Absorption organochlorines

Environmental distribution After 40 years of continuous application of DDT to vegetation (80%) and soil (20%), 73% of the total mass present in the environment in December 1990 are stored in soil, 24 % in the ocean, 2 % in vegetation, and less than one percent in the atmosphere (Table 3.2).The high storage in soil is caused by its strong absorptive capacity of organochlorine compounds, which is related to its organic matter content. The only source of DDT and DDE in the ocean is deposition... 

R. P. Moody, B. Nadeau, and I. Chu. In vitro dermal absorption of pesticides VI. In vivo and in vitro comparison of the organochlorine insecticide ddt in rat, guinea pig, pig, human and tissue-cultured skin. Toxicol. In vitro 8 1225-1232 (1994). 

X-ray absorption spectroscopy has revealed the formation of organochlorine compounds from chloride and chloroperoxidase in weathering plant material (172-174). Moreover, this technique has uncovered the bromide-to-organobromine conversion in environmental samples (174). In addition to chloroperoxidase mediated chlorination, the abiotic chlorination in soils and sediments involving the alkylation of halides during Fe(III) oxidation of natural organic phenols in soils and sediments has been discovered (175-177). 

Toxicity The acute oral LD50 and dermal LD50 toxicity of toxaphene in rats are 40 and 600 mg/kg, respectively. Toxaphene is an active nerve poison and interferes with fluxes of cations across nerve cell membranes, which increases neuronal irritability and results in convulsions and seizures. Toxaphene also has been found to damage the lungs, liver, and kidney of animals and humans. Although the dermal adsorption efficiency of toxaphene is less than that of other organochlorines, its absorption is enhanced by fat and fat solvents. Toxaphene has been shown to cause cancer in pregnant animals and to induce birth defects.68... 

Gobas FAPC, McCorquodale JR, Haffner GD. 1993. Intestinal absorption and biomagnification of organochlorines. Environ Toxicol Chem 12 567-576. 

Fig. 4.29. Extraction-time profile curves (signal height versus absorption time) for organochlorine pesticides in aqueous solutions. Conditions spiking level 0.2-1.2 ng/ml polydimethylsiloxane fibre length 100 pm magnetic stirring rate 250 rpm. Although equilibrium was not reached for some analytes, the extraction time was chosen to be 15 min. ( ) a-hexachlorocyclohexane, ( ) /3-hexa-chlorocyclohexane, (A) dieldrin, (x) aldrin, (O) 4,4 -DDT, ( ) 4,4 -DDE, ( + ) 4,4 -DDD and ( ) endosulfan sulphate. (Reproduced with permission of Elsevier.)...

Heptachlor is readily absorbed from the gastrointestinal tract, respiratory tract, and skin. As is the case with other organochlorine insecticides, the rate of absorption from the gastrointestinal tract is affected by fiber and fat content in the diet, with a lack of these favoring increased absorption. 

Dietary lipids play a unique role in the toxicity of chlorinated hydrocarbon pesticides. Dietary lipids may favor more absorption of these pesticides, but once these chemicals are absorbed into the body, they may be stored in the adipose tissue without manifestation of toxicity. For this reason, obesity in humans is considered protective against chronic toxicity of these chemicals. Similarly, the body fat in a well-fed animal is known to store organochlorine pesticides. Fat mammals, fish, and birds are thus more resistant to DDT poisoning than their thinner counterparts. In times of food deprivation, however, organic materials such as DDT and PCB can be mobilized from mammalian fat deposits and can reach concentrations potentially toxic to the animal. 

OTHER COMMENTS substance is a mixture of alpha isomer (melting point 108-110°C) and beta isomer (melting point 208-210°C) carrier solvents used in commercial formulations may change physical and toxicological properties high toxic organochlorine pesticide that does not accumulate significantly in human tissue absorption is usually increased by alcohols, oil, and emulsifiers. 

Organochlorinated Tunable dye laser absorption spectrometry Water Detection limits 10 -10 V99 ... 

Absorption. Because they are lipid-soiubie, the organochlorines are readily absorbed by the skin and mucous membranes. Inhalation does not pose a significant problem because the organochlorines are not highly volatile. 

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