A new study has found a significant association between pesticide use and increased incidence of several types of cancer across the U.S.
The research, published in Frontiers in Cancer Control and Society, estimated that differences in pesticide use patterns could account for an additional 154,541 cancer cases per year in the U.S.
Elevated pesticide use was associated with increased risk for all cancers evaluated, including leukemia, non-Hodgkin lymphoma, and bladder, colon, lung, and pancreatic cancers. The associations were particularly strong in regions with high agricultural productivity, such as the Midwest. Notably, the impact of pesticide use on cancer incidence was comparable to that of smoking for some cancer types. For non-Hodgkin lymphoma, pesticide use was associated with 154.1% more cases than smoking. For all cancers, pesticide use was associated with 18.7% more cases, for bladder cancer 19.3% more cases, and leukemia for 21%.
Researchers from Rocky Vista University College of Osteopathic Medicine and other institutions employed a novel population-based approach to assess the relationship between pesticide use patterns and cancer risk while accounting for confounding variables such as smoking rates, socioeconomic vulnerability, and agricultural land use.
Data from 3,143 counties was analyzed, focusing on the use of 69 pesticides monitored by the U.S. Geological Survey. They developed latent class analysis models to identify pesticide use patterns and then used generalized linear models to determine the effect of these patterns on cancer incidence, adjusting for covariates.
The study also identified specific pesticides that were most strongly associated with increased cancer risk in different regions. Atrazine, boscalid, dimethomorph, dicamba, dinotefuran, glyphosate, imazethapyr, and metolachlor were among the top contributors.
The effects of pesticide use remained significant even after adjusting for agricultural land use, total population and socioeconomic vulnerability using the Social Vulnerability Index (SVI). The study's generalized linear models revealed that pesticide use effects were more persistent than socioeconomic disparity factors addressed through the SVI.
Despite some limitations, such as data availability and uniformity issues, the study's findings align with previous research on the link between pesticides and cancer. The researchers noted their population-based approach provides a more holistic understanding of the community effects of overall pesticide exposure and may inform future policies regarding pesticide regulation.
While the study's ecological design precludes causal inference and individual risk assessment, it provides compelling evidence for the association between pesticide use patterns and cancer incidence at the population level.