Potential dermal and inhalation exposure to chlorpyrifos in Australian pesticide workers

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) microg 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 degrees 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.