A team of scientists this week released early results of an ongoing study spotlighting concerns about the rising use of pesticides and reproductive risks to women and children. The researchers tested and tracked, over a period of two years, the presence of the common herbicide glyphosate in the urine of 69 expectant mothers in Indiana.
The team – led by Paul Winchester, medical director of the neonatal intensive care unit at the Franciscan St. Francis Health System and professor of clinical pediatrics at Riley Hospital for Children in Indianapolis, Ind. – found glyphosate residues in 90 percent of the women, and high levels of those residues appeared to correlate with shortened pregnancies and below-average birth weights adjusted for age. The findings alarmed the researchers because such babies are at increased risk of diabetes, heart disease, high blood pressure, and lower cognitive abilities. “Gestational age maximizes the size of your brain at birth, and any shortening is essentially a reduction of IQ points,” Winchester said in an interview with FERN’s Ag Insider. “It has not just health, but lifetime achievement implications.”
This is the first time that anyone has demonstrated glyphosate is present in pregnant women in the U.S., according to Winchester. However, the results were limited by a small sample size. He and his colleagues plan to submit their research to a peer-reviewed journal within the month and they hope to expand the study later this year.
“The fact that we were able to find adverse effects on the small number of people we measured would imply a larger study is needed immediately to find out if this is prevalent everywhere,” Winchester says. “This is a critical piece of information that I think people should be concerned about.”
Glyphosate is the world’s most popular herbicide and the key ingredient in Monsanto’s Roundup weed killer. Globally, 9.4 million tons of glyphosate have been sprayed on crops, lawns, and gardens since the chemical was released on the market in 1974.
In response to the new study, Monsanto released a statement from staff medical experts Katie Karberg and Liza Halcomb. “As physicians and mothers ourselves, nothing is more important to us than the health and wellbeing of children. We stand by the safety of our products and the extensive regulatory oversight provided by agencies like the U.S. EPA,” the Monsanto officials said.
Currently, concerns about the safety of glyphosate are at the center of a major national lawsuit. Monsanto is being sued by hundreds of U.S. consumers who say the company did not warn them, despite evidence, that the chemical can cause cancers such as non-Hodgkin lymphoma, a blood disease. A key piece of testimony in the suit is a 2015 International Agency for Research on Cancer (IARC) report stating that glyphosate is “probably carcinogenic to humans.” Monsanto contests the listing, citing rulings by the EPA, the European Chemicals Agency, and the European Food Safety Authority that did not find cancer risks.
In response to the new study, Monsanto said: “The sample size in this unpublished and non-peer reviewed research is extremely small and not replicated. No conclusion about causation is supportable.” It also dismissed the scientists’ findings as “fear-mongering at its worst by activists and NGOs who are opposed to modern agriculture.”
Winchester has long studied the risks posed by agrochemicals, finding in a 2009 study that high levels of the farming chemical atrazine in water was associated with increased risk of genital birth defects in children.
In the glyphosate study, Winchester and his colleagues considered whether water might again be the exposure route for the pregnant women they monitored. After testing water samples, the scientists concluded that it was not the source. They suspect diet may play a role. The Food and Drug Administration, however, recently suspended the testing of glyphosate residues in food, citing the need for improved validation methods.
Experts say the spread of weeds resistant to glyphosate in the Midwest is triggering intensification of herbicide use over longer periods of time. “Until this year, most herbicides in the Midwest were sprayed during a six-week window, but now heavy herbicide spray season will last at least four months, placing more women and children at heightened risk,” Phil Landrigan, dean for global health at Mount Sinai Medical School and a member of the research team, said in a statement. As a result, he and his colleagues predict the risk of reproductive problems and adverse birth outcomes will rise among women and children living in rural areas.
The preliminary results of the study were presented Thursday at the biennial 2017 Children’s Environmental Health Translational Research Conference in Arlington, Va. The conference is hosted by the Children’s Environmental Health Network (CEHN), which is timing the launch of its new Healthy Kids Project to the study’s release.
Rene Ebersole, a contributor to FERN’s Ag Insider, writes and edits articles about science, health, and the environment for such publications as Outside, Modern Farmer, Popular Science, and Audubon.