The health and environmental risks of glyphosate, the pesticide known by the commercial name Roundup, have been underestimated, according to a new report published in the journal Environmental Health.

The paper was authored by 14 scientists, including Michael Hansen, Ph.D, senior scientist at Consumers Union, the policy and advocacy arm of Consumer Reports. Genetically modified (GMO) crops were developed to be resistant to the effects of glyphosate, so the pesticide would kill the weeds, but not the plants. 

In 2015, the World Health Organization’s International Agency for Research on Cancer classified glyphosate as a probable human carcinogen.

The use of glyphosate has increased nearly 15-fold since 1996, when GMO crops were first approved, according to an analysis by Charles M. Benbrook, Ph.D. (who is also one of the 14 scientist authors of the recent report) published in the journal Environmental Sciences Europe. In 2014 alone, the amount of glyphosate used was equivalent to 0.8 pounds per acre of cultivated cropland in the U.S.

Despite being the most widely applied pesticide in the world, glyphosate is not part of the USDA’s Pesticide Data Program, which measures pesticide residues on crops. That means the amount we get in our food is essentially unknown.

In a statement responding to the study, Monsanto, the maker of Roundup, said, "The overwhelming conclusion of experts worldwide has been that glyphosate, when used according to label directions, does not present an unreasonable risk of adverse effects to humans, wildlife or the environment."

Evaluating the results of studies in animals and humans, the scientists who authored the Environmental Health report determined that the existing data is not sufficient to infer that glyphosate is safe.They believe that the evidence shows that glyphosate likely causes liver and kidney damage, and possibly can disrupt the body’s endocrine system, which regulates hormones, and raises the risk of non-Hodgkin’s lymphoma.

In addition, there’s some data that suggests glyphosate has an antibiotic effect and so may create an imbalance in the ratio of healthy to unhealthy bacteria in the digestive system.

“In light of this data, we need more research on the effects glyphosate,” says Consumers Union’s Hansen. “The government should make it a priority to investigate the cancer-causing and endocrine effects of the pesticide, and begin to measure the amount of it that ends up on our food.”