, Ternes TA, Nödler K. Trifluoroacetate in Precipitation: Deriving a Benchmark Data Set. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:11210-11219. [PMID: 32806887 DOI: 10.1021/acs.est.0c02910] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Although precipitation is considered to be the most important diffuse source of trifluoroacetate (TFA) to the nonmarine environment, information regarding the wet deposition of TFA as well as general data on the spatial and temporal variations in TFA concentration in precipitation is scarce. This is the first study to provide a comprehensive overview of the occurrence of TFA in precipitation by a systematic and nation-wide field monitoring campaign. In total, 1187 precipitation samples, which were collected over the course of 12 consecutive months at eight locations across Germany, were analyzed. The median, the estimated average, and the precipitation-weighted average TFA concentration of all analyzed wet deposition samples were 0.210, 0.703, and 0.335 μg/L, respectively. For Germany, an annual wet deposition flux of 190 μg/m2 or approximately 68 t was calculated for the sampling period from February 2018 to January 2019. The campaign revealed a pronounced seasonality of the TFA concentration and wet deposition flux of collected samples. Correlation analysis suggested an enhanced transformation of TFA precursors in the troposphere in the summertime due to higher concentrations of photochemically generated oxidants such as hydroxyl radicals, ultimately leading to an enhanced atmospheric deposition of TFA during summer.
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Affiliation(s)
- Finnian Freeling
- TZW: DVGW-Technologiezentrum Wasser (German Water Centre), Karlsruher Strasse 84, 76139, Karlsruhe, Germany
| | - David Behringer
- Öko-Recherche Büro für Umweltforschung und-beratung GmbH, Münchener Strasse 23a, 60329 Frankfurt/Main, Germany
| | - Felix Heydel
- Öko-Recherche Büro für Umweltforschung und-beratung GmbH, Münchener Strasse 23a, 60329 Frankfurt/Main, Germany
| | - Marco Scheurer
- TZW: DVGW-Technologiezentrum Wasser (German Water Centre), Karlsruher Strasse 84, 76139, Karlsruhe, Germany
| | - Thomas A Ternes
- Federal Institute of Hydrology, Am Mainzer Tor 1, 56068 Koblenz, Germany
| | - Karsten Nödler
- TZW: DVGW-Technologiezentrum Wasser (German Water Centre), Karlsruher Strasse 84, 76139, Karlsruhe, Germany
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Challenges in the analytical determination of ultra-short-chain perfluoroalkyl acids and implications for environmental and human health. Anal Bioanal Chem 2020; 412:4785-4796. [PMID: 32399685 PMCID: PMC7334270 DOI: 10.1007/s00216-020-02692-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 04/17/2020] [Accepted: 04/30/2020] [Indexed: 11/23/2022]
Abstract
Ultra-short-chain perfluoroalkyl acids have recently gained attention due to increasing environmental concentrations being observed. The most well-known ultra-short-chain perfluoroalkyl acid is trifluoroacetic acid (TFA) which has been studied since the 1990s. Potential sources and the fate of ultra-short-chain perfluoroalkyl acids other than TFA are not well studied and data reporting their environmental occurrence is scarce. The analytical determination of ultra-short-chain perfluoroalkyl acids is challenging due to their high polarity resulting in low retention using reversed-phase liquid chromatography. Furthermore, recent studies have reported varying extraction recoveries in water samples depending on the water matrix and different methods have been suggested to increase the extraction recovery. The present review gives an overview of the currently used analytical methods and summarizes the findings regarding potential analytical challenges. In addition, the current state of knowledge regarding TFA and other ultra-short-chain perfluoroalkyl acids, namely perfluoropropanoic acid, trifluoromethane sulfonic acid, perfluoroethane sulfonic acid, and perfluoropropane sulfonic acid‚ are reviewed. Both known and potential sources as well as environmental concentrations are summarized and discussed together with their fate and the environmental and human implications.
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Biodegradation of mono-, di- and trifluoroacetate by microbial cultures with different origins. N Biotechnol 2018; 43:23-29. [DOI: 10.1016/j.nbt.2017.08.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 05/10/2017] [Accepted: 08/14/2017] [Indexed: 02/07/2023]
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Yeung LWY, Stadey C, Mabury SA. Simultaneous analysis of perfluoroalkyl and polyfluoroalkyl substances including ultrashort-chain C2 and C3 compounds in rain and river water samples by ultra performance convergence chromatography. J Chromatogr A 2017; 1522:78-85. [PMID: 28965989 DOI: 10.1016/j.chroma.2017.09.049] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 08/01/2017] [Accepted: 09/22/2017] [Indexed: 12/23/2022]
Abstract
An analytical method using ultra performance convergence chromatography (UPC2) coupled to a tandem mass spectrometer operated in negative electrospray mode was developed to measure perfluoroalkyl and polyfluoroalkyl substances (PFASs) including the ultrashort-chain PFASs (C2-C3). Compared to the existing liquid chromatography tandem mass spectrometry method using an ion exchange column, the new method has a lower detection limit (0.4pg trifluoroacetate (TFA) on-column), narrower peak width (3-6s), and a shorter run time (8min). Using the same method, different classes of PFASs (e.g., perfluoroalkyl sulfonates (PFSAs) and perfluorinated carboxylates (PFCAs), perfluorinated phosphonates (PFPAs) and phosphinates (PFPiAs), polyfluoroalkyl phosphate diesters (diPAPs)) can be measured in a single analysis. Rain (n=2) and river water (n=2) samples collected in Toronto, ON, were used for method validation and application. Results showed that short-chain PFAS (C2-C7 PFCAs and C4 PFSA) contributed to over 80% of the detectable PFASs in rain samples and the C2-C3 PFASs alone accounted for over 40% of the total. Reports on environmental levels of these ultrashort-chain PFASs are relatively scarce. Relatively large contribution of these ultrashort-chain PFASs to the total PFASs indicate the need to include the measurement of short-chain PFASs, especially C2 and C3 PFASs, in environmental monitoring. The sources of TFA and other short-chain PFASs in the environment are not entirely clear. The newly developed analytical method may help further investigation on the sources and the environmental levels of these ultrashort-chain PFASs.
