(Friday, July 18, 2003 -- CropChoice news) -- Associated Press, 07/11/03:
HELENA -- Babies born in high wheat-producing counties were twice as
likely to have birth defects as those born in rural counties with low wheat
production, a new federal study shows.
The research, published in the July issue of Environmental Health
Perspectives, suggests exposure to common herbicides applied to wheat could
be responsible for the increased rate of birth defects.
The study was conducted by Dr. Dina Schreinemachers, a researcher with the
Environmental Protection Agency in North Carolina. She examined more than
43,000 births from 1995 to 1997 in 147 rural counties in Montana, North
Dakota, South Dakota and Minnesota.
She divided the counties by their rates of wheat production according to
U.S. Department of Agriculture data, then compared the rates of birth
defects among children born in the counties as provided by the National
Center for Health Statistics.
Schreinemachers said results of her study indicate that in rural,
agricultural counties with high wheat production -- where the use of
chlorophenoxy herbicides is higher -- rates of certain birth defects
"significantly increased."
Specifically, instances of circulatory/respiratory and musculoskeletal
defects were twice as frequent in high-wheat counties, she said.
Even more significant, baby boys born in high-wheat counties and conceived
during April or June -- when herbicide application normally is in full
swing
-- were nearly five times as likely to have birth defects than boys
conceived during other times of the year and born in counties with low
wheat
production, the study concluded.
Death rates from birth defects among male infants in high-wheat counties
also were more than twice the rates of low-wheat counties, the study found.
Schreinemachers said Thursday the disparity between male and female infants
was not immediately clear.
"That remains a mystery," she said.
Her findings are similar to conclusions contained in a 1996 study by Dr.
Vincent Garry of the University of Minnesota.
His study of births in Minnesota between 1989 and 1992 found a higher rate
of birth defects in western Minnesota, where chlorophenoxy herbicides are
applied to wheat. That study, however, also implicated certain fungicides
as
a possible cause.
Chlorophenoxy herbicides are widely used to control weeds in grain farming.
In the four wheat-producing states included in Schreinemachers' study, more
than 85 percent of the wheat acreage was treated with herbicides such as
2,4-D and 4-chloro-2-methylphenoxyacetic acid, or MCPA, the study said.
Schreinemachers said her study does not make a direct link between birth
defects and use of the chemicals, but strongly suggests that more research
is needed.
"We do not know how much of these herbicides was used in those particular
counties, for instance" she said. "But we know that according to the USDA,
these herbicides are used most often on spring and durum wheat."
She said the data used in her study also does not indicate whether the
children with birth defects were born to parents who had direct contact
with
the herbicides.
Dr. Michael Spence, Montana's state medical officer, said he was aware of
Schreinemachers' study, but had not reviewed it yet.
However, he said the findings were not a surprise, since the herbicides
have
been linked to other health problems in previous studies.
An ongoing study funded jointly by the National Cancer Institute, National
Institute of Environmental Health and the EPA is tracking 90,000 herbicide
applicators and their spouses to look for possible health effects of
pesticides.