The International Agency for Research on Cancer, part of the World Health Organization, has classified glyphosate—commonly known as Roundup—as “probably carcinogenic to humans.” Glyphosate is one of the world’s most widely used herbicides, used in growing corn, soy, vegetables and fruits and in winemaking and home gardens. It has been used in forests to clear underbrush, in cities to deter pavement weeds and on railroad tracks to kill unwanted vegetation. It is used on sugarcane to increase crop yield and, through crop desiccation, to increase sucrose concentration before harvesting.
Monsanto developed glyphosate, which it calls Roundup, in the 1970s. Since 1980, Monsanto has developed genetically modified soy, corn, canola, cotton, sugar beets and alfalfa. These genetically modified crops are designed to resist Roundup, and farmers must purchase the seeds of these crops each year from Monsanto. The development of Roundup-resistant super-weeds has been a growing problem, requiring heavier spraying of glyphosate and other herbicides, such as 2-4D (a component of Agent Orange, used as a defoliant in the Vietnam war.) Monsanto’s patent on glyphosate expired in 2000, and many other companies now make the product worldwide.
Here’s what the new report from the International Agency for Research on Cancer said, as published in the journal Lancet Oncology:
“For the herbicide glyphosate, there was limited evidence of carcinogenicity in humans for non-Hodgkin lymphoma. The evidence in humans is from studies of exposures, mostly agricultural, in the U.S.A., Canada, and Sweden published since 2001. In addition, there is convincing evidence that glyphosate also can cause cancer in laboratory animals. On the basis of tumors in mice, the U.S. Environmental Protection Agency originally classified glyohosate as possibly carcinogenic to humans in 1985. After a re-evaluation of that mouse study, the U.S. E.P.A. changed its classification to evidence of non-carcinogenicity in humans in 1991. The U.S. E.P.A. Scientific Advisory Panel noted that the re-evaluated glyphosate results were still significant using two statistical tests recommended in the I.A.R.C. Preamble. The I.A.R.C. Working Group that conducted the evaluation considered the significant findings from the U.S. E.P.A. and several more recent positive results in concluding that there is sufficient evidence of carcinogenicity in experimental animals. Glyphosate also caused DNA and chromosomal damage in human cells, although it gave negative results in tests using bacteria. One study in community residents reported increases in blood markers of chromosomal damage (micronuclei) after glyphosate formulations were sprayed nearby.”
This is a complex subject, which is why I have excerpted the report. You can see the different opinions of the I.A.R.C. and the Food and Drug Administration. Companies making glyphosate have criticized the report in the last few days. Whether the E.P.A. will make any regulatory changes remains to be seen.
Here in West Marin, we are immensely lucky to be able to buy organic food. However, the reevaluation of glyphosate by the World Health Organization’s cancer research agency is bound to have an impact on the world and its food supply, and on the movement to label genetically modified foods.
Here are some questions to think about: Are there safer herbicides and pesticides that can be used on the cereal crops that are feeding the world? To what extent can organic agriculture and integrated pest management feed the world? Much of the United States’ genetically modified corn and soy is fed to animals destined for human consumption. If meat prices rise due to a ban on dangerous herbicides, can our society switch to eating less meat and more plant protein? Is world population growth inevitable, or can education and family planning for women in developing countries help to slow this growth? Why are we so reluctant to talk about family planning as a factor in our environmental crises?
Sadja Greenwood is a former assistant clinical professor at the University of California, San Francisco, and a Bolinas resident.