Than the One it's Replacing
Sterile Soil, Dirty Hands
An EPA-approved pesticide is worse than the one it's replacing
By Tom Philpott
Grist Magazine, Dec 6, 2007
In October, the U.S. Environmental Protection Agency granted temporary approval for use of methyl iodide, a highly toxic fumigant favored by large-scale strawberry and other fruit growers to sterilize soil ahead of planting.
The move generated outrage among scientists, though it didn't get much play in a news cycle dominated by the presidential election and high oil prices.
About a year before the unfortunate decision -- one of the most disputed in the EPA's history -- EPA director Stephen Johnson appointed a woman named Elin Miller to a high post within the agency. Before swinging through the revolving door to work as a regulator, Miller worked as CEO of the North American arm of Arysta, the Japan-based chemical giant that markets methyl iodide under the brand name Midas. Before that, Miller worked at Dow Chemical, "overseeing the company's public affairs, global pest management, and Asia Pacific operations," an EPA press release states, without an ounce of shame.
Coincidentally or not, weeks after the EPA gave methyl iodide the thumbs up, Arysta got snapped up by a European buyout firm for a cool $2.2 billion. Talk about the Midas touch.
In this age of Halliburton and Blackwater, none of this counts as remarkable or generates much discussion. Like a toxic fumigant, unchecked crony capitalism spreads a cynical haze over the political landscape. If we're powerless to stop the slow-motion calamity in Iraq, what can we do for a bunch of migrant farmworkers?
Yet each bite we take ties us to the people who grow our food. The methyl iodide situation deserves more thought.
For most of agriculture's 10,000-year history, farmers have succeeded or failed based on their ability to nurture life within soil. The microorganisms and earthworms that thrive in healthy soil metabolize nutrients and make them available for crops. They also convert animal and vegetable waste into humus, thus regenerating their own habitat and maintaining that thin layer of topsoil on which all terrestrial life depends.
In modern agriculture, however, soil operates as a medium, not a habitat: It exists to transfer synthetic, pre-metabolized nutrients from factories to crops. In this regime, any life form found in soil is at best innocuous -- and at worst a threat. When a vast field is planted in the same crop year after year, its pests concentrate in the soil, waiting to strike.
No longer an ally to farmers, life in the soil becomes a problem in need of solution. Rather than nurture it, the farmer's task becomes to eradicate it.
That's where the nation's industrial strawberry farmers -- as well as Florida's large-scale tomato growers -- find themselves. They literally fear their soil, fretting that it harbors microscopic roundworms called nematodes that feed on the roots and leaves of plants, endangering the harvest.
For decades, the preferred answer for large-scale fruit growers has been to literally sterilize soil with methyl bromide, a highly toxic fumigant sprayed onto soil before planting. Methyl bromide kills everything it contacts, turning the soil into an inert medium.
But sterilizing dirt turns out to be a dirty business: methyl bromide's death-dealing powers aren't limited to microorganisms. It has proved extremely toxic to humans and is one of the globe's most powerful ozone-depleting substances.
Way back in 1987, the United States agreed to phase out methyl bromide by 2005, under the Montreal Protocol -- a pact largely credited with saving the ozone layer. Since then, evidence of gruesome harm to farmworkers and their offspring caused by methyl bromide has piled up.
And yet, U.S. farmers still spray millions of pounds of methyl bromide onto fields each year, under exceptions to the Montreal Protocol strenuously negotiated by the Bush administration. In 2006 -- the year after the Montreal ban was supposed to become complete -- California strawberry farmers actually increased their methyl bromide use by 5 percent, applying it to an additional 2,200 acres. At a recent meeting of Montreal pact signees, Bush secured approval for U.S. farmers to use 11.8 million pounds in 2008 -- more than a third of the pre-treaty level.
The compound attacks the central nervous system, and damages the lungs and kidneys. It has been linked to reproductive disorders, including birth defects. Since farm fields directly abut subdivisions in California's agriculture-heavy counties, its use imperils not only farmworkers but also nearby residents. Clean Water Action of California cites 395 cases of methyl bromide poisoning between 1999 and 2004, the years when the phaseout should have been entering its final stage. And that number may be wildly low, since most migrant farmworkers, particularly undocumented ones, have at best limited access to medical care.
The U.S. government's official opinion on methyl bromide has been: we can't fully ban it until we find a suitable alternative. Yet methyl iodide, hailed as the answer, might be yet more toxic.
Just before approving methyl iodide in October, the EPA received a blunt letter [PDF] signed by 54 prominent scientists, including the Nobel chemist Roald Hoffman, laying out the case against the compound. "Alkylating agents like methyl iodide are extraordinarily well-known cancer hazards in the chemical community because of their ability to modify the chemist's own DNA," the scientists warned.
Susan Kegley, senior staff scientist for the Pesticide Action Network of North America, told me that methyl iodide is so carcinogenic that scientists have used it for years to induce cancer in lab tissue.
Do we really need to subject farmworkers as well as people who live near farm fields to this stuff, in order to secure a steady supply of industrial -- and flavorless -- tomatoes and strawberries?
To perform the bit of mental gymnastics that makes sterilizing soil with highly toxic substances seem not only necessary but desirable, you have to see agriculture as an industrial process whose main goal is maximum yield.
But the PANNA website lists all sorts of low-tech solutions to the nematode problem, including good old-fashioned crop rotation. And Kegley also recommends a return to old seed varieties that developed before this era of sterilized soils.
"The 'giant red' -- but tasteless -- strawberry variety that's popular now doesn't do very well in non-fumigated soil," she says. "But the smaller, less perfect-shaped strawberries that organic farmers are using now are very resistant to soil pests and fungi." As a bonus, she adds, such strawberries actually taste good. "That's the direction we're going to have to move in if we want to get beyond fumigants."
Indeed, back when farmers grew strawberries that could fend for themselves, the chemical companies had to scramble to get them to accept fumigants in the first place. Farmers had no idea that nematodes existed, much less that they might be reducing yields. Methyl bromide originated as a byproduct of the process for making leaded gasoline in the 1940s, and the petrochemical industry strained mightily to sell it to farmers. This firsthand account by a man who worked as a sales rep for Shell Oil at the time documents the elaborate machinations he went through to demonstrate the benefits of fumigation.
Even then, the government pitched in. The man credits "the generous help of [the USDA] Extension Service" with helping him convince farmers to sterilize their fields.
Of course, in the decades since, hybridized seed varieties have been developed that literally need sterile soil: and thus sacrifice farmworkers' health to bring us tasteless strawberries. It's the mind-set that got us to this point, not microorganisms in the dirt, that needs to be attacked.