(Beyond Pesticides, August, 2, 2013) A new study published in the American Journal of Epidemiology concludes that farmers using herbicides are nearly two and a half times as likely to be treated for depression as those who did not use herbicides. Furthermore, farmers who are exposed for greater periods of time are also afflicted with greater risk of developing depression, raising concerns of the harm chemicals can cause to mental health. Building on substantial research supporting the link between pesticide exposure and neurological damage, this study examines the role that pesticides play in the overall health of farmers, and gives further weight to the importance of choosing organic food.
Researchers surveyed 567 farmers from France, questioning them on the frequency of their use of fungicides, insecticides, and herbicides, to determine how pesticide exposures were linked to the risk of developing clinical depression. Lead researchers and associate professor at the Harvard School of Public Health, Marc Weisskopf, PhD, said while the results are unclear, they “suggest we should not be ignoring herbicides just because they’re targeting plants.”
Previous research has already suggested that pesticides, particularly organophosphates, cause a variety of serious neurological health problems, including Parkinson’s disease. This is not surprising, as organophosphates are known to be extremely toxic to nerve cells and deadly at large doses. Recently, organophosphate pesticides caused the deaths of 25 children in India from contaminated school lunches.
To determine chemical exposures, researchers conducted interviews, surveyed old pesticide containers, and even examined records for pesticide purchases. Beyond those measures, researchers also asked whether farmers had ever been treated for depression. The results of the study showed that of 567 farmers 83 of them self-reported treatment or hospitalization for depression, almost 15 percent. After adjusting for age and health factors like smoking, the study found that farmers that use herbicides were more than twice as likely to have been treated for depression. Similarly, those farmers who were exposed to herbicides for a greater length of time””either more hours of exposure or for a greater number of years””were also more likely to be treated for depression than those with less exposure.
Interestingly, the study found no difference in the risk of developing depression between farmers that had fungicides or insecticides compared to those that had not. Dr. Weisskopf posited that this may be because farmers are more aware of the harm fungicides and insecticides have on human health. “If (herbicides) are considered in general safer and people take less precautions because people think they’re not as bad, then that poses a problem,” he told Reuters.
While the study provides important insight into the effect of pesticides on mental health, it does not definitively prove cause and effect. Researchers accounted for age and cigarette smoking in their correlation, however there may be other health conditions or external circumstances not accounted for in the study that changed work conditions and/or made them susceptible to depression.
However, scientists not involved in the study, such as Cheryl Beseler, PhD. and researcher at Colorado State University, have supported the work and stand behind the strength of the study’s methodology. Dr. Weisskopf confirmed that “This still has to be considered a relatively first, small study. There’s more work to do, but it raises concerns that need to be looked into more fully.”
Through our Pesticide Induced Diseases Database (PIDD), Beyond Pesticides keeps track of the most recent studies related to pesticide exposure. For more information on the multiple harms pesticides can cause, see our PIDD pages on Alzheimer’s, Parkinson’s, cancer, and other diseases.
Studies such as these, highlights the importance of buying, growing, and supporting organic. Consumers choices encourage the protection of the people who help put food on our table every day by purchasing organic. By buying organic, you support an agricultural system that does not heavily rely on the widespread application of dangerous pesticides. For more information on how organic is the right choice for both consumers and the farmworkers that grow our food, see Beyond Pesticides webpage, Health Benefits of Organic Agriculture.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.