ADHD and Pesticides...a buncha bunk?

So now there's a study linking pesticides to ADHD. But it raises the question: if pesticides cause ADHD, how come in towns where produce is purchased from the same supermarket, not all children have ADHD?

You can argue that not all children eat the same produce, and we know strawberries contain more pesticides than, say, an orange. You can also argue that some people wash their produce better than others do (and some may not wash it at all).

You may be scratching your head, wondering what I'm talking about. In case you haven't been scanning news articles on the Internet lately, a study by the Official Journal of the American Academy of Pediatrics claims that their study has found a possible link between attention-deficit hyperactivity disorder and concentrations of dialkyl phosphate metabolites of organophosphates in the urine of 8-15 year olds.

I'm going to break this down a little. According to the Journal of Occupational Medicine and Toxicology, organophosphates are "the most common pesticides used in Peruvian agriculture." (Dec. 2006)Crops they're used on: potatoes, onions, tomatoes, alfalfa, apples, grapes and garlic. By the way, the study they conducted found OPs (as the chemical is called) to be dangerously toxic to agriculture workers when handled without wearing the proper attire and not taking the right precautions.

Forty OPs are registered with the EPA in the U.S., according to the Official Journal of the American Academy of Pediatrics study, and the US Pesticide Residue Program Report's 2008 study found OPs in almost a third of frozen blueberries and strawberries, and almost 20% of celery samples.

The study took urine samples from 1,139 children, and 119 met the ADHD criteria. Here we must wonder if there are biases. The diagnosis was made through interviews with a parent and based on "slightly modified criteria" from Diagnosis and Statistical Manual of Mental Disorders, Fourth Edition. This interview was conducted via telephone. I can't find any evidence of a doctor making an evaluation based on observing the child's behavior, thus may I make the hypothesis that some children may have been labeled ADHD, but perhaps not be clinically considered ADHD.

The study found that children with higher levels of dialkyl phosphate metabolites of organophosphates in their urine were more likely to be diagnosed with ADHD. Again, I question why only 119 children had this diagnosis when certainly more than that must have consumed similar levels of OPs in their diet.

I definitely believe pesticides are dangerous, even toxic, especially for the workers who use these chemicals on a daily basis, and probably for their offspring as well. But I am not quick to believe in a positive link between ADHD and OPs. Neither does the Official Journal of the American Academy of Pediatrics, which also points out that there are more studies to be done before they close the book on this case.