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U.S. regulators have relied on flawed and outdated
research to allow expanded use of an herbicide
linked to cancer, and new assessments should be
urgently conducted, according to a column published
in the New England Journal of Medicine.
The vast majority of the corn and soybeans grown in
the United States are now genetically engineered and
unlike regulatory bodies in 64 other countries, the
Food and Drug Administration (FDA) does not require
labeling of GM foods.
Two recent developments are dramatically changing
the GMO landscape.
First, there have been sharp increases in the
amounts and numbers of chemical herbicides applied
to GM crops, and still further increases — the
largest in a generation — are scheduled to occur in
the next few years.
Second, the International Agency for Research on
Cancer (IARC) has classified glyphosate, the
herbicide most widely used on GM crops, as a
“probable human carcinogen”(Guyton KZ, Loomis D,
Grosse Y, et al. Carcinogenicity of
tetrachlorvinphos, parathion, malathion, diazinon,
and glyphosate. Lancet Oncol 2015;16:490-491 -
http://www.thelancet.com/journals/lanonc/article/PIIS1470-2045%2815%2970134-8/abstract)
and classified a second herbicide,
2,4-dichlorophenoxyacetic acid (2,4-D), as a
“possible human carcinogen.”(Loomis D, Guyton K,
Grosse Y, et al. Carcinogenicity of lindane, DDT,
and 2,4-dichlorophenoxyacetic acid. Lancet Oncol
2015 June 22 - Epub ahead of print).
The National Academy of Sciences has twice reviewed
the safety of GM crops — in 2000 and 2004 (National
Research Council, Committee on Identifying and
Assessing Unintended Effects of Genetically
Engineered Foods on Human Health. Safety of
genetically engineered foods: approaches to
assessing unintended health effects. Washington, DC:
National Academies Press, 2004.). Those reviews,
which focused almost entirely on the genetic aspects
of biotechnology, concluded that GM crops noted that
genetic transformation has the potential to produce
unanticipated allergens or toxins and might alter
the nutritional quality of food.
Both reports recommended development of new
risk-assessment tools and postmarketing
surveillance. Those recommendations have largely
gone unheeded.
Widespread adoption of herbicide-resistant crops has
led to overreliance on herbicides and, in
particular, on glyphosate.
In the United States, glyphosate use has increased
by a factor of more than 250 — from 0.4 million kg
in 1974 to 113 million kg in 2014. Global use has
increased by a factor of more than 10.
Not surprisingly, glyphosate-resistant weeds have
emerged and are found today on nearly 100 million
acres in 36 states. Fields must now be treated with
multiple herbicides, including 2,4-D, a component of
the Agent Orange defoliant used in the Vietnam War.
These developments suggest that GM foods and the
herbicides applied to them may pose hazards to human
health that were not examined in previous
assessments. The National Academy of Sciences has
convened a new committee to reassess the social,
economic, environmental, and human health effects of
GM crops but this development is not expected until
at least 2016.
The time has come to revisit the United States'
reluctance to label GM foods. Labeling will deliver
multiple benefits. It is essential for tracking
emergence of novel food allergies and assessing
effects of chemical herbicides applied to GM crops.
It would respect the wishes of a growing number of
consumers who insist they have a right to know what
foods they are buying and how they were produced.
And the argument that there is nothing new about
genetic rearrangement misses the point that GM crops
are now the agricultural products most heavily
treated with herbicides and that two of these
herbicides may pose risks of cancer.
For more information
GMOs, Herbicides, and Public Health
Philip J. Landrigan, M.D., and Charles Benbrook,
Ph.D.
N Engl J Med 2015; 373:693-695August 20, 2015
DOI: 10.1056/NEJMp1505660
See also
Updated - Pesticide in food: residue adherence rates
above 97% but mixtures of pollutants may have
long-term health consequences
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