Are There Other Persistent Organic Pollutants? A Challenge for Environmental Chemists †
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.
Available from: Graham Whale
- "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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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.
Available from: Maja Kuzmanovic
- "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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ABSTRACT: Starting from measured river concentrations, emission factors of 158 organic compounds out of 199 analyzed belonging to different groups of priority and emerging contaminants [pesticides (25), pharmaceuticals and hormones (81), perfluoroalkyl substances (PFASs) (18), industrial compounds (12), drugs of abuse (8) and personal care products (14)] have been estimated by inverse modeling. The Llobregat river was taken as case study representative of Mediterranean rivers. Industrial compounds and pharmaceuticals are the dominant groups (range of 10(4)mg·1000inhab(-1)·d(-1)). Personal care products, pesticides, PFASs and illegal drugs showed a load approximately one order of magnitude smaller. Considered on a single compound basis industrial compounds still dominate (range of ca. 10(3)mg·1000inhab(-1)·d(-1)) over other classes. Generally, the results are within the range when compared to previously published estimations for other river basins. River attenuation expressed as the percentage fraction of microcontaminants eliminated was quantified. On average they were around 60-70% of the amount discharged for all classes, except for PFASs, that are poorly eliminated (ca. 20% on average). Uncertainties associated with the calculated emissions have been estimated by Monte-Carlo methods (15,000 runs) and typically show coefficients of variation of ca. 120%. Sensitivities associated with the various variables involved in the calculations (river discharge, river length, concentration, elimination constant, hydraulic travel time and river velocity) have been assessed as well. For the intervals chosen for the different variables, all show sensitivities exceeding unity (1.14 to 3.43), tending to amplify the variation of the emission. River velocity and basin length showed the highest sensitivity value. Even considering the limitations of the approach used, inverse modeling can provide a useful tool for management purposes facilitating the quantification of release rates of chemicals into the aquatic environment.
Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.
Available from: Maximiliano Cledón
- "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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ABSTRACT: Industrial revolution has led to the introduction of innumerable contaminants into the environment via industrial, agricultural, and household applications. In particular, engineered nanoparticles (ENPs), which are emerging in the natural environment and being transported in the environment, may have a significant effect on ecosystems, even though they may only be present at low concentrations. Nanotechnology is going to play a major role which will be responsible for the release of ENPs in the environmental matrices and thus has led to increased focus on environmental research for the betterment of human society. Despite widespread applications of ENPs, in recent years, their hazardous effects on the air, water, soil, and sediments have been studied, which directly impact human health. Hence, to evaluate their persistence and understand the mechanisms that affect their fate, it is necessary to obtain realistic impact due to significant concentration of ENPs. The application of analytical techniques, such as ultraviolet (UV) spectroscopy, nuclear magnetic resonance (NMR), and ICP-MS, for the detection of ENPs in the natural environment is thus the heart of environmental research. The present review highlights the conjunction of sampling and separation tools with analytical techniques for detection and analysis of ENPs in the natural environment.
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