After years of debate and strong opposition from scientists and environmental groups, the state’s Department of Pesticide Regulation (DPR) gave final approval on Dec. 1 to using the pesticide methyl iodide on California’s strawberry crops.
Methyl iodide, also known as iodomethane, is listed by the state as a carcinogen under Proposition 65. It’s a fumigant injected or drip-irrigated to eradicate weeds, insects, and plant diseases, and it replaces methyl bromide, a pesticide banned by the 1989 Montreal Protocol for its ozone-depleting properties.
The chemical’s registration comes despite studies linking its use to cancer and other serious disorders, and a risk assesment report by DPR scientists released in 2009 stating methyl iodide fumigation “results in significant health risks for workers and the general population.”
However, according to DPR director Mary Ann Warmerdam, strict state controls on the pesticide’s application will curb the risks to public health.
“We based our decision on the risk assessment by our scientists and a risk-management process that determined what measures are required to keep exposures to methyl iodide within safe levels, Warmerdam said in a statement. “With these safeguards, methyl iodide can be used without exposing workers and the public to harmful levels.”
Following the agency’s decision, a coalition of farmworker and environmental advocacy groups, including scientists, urged Governor-elect Jerry Brown to overturn it.
“This just puts a big black blotch on the environmental legacy of [Gov. Arnold] Schwarzenegger’s administration,” said Susan Kegley, a chemist and director of the Pesticide Research Institute in Berkeley.
“We think this is going to be a disaster for people living around strawberry fields, like Santa Maria, and all over the Central Coast where there will likely be some use of this chemical,” she added.
In a message posted online, United Farm Workers’ president Arturo Rodriguez voiced his displeasure and said field workers will be the first to feel the effects.
“It looks like farmworkers will continue to be society’s canaries,” Rodriguez wrote.
The U.S. Environmental Protection Agency (EPA) approved the pesticide in October 2007 as a potential replacement for methyl bromide; however, California was one of three states—along with Washington and New York—that initially refused to permit its use. The DPR received more than 50,000 public comments since April, most expressing concern about potential health effects to those living near strawberry fields.
According to scientists, methyl iodide is four times more toxic than its predecessor, and in addition to being linked with cancer and thyroid problems, the pesticide could lead to miscarriages, as well as birth defects and brain damage in high doses.
“With all the restrictions in the world, you can’t keep people from making mistakes,” Pesticide Research Institute’s Kegley said. “We’re humans. Train all you will, but accidents are going to happen.”
Among DPR’s regulations for use, allowable exposure limits for methyl iodide will be set at 96 parts per billion, about half of the limit allowed by the U.S. EPA. In addition to reduced application rates, larger buffer zones, and a ban on nighttime fumigation, methyl iodide use will be prohibited within a half-mile of hospitals, nursing homes, and in-session schools.
County agricultural commissioners will be responsible for enforcement and have the authority to deny permits and punish unlawful users.
Edwin Moscoso, an agricultural inspector/biologist with the San Luis Obispo Ag Commissioner’s Office, said methyl bromide is being used in the county and guidelines for the use of its replacement, methyl iodide, haven’t been developed yet.
“We will be working on this with the Department of Pesticide Regulation and everything should be worked out next year,” Moscoso said.
Jesse Arnold, a SLO county health commissioner, is concerned about the new pesticide and questions the logic of its approval.
“Methyl bromide is being phased out because it was found to hurt the ozone layer,” Arnold said. “The only advantage to its replacement [methyl iodide] has been that it doesn’t hurt the ozone but it’s far more toxic. It doesn’t make sense.”
Arnold said the issue will be discussed at the next county health commission meeting, set for Jan. 10, when a representative of the county Ag Commission will field questions about pesticide regulation.
According to DPR, the pesticide will be applied primarily to strawberries throughout the state, but may expand to other high-value crops such as tomatoes and flowers.
Arysta LifeScience Corp. manufactures the five products containing methyl iodide—scheduled for registration on Dec. 20—under the brand name Midas. Emergency regulations, if approved, will classify the pesticides as a restricted material, requiring a permit from the county’s agricultural commissioner to the Office of Administrative Law. Public comment on the emergency regulations will be taken by the office until Dec. 13.
But methyl iodide’s opponents aren’t throwing in the towel just yet. According to Kegley, the environmental group Earthjustice will file a lawsuit to block the registration, charging the DPR with violating elements of the California Environmental Quality Act and the federal Birth Defects Prevention Act. ∆
Jeremy Thomas is a staff writer for New Times’ sister paper Santa Maria Sun. He can be contacted at firstname.lastname@example.org. New Times Staff Writer Robert A. McDonald contributed to this article.