Refinement of risk assessment of dermally and intermittently exposed pesticide workers: a critique.

The regulatory requirements for the registration of pesticides are mainly evolved from concern about dietary exposure and risk, i.e. chronic oral exposure. Pesticide workers, however, are predominantly exposed dermally and intermittently. The present critique provides suggestions for improvement of toxicity studies to refine the risk assessment of pesticide workers. In this respect it is considered of utmost importance that toxicity studies (either toxicokinetic or toxicodynamic) should be tuned towards the anticipated exposure scenario. Apart from suggestions for improvement of dermal toxicokinetic and dynamic studies, recommendations for further research and guidance are given, amongst which the request for information on the robustness of in vitro dermal absorption studies and guidance on how to use these data. With respect to the intermittent exposure of pesticide workers it is recognised that both information on the anticipated exposure scenario as well as knowledge on the effect of intermittent exposure on the toxicity are needed. From a toxicological point of view, the setting of more than one Acceptable Operator Exposure Level (AOEL), covering effects that may arise after different periods of exposure, as well as the development of more robust acute and short term studies are strongly recommended.