Agency approves methyl iodide despite cancer warnings

The US Environmental Protection Agency has approved a chemical for use as a fumigant pesticide that is widely believed to be carcinogenic and mutagenic, dismissing warnings from dozens of chemists. 

The agency’s October 4 decision on methyl iodide (iodomethane) came only days after 54 scientists - including five Nobel laureates - sent a letter to the EPA urging it to delay approval and commission an independent review. 

’As chemists and physicians familiar with the effects of this chemical, we are concerned that pregnant women and the fetus, children, the elderly, farm workers, and other people living near application sites would be at serious risk if methyl iodide is permitted for use in agriculture (80-275 pounds per acre),’ the scientists wrote. 

’I was very sceptical that these guys would listen to us at all, and my scepticism was rewarded,’ Robert Bergman, a University of California, Berkeley chemistry professor who signed the letter, told Chemistry World. ’I don’t think they had any intention of taking our concerns seriously.’ 

"I don’t think they had any intention of taking our concerns seriously" - Robert Bergman

EPA said methyl iodide meets health and safety standards, and its one-year registration will be revisited in 2008 as part of a larger effort to review all fumigants. The new product, to be sold under the name MIDAS, will be widely available this month. 

Arysta Lifescience, which manufactures the chemical, said it worked with EPA and state authorities to ensure that the product is safe. ’Research shows that MIDAS does not deplete the ozone layer, nor does it have an adverse impact on both surface and ground water supplies,’ stated Mike Allan, the company’s global project manager. 

EPA was under some stress to approve the chemical because it is an alternative to methyl bromide - a widely used pre-plant soil fumigant being phased out internationally because it depletes the ozone layer. 

But while methyl iodide breaks down in the lower atmosphere, it can methylate DNA - causing cancer. 

Arysta’s former chief executive, Elin Miller, is now a high-level EPA official. The Japanese company reportedly spent eight years and over $11 million collecting data to convince EPA to register methyl iodide as a pesticide. 

Rebecca Trager is US correspondent for Research Day USA