Conservatism in pesticide exposure assessment

Three important factors are commonly encountered in exposure assessment tha t when combined could overestimate the exposure to pesticides by as much as two orders of magnitude. The three factors discussed are dermal absorption from laboratory animal studies, daily dose extrapolated from partial day m onitoring, and nonbolus dose from dermal or inhalation exposure. Conservati sm built into the process by each of these three factors is substantiated w ith available empirical data. The dose overestimation from these factors va ries discriminatively by exposure scenarios and peculiarities of a given ch emical, it is for this reason that a generic overestimation factor cannot b e ascribed. Following the empirical illustrations, the authors conclude tha t the most effective approach for dealing with the problem is to generate t he most appropriate data possible. This means producing human rather than l aboratory animal dermal absorption data, conducting full-day exposure monit oring studies, and whenever feasible generating dermal rather than oral tox icology data (or alternatively data on both oral and dermal pharmacokinetic s) in those cases where the dermal route predominates, (C) 2000 Academic Pr ess.