A soil fumigant that strawberry growers in San Luis Obispo County have been hoping to use may be too hazardous to safely apply, a key scientific review panel said.
That team of experts raised serious concerns about the use of methyl iodide on California farmland, saying the highly potent chemical poses significant health risks to workers and the general population.
The report from the state-appointed group comes as a blow to farmers and the makers of the fumigant — the Tokyo-based Arysta LifeScience Corp. — who have been fighting for more than a year to get the chemical approved in California.
At stake for farmers is the loss of a potential replacement for methyl bromide, which was phased out by the federal government in 2005 because it damages the Earth’s protective ozone layer.
“The products that we have just don’t do the job,” said Barry Bedwell, president of the Fresno-based California Grape and Tree Fruit League.
Fumigants are an effective tool for clearing the soil of pests, diseases and weeds and are widely used in the strawberry industry, commercial nurseries and in the planting of new trees and vines.
If approved, San Luis Obispo County farmers, particularly strawberry growers, would likely use methyl iodide, said Bob Lilley, county agricultural commissioner.
Other treatments, such as telone or metam sodium, are available, but many growers believe methyl iodide comes closer to achieving the same results as methyl bromide.
The federal EPA and virtually every other state has approved methyl iodide. But the eight-member committee reviewing the chemical for use in California found the risk of using methyl iodide, a known carcinogen, is too great, especially for workers whose protections are commonly “inappropriate, inadequate or inaccessible.”
“Due to the potent toxicity of methyl iodide ... adequate control of human exposure would be difficult, if not impossible,” wrote John Froines, chair of the review committee and a UCLA professor of environmental health sciences.
Listed by the state as a carcinogen, methyl iodide can cause thyroid cancer, respiratory tract lesions and neurological effects in laboratory animals. It also poses a threat to developing fetuses.
Mary-Ann Warmerdam, director of the Department of Pesticide Regulation, will review the panel’s findings and her own department’s research as she decides if farmers can use the chemical and if so, under what restrictions.
A department spokesman said Warmerdam is expected to make a decision soon.
Warmerdam has to balance the need for the pesticide with its toxicity, Lilley said.
Environmentalists praised the panel’s review, saying the scientists confirm what they have been saying for months: Methyl iodide is too dangerous.
“Ultimately the decision rests with DPR,” said Paul S. Towers, state director of Pesticide Watch in Sacramento. “They can either choose to ignore the science and move forward with a serious toxic chemical or listen to the science and community concerns and look for safer, long-term solutions.”Advocates have also threatened the possibility of suing the state if methyl iodide is approved.
“If they don’t make a decision that is protective of California, there are other routes we can take,” said Susan Kegley, a consulting scientist with Pesticide Action Network North America.
Supporters of the fumigant say despite the panel’s report, they hope the state agrees to register the chemical for use in the state.