Paredes-Cespedes_2026_Int.Arch.Occup.Environ.Health_99_

PURPOSE: Organophosphate (OP) pesticides are widely used in agriculture, vector control, and represent a global public health concern, particularly for occupationally exposed farmers and applicators. This study aimed to evaluate the associations among urinary dialkylphosphate (DAP) metabolites, cholinesterase activities, and butyrylcholinesterase (BuChE) polymorphisms in an indigenous population in Mexico. METHODS: A cross-sectional study was conducted among 191 farmworkers. Data were collected using a structured questionnaire addressing sociodemographic characteristics, lifestyle factors, pesticide exposure, and dietary intake. Venous blood and urine samples were obtained to determine cholinesterase activities and urinary DAP concentrations, respectively. RESULTS: Detectable urinary DAP levels were identified, with dimethylthiophosphate (DMTP) as the predominant metabolite. BuChE activity was significantly associated with dietary lipid and carbohydrate intake. A high prevalence of ancestral genotypes was observed in the BuChE gene. Age-stratified analyses demonstrated differences in cholinesterase activities, and males with low BuChE activity exhibited higher urinary DAP metabolite concentrations. CONCLUSION: These findings highlight variability in OP pesticide metabolite levels and their relationships with dietary factors and genetic background among indigenous agricultural workers. Improved understanding of these interactions is essential for mitigating exposure-related health risks in vulnerable populations.