Top Weed Killer Poses Cancer Risk Ingredient in several pesticides 'probably' causes cancer: study By Neal Colgrass, Newser Staff Posted Mar 22, 2015 3:15 PM CDT 76 comments Comments In this file photo taken Sept. 9, 2009, farm hand Jason Adler, 34 walks through a field of sugar beets full of weeds on the Rasmussen farm near Longmont, Colo. (AP Photo/Ed Andrieski, File) (Newser) – The most popular weed killer on Earth can "probably" give people cancer, according to a study posted on a World Health Organization website and in the Lancet Oncology. The study says an ingredient in several insecticides and herbicides, including the popular Roundup, is "probably carcinogenic to humans" and may give people lung cancer and non-Hodgkin’s lymphoma, Forbes reports. The study points to "convincing evidence" that the ingredient, glyphosate, gives cancer to laboratory animals; it also says "case-control studies of occupational exposure" found "increased risks for non-Hodgkin lymphoma that persisted after adjustment for other pesticides." But Monsanto issued a statement saying glyphosate is perfectly safe and approved "by all regulatory agencies around the globe." Indeed, the US and the European Union have approved glyphosate, and Monsanto says the new study contains no new data. Still, glyphosate is a "hot topic" that played a role in Vermont passing America's first law for mandatory labeling of genetically modified foods, NBC News notes. In the latest study, WHO's cancer agency had 17 experts evaluate five "organophosphate insecticides and herbicides." The most common, glyphosate, was assessed as 2A or "possibly carcinogenic," meaning the European Union wouldn't approve it. Yet glyphosate can be found in more than 750 products for home, urban, agricultural, and forest use. "People should be very careful with this stuff and consider whether they need it," says a British professor. "Home gardeners should hand weed to be on the safe side."