Organophosphate: Insecticide and Nerve Gas - 2 for the Price of 1!

By Theodora Filis

A new study links Organophosphate Pesticides (a compound marketed by many of the world’s major agrochemical companies) and Attention Deficit Hyperactivity Disorder (ADHD).

ADHD is thought to affect 3% to 7% of American children, with boys affected more heavily than girls. 


A recent study, reported in the journal of Environmental Health Perspectives, examines the effects of both prenatal and childhood exposure to the pesticides which are widely used in the United States to control insects on food crops.  EPA documents show that babies and children under five can ingest levels of the insecticide through food and water that exceed levels the agency considers safe. 

A growing body of evidence is suggesting that exposure to organophosphate pesticides (OPs) is a prime cause of attention deficit hyperactivity disorder, ADHD. The findings are considered plausible to many experts because the pesticides are designed to attack the nervous systems of insects, making it likely they should also effect the nervous systems of humans who are exposed to them.

Researchers at the University of California, Berkeley, found that prenatal levels of the pesticides were related to attention problems at age 5, with the effects apparently stronger among boys. "We were especially interested in prenatal exposure because that is the period when a baby's nervous system is developing the most," said Brenda Eskenazi. 

The aerial application of OPs (such as dimethoate) is permitted in the UK to control cereal and vegetable pests, in sheep dips, and as insecticides in military premises, on equipment and was even used on personnel during the Gulf War.

Some of the main agricultural products are Hostathion (triazophos), Metasystox-R (oxydemeton-methyl), Dursban and Lorsban (chlorpyrifos), Sumithion (fenitrothion) and Actellic (pirimiphos-methyl)(2).

EPA has ruled that OPs can’t be used for most residential applications in the US, but  they are still turning up in the fruits and vegetables. Forty OPs are registered in the US, with at least 73 million pounds used each year in agricultural and residential settings. A USDA report from 2008 found that detectable levels of OPs were contained in 28% of frozen berries, 20% of celery, and 25% of strawberries.

What's a parent to do?

To avoid potentially harmful pesticides buy local or organic whenever possible. National surveys have shown that fruits and vegetables from farmers' markets contain less pesticides even if they are not organic.

The Environmental Working Group, an advocacy organization, has compiled a list of best and worst fruits and vegetables for pesticide residue, which includes a clip-out guide for shopping.

Detoxify your lawn and garden. If you have lawn-care service, ask if the company uses the organophosphate pesticide trichlorfon; it's used almost exclusively by lawn-care companies and golf courses, according to the Environmental Protection Agency.

Clean out your garden shed. The organophosphate diazinon (brand names: Diazinon, Spectracide) was outlawed for residential use in 2004, but there may be some left in your garage or shed. Check with your community's hazardous-waste disposal program on how to safely dispose of pesticides. Organophosphates kill fish, so don't dump them down the drain.

Pick those nits. Malathion is approved for treatment of head lice in children over age 6. But do you really want a neurotoxin on your child's scalp? Non-toxic alternatives include combing, hand-picking nits, and using the face cleaner Cetaphil to suffocate adult lice.

Check your school's pest control policy. Many school districts have moved to Integrated Pest Management, which emphasizes less toxic alternatives. The National Institute for Occupational Safety and Health is a good source for information on how to implement IPM in schools, the kind of thing you could wave at a PTA meeting.