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Affiliation(s)
- Leo W Y Yeung
- Man-Technology-Environment Research Centre (MTM), Örebro University, 701 82 Örebro, Sweden; Department of Chemistry, University of Toronto,80 St George Street, Toronto, Ontario M5S 3H6, Canada.
| | | | - Scott A Mabury
- Department of Chemistry, University of Toronto,80 St George Street, Toronto, Ontario M5S 3H6, Canada.
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Miska ME, Shouakar-Stash O, Holmstrand H. Stable chlorine isotope analysis of chlorinated acetic acids using gas chromatography/quadrupole mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:2341-2348. [PMID: 26563705 DOI: 10.1002/rcm.7407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 09/23/2015] [Accepted: 09/23/2015] [Indexed: 06/05/2023]
Abstract
RATIONALE The environmental occurrence of chlorinated acetic acids (CAAs) has been extensively studied, but the sources and transport are still not yet fully understood. A promising approach for source apportionment and process studies is the isotopic characterization of target compounds. We present the first on-line stable chlorine isotope analysis of CAAs by use of gas chromatography/quadrupole mass spectrometry (GC/qMS). METHODS Following approved procedures for concentration analysis, CAAs extracted into MTBE were methylated to GC-amenable methyl esters (mCAAs). These mCAAs were then analyzed by GC/qMS for their stable chlorine isotope composition using a sample/standard-bracketing approach (CAA standards in the range δ(37) Cl -6.3 to -0.2 ‰, Standard Mean Ocean Chloride). RESULTS Cross-calibration of the herein presented method with off-line reference methods (thermal ionization and continuous-flow GC isotope ratio mass spectrometry; TI-MS and CF-GC/IRMS, respectively) shows good agreement between the methods (regression slope for GC/qMS vs reference method data sets: 0.92 ± 0.29). Sample amounts as small as 10 pmol Cl can herewith be analyzed with a precision of 0.1 to 0.4 ‰. CONCLUSIONS This method should be useful for environmental studies of CAAs at ambient concentrations in precipitations (<0.06 to 100 nmol L(-1) ), surface waters (<0.2 to 5 nmol L(-1) ) and soil (<0.6 to 2000 nmol kg(-1) dry soil) where conventional off-line methods cannot be applied.
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Affiliation(s)
- Milena E Miska
- Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm, Sweden
| | - Orfan Shouakar-Stash
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario, Canada
- Isotope Tracer Technologies Inc, Waterloo, Ontario, Canada
| | - Henry Holmstrand
- Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm, Sweden
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Wang Q, Wang X, Ding X. Rainwater trifluoroacetic acid (TFA) in Guangzhou, South China: levels, wet deposition fluxes and source implication. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 468-469:272-9. [PMID: 24035981 DOI: 10.1016/j.scitotenv.2013.08.055] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 08/14/2013] [Accepted: 08/17/2013] [Indexed: 05/06/2023]
Abstract
The origin of trifluoroacetic acid (TFA) occurring in hydrosphere has long been a controversial issue. Hydrochlorofluorocarbons and hydrofluorocarbons (HCFCs/HFCs) as replacements of chlorofluorocarbons (CFCs) are precursors of TFA in the atmosphere, their contribution to rainwater TFA is a concern as their ambient mixing ratios are continually growing. Here we present rainwater TFA monitored from April 2007 to March 2008 in urban Guangzhou, a central city in south China's highly industrialized and densely populated Pearl River Delta region. Rainwater TFA levels ranged 45.8-974 ng L(-1) with a median of 166 ng L(-1). TFA levels negatively correlated with rainfall amount, the yearly rainfall-weighted average for TFA was 152 ng L(-1). The annual TFA wet deposition flux was estimated to be 229 g km(-2) yr(-1), and the total wet deposition of TFA reached ~1.7 tyr(-1) in Guangzhou. The Two-Box model was applied to estimate attributions of HCFCs/HFCs and fluoropolymers to rainwater TFA assuming TFA generated was proportional to gross domestic product (GDP), gross industrial product (GIP) or number of private cars. The results revealed that the degradation of HCFCs/HFCs and fluoropolymers could explain 131.5-152.4 ng L(-1) rainwater TFA, quite near the observed rainfall-weighted annual mean of 152 ng L(-1), suggesting rainwater TFA in Guangzhou was predominantly originated from these anthropogenic precursors. HCFCs/HFCs accounted for 83.3-96.5% of rainwater TFA observed, while fluoropolymers' contributions were minor (~5%). HFC-134a alone could explain 55.9-90.0% of rainwater TFA, and its contribution would be greatly enhanced with its wide use in mobile air conditioning systems and rapid increase in ambient mixing ratios.
