Hearing loss among licensed pesticide applicators in the agricultural health study.

OBJECTIVE

We evaluated self-reported hearing loss and pesticide exposure in licensed private pesticide applicators enrolled in the Agricultural Health Study in 1993 to 1997 in Iowa and North Carolina.

METHODS

Among 14,229 white male applicators in 1999 to 2003, 4926 reported hearing loss (35%). Logistic regression was performed with adjustment for state, age, and noise, solvents, and metals. We classified pesticides by lifetime days of use.

RESULTS

Compared with no exposure, the odds ratio (95% confidence interval) for the highest quartile of exposure was 1.19 (1.04 to 1.35) for insecticides and 1.17 (1.03 to 1.31) for organophosphate insecticides. Odds of hearing loss were elevated for high pesticide exposure events (1.38, 1.25 to 1.54), pesticide-related doctor visits (1.38, 1.17 to 1.62) or hospitalization (1.81, 1.25 to 2.62), and diagnosed pesticide poisoning (1.75, 1.36 to 2.26).

CONCLUSIONS

Although control for exposure to noise or other neurotoxicants was limited, this study extends previous reports suggesting that organophosphate exposure increases risk of hearing loss.