Environmental issues aquatic toxicity

A9.6.4.7 The Nordic Council of Ministers issued a report (Pederson et al, 1995) entitled Environmental Hazard Classification, that includes information on data collection and interpretation, as well as a section (5.2.8) entitled QSAR estimates of water solubility and acute aquatic toxicity . This section also discusses the estimation of physicochemical properties, including log Kow For the sake of classification purposes, estimation methods are recommended for prediction of minimum acute aquatic toxicity, for ...neutral, organic, non-reactive and non-ionizable compounds such as alcohols, ketones, ethers, alkyl, and aryl halides, and can also be used for aromatic hydrocarbons, halogenated aromatic and aliphatic hydrocarbons as well as sulphides and disulphides, as cited in an earlier OECD Guidance Document (OECD, 1995). The Nordic document also includes diskettes for a computerized application of some of these methods. 

Screening smokes, by their intended use, are deliberately released into the environment, albeit in localized and very small amounts. Thus, the possibility for environmental problems, including ecotoxicological issues, needs consideration. Particular aspects that may need to be taken into account include local decontamination, phytotoxicity, effects on domestic and wild animals, avian and aquatic toxicity, contamination of food and drinking water, effects on plant sewage organisms. 

Surfactants are widely used in textiles for a multitude of purposes. Most surfactants eventually find Iheir way into the wet processing wastewater at some point. They are an important contributor to aquatic toxicity, BOD, COD, and TOC in textile wastewater. Finally, there are many types to choose from, and selecting the correct one requires a good understanding of several subtle issues with respect to performance as well as environmental protection. 

Selection of impact categories, category indicators, and characterization models. Impact categories are environmental issues of concern. Some, such as ecotoxicity (terrestrial or aquatic) and human health toxicity, are familiar from the discussion of risk characterization in Section 2.2. Others do not typically enter into environmental risk assessments outside the context of LCA. Such impact... 

Arsenic in aquatic environments is usually more concentrated in sediments and pore water than in the overlying water column (Ahmann et al., 1997 Smedley and Kinniburgh, 2002 Williams, 2001). The most abundant forms of arsenic are arsenate [As(V)] and arsenite [As(III)], but methylated forms can occur in mine-impacted environments (i.e., methylarsenic acid and dimethylarsenic acid) (Smedley and Kinniburgh, 2002) see Chapter 9.02. The principal pathway of arsenic toxicity is through dietary exposure to sediment and suspended particulates by fish, followed by human consumption. Environmental exposure to arsenic is a causal factor in human carcinogenous and other related health issues. Chronic exposure symptoms in humans include hyperkeratosis, hyperpigmentation, skin malignancies, and peripheral arteriosclerosis. Water provides the dominant pathway for arsenic exposure in humans (Williams, 2001). 

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