From LATimes.com
EPA approves new pesticide despite scientists' concerns
Chemists say
methyl iodide, a neurotoxin that can mutate DNA, has 'serious potential for
accidents.' But federal officials say safeguards in place are sufficient to
protect farm workers and field-adjacent neighborhoods.
By Marla
Cone,
October 6, 2007
Despite the
protests of more than 50 scientists, including five Nobel laureates in
chemistry, the U.S. Environmental Protection Agency on Friday approved use of a
new, highly toxic fumigant, mainly for strawberry fields.
The new pesticide, methyl iodide, is designed for growers, mainly in
In a letter
sent last month to EPA Administrator Stephen Johnson, 54 scientists, mostly
chemists, warned that "pregnant women and the fetus, children, the elderly,
farmworkers and other people living near application sites would be at serious
risk."
Methyl iodide is a neurotoxin and carcinogen that has caused thyroid tumors,
neurological damage and miscarriages in lab animals.
But EPA officials said Friday that they carefully evaluated the risks and
decided to approve its use for one year, imposing restrictions such as buffer
zones to protect farmworkers and neighbors.
"We are confident that by conducting such a rigorous analysis and developing
highly restrictive provisions governing its use, there will be no risks of
concern," EPA Assistant Administrator Jim Gulliford said in a letter sent Friday
to the scientists.
Growers, particularly those who grow strawberries and tomatoes, have been
searching for 15 years for a new soil fumigant to replace methyl bromide.
Fumigants are valuable to growers because they can be injected into the soil
before planting to sterilize the field and kill a broad spectrum of insects and
diseases without leaving residue on crops.
But fumigants are among the most potentially dangerous pesticides in use today
because the toxic gas can evaporate from the soil, exposing farmworkers and
drifting into neighborhoods.
Methyl iodide will be manufactured by Tokyo-based Arysta LifeScience Corp. and
marketed under the name Midas. Its use will be allowed on fields growing
strawberries, tomatoes, peppers, ornamentals, turf, trees and vines.
"We are conducting our own risk assessment of methyl iodide, and we expect that
process to continue for several months before we make a decision whether or how
it can be used safely in California," said Glenn Brank, a spokesman for the
state Department of Pesticide Regulation.
Robert Bergman, the Gerald E. K. Branch Distinguished Professor at UC Berkeley's
chemistry department, led the effort by scientists to persuade the EPA to reject
methyl iodide.
Among the signatories were five Nobel laureates: Robert H. Grubbs of the
California Institute of Technology; Roald Hoffmann of Cornell University;
Williams S. Knowles, formerly of Monsanto Co.; John B. Fenn of Virginia
Commonwealth University; and Richard R. Ernst of the Swiss Federal Polytechnic
Institute.
Many of the chemists -- who use small amounts of methyl iodide in their
laboratories to attach molecules and are careful to avoid exposure -- said they
are shocked that the EPA is allowing its use as a pesticide because it can drift
into neighborhoods and pollute groundwater.
"It is potentially really toxic, and it's certainly very reactive. From what we
know about its chemistry, we know this stuff reacts with DNA. It mutates it. So
it's prudent to be as careful as you can with it," Bergman said in an interview
Friday.
Bergman said he was disappointed, but not surprised, by the EPA's decision
because top officials there seemed unswayed in discussions with him and two
other scientists earlier this week.
The scientists had asked for an independent review by the National Research
Council, but the EPA rejected that because its own scientific advisory panel
already had reviewed it.
"If they're right, they shouldn't be afraid of an independent review," Bergman
said. "I don't know what the motivation is to get this stuff approved so fast.
If there is any possibility that it would be dangerous, do you not approve it,
or do you approve it and then decide, after something happens, to change your
mind? There is serious potential for accidents."
Bergman said he is particularly concerned about neighborhoods in
EPA officials called their review, which lasted four years, "one of the most
thorough analyses ever completed on a new pesticide."
The manufacturer, Arysta, has spent eight years and more than $11 million
collecting toxicological and environmental data to persuade the EPA to register
methyl iodide as a pesticide.
Arysta's former chief executive, Elin Miller, is now a top official at the EPA
and was appointed administrator of its northwest region last year.
The EPA last year dropped its plan to approve methyl iodide after objections
from the United Farm Workers, environmental groups and
EPA scientists reviewed data from test fields in
"We evaluated the probability of being exposed to concentrations that could
possibly lead to adverse health effects and found that those levels would not be
reached under the stringent use conditions that will be imposed," the EPA's
Gulliford wrote to the scientists.
Use of certified commercial applicators will be required, and buffer zones must
be maintained around fields to protect workers and bystanders. The buffers range
from 25 to 500 feet depending on the size of the field and the amount of
fumigant used.
Shovelers, tractor drivers and other employees of companies applying the
fumigant must be trained and wear respirators, and farmworkers cannot enter the
fields for five days after it is applied.
Use is prohibited within a quarter mile of a school, day care facility, nursing
home, hospital, prison or playground.
Strawberry growers alone could use 3 million pounds of methyl iodide annually to
replace methyl bromide. Only areas with special "critical use" exemptions,
largely in
The California Strawberry Commission, in a letter to the EPA last year, called
methyl iodide a "highly promising alternative" that is "essential to our
continued transition away" from methyl bromide.
Many
EPA officials said the approval is limited to one year because the agency is
developing new regulations for all fumigants.
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