Environmental toxicants’ effects

Compound Class or Principal Use Human Toxic Effects Environmental Toxic Effects... 

Gore AC (2001) Environmental toxicant effects on neuroendocrine function. Endocrine 14(2) 235-246. 

New information is constantly forthcoming. For example, approximately 600-700 DBFs have been identified in drinking water disinfected by chlorine, ozone, chlorine dioxide, chloramines, and their combinations, with new ones being discovered all the time [16]. Such complexity demonstrates the difficulty associated with trying to ascribe the causes of environmental toxic effects when people come down with strange illnesses and reactions. An example is increased rates of spontaneous abortions in women who drink water with elevated levels of THMs and other DBFs (Chapters 8 and 23). The mixture possibilities in disinfected water, for example, are endless and the exact causes of toxic consequences are extremely difficult to pin down. 

The acute toxicity of ester sulfonates is mainly related to the length of the carbon chain of the fatty acid. The acute fish toxicity of tallow-based ester sulfonates is relatively high (LC0 = 0.4-0.9 mg/L) compared with coconut-based ester sulfonates (LC0 — 46 mg/L) [113]. In spite of this relatively high fish toxicity of the long-chain ester sulfonates both acute and long-term toxic effects can be excluded for normal environmental conditions. For example, the sum of all anionic surfactants in German rivers is stable on a level far below... 

CAS = Chemical Abstracts Services DOT/UN/NA/IMCO = Department of Transportation/United Nations/North America/International Maritime Dangerous Goods Code EPA = Environmental Protection Agency HSDB = Hazardous Substance Data Bank NCI = National Cancer Institute NIOSH = National Institute for Occupational Safety and Health OHM/TADS = Oil and Hazardous Materials/Technical Assistance Data System RTECS = Registry of Toxic Effects of Chemical Substances... 

Another issue is the development and refinement of the testing protocols used in mesocosms. Mesocosms could have a more important role in environmental risk assessment if the data coming from them could be better interpreted. The use of biomarker assays to establish toxic effects and, where necessary, relate them to effects produced by chemicals in the field, might be a way forward. The issues raised in this section will be returned to in Chapter 17, after consideration of the individual examples given in Part 2. 

Thus, as with studies on the double-crested cormorant in the Great Lakes (see Chapter 16 in Walker et al. 2006), there is evidence of a continuing (although reduced) effect of p,p -DDE on reproductive success even after environmental levels had fallen and eggshell thinning was much less. This raises the possibility that p,p -DDE may have had toxic effects other than eggshell thinning on these species (Nisbet 1989). There is the further complication that other OCs such as PCBs, dieldrin, and hep-tachlor epoxide were present in the same samples and may have had toxic effects. 

A central theme of this text is the development of biomarker assays to measure the extent of toxic effects caused by chemicals both in the field studies and for the purposes of environmental risk assessment. 

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