WHO agency: Popular weed killer a probable carcinogen

PARIS, March 20 (UPI) -- The most popular herbicide worldwide, glyphosate, probably causes cancer in humans, the World Health Organization's International Agency for Research on Cancer found.

IARC, the French-based cancer research department of WHO, released its findings Friday after studying the carcinogenicity of five insecticides and herbicides.

The study classified glyphosate, which is found in weed killers like Roundup, and insecticides malathion and diazinon, as probably carcinogenic to humans. Insecticides tetrachlorvinphos and parathion were classified as possibly carcinogenic to humans.

Parathion is no longer authorized for use in the European Union and the United States. Tetrachlorvinphos is banned in the EU but is still used for livestock and domestic animals, including in flea collars.

Malathion and Diazinon are both used in agriculture and residential insect control, though the latter has faced restrictions since 2006.

Glyphosate, though, "currently has the highest global production volume of all herbicides," an IARC news release said.

"The agricultural use of glyphosate has increased sharply since the development of crops that have been genetically modified to make them resistant to glyphosate," the release said. "Glyphosate is also used in forestry, urban and home applications.

"Glyphosate has been detected in the air during spraying, in water, and in food. The general population is exposed primarily through residence near sprayed areas, home use, and diet and the level that has been observed is generally low."

The U.S. Environmental Protection Agency is scheduled to complete a new review of glyphosate rules this year.