Are There Other Persistent Organic Pollutants? A Challenge for Environmental Chemists †
Environment Canada, Montréal, Quebec, CanadaEnvironmental Science and Technology (Impact Factor: 5.33). 04/2007; 40(23):7157-66. DOI: 10.1021/es078000n
The past 5 years have seen some major successes in terms of global measurement and regulation of persistent, bioaccumulative, and toxic (PB&T) chemicals and persistent organic pollutants (POPs). The Stockholm Convention, a global agreement on POPs, came into force in 2004. There has been a major expansion of measurements and risk assessments of new chemical contaminants in the global environment, particularly brominated diphenyl ethers and perfluorinated alkyl acids. However, the list of chemicals measured represents only a small fraction of the approximately 30,000 chemicals widely used in commerce (>1 t/y). The vast majority of existing and new chemical substances in commerce are not monitored in environmental media. Assessment and screening of thousands of existing chemicals in commerce in the United States, Europe, and Canada have yielded lists of potentially persistent and bioaccumulative chemicals. Here we review recent screening and categorization studies of chemicals in commerce and address the question of whether there is now sufficient information to permit a broader array of chemicals to be determined in environmental matrices. For example, Environment Canada's recent categorization of the Domestic (existing) Substances list, using a wide array of quantitative structure activity relationships for PB&T characteristics, has identified about 5.5% of 11,317 substances as meeting P & B criteria. Using data from the Environment Canada categorization, we have listed, for discussion purposes, 30 chemicals with high predicted bioconcentration and low rate of biodegradation and 28 with long range atmospheric transport potential based on predicted atmospheric oxidation half-lives >2 days and log air-water partition coefficients > or =5 and < or =1. These chemicals are a diverse group including halogenated organics, cyclic siloxanes, and substituted aromatics. Some of these chemicals and their transformation products may be candidates for future environmental monitoring. However, to improve these predictions data on emissions from end use are needed to refine environmental fate predictions, and analytical methods may need to be developed.
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- "www.congress.gov/bill/113th- congress/house-bill/4148). The benefits of applying 3Rs approaches in ecotoxicology are potentially far reaching, particularly considering the large numbers of substances requiring approval to sell worldwide (Muir and Howard 2006). "
ABSTRACT: The ecotoxicity testing of chemicals for prospective environmental safety assessment is an area where a high number of vertebrates are used across a variety of industry sectors. Refining, reducing and replacing the use of animals such as fish, birds and amphibians for this purpose addresses the ethical concerns and the increasing legislative requirements to consider alternative test methods. Members of the UK-based National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) Ecotoxicology Working Group, consisting of representatives from academia, government organisations and industry, have worked together over the past six years to provide evidence bases to support and advance the application of the 3Rs in regulatory ecotoxicity testing. The group recently held a workshop to identify the areas of testing, demands and drivers that will impact on the future of animal use in regulatory ecotoxicology. As a result of these discussions we have developed a pragmatic approach to prioritise and realistically address key opportunity areas, to enable progress towards the vision of a reduced reliance on the use of animals in this area of testing. This paper summarises the findings of this exercise and proposes a pragmatic strategy towards our key long-term goals - the incorporation of reliable alternatives to whole organism testing into regulations and guidance, and a culture shift towards the reduced reliance on vertebrate toxicity testing in routine environmental safety assessment. This article is protected by copyright. All rights reserved.Integrated Environmental Assessment and Management 10/2015; DOI:10.1002/ieam.1703 · 1.38 Impact Factor
