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.
www.caya.eu/en