The U.S. Environmental Protection Agency has withdrawn its plan to approve a highly toxic fumigant for strawberries and other high-value crops after California officials, labor unions, environmentalists and others objected that nearby residents and farmworkers could be in danger.
The new pesticide, methyl iodide, is designed to replace methyl bromide, which is banned under an international treaty because it damages the Earth's ozone layer.
Strawberry growers, concentrated mostly in Ventura and Santa Cruz counties, have been searching for nearly 15 years for a fumigant to replace methyl bromide, which they have been phasing out but are still using under exemptions granted by the United Nations. Facing criticism that it was substituting one dangerous chemical for another, the EPA decided not to register methyl iodide, also known as iodomethane. It will reevaluate the pesticide next year.
"EPA's refusal to automatically approve the use of another dangerous chemical as an alternative to methyl bromide is encouraging," said Susan Kegley, senior scientist at the environmental group Pesticide Action Network North America. "They didn't knock it out for good, but it's a good sign that they are holding off."
Fumigants are considered particularly risky among agricultural pesticides. But they also are valuable to growers because a single injection into the soil before planting will sterilize the field and destroy an array of insects, weeds and diseases.
The new pesticide, a gas, does not leave residue in food. But it does evaporate from the soil, exposing farmworkers during application, and small amounts can drift off fields into nearby communities. In animal tests, breathing large doses of methyl iodide killed fetuses, caused thyroid tumors, damaged respiratory tracts and altered thyroid hormones, which can disrupt the development of infants' brains.
Scientists at the California Department of Pesticide Regulation raised numerous health concerns about methyl iodide, which the state has declared a cancer-causing chemical.
"While residues may not be present in crops grown in treated soil, workers and bystanders, as well as residents living near the treated fields, will be exposed to it in the air," Tobi Jones, an assistant director at the state agency, told the EPA in a letter.
