[Experimental model for the risk from multiple exposures to antiparasitic agents and residues from the food preservation process].
The human environmental hazard in the last ten years is the most important problem for public health and prevention. Particularly, in agriculture, the continuous use of increased quantities of pesticides and nitroso compounds, such as fertilizers, is involved. The evaluation of exposure risk is complex because of A: --a1) the numerous categories of chemical substances used as pesticides. --a2) the different catabolic pathways that are followed by organisms for detoxification. B: the different categories of exposed people such as: --b1) industrial workers who are exposed to a single compound, in time; --b2) agricultural workers whose exposure is multiple, prolonged over time, and often, even at high doses; --b3) general population whose exposure is from residues from the food chain. C: different kinds of exposure: --c1) accidental, acute and massive, the most studied; --c2) chronic exposure, the most difficult to quantity and of which we do not have any chemical features available, nor do we have parameters or sensitive or specific exposure indexes. The complexity of exposure and the difficulty to derive adequate indexes both in rural environments and in the general population, explains why there are no existing regulation parameters regarding exposure of agricultural workers where as they exist for industrial workers (MAC and TLV). When it is not possible to evaluate the quantity of substances that are used and absorbed during the work shift, it is necessary to revert to effect index measurements. On one hand these refer to the chemical nature of the substances employed and to the knowledge regarding the catabolism that, from the compound, brings about metabolic inactivation, and on the other hand refers to metabolic modification which is easily measured with blood tests and urinalysis. For example urinary metabolites of substances assumed through various ways (DichloroDiphenyl Acetic Acid-DDA-) and DDT or modifications of enzymes activity e.g. cholinesterasis following the manipulation of phosphoric compounds or alkaline phosphatasis from dithiocarbamates. Our experimental testing found that the systematic reduction of enzymes activity in serum of workers exposed to dithiocarbamates cannot be explained exclusively considering the chelating action of dithiocarbammates. In fact the chelating of zinc, a metal which is present in the prosthetic group of alkaline phosphatasis, can be carried out placing the serum enzymes in the presence of growing concentrations of dithiocarbamates. The concentration of dithiocarbamates that is able to determine the complete inactivation of the enzymes is high, equal to 8 mg/ml.(ABSTRACT TRUNCATED AT 400 WORDS)
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D000818:Animals; D004347:Drug Interactions; D004789:Enzyme Activation / Q000187:drug effects; D005506:Food Contamination; D005520:Food Preservatives / Q000494:pharmacology; D008099:Liver / Q000201:enzymology; D008297:Male; D009929:Organ Size / Q000187:drug effects; D010573:Pesticide Residues; D010575:Pesticides / Q000494:pharmacology; D011817:Rabbits; D012306:Risk
D005520:Food Preservatives; D010573:Pesticide Residues; D010575:Pesticides
Un modello sperimentale per la valutazione del rischio da esposizione multipla ad antiparassitari ed a residui di processo conserviero-alimentare.