Pesticide exposure and adverse health effects associated with farmwork in Northern Thailand

Objectives To assess pesticide exposure and understand the resultant health effects of agricultural workers in Northern Thailand. Methods This was a cross‐sectional study. We quantified exposure to pesticides, including chlorpyrifos, methomyl, and metalaxyl, by air sampling and liquid chromatography/mass spectrometry. We estimated differences in self‐reported health outcomes, complete blood counts, cholinesterase activity, and serum/urine calcium and creatinine concentrations at baseline between farmworkers and comparison workers, and after pesticide spraying in farmworkers only. Results This study included 97 men between the ages of 22 and 76 years; 70 were conventional farmworkers; and 27 did not report any prior farmwork or pesticide spraying. None of the farmworkers wore standardized personal protective equipment (PPE) for the concentrated chemicals they were working with. Methomyl (8.4‐13 481.9 ng/m3), ethyl chlorpyrifos (11.6‐67 759 ng/m3), and metalaxyl (13.9‐41 191.3 ng/m3) were detected via personal air sampling. When it came to reporting confidence in the ability to handle personal problems, only 43% of farmworkers reported feeling confident, which reflects higher stress levels in comparison to 78% of comparison workers (P = .028). Farmworkers also had significantly lower monocyte counts (P = .01), serum calcium (P = .01), red blood count (P = .01), white blood cell count (P = .04), and butyrylcholinesterase activity (P