Could pesticide toxicology studies be more relevant to occupational risk assessment?

Pesticide toxicology study design has evolved from concern for oral exposur e via food residues. The emphasis on the oral route does not generally appl y to workers that are exposed primarily via the dermal route either handlin g pesticides or re-entering treated fields. As a result numerous assumption s about how oral toxicology results relate to dermal exposure must be made when conducting worker risk assessments. These assumptions introduce a high degree of uncertainty. Alternative toxicology study designs are suggested to reduce uncertainty when assessing risk. Because the dermal route is so i mportant to chararterizing occupational risk, methods to improve the accura cy of dermal absorption estimates are suggested, including the use of human subjects to study dermal absorption, Additional suggestions include tailor ing dermal, oral and inhalation kinetic study designs to reflect worker exp osure dosages, Suggestions are made to routinely conduct a single dose toxi city study patterned after the neurotoxicity study design to distinguish si ngle dose effects and NOAELs from those resulting from multiple doses, Fina lly, interspecies pharmacokinetics studies are proposed to determine which toxicology study regimen of dosing best reflects intermittent worker exposu re. (C) 2001 Published by Elsevier Science Ltd on behalf of British Occupat ional Hygiene Society.