Pesticide sought by Calif. growers
Foes want to stop known carcinogen.
Robert Rodrigouz
Fresno Bee
09/13/2009
A highly potent chemical capable of clearing farmland of pests, disease and weeds is attracting fierce opposition from environmental groups and some scientists in California -- even as growers look to it as a crucial replacement for a banned fumigant.
The makers of methyl iodide have asked the California Department of Pesticide Regulation for permission to use the powerful chemical in the lucrative California market.
The state is a leading producer of fresh fruits and vegetables, and growers here use a lot of fumigant. Access to the state's market could be a boon to Tokyo-based Arysta LifeScience Corp., producers of methyl iodide.
But standing firmly in their way are environmentalists and scientists who say the fumigant -- a known carcinogen -- is highly toxic and poses a serious health threat.
"This is worth going to the mat over," said Susan Kegley, a scientist with the Pesticide Action Network North America in San Francisco. "This is so toxic, and exposure to it is almost guaranteed."
For growers and farm industry groups, the stakes are high. They see methyl iodide as a drop-in replacement for methyl bromide, which was phased out by the federal government in 2005 because it damaged Earth's protective ozone layer. Like methyl iodide, methyl bromide is injected into the soil and covered with a tarp to prevent gas from escaping.
Although methyl bromide is still used, growers need special permission. And growers say alternatives, such as telone and metam sodium, are not as effective at killing pests, diseases and weeds.
Without good pest control, crop yields and product quality will suffer, farmers say.
"The bottom line is that growers need soil fumigants to be sustainable and produce the necessary amount of food at prices that consumers demand," said Barry Bedwell, president of the Fresno-based California Grape & Tree Fruit League. "So if not this material, then what?"
But California pesticide regulators aren't ready to give the fumigant a free pass.
The state's preliminary review of toxicology studies found exposure to methyl iodide in animals can cause fetal death, delayed fetus development and disturbed thyroid function. The state has called for a review of the risks by a scientific panel whose first meeting will be Sept. 24-25 in Sacramento. Both sides plan to weigh in during the public testimony portion of the meeting.
California department of pesticide officials expect to rule on Arysta's request by the end of the year.
Officials with Arysta LifeScience Corp. hope they can secure California's approval, noting that 47 other states have accepted the chemical.
The U.S. EPA registered the fumigant in 2007 with restrictions on its use, including the use of trained applicators, buffer zones around treated fields and bans within a quarter-mile of sensitive areas such as schools, hospitals and nursing homes.
As a result of the EPA's ruling, many states have allowed its use. But California, at the urging of environmentalists, is asking for a further scientific review of the risks.
"It is not surprising that we are getting this kind of reaction," said Michael Allan, global business development manager for Arysta. "There still needs to be a lot of general education about the value of this tool. But people don't understand that we have minimized risks to protect the environment."
Allan said the company is working to minimize the risks by requiring fumigant applicators to undergo special training. And it takes only about half as much methyl iodide to have the same effect as methyl bromide, he said.
Dave Cox, CEO of L.E. Cooke Co., a nursery in Visalia, used methyl iodide on a trial basis and says it closely matches methyl bromide's effectiveness.
As a nursery owner, Cox must ensure that his stock of fruit trees is free of worm-like pests known as nematodes, which gnaw at the roots.
"The risk of not having something effective is huge," Cox said. "The state sets a zero-tolerance for nematodes on new trees. I can't have even one."
Opponents say that while they understand the need for farmers to remain productive, the risk of using methyl iodide is too great.
"We know that even in small amounts it can be very toxic," said Robert Bergman, a chemist at the University of California at Berkeley and member of the National Academy of Sciences. "And in agriculture, you are talking about hundreds of pounds being put into the ground and covered with a tarp."
