Pesticide exposure and all health outcomes: An umbrella review of meta-analyses of observational studies.

Although pesticide exposure occurs through multiple pathways and has been linked to diverse health outcomes, the overall evidence remains unclear. We systematically searched PubMed/MEDLINE, Embase, CINAHL, and Google Scholar up to November 20, 2025, for meta-analyses examining pesticide exposure and adverse health outcomes. We recalculated pooled estimates using random-effects models and converted all effect metrics to equivalent odds ratios with 95% confidence intervals. The quality of included reviews was assessed using AMSTAR 2, and the credibility of evidence was graded using predefined criteria (Class I to IV). A total of 53 meta-analyses covering 235 associations were included. Among the 77 main associations, 48.1% achieved statistical significance, of which 51.4% were supported by highly suggestive or suggestive evidence. Significant associations with pesticide exposure were observed across several health domains, particularly oncological, metabolic, neurological, and respiratory outcomes, with additional signals emerging in subgroup analyses. Particularly, exposures to organochlorine pesticides had increased odds of non-Hodgkin lymphoma. Exposure to dichlorodiphenyldichloroethylenes was associated with diabetes mellitus and non-Hodgkin lymphoma, while exposure to organochlorine insecticides was associated with hypothyroidism. Pesticide exposure was associated with childhood lower respiratory infections among respiratory outcomes. These findings identify priorities for prevention and highlight the need for better exposure assessment.