Chemical consent

The pesticide lined up to replace methyl bromide in California farming is … what?!

Martha Guzman-Acevesof California Rural Legal Assistance spoke against the use of methyl iodide as a pesticide.

Martha Guzman-Acevesof California Rural Legal Assistance spoke against the use of methyl iodide as a pesticide.

Photo By Sena Christian

When scientists use the chemical methyl iodide in a laboratory setting, they slip on gloves and wear ventilation hoods. The chemical is so toxic, they transfer the liquid in sealed tubes with syringes to prevent accidental releases into the air. Sometimes, methyl iodide is used to induce cancer in lab animals.

Experts handle even small quantities of this chemical with extreme care.

Yet the state of California is now considering registering methyl iodide for use as a fumigant pesticide for agriculture. The chemical would replace methyl bromide, an ozone-layer depleter, but critics worry that while methyl iodine doesn’t deplete the ozone, it may, in fact, pose more danger to human health and the environment.

“It’s not a friendly chemical,” said Susan Kegley, a consulting scientist with the Pesticide Action Network. “This is an old technology. This is going backward in creating sustainable agriculture in California.”

Breathing the toxic fumes released by methyl iodide can cause lung, liver, kidney and neurological damage. Acute poisoning causes nausea, dizziness, coughing and vomiting. Additionally, California’s Proposition 65 lists methyl iodide as a known cancer-causing agent.

While critics express concern about the potential impact of this pesticide on farmworkers who would interact with methyl iodide on a regular basis, those who support the registration said the chemical is safe when used properly and argue that California agriculture cannot economically withstand any more restrictions, as farmers already face a water crisis.

“I wish we didn’t need these products, but reality is if we’re going to have a domestic food supply, we have to have them to compete,” said Barry Bedwell, president of California Grape and Tree Fruit League, during a special legislative hearing hosted by the Assembly Labor and Employment Committee last week. “To replant without a soil fumigant is suicide.”

The current fumigant of choice for specialty crops—methyl bromide—controls insects, nematodes, weeds, pathogens and rodents. Applicators inject the gas into the soil 12 to 24 inches deep before a crop is planted; the chemical sterilizes the soil by killing most of the soil organisms. Methyl iodide would function the same way, and would be applied to tomato and strawberry fields, nurseries and orchards across the state.

The international Montreal Protocol required developed nations to phase out the production of methyl bromide (and other substances that deplete the ozone layer) by 2005; but the United States received an exemption, saying it hadn’t yet found a viable and safe alternative.

The U.S. Environmental Protection Agency eventually found what it considered a “safe” alternative in methyl iodide, which it registered in October 2007 during the Bush administration, despite thousands of public comments in opposition and a letter signed by 54 scientists urging former EPA administrator Stephen Johnson to reject registration because of the product’s high risk.

The letter states: “Because of methyl iodide’s high volatility and water solubility, broad use of this chemical in agriculture will guarantee substantial releases to air, surface waters and groundwater, and will result in exposures for many people. In addition to the potential for increased cancer incidence, U.S. EPA’s own evaluation of the chemical also indicates that methyl iodide causes thyroid toxicity, permanent neurological damage, and fetal losses in experimental animals.”

After the EPA’s registration, 47 other states followed suit. California’s Department of Pesticide Regulation had already begun its registration process when, in July, state Assemblyman William Monning and Sen. Mark Leno authored a letter—signed by 25 legislators—urging an external scientific review panel to publicly consider public-health risks. Two days later, DPR agreed (the hearing will be held in late September).

During last week’s hearing, Martha Guzman Aceves of California Rural Legal Assistance said that the state’s farmworkers and their children will be most affected by methyl iodide. These workers—70 percent of whom lack health insurance—often don’t report getting “drifted” by toxic pesticides, accepting exposure as a regular risk of their occupation.

But farmers also care about the health of farmworkers and their own families who may live on the land, and don’t spray pesticides unnecessarily, a panel of farmers said at the hearing.

“Fumigation is taken very seriously, there’s no doubt about it,” said Bill Lewis, president and CEO of Arysta LifeScience North America, the manufacturer of Midas, the brand name of the fumigant.

He added that he has received no reports of incidents in other states where farmers use methyl iodide. He said this fumigant—which is professionally applied—would actually reduce the use of other toxic herbicides and insecticides.

At the hearing, Jim Cochran, an organic farmer, talked about his experience growing strawberries successfully without soil fumigants since 1983. Organic farmers manage soil pathogens and fertility through such practices as crop rotation, composting, and the application of broccoli and mustard residues.

Cochran warned of the impact of registering methyl iodide on agriculture through an analogy to the automobile industry: “We have an opportunity like what Detroit missed 15 years ago.” The point being that the American automobile industry ultimately failed not because government over-regulated, but because industry refused to evolve.