By Bara Vaida
WebMD Health News
April 7, 2015 -- An international group of health experts is questioning the safety of a widely used pesticide that had long been considered not harmful by U.S. regulators.
The International Agency for Research on Cancer (IARC), a research arm of the World Health Organization, in March said that glyphosate is a “probable” cancer-causing substance, or carcinogen. It’s a key ingredient in hundreds of crop-control agents and weed killers, such as Bronco, Glifonox, KleenUp, Ranger Pro, Rodeo, Roundup, and Weedoff.
The finding -- challenged by Roundup maker Monsanto -- comes decades after the U.S. Environmental Protection Agency said glyphosate is safe for people. The agency reaffirmed that decision in 2012.
It is the most widely used pesticide worldwide, sprayed on everything from golf courses to home gardens. The chemical is mainly used in agriculture, and sprayed on genetically modified crops like soy, corn, and cotton. The plants are designed to resist the pesticide, which is used to kill weeds around them.
In a fact sheet, the EPA says workers or home gardeners might breathe it in or get it on their skin “during spraying, mixing, and cleanup.”
Expert: 'Be a Little Concerned'
Aaron Blair, PhD, of the National Cancer Institute, and a lead researcher on the IARC’s study, says a panel of 17 scientists from around the world concluded that glyphosate might be dangerous. They looked at all publicly available and published studies on the chemical and its relationship to cancer. That included studies on people, animals, and laboratory cells. The panel didn’t consider reviews done by regulatory agencies.
In 3 out of the 4 human studies of American, Canadian, and Swedish agricultural workers, the IARC panel found a link between glyphosate and non-Hodgkin lymphoma, a cancer of the immune system. A fourth multi-year study of 80,000 American farmers showed no relationship, Blair says.
Evidence from animal studies also showed a link between glyphosate and rare kidney and pancreatic cancers. Cell studies showed abnormal changes to cell DNA when it was exposed to glyphosate. The combination of all the studies led the IARC to conclude that it is a “probable” carcinogen, Blair says.
“Probable means that there was enough evidence to say it is more than possible, but not enough evidence to say it is a carcinogen,” Blair says.
“It means you ought to be a little concerned about” glyphosate, he says.
He could not say if glyphosate would “probably” cause cancer, because that question is connected to the level and type of exposure to the chemical. Blair’s group doesn’t consider factors like those.
source : Does This Common Pesticide Cause Cancer?