Modeling Agrochemical Contamination in Drinking Water and Chronic Disease Risk in U.S. Farmers

Agrochemical contamination of drinking water represents an underrecognized environmental health risk in agricultural communities, particularly among farmers who rely on private wells for long-term water consumption. Intensive use of pesticides, herbicides, and nitrogen-based fertilizers can lead to groundwater and surface water contamination through leaching, runoff, and subsurface transport, resulting in chronic low-level exposure. Existing monitoring and biomonitoring approaches are often insufficient to capture cumulative and historical exposure relevant to chronic disease development. This review synthesizes current modeling approaches used to estimate agrochemical contamination in drinking water and examines how these modeled exposures have been linked to chronic disease risk among farmers. Environmental fate and transport models, spatial and temporal exposure models, and emerging mixture-based frameworks are reviewed to illustrate how long-term drinking water exposure is reconstructed and applied in epidemiologic research. Evidence linking modeled exposure to cancer, neurologic, endocrine, metabolic, and renal outcomes is summarized, with attention to exposure duration, latency, and population-specific vulnerabilities. Overall, the literature indicates that drinking water is a critical and continuous exposure pathway contributing to chronic disease risk in farming populations, particularly where regulatory oversight of private wells is limited. Future research should prioritize integrated modeling–biomonitoring frameworks, improved mixture assessment, and the use of conceptual diagrams to clarify exposure mechanisms. Strengthening these approaches will support more effective surveillance, risk assessment, and preventive strategies aimed at protecting farmer health and reducing long-term disease burden.