The International Agency for Research on Cancer (IARC), 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, fruits, winemaking, and in 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 1970’s. Since 1980, Monsanto has developed genetically modified soy, corn, canola, cotton, sugar-beets and alfalfa. These GMO crops are designed to resist the herbicide Roundup, which is used to kill weeds and increase crop yields. The seeds of these modified crops must be purchased again each year from Monsanto by the farmer. The development of super-weeds, resistant to Roundup, has recently 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 IARC report 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 USA , 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 US
Environmental Protection Agency originally classified glyohosate as possibly carcinogenic to humans in 1985. After a re-evaluation of that mouse study, the US EPA changed its classification to evidence of non-carcinogenicity in humans in 1991. The US EPA Scientific Advisory Panel noted that the re-evaluated glyphosate results were still significant using two statistical tests recommended in the IARC Preamble. The IARC Working Group that conducted the evaluation considered the significant findings from the US EPA 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 quoted the IARC’s document precisely. You can see the different opinions of the IARC and the US FDA. Companies making glyphosate have criticized the report in the last few days. Whether the US EPA 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 re-evaluation of glyphosate by the WHO’s IARC 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 topics to think about:.
*Are there safer herbicides and pesticides that can be used on cereal crops that are feeding the world?
*To what extent can organic agriculture and integrated pest management feed the world?
*Much of US GMO corn and soy is fed to animals destined for human consumption. If meat prices rise due to a ban on dangerous herbicides, can we switch as a society 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?
Stay tuned. The discussion on glyphosate is only beginning.
Sadja Greenwood, MD, MPH past issues on this blog
p.s. Here are two unrelated topics you may enjoy reading about:
*Science Daily 3/12/15 You are when you eat – limiting flies to specific eating hours protects their hearts against aging, study finds.