DERMAL-ORAL TOXICITY RELATION AT RISK ASSESSMENT OF DERMAL EXPOSURE TO PESTICIDES

Y.I. Kundiev, V.V. Kirsenko, T.A. Yastrub

The substantiation of acceptable exposure level under different routes of administration into the body is the binding component of the risk assessment of dangerous exposure to pesti-cides in the workplace. At insufficiency of the experimental data on dermal absorption of pesti-cides for application in operator exposure models the results of experiments per os with correct-ing coefficient — "the factor of dermal absorption" (AF) or "dermal-oral coefficient" (DOK) are used. As usually AF (DOK) meaning is 0,1 and shows a ratio of effective amounts of toxic sub-stance at dermal to oral administration. The analysis of such ratio for many of the modern pesti-cides with dermal toxicity (148 from 730, registered in the different countries over the world) has shown that in overwhelming majority of cases the value AF considerably exceeds 0,1: in 60 % cases they are between 0,1—1,0, and in 10 % — < 1. The analysis of allocation of AF values among the most spread classes of pesticides (organophosphorus, synthetic pyrethroid, derivatives of aryloxialkancarbonic acids, etc.) has shown, that average value of AF = 0,6 is the most rea-sonable for all classes of pesticides and there is no necessity to differentiate them between these classes; at the same time, on the contrary, the analysis of allocation of AF values among pesti-cides of different hazard classes, has proved the expedience to accept the value AF = 1,0 for the very toxic pesticides (I hazard class). The different risk assessment values of operator dermal exposure to some pesticides (e.g. "Punch, 40 % EC", "Tanos, WG" and "Sumilex, 50 % WP") resulting from different AF meaning are shown.

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