Olfactory Function in Latino Farmworkers Over 2 Years Longitudinal Exploration of Subclinical Neurological Effects of Pesticide Exposure

Objective: We compared patterns of olfactory function over 2 years in pesticide-exposed male Latino farmworkers and male Latino workers in industries without pesticide exposure. Methods: At five points over 2 years, workers completed tests of odor threshold (16 concentrations of n-butanol) using a well-established methodology. Tests at two or more time points were completed by 156 farmworkers and 118 non-farmworkers. Results: Farmworkers required significantly higher odorant concentrations at Contact 1 and across the 2-year follow-up to detect the odor. When adjusted for Contact 1, between-group differences persisted, but odor threshold performance did not worsen over time. Conclusions: Pesticide exposure has been linked to neurodegenerative disease, as has declining olfactory function. Persistently poorer olfactory function among pesticide-exposed workers suggests the need to monitor neurological function in this vulnerable worker population.