- PHOTO BY STEVE E. MILLER
- PERFECTION AT A PRICE : A powerful fumigant known as methyl bromide is still used on SLO County strawberry fields, in spite of a mandated phase-out of the ozone-depleting chemical by 2005.
used as a pesticide on strawberries on the Central Coast.
Stockpiles of the toxic gas are legal for growers to use on strawberries in the United States—the result of an “essential use” exemption from the Montreal Protocol. The agreement required a halt to the manufacture and import of methyl bromide and mandated a “phase-out” of the chemical by 2005.
Far from tailing off, its use has held steady in Santa Barbara County over the past few years, and is seeing an increase SLO County.
According to the state’s Department of Pesticide Regulation, farmers in SLO County fumigated 129 acres of strawberries in 2006, 492 acres in 2007, and 1,045 acres in 2008.
SLO County Deputy Ag Commissioner Janice Campbell attributed the upswing in methyl bromide to a rise in strawberry production in the county, which nearly doubled its strawberry acreage from 800 in 2005 to 1,523 in 2008.
Campbell said pressure on growers to convert from vegetables to strawberries—a higher cash crop—coupled with stricter clean air requirements in places like Ventura County is pushing strawberry growers to Nipomo, Arroyo Grande, and the Oso Flaco Valley—the latter being the only area in the county where methyl bromide is still being used, according to SLO County Agricultural Inspector Lisa Chadwick.
Growers will likely continue to use the stockpiled methyl bromide remaining until the supply is used up, because it’s unmatched as a pest-eradicator.
“There’s not a replacement control method that works just as well,” Campbell said. “The strawberry growers don’t have any other alternatives, so they’re trying to hold on to what they have.”
In fact, a committee established by the Montreal Protocol found no suitable alternative to methyl bromide as a pesticide for strawberries, though many farmers have switched to 1,3-Dichloropropene, a fumigant sold under the brand name Telone.
Since it’s not as effective a pest control as methyl bromide, farmers tend to alternate between the two, Campbell said.
Unlike other options, methyl bromide can penetrate deep within the soil and kill weed seeds and microscopic pests called nematodes.
According to SLO County Ag Commissioner Bob Lilley, strawberries are so disease-prone that pre-plant fumigation is considered necessary.
“The growers prefer methyl bromide because it works the best,” he said. “It’s a broad-spectrum fumigant, so it pretty much kills all the major organisms that would be a problem for strawberries.”
According to the Pesticide Action Network of North America, California strawberries are one of the largest single-crop users of methyl bromide in the world. Farmers treat their fields with it before planting, generally during the fall fumigation season that runs from August to October. The chemical is “shanked,” meaning it’s injected into the soil with a plastic tarp pulled behind it to hold the gas in.
The Department of Pesticide Regulation classifies methyl bromide as “restricted,” meaning it can only be possessed or used under the supervision of licensed or certified inspectors. Growers are required to qualify for a site- and time-specific restricted materials permit from the county Ag Commissioner’s office.
In addition to emissions standards and other regulations, the permit requires the grower to set up a buffer zone around the perimeter of the field to protect the health and safety of neighbors.
“We have a wide range of regulations and permit conditions governing the use, so that’s our job to enforce those,” Lilley said. “A permit is a discretionary thing, like a driver’s license. It’s not a right. In some situations, we might deny the permit if it were necessary.”
While there’s no indication of the amount of methyl bromide remaining in stock, Campbell said she expects its use to level off in 2009 due to the struggling economy.
Environmentalists, meanwhile, continue to raise concerns not only over the fumigant’s effects on soil and air quality, but its toxicity in humans.
According to the National Pesticide Information Center, methyl bromide is highly toxic and causes cell damage in humans. It’s also corrosive to skin and eyes and can even cause death in cases of severe poisoning.
Linda Krop, chief counsel of the Environmental Defense Council, said her group is concerned by the health danger posed by exposure to the chemical by farm workers and neighbors of fields where it’s applied.
“We oppose the continued use of methyl bromide,” Krop said. “We don’t think it’s adequately regulated to protect public health and the environment, and we’d really like to see the government move forward on its promises to phase it out.”
As supplies of methyl bromide wane, state lawmakers are debating the approval of a replacement pesticide: methyl iodide.
California classified methyl iodide as a carcinogen under a provision of Proposition 65 in 1986. It’s one of few states, besides Washington and New York, that has yet to approve the chemical for use as a fumigant.
The federal Environmental Protection Agency cleared the chemical for use without restrictions in 2008. According to its website, the agency has no information on the carcinogenic effects of methyl iodide in humans, but has “limited evidence” it causes cancer in animals.
According to Lilley, methyl iodide is undergoing a review for approval by state lawmakers. On Aug. 19, state legislators held a hearing in Sacramento to discuss the potential hazards of methyl iodide. The DPR will also be holding a public Scientific Review Panel hearing on the matter on Sept. 24 and 25.
Krop said the Environmental Defense Council opposes methyl iodide as a replacement, but the sooner methyl bromide is gone, the better.
“It really needs to be phased out,” she said. “The farmers have known for years that they have to switch to other alternatives.”
Jeremy Thomas is a staff writer for New Times’ sister paper, the Santa Maria Sun. He can be reached at firstname.lastname@example.org.