Objectives: Rhinitis is common, but the risk factors are not well described. To investigate the association between current rhinitis and pesticide use, we used data from 2245 Iowa commercial pesticide applicators in the Agricultural Health Study.
Methods: Using logistic regression models adjusted for age, education and growing up on a farm, we evaluated the association between current rhinitis and 34 pesticides used in the past year.
Results: 74% of commercial pesticide applicators reported at least one episode of rhinitis in the past year (current rhinitis). Five pesticides used in the past year were significantly positively associated with current rhinitis: the herbicides 2,4-D, glyphosate and petroleum oil, the insecticide diazinon and the fungicide benomyl. The association for 2,4-D and glyphosate was limited to individuals who used both in the past year (OR 1.42, 95% CI 1.14 to 1.77). Both petroleum oil and diazinon showed consistent evidence of an association with rhinitis, based on both current use and exposure-response models. We saw no evidence of confounding by common agricultural rhinitis triggers such as handling grain or hay.
Conclusions: Exposure to pesticides may increase the risk of rhinitis.