Assessment of peripheral nerve function in an Ecuadorian rural population exposed to pesticides

To explore the peripheral nervous system effects of regular agricultural pesticide use, a cross-sectional survey was conducted in highland Ecuador. Participants were 144 occupationally exposed farm members, 30 female farm members with little direct exposure, and 72 unexposed local town residents, frequency matched to the exposed people on age, sex, and education. Organophosphorus and carbamate insecticides and dithiocarbamate fungicides accounted for the majority of pesticide applications, with leaking backpack sprayers, minimal use of personal protective equipment, and frequent dermal contact being the norm. In polytomous logistic regression analyses, applicators had significantly greater odds for more current peripheral nerve symptoms (odds ratio OR = 3.1), signs of poor coordination (OR = 4.3), abnormal deep tendon reflexes (OR = 2.9), and reduced power (OR = 2.1) compared to controls. Mean toe vibration threshold scores, on a logarithmic scale, were significantly higher among applicators (beta = 0.035) and those reporting previous pesticide poisonings (beta = 0.074). Such indicators of peripheral nervous system effects may be due to a variety of factors, including high pesticide exposure conditions.