Pesticides Link to ADHD in children

Children's exposure to pesticides, even at a low level, was linked with 100% increased risk of ADHD  by a new study published in the journal Pediatrics. These pesticides are likely to be coming from food ingested by the children.

The study, by two teams from Harvard University and University of Montreal, looked at data from a representative sample of over 1,100 children, and correlated organophosphate pesticides levels detected in urine analysis and ADHD diagnostic. It found that higher level of exposure correlated with higher risk of ADHD. More troubling - it found that low levels of exposure, above the median of detectable concentration, doubled the risk of ADHD compared to children with undetectable levels of organophosphates. "I was quite surprised to see an effect at lower levels of exposure," said lead author Bouchard.

The study did not prove causality between organophosphates and ADHD - only a link. However, says Bouchard, it is already known that organophosphates disrupt neurochemical brain activity. Dr. Goldstein, a specialist in child neurology , and a faculty member of the American Academy of Neurology, quoted by Medsdcape Today, said that the data on organophosphates and ADHD "look like the data we saw 30 to 40 years ago with lead exposure, and it may turn out to be the same thing — that even small exposures (to organophosphate pesticides) are very harmful to kids."

The incidence of ADHD diagnostics has drastically increased in the past 30 years, with some rejecting the responsibility on environmental factors, while others believe that the syndrome is over-diagnosed. The CDC reports 7% incidence in 2006. Some recent studies consider that close to 10% of the children population is affected. More than 10% of the children in the present study met the diagnostic criteria for ADHD.

The results of this study are particularly worrisome because it is hard to avoid exposure to organophosphates, which are a commonly used pesticide. What can you do to decrease your children's exposure to organophosphates?

• Thoroughly wash all fruits and vegetables before bringing them to the table, using a product brush when possible (Consumer Reports recently showed that product washing liquids are only marginally better than a good water wash).

• Switch to organic fruits and vegetables for those most often found with high concentrations of pesticides. Combining data from the Environmental Working Group, and the 2002 Consumers Union study, both consumer advocacy groups, we find that 15 fruits and vegetables with a high concentration of residual pesticides are celery, peaches, strawberries, apples, domestic blueberries, nectarines, sweet bell peppers, spinach, kale, collard greens, cherries, potatoes, imported grapes, lettuce, and pears. The 15 produce with the least amount of pesticide residues are onions, avocados, sweet corn, pineapples, mango, sweet peas, asparagus, kiwis, cabbage, eggplant, cantaloupe, watermelon, grapefruit, sweet potatoes, and sweet onions. The EWG has gathered its lists on a handy wallet card.

• Stop using organophosphates for your lawn and garden - make sure that neither you nor your lawn service use Diazinon, Spectracide, trichlorphon, Malathion or other organophosphates.

• Do not use malathion-based products to treat head lice.

• Check what pesticides are being used by your school. Are they using the preferred Integrated Pest Management approach?

 Want to read more about it? Check out Reuters, Medscape, US News, Time, Business Week, CBS, Food Safety News, CNN, and The Atlantic. WebMD, normally a trusted source, is misquoting the actual data in the study in its present version.

The study in Pediatrics

Update: added sources, updated produce lists