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Affiliation(s)
- Qiaoyun Wang
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; Guangzhou Institute of Measuring and Testing Technology, Guangzhou 510663, China
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Henne S, Shallcross DE, Reimann S, Xiao P, Brunner D, O'Doherty S, Buchmann B. Future emissions and atmospheric fate of HFC-1234yf from mobile air conditioners in Europe. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:1650-8. [PMID: 22225403 DOI: 10.1021/es2034608] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
HFC-1234yf (2,3,3,3-tetrafluoropropene) is under discussion for replacing HFC-134a (1,1,1,2-tetrafluoroethane) as a cooling agent in mobile air conditioners (MACs) in the European vehicle fleet. Some HFC-1234yf will be released into the atmosphere, where it is almost completely transformed to the persistent trifluoroacetic acid (TFA). Future emissions of HFC-1234yf after a complete conversion of the European vehicle fleet were assessed. Taking current day leakage rates and predicted vehicle numbers for the year 2020 into account, European total HFC-1234yf emissions from MACs were predicted to range between 11.0 and 19.2 Gg yr(-1). Resulting TFA deposition rates and rainwater concentrations over Europe were assessed with two Lagrangian chemistry transport models. Mean European summer-time TFA mixing ratios of about 0.15 ppt (high emission scenario) will surpass previously measured levels in background air in Germany and Switzerland by more than a factor of 10. Mean deposition rates (wet + dry) of TFA were estimated to be 0.65-0.76 kg km(-2) yr(-1), with a maxium of ∼2.0 kg km(-2) yr(-1) occurring in Northern Italy. About 30-40% of the European HFC-1234yf emissions were deposited as TFA within Europe, while the remaining fraction was exported toward the Atlantic Ocean, Central Asia, Northern, and Tropical Africa. Largest annual mean TFA concentrations in rainwater were simulated over the Mediterranean and Northern Africa, reaching up to 2500 ng L(-1), while maxima over the continent of about 2000 ng L(-1) occurred in the Czech Republic and Southern Germany. These highest annual mean concentrations are at least 60 times lower than previously determined to be a safe level for the most sensitive aquatic life-forms. Rainwater concentrations during individual rain events would still be 1 order of magnitude lower than the no effect level. To verify these results future occasional sampling of TFA in the atmospheric environment should be considered. If future HFC-1234yf emissions surpass amounts used here studies of TFA accumulation in endorheic basins and other sensitive areas should be aspired.
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Affiliation(s)
- Stephan Henne
- Laboratory for Air Pollution/Environmental Technology, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
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Shroads AL, Guo X, Dixit V, Liu HP, James MO, Stacpoole PW. Age-dependent kinetics and metabolism of dichloroacetate: possible relevance to toxicity. J Pharmacol Exp Ther 2007; 324:1163-71. [PMID: 18096758 DOI: 10.1124/jpet.107.134593] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Dichloroacetate (DCA) is an investigational drug for certain metabolic diseases. It is biotransformed principally by the zeta-1 family isoform of glutathione transferase (GSTz1), also known as maleylacetoacetate isomerase (MAAI), which catalyzes the penultimate step in tyrosine catabolism. DCA causes a reversible peripheral neuropathy in several species, including humans. However, recent clinical trials indicate that adults are considerably more susceptible to this adverse effect than children. We evaluated the kinetics and biotransformation of DCA and its effects on tyrosine metabolism in nine patients treated for 6 months with 25 mg/kg/day and in rats treated for 5 days with 50 mg/kg/day. We also measured the activity and expression of hepatic GSTz1/MAAI. Chronic administration of DCA causes a striking age-dependent decrease in its plasma clearance and an increase in its plasma half-life in patients and rats. Urinary excretion of unchanged DCA in rats increases with age, whereas oxalate, an end product of DCA metabolism, shows the opposite trend. Low concentrations of monochloroacetate (MCA), which is known to be neurotoxic, increase as a function of age in the urine of dosed rats. MCA was detectable in plasma only of older animals. Hepatic GSTz1/MAAI-specific activity was inhibited equally by DCA treatment among all age groups, whereas plasma and urinary levels of maleylacetone, a natural substrate for this enzyme, increased with age. We conclude that age is an important variable in the in vivo metabolism and elimination of DCA and that it may account, in part, for the neurotoxicity of this compound in humans and other species.
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Affiliation(s)
- Albert L Shroads
- Departments of Medicine, University of Florida Colleges of Medicine and Pharmacy, University of Florida, Gainesville, Florida, USA
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14
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Jia M, Coats B, Chadha M, Frentzen B, Perez-Rodriguez J, Chadik PA, Yost RA, Henderson GN, Stacpoole PW. Human kinetics of orally and intravenously administered low-dose 1,2-(13)C-dichloroacetate. J Clin Pharmacol 2007; 46:1449-59. [PMID: 17101744 DOI: 10.1177/0091270006292627] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Dichloroacetate (DCA) is a putative environmental hazard, owing to its ubiquitous presence in the biosphere and its association with animal and human toxicity. We sought to determine the kinetics of environmentally relevant concentrations of 1,2-(13)C-DCA administered to healthy adults. Subjects received an oral or intravenous dose of 2.5 microg/kg of 1,2-(13)C-DCA. Plasma and urine concentrations of 1,2-(13)C-DCA were measured by a modified gas chromatography-tandem mass spectrometry method. 1,2-(13)C-DCA kinetics was determined by modeling using WinNonlin 4.1 software. Plasma concentrations of 1,2-(13)C-DCA peaked 10 minutes and 30 minutes after intravenous or oral administration, respectively. Plasma kinetic parameters varied as a function of dose and duration. Very little unchanged 1,2-(13)C-DCA was excreted in urine. Trace amounts of DCA alter its own kinetics after short-term exposure. These findings have important implications for interpreting the impact of this xenobiotic on human health.
