Pesticides have long been used to decrease the risk of insect damage in food crops, though over the years they have been associated with disorders such as Parkinson’s and now Attention Deficit Hyperactivity Disorder (ADHD).

Scientists at Harvard School of Public Health surveyed 1,000 children ages 8-13 for their levels of ADHD and then screened their urine samples for traces of organophosphate pesticides. The study found a correlation between higher levels of ADHD and a greater amount of organophosphate pesticides.

“It’s not a causal relationship at all,” said Alan Kolok, Professor in the Department of Environmental, Agricultural, and Occupational Health at the U. Nebraska Medical Center. “It’s just an association.”

Pesticides have been targeted for containing neurotoxins that are used against the insects.

“It stands to reason that these neurotoxins can affect humans,” Kolok said, though adding that the human and insect brains are quite different and that the level of exposure to the neurotoxins experienced by humans is very low.

Organic foods are those that are produced free of pesticides, automatically reducing any risks that may exist with pesticides.

“Your exposure to pesticides from those organic fruits and vegetables will be zero, and that is ideal,”  Kolok said. “(But) some people can’t afford organic fruits and vegetables all the time.”

Kolok argues that the study is not definitive in the connection between ADHD levels and pesticides, hypothesizing that the children were probably exposed by unwashed foods containing higher amounts of pesticides than washed foods would have.

“If your fruits and vegetables are washed off well you should be okay,” Kolok said. “(The study) is a refinement more than it is a breakthrough.”