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- "Among the different types of FRs, brominated flame retardants (BFRs) constitute approximately 20–25% by volume of the global FR production . Several BFRs are bioaccumulative, persistent and some are also included in the long-range atmospheric transport (LRAT) potential group  . Due to this, BFRs are found in measurable quantities in the environment, in wildlife and in humans  . "
ABSTRACT: The brominated flame retardants (BFRs) 1,2-Dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH or DBE-DCBH) and allyl 2,4,6-tribromophenyl ether (ATE or TBP-AE) are alternative BFRs that have been introduced to replace banned BFRs. TBECH is a potential endocrine disrupter in human, chicken and zebrafish and in a recent study we showed that ATE, along with the structurally similar BFR 2,3-dibromopropyl 2,4,6-tribromophenyl ether (DPTE or TBP-DBPE) and its metabolite 2-bromoallyl 2,4,6-tribromophenyl ether (BATE or TBP-BAE) and are potential endocrine and neuronal disrupters in human. In this study we analyzed ATE, BATE and DPTE for zebrafish androgen receptor (zAR) modulating properties. In silico analysis with two softwares, Molecular Operating Environment (MOE) and Internal Coordinate Mechanics (ICM), showed that ATE, BATE and DPTE bind to zAR. In vitro activation assay revealed that these three BFRs down-regulate 11-ketotestosterone (KT) mediated zAR activation. Exposure to 10 μM DPTE resulted in reduced hatching success and like TBECH, BATE and DPTE at 10 μM also had teratogenic properties with 20% and 50% back-bone curvature respectively. Transcript analysis in zebrafish embryos as well as in juveniles showed down-regulation of the androgen receptor and androgen response genes, which further support that these BFRs are androgen antagonists and potential endocrine disrupting compounds. Genes involved in steroidogenesis were also down-regulated by these BFRs. In view of this, the impact of these BFRs on humans and wildlife needs further analysis. Copyright © 2015. Published by Elsevier Ireland Ltd.Chemico-biological interactions 03/2015; 37. DOI:10.1016/j.cbi.2015.03.023 · 2.58 Impact Factor
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- "In this regard, human biomonitoring (HBM) is a very useful assessment tool for evaluating exposure to chemicals present in the environment and consequently, represents the rationale for prevention measures (NHANES IV, 2009; Muir and Howard, 2006; Zhou and Huang, 2001; Esteban and Castaño, 2009). For this reason, there has been an increase in HBM studies as a consequence of risks and effects on human health when exposed to those contaminants. "
ABSTRACT: The aim of this study was to evaluate the deoxyribonucleic acid (DNA) damage (as a biomarker of biological effects) in children living in areas at high risk of contamination in Mexico using the comet assay. The alkaline comet assay was performed in order to assess DNA damage levels in blood cells of 276 children living in eleven communities in four states of Mexico. Moreover, levels of arsenic and 1-hydroxypyrene (1-OHP) in urine and lead and total DDT [sum of 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE) and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT)] in blood were quantified. We found urinary 1-OHP levels between <LOD and 14.5μmol/mol creatinine; for arsenic, the urinary levels were 3.5-180μg/g creatinine (range). Lead levels in blood ranged from 0.5 to 24μg/dL and finally, the levels of total DDT (DDE and DDT) ranged from <LOD to 32,000ng/g lipid. Regarding DNA damage (comet assay), the most important finding in our study was that children exposed to a chemical mixture [high levels of exposure to polycyclic aromatic hydrocarbons (PAHs) and DDT were found] had the significant highest DNA damage level (p<0.05) in their blood cells (olive tail moment=7.5±3.5), when compared with DNA damage levels in children living in the other scenarios assessed in this work. Finally, significant correlations were observed between urinary arsenic levels (r=0.32, p<0.05); urinary 1-OHP levels (r=0.65, p<0.01); total DDT in blood levels (r=0.59, p<0.01) and DNA damage. In conclusion, the data indicates that children living in areas which are at high risk of contamination showed high levels of biomarkers of exposure in urine or blood. Moreover, the exposure levels contribute to DNA damage and suggest an increased health risk in studied sites at risk of great pollution. Copyright © 2015 Elsevier B.V. All rights reserved.Science of The Total Environment 03/2015; 518-519C:38-48. DOI:10.1016/j.scitotenv.2015.02.073 · 4.10 Impact Factor
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