Environmental pesticide exposure and its association with hematological parameters and inflammation indices among school-aged children in Mexico

Few studies have investigated the association between pesticide exposure and immune-inflammatory indices in children. We conducted a cross-sectional study of 369 school-aged children from three Mexican communities with varying levels of agricultural production. Blood samples were collected to calculate immune-inflammatory indices, and pooled hand-washing samples from 30 randomly selected children per community were analyzed for pesticide metabolites. Urinary dialkylphosphates (DAP) were determined in pooled samples per community. Multivariable logistic regression models assessed associations between pesticide exposure and immune-inflammatory indices (>median vs. <median). We detected ten classes of pesticides in hand-washing samples, including benzimidazoles, carbamates, neonicotinoids, organochlorines, organophosphates, and N-(phosphonomethyl)glycine. Total pesticide residue concentrations were 6.6 µg/L and 5.5 µg/L in the two highest production communities, compared to 0.3 µg/L in the reference community. Bifenthrin, chlorpyrifos, malathion, and carbendazim were present across all communities, with AMPA (a glyphosate metabolite) in the highest concentrations in agricultural areas. Urinary DAP were significantly higher in children from agricultural communities. Children in the largest agricultural community had lower hemoglobin and lymphocyte counts but higher neutrophil and eosinophil counts. Regression models showed increased odds of elevated systemic inflammation indices, particularly in children from the two highest production areas. Our adjusted models revealed significant associations between pesticide exposure and platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), and eosinophil-to-lymphocyte ratio (ELR), in community B compared to community C, emphasizing the need for targeted interventions in high-exposure communities.