Effects of street clothing, sunscreen, and temperature on skin absorption of organophosphate pesticides - a review and case study of diazinon

Abstract

There is increasing concern about occupational and community exposure to accidental or deliberate release of organophosphate pesticides (OPs). The protection afforded by street clothing and personal skin products for dermal exposure is poorly understood. A literature review was conducted and an in-vitro study carried out with diazinon, as a case example. The objectives were to assess the modifying effects of sunscreen, clothing, and temperature, on epidermal absorption and penetration. Diazinon in-vitro work was performed with static Franz cells in accordance with OECD protocols. Application of oil-based sunscreen on hydrated exposed skin was performed as per Australian Standard 2604:1998. A formal review of the literature revealed a significant knowledge gap with respect to dermal exposure and uptake of OPs in civilian exposure incidents. Recent work in the United Kingdom showed cotton shirt material significantly reduced dermal absorption of dichlorvos and chlorpyrifos, and post-exposure removal of clothing with immediate skin surface decontamination further reduced absorption compared with removal of clothing alone. Diazinon in-vitro studies revealed the skin to be a good barrier to penetration. Sunscreen and denim fabric seemed to act as an extra barrier for absorption and penetration, whereas elevated temperatures (37°C) seemed to aid diazinon penetration through the skin. The findings suggest emergency responders and hygienists recommend removal of bulky clothing and early decontamination of the skin following OP exposure to minimise the potential for dermal absorption and localised toxicity within the skin. Further studies of street clothing and sunscreen should be conducted with a wide range of substances.