Heavy use of the world's most popular herbicide could be linked to a range of health problems and diseases, including Parkinson's, infertility and cancers, according to a new study.
The peer-reviewed report, published last week in Entropy, an interdisciplinary open-access scientific journal, said evidence indicates that residues of glyphosate, best known as the active ingredient in Roundup, has been found in food.
Those residues enhance the damaging effects of other foodborne chemical residues and toxins in the environment to disrupt normal body functions and induce disease, according to the report, authored by Stephanie Seneff, a research scientist at the Massachusetts Institute of Technology, and Anthony Samsel, a retired science consultant from Arthur D. Little, Inc.
Samsel is a former private environmental government contractor as well as a member of the Union of Concerned Scientists.
"Negative impact on the body is insidious and manifests slowly over time as inflammation damages cellular systems throughout the body," the study says.
We "have hit upon something very important that needs to be taken seriously and further investigated," Seneff said.
Environmentalists, consumer groups and plant scientists from several countries have warned that heavy use of glyphosate is causing problems for plants, people and animals.
The U.S. Environmental Protection Agency (EPA) is conducting a standard registration review of glyphosate and has set a deadline of 2015 for determining if glyphosate use should be limited. The study is among many comments submitted to the agency.
Monsanto is the developer of both Roundup herbicide and a suite of crops that are genetically altered to withstand being sprayed with the product.
These biotech crops, including corn, soybeans, canola and sugarbeets, are planted on millions of acres in the U.S. annually.
Monsanto and other leading industry experts have said for years that glyphosate is proven safe, and has a less damaging impact on the environment than other commonly used chemicals.
Jerry Steiner, Monsanto's executive vice-president of sustainability, reiterated that in a recent interview when questioned about the study.
"We are very confident in the long track record that glyphosate has. It has been very, very extensively studied," he said.
Of the more than two dozen top herbicides on the market, glyphosate is the most popular. In 2007, as much as 185 million pounds of glyphosate was used by U.S. farmers, double the amount used six years ago, according to EPA data.
-- Carey Gillam is a commodities reporter covering Monsanto and other ag companies for Reuters in St. Louis.