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Affiliation(s)
- Minghong Jia
- General Clinical Research Center, University of Florida, 1600 Archer Road, Gainesville, Florida 32610, USA
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15
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Matucha M, Rohlenová J, Forczek ST, Uhlírová H, Gryndler M, Fuksová K, Schröder P. Determination of trichloroacetic acid in environmental studies using carbon 14 and chlorine 36. CHEMOSPHERE 2006; 63:1924-32. [PMID: 16313943 DOI: 10.1016/j.chemosphere.2005.10.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2005] [Revised: 10/06/2005] [Accepted: 10/06/2005] [Indexed: 05/05/2023]
Abstract
Radioisotopes carbon 14 and chlorine 36 were used to elucidate the environmental role of trichloroacetic acid (TCA) formerly taken to be a herbicide and a secondary air pollutant with phytotoxic effects. However, use of 14C-labeling posed again known analytical problems, especially in TCA extraction from the sample matrix. Therefore--after evaluation of available methods--a new procedure using decarboxylation of [1,2-14C]TCA combined with extraction of the resultant 14C-chloroform with a non-polar solvent and its subsequent radiometric measurement was developed. The method solves previous difficulties and permits an easy determination of amounts between 0.4 and 20 kBq (10 - 500 ng g(-1)) of carrier-less [1,2-14C]TCA in samples from environmental investigations. The procedure is, however, not suitable for direct [36Cl]TCA determination in chlorination studies with 36Cl. Because TCA might be microbially degraded in soil during extraction and sample storage and its extraction from soil or needles is never complete, the decarboxylation method--i.e. 2 h TCA decomposition to chloroform and CO2 in aqueous solution or suspension in closed vial at 90 degrees C and pH 4.6 with subsequent CHCl3 extraction-is recommended here, estimated V < 7%. Moreover, the influence of pH and temperature on the decarboxylation of TCA in aqueous solution was studied in a broad range and its environmental relevance is shown in the case of TCA decarboxylation in spruce needles which takes place also at ambient temperatures and might amount more than 10-20% after a growing season. A study of TCA distribution in spruce needles after below-ground uptake shows the highest uptake rate into current needles which have, however, a lower TCA content than older needle-year classes, TCA biodegradation in forest soil leads predominatingly to CO2.
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Affiliation(s)
- Miroslav Matucha
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, CZ-14220 Prague, Czech Republic.
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16
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Lewis TE, Wolfinger TF, Barta ML. The ecological effects of trichloroacetic acid in the environment. ENVIRONMENT INTERNATIONAL 2004; 30:1119-1150. [PMID: 15337357 DOI: 10.1016/j.envint.2004.04.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2003] [Accepted: 04/05/2004] [Indexed: 05/24/2023]
Abstract
Trichloroacetic acid (TCAA) is a member of the family of compounds known as chloroacetic acids, which includes mono-, di- and trichloroacetic acid. The significant property these compounds share is that they are all phytotoxic. TCAA once was widely used as a potent herbicide. However, long after TCAA's use as a herbicide was discontinued, its presence is still detected in the environment in various compartments. Methods for quantifying TCAA in aqueous and solid samples are summarized. Concentrations in various environmental compartments are presented, with a discussion of the possible formation of TCAA through natural processes. Concentrations of TCAA found to be toxic to aquatic and terrestrial organisms in laboratory and field studies were compiled and used to estimate risk quotients for soil and surface waters. TCAA levels in most water bodies not directly affected by point sources appear to be well below toxicity levels for the most sensitive aquatic organisms. Given the phytotoxicity of TCAA, aquatic plants and phytoplankton would be the aquatic species to monitor for potential effects. Given the concentrations of TCAA measured in various soils, there appears to be a risk to terrestrial organisms. Soil uptake of TCAA by plants has been shown to be rapid. Also, combined uptake of TCAA from soil and directly from the atmosphere has been shown. Therefore, risk quotients derived from soil exposure may underestimate the risk TCAA poses to plants. Moreover, TCE and TCA have been shown to be taken up by plants and converted to TCAA, thus leading to an additional exposure route. Mono- and di-chloroacetic acids can co-occur with TCAA in the atmosphere and soil and are more phytotoxic than TCAA. The cumulative effects of TCAA and compounds with similar toxic effects found in air and soil must be considered in subsequent terrestrial ecosystem risk assessments.
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Affiliation(s)
- T E Lewis
- National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Mail Code B-243-01, Research Triangle Park, NC 27711, USA.
