WHO on Weedkiller, Insecticides: 'Probably Carcinogenic'


Glyphosate isn't a household name, but it's a component of a product that is: Monsanto-brand Roundup weed control. Herbicide glyphosate and insecticides malathion and diazinon are also the targets of a World Health Organization ruling that says the chemicals are likely cancer-causers. 

The agency said on March 20 that the substances, which are used on residential lawns and tens of thousands of acres of agricultural land across North America, are "probably carcinogenic to humans." The analysis came from the International Agency for Research on Cancer, the cancer research arm of the WHO. The U.S. Environmental Protection Agency said Friday that it would "consider" the evaluation.

IARC pointed to glyphosate, which is currently used in more than 750 different herbicide products. Its use has been detected in the air during spraying, in water and in food. WHO experts said there was "limited evidence" in humans that the herbicide could cause non-Hodgkin's lymphoma, but there was "convincing" evidence that glyphosate could cause other forms of cancer in rats and mice. A panel from IARC confirmed that glyphosate had been found in the blood and urine of agricultural workers, showing the chemical can be absorbed by the body.

The details from IARC were published Friday in the journal Lancet Oncology.

Monsanto, manufacturer of Roundup, quickly pushed back

"All labeled uses of glyphosate are safe for human health," stated Phil Miller, Monsanto's global head of regulatory and government affairs, in a statement. The company pointed to a 2012 assessment from the EPA that said glyphosate met statutory safety standards and that the chemical "could continue to be used without unreasonable risks to people or the environment."

Meanwhile, a spokeswoman for IARC said the research group is concerned about occupational exposure more than domestic use.

"It's agricultural use that will have the biggest impact," said Kate Guyton, of IARC. " For the moment, it's just something for people to be conscious of."