Article

Are There Other Persistent Organic Pollutants? A Challenge for Environmental Chemists †

Environment Canada, Montréal, Quebec, Canada
Environmental Science and Technology (Impact Factor: 5.33). 04/2007; 40(23):7157-66. DOI: 10.1021/es078000n
Source: PubMed

ABSTRACT

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). "
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    • "Developed societies are characterized by a growing use of chemicals in their urban, industry and agriculture activities (Muir and Howard, 2006; Arnot et al., 2006). Depending on their production volumes, mode of use and properties, chemicals may reach the aquatic environment from both point and non-point sources resulting on a potential threat to the water cycle and the aquatic ecosystems (Vörösmarty et al., 2010). "
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    • "As a result, numerous products are formed about which, in most cases, almost nothing is known at present. These products, due to numerous contaminants present in natural systems, increase the complexity of the problem and are more persistent (Muir and Howard 2006) and/or have different toxicity compared to their parent compounds. Moreover, there has been an increased release of emerging contaminants in air, water, soil, and sediments, which are recognized as pharmaceuticals, personal care products, hormones, disinfectants, surfactants, and their metabolites, nanoparticles, and other organic/inorganic contaminants (Mihranyan et al. 2012;Mukal et al. 2009). "
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