Persistent toxic substances emission

The WFD, so far, has identified 33 priority hazardous pollutants (PHS), for which Environmental Quality Standards (EQS) have been set. To some extent, these EQS can be met through the establishment of emission control measures. These PHS may originate from several different sources and activities. The main sources of toxic substances to water bodies in Europe may be categorised as agriculture, sewage treatment plants, urban runoff, industry, contaminated lake/ river sediment, soils and landfills. Input via atmospheric transport and deposition has also been identified as an important source both far from and close to source areas. Many of the PS are today banned in Europe, but due to their persistence they are still present in the environment [30]. 

A voluntary programme coordinated by Environment Canada to encourage mills to reduce/eliminate emissions to the environment of persistent, bio-accumulative and/or toxic substances. 

It is now obvious that atmospheric transport of persistent toxic organic substances is the major pathway between ecosystems. For dioxin, volatilization of residues from contaminated soils was first noted as a concern at Seveso, Italy (4). The National Research Council of Canada reported that atmospheric emissions were the major source of chlorinated dioxins in the Canadian environment (5). A recent Ontario report estimates that from 8 10 kg of 2,3,7,8 -TCDD equivalents enter the Ontario environment annually from combustion of municipal refuse and sewage sludge and that all other combustion sources contribute from 20 -50 kg annually (6). The only other major source considered was from the use and disposal of chlorinated phenols. 

Abstract Phthalates are chemicals that have been used for over 80 years in large quantities due to their wide range of applications, mainly in the plastic industry. For many years, these compounds were not considered dangerous for humans due to their low toxicity shown in the preliminary studies and their low persistence. However, research conducted in recent years has evidenced their activity as endocrine disrupters, and they are now considered as emerging contaminants and included in the priority list of dangerous substances in the legislation of many countries. This chapter provides an overview on the properties, major uses, emission sources, environmental and human levels, current legislation, behavior and fate of phthalates, and their metabolites, with special emphasis on their toxicity and human exposure. 

The toxicity, bioaccumulative potential, and ecological impact of organohalogenated substances such as polychlorinated biphenyls (PCBs), polychlorinated dibenzofurans (PCDFs), polychlorinated d iben zo -pa ra - diox i n s (PCDDs), or polybrominated diphenylethers (PBDEs) have been extensively reviewed.95 98 All are referred to as persistent organic pollutants (POPs), that is, chemical substances that remain in the environment, bioaccumulate through the food chain, and pose a risk to human health and the environment. The international community is calling for action to reduce and then eliminate the production or formation of these substances and to monitor their emission. In this case, the detectability obtainable by analytical methods should be very low, since the limits established for these residues are in the ng per liter range. 

The Stockholm Convention (UNEP 2009a) entered into force in 2004, restricting 12 persistent and bio-accumulating toxic chemicals. An additional 9 substances were included in 2009. In coming decades, the major issue under the convention will be the reduction of emissions of dioxins and furans from combustion. 

The conventional approach to controlling releases of hazardous substances involves establishing safe levels for specific substances that allow environmental quality objectives and associated standards to be set and licence conditions or fixed emission limits to be determined. Environmental safe levels take account of the toxicity of the substance, its persistence and ability to bioaccumulate, and in some cases can include mutagenicity, carcinogenicity and reproductive impairment. Whitehouse and Cartwright (1998) discuss the need for environmental standards and identify the following purposes ... 

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