Organochlorine compounds pesticides

Technical chlordane is an organochlorine compound first introduced into the United States in 1947 in a variety of formulations for use as a broad-spectrum pesticide. By 1974, about 9.5 million kg of chlordane were being produced annually. Concern over the potential carcinogenicity of chlordane has led to sharply curtailed production. Since 1983, chlordane use in the United States has been prohibited, except for control of underground termites. 

GC is coupled with many detectors for the analysis of pesticides in wastewater. At the present time the most popular is GC-MS, which will be discussed in more detail later in this section. The flame ionization detector (FID) is another nonselective detector that identifies compounds containing carbon but does not give specific information on chemical structure (but is often used for quantification because of the linear response and sensitivity). Other detectors are specific and only detect certain species or groups of pesticides. They include electron capture,nitrogen-phosphorus, thermionic specific, and flame photometric detectors. The electron capture detector (ECD) is very sensitive to chlorinated organic pesticides, such as the organochlorine compounds (OCs, DDT, dieldrin, etc.). It has a long history of use in many environmental methods,... 

The specific mechanism by which chlordecone is transferred from the gut, lungs, or skin to the blood is not known. However, the preferential distribution of chlordecone to the liver rather than the fat tissues suggests that it may be transported in the plasma differently from other organochlorine compounds (Soine et al. 1982). In vitro and in vivo studies of human, rat, and pig plasma showed that chlordecone is preferentially bound by albumin and high-density lipoproteins (HDL), which may explain its tissue distribution. Other organochlorine pesticides such as aldrin and dieldrin bind to very-low-density lipoproteins (VLDL) and low-density lipoproteins (LDL) and distribute preferentially to fat (Soine et al. 1982). 

PolishukZW, Ron M, Wassermann M, et al. 1977b. Pesticides in people Organochlorine compounds in human blood plasma and milk. Pestic Monit J 10(4) 121-129. 

Protection of water sources is critical to economic viability as well as to human and environmental health. This has been evident for many decades, but just in the 1980s, the European Community started to adopt legislative measures to evaluate and preserve groundwater and also to implement bans on pesticides which at first concerned mainly persistent organochlorine compounds. Along the years, various European Community Directives have addressed these issues in the European Union, among them ... 

G. Liljegren et al., Case-control Study on Breast Cancer and Adipose Tissue Concentrations of Congener Specific Polychlorinated Biphenyls, DDE and Hexachlorobenzene, Eur. J. Cancer Prev. 7 (1998) 155-40 R. J. Helzlsouer et al., Serum Concentrations of Organochlorine Compounds and the Subsequent Development of Breast Cancer, Cancer Epidemiol. Biomarkers. Prev. 8 (1999) 525-52 J. F. Dorgan, Serum Organochlorine Pesticides and PCBs and Breast Cancer Risk Results from a Prospective Analysis, Cancer Causes and Control 10 (1999) 1-11 G. A. S. Mendonca et al., Organochlorines and Breast Cancer a Case-control Study in Brazil, Int. 

Several intermediates have been identified in the process of pesticide degradation, unlike degradation of volatile organochlorine compounds. Stability... 

Many organochlorine pesticides (OCPs), which have shown undesirable effects in humans and the environment, have been banned in developed countries. Even so, OCPs deserve particular attention, for they are very stable and can accumulate in food chains (9). Products of animal origin as well as human mother s milk almost always contain residues of organochlorine compounds. The residue content of this milk is 10-30 times higher than that of cow s milk (10,11). 

Hylin JW, Spenger RE, Gunther FA (1969) Potential Interferences in Certain Pesticide Residue Analyses from Organochlorine Compounds Occurring Naturally in Plants. Residue Rev 26 127... 

Pesticides are also a major source of concern as water and soil pollutants. Because of their stability and persistence, the most hazardous pesticides are the organochlorine compounds such as DDT, aldrin, dieldrin, and chlordane. Persistent pesticides can accumulate in food chains for example, shrimp and fish can concentrate some pesticides as much as 1000- to 10,000-fold. This bioaccumulation has been well documented with the pesticide DDT, which is now banned in many parts of the world. In contrast to the persistent insecticides, the organophosphorus (OP) pesticides, such as malathion, and the carbamates, such as carbaryl, are short-lived and generally persist for only a few weeks to a few months. Thus these compounds do not usually present as serious a problem as the earlier insecticides. Herbicides, because of the large quantity used, are also of concern as potential toxic pollutants. Pesticides are discussed in more detail in Chapter 5. 

Log-log plots of the particle/gas partition coefficient (Kp) for PAHs (top) and organochlorine compounds (PCBs, pesticides) (bottom) vs. the octanol-air partition coefficient (Koa). Points denote individual field studies. Figures and data from Finizio et al. (1997). 

The phenomenal success of DDT stimulated further research, and by 1946 the two DDT analogs, DDD and methoxychlor (Table 1,A) had been produced (Tables are at the end of the chapter). The observation of greater insecticidal activity in those organochlorine compounds that lose their HC1 more easily led to yet another group of chlorinated derivatives, the condensed ring chlorocyclodienes (Table 1,B). Thus, nearly all of the chlorinated pesticides currently in use had been... 

Persistent organic pollutants (POPs) are organochlorine compounds widely used as pesticides and/or industrial chemicals. These chemicals share four common properties highly toxic, persistent, capable of long-range transport and bio-accumulation in the fatty tissues of living... 

Because of the high and similar values of the rate constants, it is said that these free radicals react nonselectively with the organic matter present in water, although, as deduced from the above range of values, there are compounds that react with them almost three orders of magnitude faster than others. Among the most common water pollutants, phenols and some pesticides are substances that react rapidly with hydroxyl radicals, whereas some organochlorine compounds are less reactive. 

The treatment is effective for decomposing organochlorinated compounds such as trichloroethylene (TCE), tetrachloroethylene, etc. It is excellent for the post-treatment of water submitted to disinfection treatments with chlorine or chlorine dioxide because it can decompose THM or related compounds. One of the principal fields of application is in the degradation of pesticides [45]. 

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