An international committee of cancer experts shocked the agribusiness world a few days ago when it announced that two widely used pesticides are "probably carcinogenic to humans." The well-respected International Agency for Research on Cancer published a brief explanation of its conclusions in The Lancet and plans to issue a book-length version later this year.
The announcement set off a wave of feverish reaction, because one of these chemicals, glyphosate, is a pillar of large-scale farming. Better known by its trade name, Roundup, glyphosate is the most popular weedkiller in the world.
The IARC's assessment leaves many questions unanswered, including how much risk glyphosate poses.
"What the IARC performs is hazard assessment," says Aaron Blair, who chaired the group of scientists that prepared the IARC's assessment of glyphosate. Blair is a scientist emeritus at the National Cancer Institute. Hazard assessment, he explains, is concerned with a simple question: Could a substance cause damage "in some circumstance, at some level of exposure?" How commonly such circumstances or exposures actually occur in the real world, he says, is an entirely different question, and not one that IARC tries to answer.
In other words, the IARC is saying that glyphosate probably could cause cancer in humans, but not that it probably does.
Blair points out that society often chooses simply to accept certain hazards. Among the other things that the IARC says probably cause cancer are burning wood in home fireplaces, disruption of circadian rhythms by working overnight shifts and working as a hairdresser.
Read full, original article: A Top Weedkiller Could Cause Cancer. Should We Be Scared?