Indigenous Corn In Mexico Is Threatened by DNA from Genetically
In November 2001, Ignacio Chapela and David Quist, two scientists from the
University of California at Berkeley, published an article in the scientific
journal Nature revealing that indigenous corn in Oaxaca, Mexico was contaminated
with DNA (deoxyribonucleic acid) from genetically modified organisms (GMOs).
The biotech industry has been working ferociously to discredit this research.
Many of the anti-Chapela/Quist editorials and articles have been directly
traced back to Monsanto’s public relations firm. Pressure and criticism
from a small group of influential biotech supporters caused Nature to withdraw
the article in April 2002. Since this event, the biotech industry has reported
that the genetic contamination in Mexico never occurred. Unfortunately, most
of the mainstream media coverage in the recent months has focused on the
controversy over Chapela and Quist’s research and has disregarded the
ramifications this contamination will have. The introduction of DNA from
genetically altered material into indigenous corn in Mexico could cause the
native corn to lose its ability to produce and reproduce in its natural environment,
destabilizing the economic livelihood of the campesinos (small-scale farmers).
Most of the pro-biotech editorials and articles conveniently ignore the
fact that two Mexican governmental agencies, the National Commission
(Conabio) and the National Ecological Institute (INE), sampled indigenous
corn from twenty communities in Oaxaca and two in Puebla (two states in
southern Mexico). They found that 95% of these communities had a 1-35%
rate. This means that between 1% and 35% of the indigenous kernels they
sampled contained traces of DNA from genetically modified organisms (GMOs).
8% of the 1,876 of the seedlings they tested were polluted by GMOs. At
the Biosafety Conference that convened in The Hague at the end of April
Jorge Soberon, director of Conabio, declared this genetic pollution as
the worst case of GMO contamination in crops ever reported in the world.
Corn: The Life-force of the Campesino in Mexico
Campesinos and corn have a symbiotic relationship. Without the other, neither
could survive. The lifestyle of the campesino depends on corn, which provides
their nutrition, economic livelihood and basis for many religious ceremonies.
In order to ensure the continued existence of the corn, campesinos must disperse
the seed. Without human intervention, the cob would fall on the ground and
all the kernels would compete with each other. After a few generations the
corn would no longer be able to reproduce. Mexican campesinos maintain current
varieties and facilitate the evolution of new varieties. These new varieties
will evolve only if farmers remain the stewards of corn and the protectors
There are over 20,000 varieties of corn in Mexico and Central America .
In southern and central Mexico, approximately 5,000 varieties have been
. In one village in Oaxaca, researchers found 17 different environments
where 26 varieties of corn were growing . Each variety has evolved to
elevation levels, soil acidity, sun exposure, soil type, and rainfall.
When more varieties are grown in close proximity to each other, the corn
vulnerable to insect and disease epidemics.
Underlying Causes of the Contamination
Mexican agricultural policy, NAFTA, and the lack of awareness of GMOs amongst
campesinos are the underlying causes of the genetic contamination in the
corn in Oaxaca, Mexico. While NAFTA was being negotiated a comparative advantage
analysis was conducted between the three NAFTA countries to determine what
each country should produce for export. Ironically, the United States was
chosen to produce corn since its large-scale monocultural corn farms yield
approximately 75% more corn per acre than subsistence farmers in Mexico do
. Because of this comparative advantage it was decided that Mexico should
cultivate labor-intensive horticultural crops, since it has a large cheap
labor force. This comparative advantage analysis failed to take into consideration
the impacts it will have on the campesino way of life and the survival of
maize biodiversity. Also, the large subsidies that US corn farmers receive
from the US government were overlooked, which skews the comparative advantage
equation. Some US corn farmers receive 42% of their income from government
Umberto Rosales, an engineer from the Mexican Secretariat for Agriculture,
Livestock, Fisheries and Food (SAGARPA) stated in an interview that Mexican
campesinos should produce higher yields of corn, cultivate a more profitable
crop or leave the land. SAGARPA has taken measures to implement this policy,
resulting in the displacement of tens of thousands of campesinos.
NAFTA facilitated the further liberalization of the corn market in Mexico.
The Agricultural Agreement of NAFTA eliminated all tariffs on agricultural
goods either immediately or in a 5, 10, or 15-year period. A duty-free quota
system was established for corn with a 15-year phase out period. The first
year of NAFTA 2.5 million metric tons of corn were permitted to enter Mexico
from the United States, tariff-free. This number was to increase 3% annually
for fourteen years, completing the 15-year phase-out period. All corn imports
from the United States that surpassed the duty-free quota were supposed to
be subjected to a tariff, which would also be gradually eliminated over fifteen
This phase-out period, however, did not last for the anticipated time. In
1996, corn imports exceeded the quota by over 3 million tons and tariffs
Every year since the implementation of NAFTA (with the exception of 1995) the
quota was surpassed and tariffs were not applied. According to Alejandro Nadal,
from the Mexico College’s Science and Technology Program, over $2 billion
of fiscal revenue were foregone between 1994-1998 in Mexico because tariffs
were never collected from the corn that exceeded the quota rate. Since the
Mexican government did not impose the tariffs, US corn exporters were given
the green light to send their crop to Mexico.
Since 1998 there has been a moratorium on the cultivation of GM corn in Mexico.
