A coalition of farmworker advocates and environmental groups has filed a lawsuit against the US Environmental Protection Agency, seeking to force a halt to the use of four organophosphate pesticides. Some of these pesticides have been detected in California's rural schoolyards and homes, Sequoia National Park and Monterey Bay. The four organophosphates at issue in the case are methidathion, oxydemeton-methyl, methamidophos and ethoprop. They are used primarily in California on a wide variety of fruit, vegetable, and nut crops.

'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 in the case, filed in U.S. District Court in San Francisco.

'It is inexcusable for EPA to allow use of pesticides that they know are harming people, especially children.'

The lawsuit alleges that the four pesticides were registered and are used in violation of the Federal Insecticide, Fungicide, and Rodenticide Act and the Endangered Species Act.

The plaintiffs seek a ruling that requires the EPA to make new re-registration eligibility decisions for the four pesticides.

The EPA has documented that 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 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.

The EPA has long recognized that the four organophosphates can poison farmworkers. Yet in 2002 and 2006, the agency decided that growers could continue using these poisons without considering the risks posed to rural children and families when these four 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.

The four poisons at issue in the lawsuit are all organophosphate pesticides derived from nerve gas developed during World War II.

They harm humans and wildlife by inhibiting the ability to produce cholinesterase, an enzyme necessary for the proper transmission of nerve impulses.

Symptoms include muscle spasms, confusion, dizziness, loss of consciousness, seizures, abdominal cramps, vomiting, diarrhea, cessation of breathing, paralysis, and death. Acute poisonings can cause 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 organophosphates, each of the pesticides targeted in the lawsuit poses unique risks to children, farmworkers, and wildlife.

Exposure to methidathion is believed to cause cancer. In 2008, the California Department of Pesticide Regulation listed methidathion as a toxic air contaminant because of methidathion's carcinogenicity and neurotoxic effects.