Skip to Navigation
Skip to Content
Share this page


Welcome to PSR's Environmental Health Policy Institute, where we ask questions -- then we ask the experts to answer them. Join us as physicians, health professionals, and environmental health experts share their ideas, inspiration, and analysis about toxic chemicals and environmental health policy.


More Topics »

The Story of Strawberries

Posted on February 24, 2011

By Susan Kegley, PhD

This essay is in response to: How does our food production system drive our exposure to toxic chemicals?

I remember looking forward to May when I was a child—strawberry season! I would go to a local farm with my grandmother to pick sweet red strawberries for jam, shortcake, and just plain eating. It was a special treat because the luscious fruit was only in season for a short time each year, and the harvest was limited by farmers’ need to rotate to a different crop after a few years. Fast-forward to 2010 and you’ll find shoppers casually putting strawberries in their baskets in January at inflation-adjusted prices comparable to those in 1970. But what appears to be a success of our food production system (More! Cheaper! Easier!) actually comes at great cost to our health and the environment.

Strawberries are the poster child that reveals how our current methods of producing food have placed us in harm’s way. The most damaging part of modern conventional strawberry farming begins before the berries are planted. Instead of rotating crops to clear the soil of disease, conventional strawberry growers inject highly toxic fumigant pesticides such as methyl bromide, Telone, metam sodium, and chloropicrin into the soil at hundreds of pounds per acre. These chemicals are gases (or nearly so) at ambient temperatures and rapidly escape from the soil and the tarps placed on top of the soil, drifting into neighborhoods, schoolyards, workplaces, and parks at concentrations that have not infrequently been high enough to cause mass evacuations and hospitalizations. Lower concentrations of these chemicals in the air near application sites are more common, and although the immediate effects are less obvious, animal studies tell us that chronic effects such as respiratory disease, cancer, and developmental impairment are likely.

In its infinite wisdom, the US EPA recently (2006) registered a new fumigant—methyl iodide—as a replacement for methyl bromide, which is being phased out because it is a stratospheric ozone depletor. From my chemist’s point of view, this decision takes us from the frying pan into the fire. Methyl iodide is a potent alkylating agent that is a carcinogen, a thyroid toxicant, and a neurotoxicant. The toxic effect that was observed in laboratory animals at the lowest dose is fetal death late in pregnancy—stillbirth. Methyl iodide interferes with the proper balance of thyroid hormones necessary for maintaining a successful pregnancy and the fetus is aborted. With no hint of irony, in 2009 EPA rewarded the manufacturer of this pesticide, Arysta Life Sciences, with an Ozone Layer Protection Award for the introduction of methyl iodide. Images of the fox guarding the henhouse should immediately come to mind, and one should begin to wonder whom, after all, the EPA is protecting.

Once strawberries are planted, a continuous regimen of insecticides and fungicides are applied. Because of special breeding to maximize yields under conventional production methods (i.e., in fumigated soil), conventional strawberries no longer have much resistance to disease and predation by insects. It all adds up, and over the course of 2009 in California, 9.86 million pounds of chemicals were applied to 39,800 acres of strawberries, a total of 248 pounds per acre. In 2008, the US Department of Agriculture found 54 different chemical residues on strawberries ( The carcinogenic fungicide captan was found on 55% of samples tested. The reproductive toxicant fungicide pyraclostrobin was found on 52.9% of samples tested. And then there are the 52 others. And then there are the numerous unknown “inert” ingredients with unknown toxicity that accompany the pesticide active ingredients. EPA legally cannot even publicly identify these chemicals because this is “confidential business information.”

While the acute effects from fumigant poisonings are obvious, we don’t know precisely what effects the more insidious low-dose chronic exposure are having on the health of our population. What we do know is that the age-adjusted incidence of certain diseases that have been epidemiologically linked to pesticides is increasing—non-Hodgkins lymphoma, childhood leukemias, early breast cancer, asthma, autoimmune and thyroid disease, and developmental disorders. Perhaps it’s time to re-examine our approach to food production.

Individuals can to some extent protect themselves and their families by buying organic food, but systemic change is necessary to reduce the population-wide burden of pesticide exposure. This end result can best be achieved using both carrots and sticks. The necessary “sticks” include elimination of soil fumigants as an option for food production (as Europe has done) and increasing restrictions that make it more difficult and expensive to acquire and use other toxic pesticides. “Carrots” should include a national investment in the wide dissemination of existing agricultural production methods that don’t rely on toxic chemicals and research into new ones. Support for farmers to transition to these methods would also be helpful, such as improved insurance and loan programs that don’t require the use of toxic pesticides. Working together, EPA and the USDA could protect farmers, farm workers, rural residents, and consumers. The challenge will be to motivate them to do so.


de'myha said ..


December 5, 2012
Ethel said ..

As one of many who personally experience serious health effects from agricultural and structural pesticides that have been used in my work place as well as public places such as schools, restaurants, grocery stores and offices, as well as on neighboring farms, Dr. Susan Kegley's article is timely and extremely important. Those who currently inform the EPA or USDA of chemical injury from exposure to pesticedes become a "public enemy" in the eye of these entities. The person reporting the incident becomes a target of unreasonable "testing" and interrogation often resulting in the requiring of detrimental and invasive medical testing. All this when the effects of exposure to these pesticides is already known. In the eyes of these governmental agencies it is the responsibility of the injured to prove beyond any doubt that and only that pesticide is the cause of the problem. In a time when medical costs and insurance premiums are overwhelmingly huge for our country in general, it is time to look to the root causes of so much illness. When the government chooses to protect the profits of chemical companies over the health of its people, huge medical costs are inevitable. Only through prevention of disease and the support of healthy foods, air and water will our country's overall health improve and the costs of mecical treatment go down.

March 7, 2011
Arlene said ..

Excellent article Thanks so much for your good work

February 28, 2011
sean said ..

excellent. especially ideas on how to move forward. thank you

February 27, 2011

Comments closed.