Lawsuit Challenges EPA on Four Deadly Pesticides

The pesticides poison farmworkers and drift onto rural schoolyards and homes


Patti Goldman, Earthjustice, (206) 343-7340, ext. 32
Shelley Davis, Farmworker Justice, (202) 293-5420, ext. 311
Dr. Margaret Reeves, Pesticide Action Network North America, (510) 593-4351
Jay Feldman, Beyond Pesticides, (202) 543-5450, ext. 15
Mae Wu, Natural Resources Defense Council, (202) 289-2409

As part of a campaign to protect people and the environment from toxic chemicals, today a coalition of farmworker advocates and environmental groups filed a lawsuit against the Environmental Protection Agency (EPA) to stop the use of four deadly pesticides derived from nerve gas developed during World War II. Used on a wide variety of fruits and vegetables, these organophosphate pesticides have been detected in rural schoolyards and homes, Sequoia National Park, and Monterey Bay. Countries including Canada and Sri Lanka have banned at least one of these pesticides because of their harmful impacts.

“These four pesticides put thousands of farmworkers and their families at risk of serious illness every year,” said Patti Goldman, an attorney for Earthjustice, the environmental law firm that represents the coalition. “It is inexcusable for EPA to allow use of pesticides that they know are harming people, especially children.”

Children are especially susceptible to poisoning from organophosphates. Exposure can cause dizziness, vomiting, convulsions, numbness in the limbs, loss of intellectual functioning, and death. Some organophosphates also cause hormone disruption, birth defects, and cancer.

“Farmworkers, and all people living in and near agricultural regions, especially children, are at great risk of neurological and developmental damage due to exposure to these toxins,” said Dr. Margaret Reeves, senior scientist at Pesticide Action Network North America, one of the plaintiffs in the lawsuit.

EPA has long recognized that the four organophosphates — methidathion, oxydemeton-methyl, methamidophos, and ethoprop — can poison farmworkers. However, in 2002 and 2006, EPA decided that agri-business could continue selling and using these poisons without considering the risks posed to rural children and families when the pesticides drift into schoolyards, outdoor play areas, and homes. 

“EPA knows that children in rural communities are exposed to these poisons, yet EPA has not even attempted to assess the risks resulting from such exposures,” said Shelley Davis, an attorney for Farmworker Justice. “By ignoring the risks that pesticides pose to our children, EPA has failed us all.”

The lawsuit was brought by Earthjustice and Farmworker Justice on behalf of Pesticide Action Network North America, United Farm Workers, Teamsters Local 890 in California, Sea Mar Community Health Centers, Pineros y Campesinos Unidos del Noroeste, Beyond Pesticides, Natural Resources Defense Council, Farm Labor Organizing Committee. California Rural Legal Assistance is also participating in the case on behalf of Moises Lopez, an individual farmworker in California.

How Bad Are These Four Poisons?

The four poisons at issue in the lawsuit are all organophosphate (OP) pesticides. OP pesticides are derived from nerve gas poisons developed during World War II. They are acutely toxic and cause systemic illnesses to humans and wildlife by inhibiting the ability to produce cholinesterase, an enzyme necessary for the proper transmission of nerve impulses. Symptoms of cholinesterase inhibition include muscle spasms, confusion, dizziness, loss of consciousness, seizures, abdominal cramps, vomiting, diarrhea, cessation of breathing, paralysis, and death. Acute poisonings can also cause chronic (long-term) effects, such as permanent nerve damage, loss of intellectual functions, and neurobehavioral effects. In addition to cholinesterase inhibition, which is common to all OPs, each of the pesticides targeted in the lawsuit poses unique risks to children, farmworkers, and wildlife.


In addition to cholinesterase inhibition, exposure to methidathion is believed to cause cancer. While incident reporting databases vastly under-report actual incidents, methidathion is regularly among the top pesticides associated with pesticide poisonings. In 2001, the Canadian Pest Management Regulatory Agency cancelled all methidathion registrations, noting the high worker and environmental risks and the availability of alternatives. In 2008, the California Department of Pesticide Regulation listed methidathion as a toxic air contaminant because of methidathion’s carcinogenicity and neurotoxic effects. Methidathion has been found in the air far from the farm fields where it is used, such as in Sequoia National Park. 

In 2004, EPA estimated that 90% to 95% of methidathion use occurred in California. Approximately 48,000 pounds of methidathion are applied in California annually, primarily on artichokes, oranges, almonds, peaches, and olives. 


Oxydemeton-methyl (ODM) is a reproductive toxin and is associated with decreased size and viability of offspring, decreased fertility, and decreased size of reproductive organs. It has also been associated with birth defects. Of more than 600 entries in the poison control database regarding ODM poisonings, approximately 5% were farmworkers, 74% were adult bystanders, and 20% were children under six. ODM is documented as causing die-offs in migratory birds. According to EPA, ODM poses severe risks to threatened and endangered species. 

Approximately 130,000 pounds of ODM were used in California in 2005, primarily on broccoli, lettuce, cauliflower, corn, cabbage, and Brussels sprouts. EPA estimates that 75% of Brussels sprouts, 62% of broccoli, and 46% of cauliflower are treated with ODM.


EPA has suggested that methamidophos “poses one of the highest risks to workers of any organophosphate insecticide currently registered.”  It is one of the pesticides that EPA has designated for screening as a potential endocrine disrupting chemical. There are documented die-offs of sage grouse associated with methamidophos use in the potato-growing regions of the Pacific Northwest. This poison is also believed to have significant impacts on honey bees — a field study of the effects of methamidophos on honey bees demonstrated that the chemical can severely reduce the foraging activity of bees for a prolonged period of time after application. Methamidophos use is banned or severely restricted in Kuwait, Indonesia, Samoa, and Sri Lanka as a result of the risks it poses to human and environmental health.

In 2000, approximately 640,000 pounds of methamidophos active ingredient were used in the U.S. Most of this use was on potatoes (77% ), followed by cotton (12%), fresh and processed tomatoes (5%), and California alfalfa grown for seed (5%).


Ethoprop is listed as a “known carcinogen” under California’s Proposition 65 Carcinogen List. EPA has found that ethoprop poses cancer risks to farmworkers far exceeding what the agency considers acceptable for pesticides. There are documented incidents of ethoprop drifting from fields following application and poisoning children and other bystanders in agricultural communities. Ethoprop is also associated with massive fish kills after being used on golf courses before that use was banned. Fish kills have also been documented after application of ethoprop to tobacco fields, which EPA still allows. In the 1980s, the U.S. Fish and Wildlife Service found that ethoprop uses jeopardized the survival and recovery of threatened and endangered species. When released into the environment, ethoprop degrades into other toxic chemicals that also pose cancer and non-cancer toxicological risks of concern.

Approximately 700,000 pounds of ethoprop are used in the U.S. annually. Ethoprop is primarily used on potatoes, sugarcane, and tobacco.

Read the complaint (PDF)

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