Over objections from its own scientific advisers, the Schwarzenegger administration yesterday issued its final approval of a highly toxic pesticide that conventional strawberry growers say is critical to their $2 billion industry.
Speaking in a conference call to reporters, Mary-Ann Warmerdam, whom Schwarzenegger appointed in 2004 to direct the state's Department of Pesticide Regulation, said that "methyl iodide is the most evaluated pesticide in the department's history."
That evaluation process included the appointment of a panel of scientists hand-picked from universities and research institutions across the country. Known as the Scientific Review Committee, its job was to help the regulation department consider how toxic methyl iodide might be to farm workers and people who live near strawberry fields.
Arguably, no one is more steeped in the science of methyl iodide and its potential health effects than these eight scientists. And every member of the panel had strenuously objected to the pesticide's approval.
"It is my personal opinion that this decision will result in serious harm to California citizens, and most especially to children," wrote panel member Theodore Slotkin, a professor of pharmacology and cancer biology at Duke University, in an e-mail yesterday.
His statement echoed those from the seven other scientists on the panel, who began publicly criticizing Warmerdam back in April when the DPR announced its initial plans to let California growers use methyl iodide in their fields.
Methyl iodide is a fumigant used by farmers to sterilize soil before plants go in. It was developed as an alternative to methyl bromide, which is being phased out under international treaty because it damages the ozone layer.
But while methyl iodide is safe for the ozone, lab tests show it causes cancer and miscarriages in rabbits.
Earlier this year, Slotkin and the other panel members issued a report warning that methyl iodide is too toxic to be used safely outside of a laboratory. Agreeing with the assessment by staff scientists at the regulation department, they said that exposure to more than 0.8 parts per billion of methyl iodide over an eight-hour work day could cause cancer or miscarriage in farm workers.
The exposure level approved by the regulation department on Wednesday is 96 parts per billion – 120 times higher than the levels staff scientists and panel members say is safe.
"If [the Department of Pesticide Regulation] had said at the outset that they would ignore the science if it didn't suit them, none of us would have participated in the review, I'm sure," said panel-member Paul Blanc, Chief of the Division of Occupational and Environmental Medicine at University of San Francisco, speaking in an interview on Wednesday night.
This isn't the first time scientists have spoken out against the use of methyl iodide as a pesticide.
In 2007, when the U.S. Environmental Protection Agency was considering approving methyl iodide, it received a letter from 54 scientists – including four Nobel laureates – urging the agency to deny registration. "We are perplexed that U.S. EPA would even consider the introduction of a chemical like methyl iodide into agricultural use," the scientists wrote.
Ultimately, the EPA did approve methyl iodide in agricultural use at exposure levels many times higher than what will be allowed in California, where state law requires a separate review process. However, in August, the EPA said it will take another look at methyl iodide, in response to a request from Sen. Dianne Feinstein.
Currently, 47 states allow farmers to use methyl iodide. In June, Washington State's department of agriculture declined to approve the fumigant, citing concerns about farmworker safety.
Of particular issue to the scientists on California's review panel is the possibility that pregnant women or children might come into contact with methyl iodide or its fumes.
If methyl iodide can cause both brain damage and fetal miscarriage, they argue, then even small amounts of it might also cause subtle, hard-to-detect damage in the brains of developing fetuses or young children, such as reduced IQ.
The Department of Pesticide Regulation, they say, neglected to study these potential effects. "We were actually, I don’t want to use the word horrified that there would even be a consideration of registration without data about neurotoxicity," said Ronald Melnick, a senior toxicologist at the National Institutes of Health, in an interview last June.
In his e-mail late night, Duke's Theodore Slotkin said he has seen no reassurance "that the proposed standards of exposure will provide adequate safety margins to prevent neurobehavioral damage to children."
In the final approval notice, Department of Pesticide Regulation director Warmerdam addressed the scientists' concern about neurotoxicity: "DPR risk managers reviewed all the information available to them and concluded, consistent with the U.S. EPA's evaluation, that a [study of neurotoxic effects on developing fetuses] would not be required," she wrote.
Warmerdam read aloud a list of rules that farmers will have to follow when using methyl iodide. The list includes buffer zones, department-approved tarps and notification procedures. Many of the regulations have been strengthened since the department's initial approval in April.
"With these health safeguards in place," she said, "methyl iodide can be used without exposing workers and the public to harmful levels of [the chemical]."
Immediately after the department's announcement, opponents of the decision held their own conference call. They urged Gov.-elect Jerry Brown to reverse the approval when he takes office in January. Should he fail to take it up, they said, there's always the courts.
"I do not believe this is the last chapter [in the methyl iodide saga]," said panel member and UCSF physician Paul Blanc. "I don't think it's even the next-to-last chapter."