Hofmann_2010_Occup.Environ.Med_67_375

Objective To identify potential risk factors for serum cholinesterase (BCHE) inhibition among agricultural pesticide handlers exposed to organophosphate (OP) and N-methyl-carbamate (CB) insecticides. METHODS: We conducted a longitudinal study among 154 agricultural pesticide handlers who participated in the Washington State cholinesterase monitoring program in 2006 and 2007. BCHE inhibition was analysed in relation to reported exposures before and after adjustment for potential confounders using linear regression. ORs estimating the risk of BCHE depression (>20% from baseline) were also calculated for selected exposures based on unconditional logistic regression analyses. RESULTS: An overall decrease in mean BCHE activity was observed among study participants at the time of follow-up testing during the OP/CB spray season relative to pre-season baseline levels (mean decrease of 5.6%, p<0.001). Score for estimated cumulative exposure to OP/CB insecticides in the past 30 days was a significant predictor of BCHE inhibition (beta=-1.74, p<0.001). Several specific work practices and workplace conditions were associated with greater BCHE inhibition, including mixing/loading pesticides and cleaning spray equipment. Factors that were protective against BCHE inhibition included full-face respirator use, wearing chemical-resistant boots and storing personal protective equipment in a locker at work.
CONCLUSIONS: Despite existing regulations, agricultural pesticide handlers continue to be exposed to OP/CB insecticides at levels resulting in BCHE inhibition. These findings suggest that modifying certain work practices could potentially reduce BCHE inhibition. Replication from other studies will be valuable.