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17
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Hanson ML, Solomon KR. Haloacetic acids in the aquatic environment. Part I: macrophyte toxicity. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2004; 130:371-383. [PMID: 15182970 DOI: 10.1016/j.envpol.2003.12.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2003] [Accepted: 12/26/2003] [Indexed: 05/24/2023]
Abstract
Haloacetic acids (HAAs) are contaminants of aquatic ecosystems with numerous sources, both anthropogenic and natural. The toxicity of HAAs to aquatic plants is generally uncharacterized. Laboratory tests were conducted with three macrophytes (Lemna gibba, Myriophyllum sibiricum and Myriophyllum spicatum) to assess the toxicity of five HAAs. Myriophyllum spp. has been proposed as required test species for pesticide registration in North America, but few studies have been conducted under standard test conditions. The HAAs in the present experiments were monochloroacetic acid (MCA), dichloroacetic acid (DCA), trichloroacetic acid (TCA), trifluoroacetic acid (TFA) and chlorodifluoroacetic acid (CDFA). MCA was the most toxic to Myriophyllum spp. with EC50 values ranging from 8 to 12.4 mg/l depending on the endpoint, followed by DCA (EC50 range 62-722.5 mg/l), TCA (EC50 range 49.5-1702.6 mg/l), CDFA (EC50 range 105.3 to >10,000 mg/l) and with TFA (EC50 range 222.1 to 10,000 mg/l) the least toxic. Generally, L. gibba was less sensitive to HAA toxicity than Myriophyllum spp., with the difference in toxicity between them approximately threefold. The range of toxicity within Myriophyllum spp. was normally less than twofold. Statistically, plant length and node number were the most sensitive endpoints as they had the lowest observed coefficients of variation, but they were not the most sensitive to HAA toxicity. Toxicological sensitivity of endpoints varied depending on the measure of effect chosen and the HAA, with morphological endpoints usually an order of magnitude more sensitive than pigments for all plant species. Overall, mass and root measures tended to be the most sensitive indicators of HAA toxicity. The data from this paper were subsequently used in an ecological risk assessment for HAAs and aquatic plants. The assessment found HAAs to be of low risk to aquatic macrophytes and the results are described in the second manuscript of this series.
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Affiliation(s)
- Mark L Hanson
- Centre for Toxicology and Department of Environmental Biology, University of Guelph, Guelph, Ontario, Canada, N1G 2W1
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18
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Hanson ML, Solomon KR. Haloacetic acids in the aquatic environment. Part II: ecological risk assessment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2004; 130:385-401. [PMID: 15182971 DOI: 10.1016/j.envpol.2003.12.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2003] [Accepted: 12/26/2003] [Indexed: 05/24/2023]
Abstract
Haloacetic acids (HAAs) are environmental contaminants found in aquatic ecosystems throughout the world as a result of both anthropogenic and natural production. The ecological risk posed by these compounds to organisms in freshwater environments, with a specific focus on aquatic macrophytes, was characterized. The plants evaluated were Lemna gibba, Myriophyllum spicatum and M. sibiricum and the HAAs screened were monochloroacetic acid (MCA), dichloroacetic acid (DCA), trichloroacetic acid (TCA), trifluoroacetic acid (TFA) and chlorodifluoroacetic acid (CDFA). Laboratory toxicity data formed the basis of the risk assessment, but field studies were also utilized. The estimated risk was calculated using hazard quotients (HQ), as well as effect measure distributions (EMD) in a modified probabilistic ecological risk assessment. EMDs were used to estimate HAA thresholds of toxicity for use in HQ assessments. This threshold was found to be a more sensitive measure of low toxicity than the no observed effect concentrations (NOEC) or the effective concentration (EC10). Using both deterministic and probabilistic methods, it was found that HAAs do not pose a significant risk to freshwater macrophytes at current environmental concentrations in Canada, Europe or Africa for both single compound and mixture exposures. Still, HAAs are generally found as mixtures and their potential interactions are not fully understood, rendering this phase of the assessment uncertain and justifying further effects characterization. TCA in some environments poses a slight risk to phytoplankton and future concentrations of TFA and CDFA are likely to increase due to their recalcitrant nature, warranting continued environmental surveillance of HAAs.
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Affiliation(s)
- Mark L Hanson
- Centre for Toxicology and Department of Environmental Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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19
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Dickey CA, Heal KV, Stidson RT, Koren R, Schröder P, Cape JN, Heal MR. Trichloroacetic acid cycling in Sitka spruce saplings and effects on sapling health following long term exposure. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2004; 130:165-176. [PMID: 15158031 DOI: 10.1016/j.envpol.2003.12.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2003] [Accepted: 12/18/2003] [Indexed: 05/24/2023]
Abstract
Trichloroacetic acid (TCA, CCl(3)COOH) has been associated with forest damage but the source of TCA to trees is poorly characterised. To investigate the routes and effects of TCA uptake in conifers, 120 Sitka spruce (Picea sitchensis (Bong.) Carr) saplings were exposed to control, 10 or 100 microg l(-1) solutions of TCA applied twice weekly to foliage only or soil only over two consecutive 5-month growing seasons. At the end of each growing season similar elevated TCA concentrations (approximate range 200-300 ng g(-1) dwt) were detected in both foliage and soil-dosed saplings exposed to 100 microg l(-1) TCA solutions showing that TCA uptake can occur from both exposure routes. Higher TCA concentrations in branchwood of foliage-dosed saplings suggest that atmospheric TCA in solution is taken up indirectly into conifer needles via branch and stemwood. TCA concentrations in needles declined slowly by only 25-30% over 6 months of winter without dosing. No effect of TCA exposure on sapling growth was measured during the experiment. However at the end of the first growing season needles of saplings exposed to 10 or 100 microg l(-1) foliage-applied TCA showed significantly more visible damage, higher activities of some detoxifying enzymes, lower protein contents and poorer water control than needles of saplings dosed with the same TCA concentrations to the soil. At the end of each growing season the combined TCA storage in needles, stemwood, branchwood and soil of each sapling was <6% of TCA applied. Even with an estimated half-life of tens of days for within-sapling elimination of TCA during the growing season, this indicates that TCA is eliminated rapidly before uptake or accumulates in another compartment. Although TCA stored in sapling needles accounted for only a small proportion of TCA stored in the sapling/soil system it appears to significantly affect some measures of sapling health.
