Chlorine biological effects

Elliott, J.E., Wilson, L.K., and Henny, C.J. et al. (2001). Assessment of biological effects of chlorinated hydrocarbons in osprey chicks. Environmental Toxicology and Chemistry 20, 866-879. 

Although the effects of chronic exposure of humans to low levels of POPs are difficult to predict, some biological effects have been described. For example, exposure of children to PCBs and PCDD/Fs may be linked to an elevated risk for infectious diseases. Exposure of pregnant women to PCDD/Fs may cause lower fertility in their male offspring. The adverse effects to human health of acute and chronic exposure of high concentrations of POPs, especially among industrial workers exposed to daily intakes of chemicals, are more evident. Elevated concentrations of DDE and TCDD have been associated with the development of cancers such as breast cancer, leukaemia and thyroid cancer. Dioxin exposure may also be associated with immunotoxicity, reproductive diseases and neurotoxicity. Extreme exposure to chlorinated compounds has resulted in death [101]. 

Deaths of target organisms associated with intentional pesticide applications to insect-infested crops, weed-choked roadsides, and nematode-laced fields are predictable, desirable, and relatively easy to measure. Likewise, catastropic releases of chlorine from ruptured tank cars or of crude oil from scuttled supertankers may produce a spectrum of biological effects including toxicity. These events are easily associated with exposures to toxic substances and particular environmental circumstances. 

Committee on Medical and Biological Effects of Environmental Pollutants, National Research Council Chlorine and Hydrogen Chloride, pp 116-123. Washington, DC, National Academy of Sciences, 1976... 

These chemicals have received intense international attention in recent years because of their ubiquity, persistence, high bioaccumulation potential and harmful biological effects. Under the Stockholm Convention on POPs (see Chapter 1), 12 chlorinated chemical substances have been banned or severely restricted. These include dioxins and furans (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans, PCDD/Fs),... 

Watanabe Y. 1983. [Studies on biological effects of hydrocarbons. III. Chlorinated hydrocarbons]. Kanagawa-ken Taiki Osen Chosa Kenkyu Hokoku 25 146-152. (Japanese). 

The most common use of chlorine in sewage treatment is for disinfection, which usually is the last treatment step in a secondary biological wastewater treatment plant. Where the treated secondary effluent is fed into a stream to be used for water supply or for recreational purposes, chlorination is effective in destroying the disease-producing pathogens found in treated wastewater. Other principal uses of chlorine are odor control and control of bulking in activated sludge. 

The gas-phase chemistry reviewed in this chapter shows how the pattern of substitution of chlorine and fluorine atoms on the parent hydrocarbon affects its atmospheric degradation. Although numerous reaction details need to be investigated and some discrepancies resolved, a core of reliable data is available from which one can deduce which HFC or HCFC may have deleterious atmospheric consequences and which potential substitute appears environmentally acceptable. However, the work is not finished. This work has dealt only with the gas-phase chemistry. Research is still needed into the heterogeneous chemistry of HFC and HCFC degradation products and into the biological effects that they may have. It is then up to the atmospheric modelers to combine this scientific information with emission scenarios and meterology to ascertain the feasibility of a particular CFC substitute. 

Fiedler, H. C. Lau, 1998. Transformation of chlorinated xenobiotics in the environment. In Schu-urmann, G. B. Marker (eds.) Ecotoxicology Ecological Fundamentals, Chemical Exposure and Biological Effects. John Wiley and Sons, New York, 900 pp. 

While 2-chlorohexadecanal is produced in both atherosclerotic lesions and infarcted myocardium, it remains to be seen whether this aldehyde gives rise to chlorinated lipid metabolites as well as the putative incorporation of chlorinated aliphatic groups into complex lipids including triglycerides, phospholipids, and cholesteryl esters. Furthermore, these metabolites need to be assessed in experiments designed to demonstrate biological effects of a-chlorofatty aldehyde. 

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