Glyphosate is the active ingredient in Roundup, the most heavily
used herbicide in the United States and worldwide, the study team
writes in the journal Environmental Health.
“Glyphosate is often used on major crops on a day-to-day basis . . .
but we hardly know anything about how humans are exposed,” said lead
author Shahid Parvez, a researcher at the Indiana University
Fairbanks School of Public Health in Indianapolis.
“We’ve received an overwhelming response because there’s a lot of
concern about this chemical,” Parvez told Reuters Health in a
telephone interview. “We don’t want to cause unnecessary panic, but
we do want to understand how it affects pregnancy and human health."
Nearly 300 million pounds of Roundup are applied across U.S. farms
each year, with the heaviest use in the Midwest, Parvez and his
colleagues write.
In 2015 and 2016, the researchers recruited 71 pregnant women in
central Indiana and surveyed them about their food and beverage
consumption, lifestyle, stress and where they lived. The women also
provided two urine samples and two drinking water samples from their
homes.
Researchers tested the water and urine for glyphosate and divided
women into four groups based on their urine concentration of the
chemical. After women gave birth, researchers used medical records
to determine their pregnancy length.
Overall, 93 percent of the women had detectable glyphosate in their
urine while pregnant. Those who lived in rural areas had higher
levels than suburban residents.
Women who drank more than 24 ounces of caffeinated beverages per day
also had higher glyphosate concentrations than others. However, none
of the drinking water samples had detectable glyphosate.
Pregnancy typically lasts 39-40 weeks; births after 37 weeks are
considered full-term. All but two births in this study group were
full-term, although researchers found that on average, women with
more glyphosate in their urine delivered earlier than women with
less or none.
Glyphosate was not associated with other fetal growth indicators
such as birth weight or head circumference.
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“It was mind-boggling that glyphosate was so prevalent in urine
samples . . . but it was a pleasant surprise that none of the
drinking water came out positive,” Parvez said. “Now we want to
learn more about dietary intake and environmental factors such as
contaminated air.”
The research team was also surprised by the link between caffeine
intake and high glyphosate levels in urine.
“It makes sense to us since there are many different food products
imported from Southeast Asia and South America but we don’t know
what they contain,” he said. “It indicates a need to think about
these food products, such as coffee beans and other drinks that we
import.”
In addition to its small size, the study is limited by its lack of
geographic and racial diversity. More than 94 percent of the women
were white, and they came from nine counties that represented a mix
of rural, suburban and urban locales, as well as public and well
water lines, the authors note.
“Unfortunately, in cases of prenatal exposures, results can take
months to years after a child is born to be observable,” said
Charles Benbrook, a visiting scholar at the Johns Hopkins University
School of Public Health in Baltimore who wasn’t involved in the
study.
Benbrook also works with the Children’s Environment Health Network
in Washington, D.C., which offers resources on its website for
protecting children from chemical exposures (https://bit.ly/2g6oeY2).
In general, Benbrook advised pregnant women to avoid spraying
herbicides on the lawn or treating the house for insects when they
could be exposed during their first trimester. In addition, he
recommended waiting to buy a new car, couch or other home item that
could contain chemicals.
“More research needs to be done, but the precautions are common
sense,” he said. “Be vigilant and careful, especially those living
in areas where corn and soybeans are grown.”
SOURCE: https://bit.ly/2pRrYlr Environmental Health, online March 9,
2018.
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