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Affiliation(s)
- C A Dickey
- School of GeoSciences, University of Edinburgh, Darwin Building, Mayfield Road, Edinburgh EH9 3JU, UK
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20
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Lifongo LL, Bowden DJ, Brimblecombe P. Photodegradation of haloacetic acids in water. CHEMOSPHERE 2004; 55:467-476. [PMID: 14987945 DOI: 10.1016/j.chemosphere.2003.11.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2003] [Revised: 09/02/2003] [Accepted: 11/03/2003] [Indexed: 05/24/2023]
Abstract
The global distribution and high stability of some haloacetic acids (HAAs) has prompted concern that they will tend to accumulate in surface waters and pose threats to humans and the ecosystem. It is important to study the degradation pathways of HAAs in aqueous systems to understand their ecotoxicological effects. Previous studies involving thermal degradation reactions show relatively long lifetimes for HAAs in the natural environment. Photolysis and photocatalytic dissociation are potentially efficient routes for the degradation of HAAs such as trichloroacetic acid to hydrochloric acid, carbon dioxide and chloroform, although such processes are poorly understood in surface waters. In our present study, we have used light to degrade the HAAs in the presence of titanium dioxide suspensions. All chloro and bromo HAAs degrade in photocatalysis experiments and the rate of degradation is directly proportional to the number of halogen atoms in the acid molecule. The half-lives of the HAAs from the photodegradation at 15 degrees C in the presence of suspended titanium dioxide photocatalyst are 8, 14, 83 days for the tri-, di- and mono-bromoacetic acids. Tri-, di- and mono-chloroacectic acids have half-lives of 6, 10 and 42 days respectively. The mixed bromochloro and chlorodifluoroacetic acids degrade with half-lives of 18 and 42 days respectively. Our results therefore suggest that the photocatalytic process can provide an additional degradation pathway for the HAAs in natural waters.
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Affiliation(s)
- Lydia L Lifongo
- School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK
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21
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Hoekstra EJ. Review of concentrations and chemistry of trichloroacetate in the environment. CHEMOSPHERE 2003; 52:355-369. [PMID: 12738258 DOI: 10.1016/s0045-6535(03)00213-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This paper reviews the concentrations of trichloroacetate (TCA) in the atmosphere-plant-soil system. Data originate mainly from Europe. The median TCA concentration in rainwater and canopy drip decreased until 1995. From then the median TCA concentration in rainwater remains rather constant while for canopy drip later data are not available. The same seems to hold for concentrations in air although a very limited data set is available. The median concentrations in coniferous needles and groundwater are constant for the period observed. The median TCA concentrations in soil decreased until 1992 and then remained constant.The TCA formation from chlorinated solvents in the atmosphere may explain a substantial percentage of the TCA amount in the atmosphere. The TCA concentrations in rainwater and canopy drip indicate that there will be other sources contributing to 10-50%. Waste incineration, biomass burning and natural formation in the marine boundary layer are potential candidate sources of TCA, but nothing can be said as yet on their TCA emission rates. Anthropogenic emissions of chlorine could also be a source.TCA can be formed from chlorinated solvents by biota. However, for coniferous trees the uptake of TCA from soil may be the predominant route. Biotic and abiotic reactions can cause to formation of TCA in soil, but also formation of TCA from chlorinated solvents by biota that excrete TCA, may contribute. Mass balance calculations of the bioactive soil top layer show that the production rate of TCA in certain soil types could be substantial. The mass balance calculations could not distinguish between natural and anthropogenic sources in soil.
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Affiliation(s)
- Eddo J Hoekstra
- Inland and Marine Waters Unit, Institute for Environment and Sustainability, DG Joint Research Centre, European Commission, Via E Fermi 1 (TP 300), Ispra, VA 21020, Italy.
