Abstract:
The aims of this study were to examine the prevalence of cognitive impairment and the association between pesticide exposure and cognitive impairment among adult farmers in Doi Tao District, Chiang Mai Province. This cross-sectional study included 303 pesticide-using farmers over the age of 50 in Doi Tao District. The Thai version of the Montreal Cognitive Assessment (MoCA) test was used to assess cognitive impairment. The pesticide exposure score was calculated using an algorithm that considered personal protective equipment (PPE) scores, exposure intensity scores, and lifetime application days. Scores were classified as high or low exposure based on their median. Spearman's rank correlation coefficient (rs) and linear regression were used for data analysis. The findings revealed that the prevalence of cognitive impairment among the farmers was 93.7%, with an average MoCA score of 19.6. The MoCA score was negatively correlated with the pesticide exposure score (rs = -0.225, p < 0.001), PPE score (rs = -0.163, p = 0.004), exposure intensity score (rs = -0.184, p = 0.001), and lifetime application days (rs = -0.145, p = 0.011). When adjusted for sex, age, education, income sufficiency, and body mass index, the analysis found that farmers with high pesticide exposure had significantly lower MoCA scores than those with low pesticide exposure, with a difference of 0.77 points (95% CI: -1.47, -0.06). Farmers with higher PPE scores had MoCA scores 0.75 points lower (95% CI: -1.46, -0.05), and those with higher exposure intensity had scores 0.97 points lower (95% CI: -1.66, -0.27). In conclusion, Thai farmers are at risk of cognitive impairment linked to occupational pesticide exposure, depending on their PPE use and exposure intensity. Therefore, activities should be organized to prevent and reduce farmers exposure to pesticides, particularly by promoting the use of PPE.