Potential dermal and inhalation exposure to chlorpyrifos in Australian pesticide workers

Abstract

Chlorpyrifos inhalation, dermal exposure and working practices of 28 pesticide applicators in Western Australia were assessed during a series of single property applications of a 0.5% (n=2) or 1% (n=26) concentration of active ingredient in water solution. Deposition on new cotton gloves worn beneath applicators' usual protective gloves was 2.4 (range 0.12–86.1) mg h-1. Median deposition of chlorpyrifos onto a new cotton overall worn over other clothing (24 sections removed, corrected for body proportions) was 11.1 (range 0.2–41.9) mg h-1. Deposition onto seven patches taped to the applicators' skin was 0.04 (range 0.01–4.7) mg h-1. Inhalation concentration was 5.7 (range 0.7–219) µg m-3 time weighted average. In one group of 17 applicators' applying to existing properties, breathing zone air concentration correlated (P<0.05) with ambient air temperature (15–38°C). The questionnaire results (29 respondents) indicated applicators' practices led to increased exposure, in particular concerning poor usage and condition of protective equipment and a high frequency of splashes and spills onto the body. Prevention of deposition on clothing, in particular on the lower body is suggested, as well as improved working practices.