Harvard study shows possible connection between pesticides and ADHD

growing applesA study published in the latest issue of Pediatrics takes a closer look at the relation between the ingestion of certain pesticides and cases of attention deficit hyperactivity disorder in children. Children’s Hospital Boston’s  Robert Wright, MD, MPH, and David Bellinger, PhD were co-authors on the study.

“Research shows the number of cases of ADHD is rising in the country, but it’s not very clear why,” says Wright. “One potential cause of this could be the chemicals we’ve introduced into our environments over the years at higher and higher rates, including pesticides.”

 By analyzing the urine of its test subjects for traces of specific phosphates often found in pesticides, and comparing the data with ADHD information provided by the National Health and Nutrition Examination Survey, the study concluded that children with higher levels of dialkyl phosphate in their systems were more likely to be diagnosed as having ADHD.

Robert Wright, MD, MPH
Robert Wright, MD, MPH

Dialkyl phosphates are generally found in organophosphates— a key ingredient in various pesticides used in North America. Though organophosphates are found in pesticides for multiple uses, kids are most likely to come in contact with them by eating fruits or vegetables that have been treated with the chemicals during growth.

While the findings should be of interest to parents, the authors of the study say their work thus far only proves an association between ADHD and traces of dialkyl phosphate, not a direct cause and effect relationship. They recommend further study be done on the subject to see if any kind of direct causal correlation between ADHD diagnoses and pesticide ingestion can be proven.

Washing TomatoesIn the meantime parents are urged to avoid house hold pesticides in areas where their kids spend a lot of time, and if possible, buy organic fruits and vegetables that are guaranteed not to have been exposed to organophosphates. Of course for many parents 100 percent organic produce isn’t an option, so moms and dads should always thoroughly wash their store bought fruits and veggies prior to giving them to the kids.

“We don’t want to discourage anyone from feeding their kids fruits and vegetables,” says Wright. “It just puts more weight on the importance of washing fruits and vegetables more thoroughly before serving them to rinse any unwanted residue off.”

Wright says he plans to continue his research studying the relationship between ADHD and pesticides, and that programs at the National Institute for Environmental Health Sciences are also looking at similar data because of the potential threat these chemicals may pose to children.   

“We need to be cautious when considering the harm and benefits of using so many pesticides,” says Wright. “Obviously the benefits are we’re going to grow more food cost effectively, but if we’re not careful these chemicals can be toxic to humans as well as insects. We need to be mindful of that so we don’t inadvertently expose children to undo risks.”

2 thoughts on “Harvard study shows possible connection between pesticides and ADHD

  1. the authors should look at the work of Hertha Hafer done in the 70’s regarding phosphates in general. her book ” The Hidden Drug: Dietary Phosphates” clearly identified phosphates, not pesticides as the problem. An institution with the resources to test the hypothesis could prove or disprove the theory. could it be that the food industry and the psychiatric industry don’t want the proof to exist?

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