(Beyond Pesticides, June 6, 2008) A recent study by the National Institutes of Health (NIH), including the National Institute of Environmental Health Sciences (NIEHS) and the National Cancer Institute (NCI), finds pesticide applicators with regular exposure to pesticides to be at a greater risk of type-2 diabetes. Published in the American Journal of Epidemiology (DOI: 10.1093/aje/kwn028), the study shows specific pesticides produce between a 20 and 200 percent increase in risk. Researchers looked at data from 31,787 pesticide applicators in North Carolina and Iowa over a period of five years. In that period, 1,171, or 3.7 percent, had developed diabetes, particularly for applicators in the highest category of lifetime days of use of any pesticide.
“The results suggest that pesticides may be a contributing factor for diabetes along with known risk factors such as diabetes, lack of exercise and having a family history of diabetes,” said Dale Sandler, PhD, chief of the Epidemiology Branch of NIEHS. “Although the amount of diabetes explained by pesticides is small, these new findings may extend beyond the pesticide applicators in the study.”
Freya Kamel, PhD, of NIEHS noted that “all of the seven pesticides” associated with an increased risk of type 2 diabetes are chlorinated compounds: aldrin, chlordane, heptachlor, dichlorvos, trichlorfon, alachlor, and cyanazine. “We don’t know yet what the implication of that is, but it can’t be a coincidence. I think it’s an important clue for future research,” said Dr. Kamel. Trichlorfon bore the strongest correlation; applicators who used it both frequently and infrequently show an 85 percent increase in risk for diabetes, while those who applied it more than 10 times experience nearly a 250 percent increase in risk.
“This is one of the largest studies looking at the potential effects of pesticides on diabetes incidence in adults,” said Dr. Kamel. “It clearly shows that cumulative lifetime exposure is important and not just recent exposure.” Weight and fitness also play a roll, researchers reported, as chemicals may be stored in body fat.
This is not the first study to report on the link between organochlorine pesticides and diabetes. Earlier this year, University of Cambridge scientists studied the role that persistent organic pollutants (POPs) play in the risk of adult onset diabetes, as did a study in 2007. The study looked at in this latest research also offer a wealth of connections to other health effects, including cancer, endocrine disruption, developmental effects, neurotoxicity, and others.
To find out how you can manage homes, buildings, lawns and landscapes without using toxic chemicals, visit Beyond Pesticides’ alternatives fact sheets. To find a pest control company in your area that uses less- and non-toxic products, visit the Safety Source for Pest Management.