California’s Environmental Protection Agency (Cal/EPA) has issued plans to list glyphosate—the toxic active ingredient in the Roundup herbicide—as known to cause cancer. Under California’s Proposition 65 the state is required to publish a list of chemicals known to cause cancer or birth defects or other reproductive harm. California is the first US state to make this assessment.
“As far as I’m aware, this is the first regulatory agency in the U.S. to determine that glyphosate is a carcinogen,” Dr. Nathan Donley, a scientist at the Center for Biological Diversity told EcoWatch. “This is a very big deal.”
Roundup, Monsanto’s flagship herbicide, is sprayed on crops all over the world and is the most popular weed-killer in the U.S. Besides glyphosate, three other chemicals—tetrachlorvinphos, parathion and malathion—were also listed as cancer-causing by the Cal/EPA. Businesses with 10 or more employees that use chemicals on the list must provide a “clear and reasonable warning” of the product’s potential dangers.
A number of studies have raised concerns about glyphosate. One recent study on rats suggests that long-term exposure to tiny amounts of the chemical (thousands of times lower than what is allowed in drinking water in the US) could lead to liver and kidney problems.
The study, published in Environmental Health on August 25, was the first to examine the impacts of chronic, low exposure of Roundup on genes in livers and kidneys and suggests another potential health impact for people and animals from the widely used weed killer. “Given even very low levels of exposure, Roundup can potentially result in organ damage when it comes to liver and kidney function,” said senior author Michael Antoniou, head of the Gene Expression and Therapy Group at King’s College London. “The severity we don’t know, but our data say there will be harm given enough time.”
The research was conducted by an international group of scientists from the UK, Italy and France. As the dose used is “environmentally relevant in terms of human, domesticated animals and wildlife levels of exposure,” the results potentially have significant health implications for animal and human populations, the study warned.
Given that they “used very low dose levels in drinking water … this study should have some kind of public health influence” in a country that “uses a lot of glyphosate and it’s found widely across US streams,” said Nichelle Harriott, science and regulatory director at Beyond Pesticides, a Washington D.C.-based nonprofit organization that advocates against toxic pesticides.
According to the New England Journal of Medicine, the use of glyphosate in herbicides has increased by more than 250 times in the United States in the last 40 years.