Chlorinated Hydrocarbons and Pyrethrins/Pyrethroids

Publisher Summary This chapter discusses chlorinated hydrocarbons and pyrethrins/pyrethroids. Chlorinated hydrocarbon insecticides were heavily used after their introduction, but due to ecological considerations, have been banned in most countries for the past three decades. There is an increasing concern that chlorinated hydrocarbon and pyrethroid insecticides produced reproductive and developmental toxicity. There is evidence suggesting that effects of the pyrethroids on dopaminergic nerve pathways may be a contributory factor in the etiology of environmentally induced Parkinson's disease. Pyrethroids (synthetic pyrethrins) are one of the important groups of insecticides, with low mammalian toxicity and rapid rate of degradation, are used widely as insecticides both in the house and in agriculture, and in medicine for the topical treatment of external parasites. The characterization of toxicokinetic profiles of insecticides including absorption, distribution, metabolism and excretion is important in evaluating their dosimetry, biological response and risk assessment in human beings exposed to these compounds. Due to their high lipid solubility, chlorinated hydrocarbon insecticides can be absorbed orally and topically and may undergo chemical or biochemical transformations by various mechanisms. The acute toxic signs associated with DDT and chlorinated benzene types of insecticides include paresthesia of the tongue, lips and face, apprehension, tremors and convulsions. Stimulation of the central nervous system is the most prominent effect. This chapter explains the risk assessment of this exposure which includes four steps: hazard identification, dose–response, assessments, exposure estimates and risk characterization. It also throws some light on the treatment options on the exposure of chlorinated hydrocarbons and pyrethrins/pyrethroids