THE BLOG
10/16/2012 02:58 pm ET | Updated Dec 16, 2012

The Stanford Study's Pesticide Problem

Environmental Working Group Senior Research Analyst Sonya Lunder co-authored this post:

Good news! Recently, another pesticide used by conventional agriculture was targeted by the Environmental Protection Agency (EPA) for phase out after the agency finally determined the risks the chemical posed to human health and the environment outweighed the economic benefits for agribusiness. An occasional fate for pesticides once broadly used on crops and also thought to be safe, courtesy of a health review process by EPA that started in earnest in 1996 with passage of the historic Food Quality Protection Act, or FQPA.

The pesticide in question is the neurotoxic Azinphos-methyl, or AZM, which is from the organophosphate clan of insecticides that brought us such disreputables as parathion, chlorpyrifos and many other second cousins of Nazi-era nerve gas.

First used by chemical agriculture as an insecticide in 1959, AZM was thought to be safe until it came under the microscope at EPA in 1996 as a potential health risk, especially to farmworkers who could experience a number of side effects, including convulsions, dizziness, headaches, nausea and difficulty breathing if AZM is inhaled. Studies have shown it to be toxic to the nervous system in people, and poisonous to birds, fish and bees.

In addition to farmworkers being exposed, millions of Americans, including young children and pregnant women, have been eating it regularly, albeit mostly at relatively low levels, since the Eisenhower administration and are still consuming it today if they dine on conventional apples, blueberries, pears and other produce on which the chemical is sprayed.

In its latest round of pesticide residue tests, the U.S. Department of Agriculture found AZM on between 7 and 9 percent of apples and pears it tested.

This is just one example of a noxious pesticide used for decades by conventional agriculture that will soon be banned from being sprayed on fruits and vegetables due to health and environmental risks. In fact, over the years EPA has barred well over 50 crop chemicals used in conventional agriculture for human health and environmental reasons.

Now, EPA doesn't ban or restrict pesticides on a whim - far from it. EPA proceeds at a glacial pace. The restrictions on AZM, which will be complete in 2013 is nearly 20 years in the making. EPA's health assessments include hundreds of pages of documentation, many rounds of public comment and occasionally a lawsuit. So when one finally is tossed out of the toolbox of chemical agriculture it's a big deal.

And, just how many pesticides once approved for organic agriculture have also been banned or restricted over health and environmental concerns by EPA? Is it fifty, forty, thirty? We decided to ask a couple of experts in the field:

"With the exception of one bad actor (rotenone), which is no longer in use and roundly panned by the organic industry, I cannot think of a single pesticide approved for use on organic farms that has been banned by a regulatory agency like the EPA for excessive risk to human health or the environment," said Professor Charles Benbrook of the Center for Sustaining Agriculture and Natural Resources at Washington State University.

"I know of only one pesticide used in organic agriculture that has been cancelled by EPA -- rotenone," said Terry Shistar, science consultant with Beyond Pesticides, a nonprofit research organization working to protect the public from the risks of pesticide exposure.

EPA has removed exactly one pesticide approved for use by USDA on organic farms.

Why the big difference between the number of pesticides banned for both versions of fruits and veggies?

The chemicals applied on organic produce are generally far less toxic compared to those used in conventional farming and far fewer of them are used. However, the researchers of the now-infamous Stanford study ignored this big difference between organic and conventional foods.

In his critique of the Stanford study, Professor Benbrook wrote:

The potential health risk of pesticide residues in organic foods compared to conventional foods typically averages 10 to 20-times smaller than that in conventional foods. This is because: (a) most residues in organic food occur at much lower levels than in conventional food, (b) residues are not as likely in organic foods, (c) multiple residues in a single sample are rare in organic food but common in conventional produce, and (d) high-risk pesticides rarely appear as residues in organic food, and when they do, the levels are usually much lower than those found in conventional food (especially the levels in imported produce).

And what about the differences organic and conventional produce operations have on our environment? Let's just take water.

Pesticides used in conventional agriculture are common pollutants in drinking water due to field runoff into nearby rivers and streams and aerial application from crop dusters that can coat the water's surface with chemicals. So, we're not only eating pesticides with much of our food, in many areas of the country we're also drinking them. The most recent analysis by EWG of municipal water utility tests from around the country estimated that more than 215 million Americans were exposed to agriculture chemicals from drinking water, including several highly toxic organophosphate pesticides and the notorious atrazine used in corn and sugar fields that is believed responsible for heightened risk of breast cancer and sex changes in male frogs living in lakes and streams contaminated with the chemical.

From the February 2012 issue of Mother Jones, a profile by Dashka Slater of UC Berkeley biologist Tyrone Hayes who is one of the world's leading experts on the subject of atrazine:

Slater wrote:

Genetically, Darnell (a frog) is male. But after being raised in water contaminated with the herbicide atrazine at a level of 2.5 parts per billion -- slightly less than what's allowed in our drinking water -- he developed a female body, inside and out. He is also the mother of his children, having successfully mated with other males and spawned clutches of eggs.

Even more worrisome, the endocrine disruptor atrazine alters frog development through basically the same mechanism that it promotes the growth of cancer cells in human breast tissue.

EWG's review of the nation's water utility tests found the tap water for more than 27.2 million people in 33 states had various levels of atrazine, and 17 million Americans had levels of the pesticide in their water above established health guidelines, courtesy of conventional agriculture. The team from Palo Alto decided to leave out conventional agriculture's ample footprint on our drinking water, too.

And, of course, let's not forget about those who actually handle the pesticides. Farmworkers who tend the fields of conventional crops and come into direct contact with highly toxic pesticides often become ill. The EPA has estimated that between 10,000 and 20,000 pesticide poisonings occur annually among agriculture workers in the U.S. and over the years some have died as a result. That's not the case with those folks who labor on organic farms; mainly due the fact the the relatively small number of pesticides used on organic food are much less hazardous to one's health -- another glaring omission by our friends at Stanford.