A Dangerous Pesticide That Will Soon Be All Over California


Jeff Kubina/flickr

Several years ago, looking into the differences between organic and conventional farming methods, I focused on strawberries as a case study.

At the time, conventional growers depended on methyl bromide, a potent neurotoxin that is injected into the soil to kill pests and diseases. The applicators wore full-body suits with gas masks. The ground was covered in plastic to help keep the toxic gas contained. These fields looked like something out a futuristic moonscape, covered in plastic with workers in full hazmat suits. It was just one of the many toxic chemicals used in the conventional strawberry regime. I described all this in a chapter of my book Organic, Inc. Many people told me that after they read that chapter they never bought a conventional strawberry again.

Methyl bromide was always particularly controversial. Law suits were filed because of drift of this pesticide to nearby public schools on the central coast of California, the heart of the strawberry industry. The issue for the courts: Was the drifting chemical at sufficiently low levels to be safe?

Like methyl bromide, methyl iodide is most hazardous to those who use it in the fields and to those who come into contact with
its drift.

You had the usual sides drawn, with growers who feared losing a cherished tool and farmworker and environmental advocates worried about toxicity. The result was that the state set what it considered a "safe level" of use, with widened buffer zones and requirements on when the chemical could be sprayed. But I found the evidence of a "safe level" less than convincing. Knowledge about the effects of chronic exposure to the chemical was not iron clad and a panel that explored the issue was split.

Organic growers, of course, avoided all chemicals and relied on crop rotations, beneficial insects and vacuums to suck up the bugs. (A New York Times article explains organic methods here). Though their yield was lower, organic farmers were successful because of the premium paid for organic.

Methyl bromide eventually was phased out under a UN treaty because it contributed to a hole in the ozone layer. Growers got extensions for years to keep using the chemical, but they knew the end was in sight and so turned to other chemicals. Methyl iodide was the most promising, though even conventional growers told me that they thought the chemical was more toxic than methyl bromide. Its saving grace—no ozone depletion in the atmosphere.

This week, California, which has among the most rigorous pesticide regulations in the nation, approved methyl iodide for use. This came despite the unanimous findings of its own scientific panel against approval of the chemical. California Watch quoted a member of this panel.

"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.

But the state overruled the panel and found that, based on a risk assessment, the pesticide could be safely used. In doing this, they followed 47 states. Had they outlawed it, California growers no doubt would have argued they were no longer competitive.

Like methyl bromide, methyl iodide is most hazardous to those who use it in the fields and to those who come into contact with its drift. It does not linger, like other pesticides, on the fruit itself. I wonder, if the state or even the EPA would have thought differently about the pesticide, if there was a consumer risk. Farm workers and farm communities tend to be abstract and distant—we don't know who these people are. Often, because they are immigrants, they remain silent. We don't attend the schools abutting the fields. I just wonder, if we did, whether the outcome would have been different.

This post also appears on chewswise.com.