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22
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Ahlers J, Regelmann J, Riedhammer C. Environmental risk assessment of airborne trichloroacetic acid--a contribution to the discussion on the significance of anthropogenic and natural sources. CHEMOSPHERE 2003; 52:531-537. [PMID: 12738278 DOI: 10.1016/s0045-6535(03)00201-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In environmental risk assessments the question has to be answered, whether risk reduction measures are necessary in order to protect the environment. If the combination of natural and anthropogenic sources of a chemical substance leads to an unacceptable risk, the man-made emissions have to be reduced. In this case the proportions of the anthropogenic and natural emissions have to be quantified. Difficulties and possible solutions are discussed in the scope of the OECD- and EU-risk assessments of trichloroacetic acid (TCA) and tetrachloroethylene. In the atmosphere, TCA is formed by photo-oxidative degradation of tetrachloroethylene (PER) and 1,1,1-trichloroethane. The available data on atmospheric chemistry indicate that tetrachloroethylene is the more important pre-cursor. With its high water solubility and low volatility, TCA is adsorbed onto aerosol particles and precipitated during rainfalls. Extended monitoring in rainwater confirmed the global distribution of airborne TCA. TCA reaches soils by dry and wet deposition. In addition formation of TCA from tetrachloroethylene in plants was observed. Consequently, high concentrations were detected in needles, leaves and in forest soil especially in mountain regions. The effect assessment revealed that plants exposed via soil are the most sensitive species compared to other terrestrial organisms. A PNECsoil of 2.4 microg/kg dw was derived from a long-term study with pine and spruce seedlings. When this PNEC is compared with the measured concentrations of TCA in soil, in certain regions a PEC/PNEC ratio >1 is obtained. This clearly indicates a risk to the terrestrial ecosystem, with the consequence that risk reduction measures are deemed necessary. To quantify the causes of the high levels of TCA in certain soils, and to investigate the geographical extent of the problem, intensive and widespread monitoring of soil, air and rainwater for TCA and tetrachloroethylene would be necessary to be able to perform a full mass balance study at an appropriate number of sites. In addition, measurements of the 14C content in TCA isolated from soil could clarify whether a significant proportion of the TCA occurs from natural sources. The possible formation of TCA in soil can also be tested by incubation of isotope enriched inorganic chloride with subsequent mass spectrometry of TCA.
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Affiliation(s)
- Jan Ahlers
- Umweltbundesamt, Bismarckplatz 1, 14193 Berlin, Germany.
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23
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Hanson ML, Sibley PK, Mabury SA, Muir DCG, Solomon KR. Field level evaluation and risk assessment of the toxicity of dichloroacetic acid to the aquatic macrophytes Lemna gibba, Myriophyllum spicatum, and Myriophyllum sibiricum. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2003; 55:46-63. [PMID: 12706393 DOI: 10.1016/s0147-6513(02)00094-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Dichloroacetic acid (DCA), a haloacetic acid, is a common contaminant of aquatic ecosystems. A study to investigate potential phytotoxic effects on rooted and floating macrophytes (Myriophyllum spicatum, M. sibiricum, and Lemna gibba) was conducted. Replicate 12,000 L outdoor microcosms (n = 3) were treated with 3, 10, 30, and 100 mg/L of DCA that had been neutralized to the sodium salt, plus controls. Plants were sampled regularly over 21 days and assessed for a variety of endpoints including plant growth, root growth, number of nodes, wet and dry mass, chlorophyll-a, chlorophyll-b, carotenoids, and citrate levels. EC10, EC25, and EC50 values were calculated for each endpoint that exhibited a concentration-response. Overall, M. sibiricum was slightly more sensitive than M. spicatum to DCA exposure. The most sensitive plant endpoints were wet mass and plant length. Pigments showed no response with exposure to DCA. The probability of current concentrations of DCA in Canadian lake water and Swiss river waters exceeding thresholds of toxicity derived from single species effect measure distributions (EC10s) is << 0.01%. The use of effect measure distributions holds promise as a new risk assessment technique for aquatic plants. Currently, environmental levels of DCA do not pose a risk to these plants.
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Affiliation(s)
- Mark L Hanson
- Department of Environmental Biology, Centre for Toxicology, University of Guelph, Ont., N1G 2W1, Guelph, Canada
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24
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Matucha M, Forczek ST, Gryndler M, Uhlírová H, Fuksová K, Schröder P. Trichloroacetic acid in Norway spruce/soil-system. I. Biodegradation in soil. CHEMOSPHERE 2003; 50:303-309. [PMID: 12656249 DOI: 10.1016/s0045-6535(02)00638-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Trichloroacetic acid (TCA) as a phytotoxic substance affects health status of coniferous trees. It is known as a secondary air pollutant (formed by photooxidation of tetrachloroethene and 1,1,1-trichloroethane) and as a product of chlorination of humic substances in soil. Its break-down in soil, however, influences considerably the TCA level, i.e. the extent of TCA uptake by spruce roots. In connection with our investigations of TCA effects on Norway spruce, microbial processes in soil were studied using 14C-labeling. It was shown that TCA degradation in soil is a fast process depending on TCA concentration, soil properties, humidity and temperature. As a result, the TCA level in soil is determined by a steady state between uptake from the atmosphere, formation in soil, leaching and degradation. The process of TCA degradation in soil thus participates significantly in the chlorine cycle in forest ecosystems.
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Affiliation(s)
- M Matucha
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Vídeòska 1083, CZ-14220 Prague, Czech Republic.
