Pesticide Exposure and Cancer Risk: A Cross-Sectional Study on Farmers in Nakhon Sawan, Thailand

Introduction Cancer is a leading cause of disease burden worldwide. Although much of the existing literature, primarily from Western countries, suggests an association between pesticide exposure and cancer risk, these findings may not be directly applicable to the Thai population. This is due to differences in social, economic, and public health contexts, as well as variations in health status, pesticide use patterns, and self-protection behaviors. This study aimed to investigate the relationship between pesticide exposure and cancer risk among Thai farmers. The findings are expected to contribute valuable insights for public health prevention and control programs, as well as enhance the existing body of literature. Methods In this cross-sectional study, data were collected from 10,646 farmers aged 20 years and older through in-person interviews using a structured questionnaire. The association between pesticide exposure and cancer was analyzed using logistic regression, adjusting for potential confounding factors. Results The study identified a significant association between the historical use of pesticides, including insecticides, herbicides, and fungicides, and cancer risk. Among 39 individual pesticides examined, sixteen were found to have a significant odds ratio. The study’s results aligned with existing literature regarding the potential effects of glyphosate, paraquat, 2,4-D, folidol, chlorpyrifos, EPN, mevinphos, dichlorvos, endosulfan, dieldrin, mancozeb, maneb, and copper sulfate. Additionally, this study newly identified a significant association with propineb (OR = 2.41, 95% CI: 1.39–4.17), carbendazim (OR = 1.77, 95% CI: 1.11–2.81), and benomyl (OR = 4.04, 95% CI: 1.69–9.63). Conclusion The study found cancer prevalence among farmers in Nakhon Sawan, Thailand, to be associated with historical pesticide use. These findings aligned with existing literature, underscoring the potential effects of long-term pesticide exposure on cancer risk. This issue warrants increased public attention and stricter regulation of pesticide use. An effective exposure prevention program should be urgently implemented, particularly for Thai farmers.