A new study from the University of Iowa suggests that people who have higher levels of a chemical in their body that indicates exposure to commonly used insecticides die of cardiovascular disease at a significantly higher rate.

Findings from the study, published in the journal JAMA Internal Medicine, suggest those who have high levels of exposure to pyrethroid insecticides are three times more likely to die of cardiovascular disease than people with low or no exposure.

Wei Bao, assistant professor of epidemiology in the University of Iowa College of Public Health and the study’s corresponding author, says the findings come from an analysis of a nationally representative sample of American adults, not just those who work in agriculture. That means the findings have public health relevance to the general population.

He also cautions that as an observational study, the research does not determine if the people in the sample died as a direct result of their exposure to pyrethroids. He says that the results indicate a high likelihood of a link, but more research is needed to replicate the findings and determine the biological mechanisms.