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25
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Hanson ML, Sibley PK, Ellis DA, Mabury SA, Muir DCG, Solomon KR. Evaluation of monochloroacetic acid (MCA) degradation and toxicity to Lemna gibba, Myriophyllum spicatum, and Myriophyllum sibiricum in aquatic microcosms. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2002; 61:251-273. [PMID: 12359395 DOI: 10.1016/s0166-445x(02)00089-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The fate of monochloroacetic acid (MCA), a common phytotoxic aquatic contaminant, and its toxicity to the aquatic macrophytes Lemna gibba (L. gibba), Myriophyllum spicatum (M. spicatum), and Myriophyllum sibiricum (M. sibiricum) under semi-natural field conditions was studied. Replicate 12,000 l enclosures were treated with 0, 3, 10, 30 and 100 mg/l of MCA. Each microcosm was stocked with eight individual apical shoots of M. spicatum and M. sibiricum 1 day prior to initiation of exposure. Plants were sampled after 4, 7, 14 and 28 days of exposure and their response assessed using numerous somatic and biochemical endpoints. L. gibba was introduced into the microcosms the day of MCA treatment and monitored regularly for 21 days. The half-life of MCA in the water column ranged between 86 and 523 h. The most sensitive plant species was M. spicatum, followed by M. sibiricum and L. gibba. All species demonstrated toxicity within a threefold range of each other. Endpoint sensitivity varied depending on the duration of exposure and the level of effect chosen. Most species endpoint EC(x) values were less than an order of magnitude different. Citrate levels in Myriophyllum spp. were not influenced by exposure to MCA. The toxicity of MCA to M. spicatum and M. sibiricum was very similar and thus highly predictive of toxicity observed for each other. The EC(10) was a more conservative estimate of toxicity than the statistically derived no observed effect concentration. Current concentrations of MCA are not likely to pose a risk to these aquatic plants in surface waters.
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Affiliation(s)
- Mark L Hanson
- Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
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Abstract
Suppositions that the trichloroacetic acid (TCA, CCl3C(O)OH) found in nature was a consequence solely of the use of chlorinated hydrocarbon solvents prompted this critical review of the literature on its environmental fluxes and occurrences. TCA is widely distributed in forest soils (where it was rarely used as an herbicide) and measurements suggest a soil flux of 160 000 tonnes yr(-1) in European forests alone. TCA is also produced during oxidative water treatment and the global flux could amount to 55 000 tonnes yr(-1) (from pulp and paper manufacture, potable water and cooling water treatments). By contrast, the yields of TCA from chlorinated hydrocarbon solvents are small: from tetrachloroethene 13 600 tonnes yr(-1) and from 1,1,1-trichloroethane 4300 tonnes yr(-1) on a global basis, at the atmospheric burdens and removal rates typical of the late 1990s. TCA is ubiquitous in rainwater and snow. Its concentrations are highly variable and the variations cannot be connected with location or date. However, there is no significant difference between the concentrations found in Chile and in eastern Canada (by the same analysts), or between Malawi and western Canada, or between Antarctica and Switzerland, nor any significant difference globally between the concentrations in cloud, rain and snow (although local enhancement in fog water has been shown). TCA is present in old ice and firn. At the deepest levels, the firn was deposited early in the 19th century, well before the possibility of contamination by industrial production of reactive chlorine, implying a non-industrial background. This proposition is supported by plume measurements from pulp mills in Finland. TCA is ubiquitous in soils; concentrations are very variable but there are some indications that soils under coniferous trees contain higher amounts. The concentrations of TCA found in plant tissue are region-specific and may also be plant-specific, to the extent that conifers seem to contain more than other species. TCA is removed from the environment naturally. There is abundant evidence that soil microorganisms dehalogenate TCA and it is lost from within spruce needles with a half-life of 10 days. There is also recent evidence of an abiotic aqueous decarboxylation mechanism with a half-life of 22 days. The supposedly widespread effects of TCA in conifer needles are not shown in controlled experiments. At concentrations in the needles of Scots pine similar to those observed in needles in forest trees, changes consequent on TCA treatment of field laboratory specimens were almost all insignificant.
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Affiliation(s)
- A McCulloch
- School of Chemistry, University of Bristol, UK.
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27
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Hanson ML, Sibley PK, Mabury SA, Solomon KR, Muir DCG. Trichloroacetic acid (TCA) and trifluoroacetic acid (TFA) mixture toxicity to the macrophytes Myriophyllum spicatum and Myriophyllum sibiricum in aquatic microcosms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2002; 285:247-259. [PMID: 11878273 DOI: 10.1016/s0048-9697(01)00955-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Trichloroacetic acid (TCA) and trifluoroacetic acid (TFA) have been detected together in environmental water samples throughout the world. TCA may enter into aquatic systems via rainout as the degradation product of chlorinated solvents, herbicide use, as a by-product of water disinfection and from emissions of spent bleach liquor of kraft pulp mills. Sources of TFA include degradation of hydrofluorocarbons (HFCs) refrigerants and pesticides. These substances are phytotoxic and widely distributed in aquatic environments. A study to assess the risk of a binary mixture of TCA and TFA to macrophytes in aquatic microcosms was conducted as part of a larger study on haloacetic acids. M. spicatum and M. sibiricum were exposed to 0.1, 1, 3 and 10 mg/l of both TCA and TFA (neutralized with sodium hydroxide) in replicate (n = 3) 12000 l aquatic microcosms for 49 days in an one-way analysis of variance design. Each microcosm was stocked with 14 individual apical shoots per species. The plants were sampled at regular intervals and assessed for the somatic endpoints of plant length, root growth, number of nodes and wet and dry mass and the biochemical endpoints of chlorophyll-a, chlorophyll-b, carotenoid content and citric acid levels. Results indicate that there were statistically significant effects of the TCA/TFA mixture on certain pigment concentrations immediately after the start of exposure (2-7 days), but the plants showed no signs of stress thereafter. These data suggest that TCA/TFA mixtures at environmentally relevant concentrations do not pose a significant risk to these aquatic macrophytes.
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Affiliation(s)
- Mark L Hanson
- Centre for Toxicology, Department of Environmental Biology, University of Guelph, ON, Canada.
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