Before NAFTA was implemented, the US exported approximately 2 million metric
tons of corn annually to Mexico. In 2001, Mexico received 6.2 million tons
of imported corn from the US , more than tripling pre-NAFTA rates. It is estimated
that 26% of the corn grown in the US last year was genetically modified . Both
the European Union and Japan have banned the importation of GM foods, which
disproportionately increases the amount of genetically engineered foods that
enter into other countries. Thirty to forty percent of the corn exported from
the United States to Mexico is from GM varieties. Mexican agricultural policy
and NAFTA (which is part of Mexico’s agricultural policy) have enabled
corn polluted with DNA from GMOs to enter rural Mexico. Both have encouraged
campesinos to abandon their land, demanding an increase in corn imports. These
heavily subsidized US imports have flooded the Mexican corn market and driven
down the prices of corn by 45%, undermining the campesinos ability to make
an economic livelihood.
Another underlying cause of the contamination is the lack of understanding
campesinos have about GMOs. I interviewed 29 campesino families in the Sierra
Juárez and 59% of them had heard of GMOs but only 14% actually understood
that genetic engineering involves the transfer of genes from one species to
another. Neither SAGARPA nor Diconsa are taking steps to educate the campesinos
that corn in their area is polluted with DNA from genetically engineered organisms.
Aurelio Bautista, a technician from SAGARPA in Calpulalpan (a village in the
Sierra Juárez) stated that he believes the contamination in the Sierra
Juárez is only a rumor. Even though government agencies have taken samples
from Calpulalpan and it is one of the most highly publicized communities that
has GM corn contamination, Bautista nervously insisted that Calpulalpan did
not have polluted corn. These types of blatant lies have lead to further misunderstanding
and misinformation about genetically modified organisms in Oaxaca.
Direct Causes of the Contamination
The primary direct source of the genetic contamination came from the imported
corn from the United States. Diconsa, a Mexican state-run grain distributor,
facilitated the dispersion of this genetically altered corn. Diconsa delivers
grain and other supplies to stores throughout rural areas of Mexico. According
to Manuel Mérida from Diconsa warehouse in Oaxaca City, 40% of the
corn distributed by Diconsa last year in Oaxaca originated from the United
States. Conabio and INE found a 37% GM contamination rate in the corn in
the Diconsa warehouse in Ixtlán (of the Sierra Juárez). When
I spoke with a worker at the Ixtlán store she reported that a representative
from Diconsa informed her there were no GMOs in the Diconsa corn in the store.
Another worker at the Guelatoa Diconsa store was told “GM corn is colored
and Diconsa only sells white corn, so there is nothing to worry about.” There
are no signs in the stores warning campesinos not to cultivate the Diconsa
corn, even though it is tainted with DNA from GMOs. Six workers at Diconsa
stores throughout the Sierra Juárez with whom I spoke stated that
campesinos know not to plant Diconsa corn and only cultivate their criollo
(indigenous) varieties. However, two of the twenty-nine campesino families
I interviewed admitted they had at one point experimented with Diconsa corn.
Diconsa corn has made its way into the ground through many avenues. For centuries,
farmers have conducted agricultural experiments. A few campesinos in the
Sierra Juárez have tried planting Diconsa corn, since they had never
been informed of its dangers. Diconsa corn falls off trucks during delivery
and grows on the side of roads. Also, the Diconsa corn that is used as livestock
feed often ends up germinating when the animals do not consume it all. Mexican
scholars fear that if the corn can reach rural areas such as the Sierra Juárez
then other areas throughout Mexico must also have contamination.
Diconsa corn is now cross-pollinating with criollo varieties and has become
a direct source of the contamination. Even if imports of genetically modified
corn stop, cross-pollination will continue to be a direct source of pollution.
Other potential sources of contamination that have been discussed include
illegal planting by multinational corporations, government distribution
of GM seed, and international food aid. None of these possibilities have
confirmed and need to be researched further.
Effects of the Contamination
Corn originated in southern Mexico where over 5,000 varieties exist today.
As genetically modified corn cross-pollinates with indigenous corn varieties
the DNA from GMOs could dominate the physical characteristics and genetic
composition, making the indigenous corn less suitable for its unique environment.
As indigenous corn varieties lose their ability to produce in southern Mexico,
yields will decrease and the campesinos’ livelihood will be undermined.
The natural evolution of new corn varieties is also threatened due to this
pollution. The biotechnology industry has countered the negative publicity
and replied that the GM corn will only increase biodiversity because it introduces
new genes into the environment.
One of the most popular types of genetically engineered corn is an insecticide
producing corn called Bt corn. It contains a toxin derived from Bacillus
thuringiensis (Bt), a naturally occurring soil bacterium. Corporations have
genetically inserted the gene for this toxin into crops to function as an
insecticide against harmful insects, such as the European corn borer and
the Colorado potato beetle. However, Bt crops also kill and adversely effect
beneficial insects, like monarch butterflies, bumblebees, and lacewings.
Swiss scientists showed that lacewings die when they feed on larvae of the
European corn borer that have ingested Bt toxin. Iowa State University researchers
found that 19% of monarch caterpillars died within 48 hours after feeding
on milkweed plants that were growing in or on the edge of Bt cornfields.
In Venezuela and New York, scientists discovered that the Bt toxin secreted
from Bt corn remained bound to soil particles in its active, lethal state
for more than seven months.
Research must be conducted to ascertain what effects the Bt corn will have
on insects and soil microorganisms in Oaxaca. As Bt corn cross-pollinates
with indigenous varieties of corn, the pollution will only replicate itself
causing more damage to insects. Also, the genetically altered corn could
cross with teosinte, the wild ancestor of corn, which grows in and around
the edges of cornfields in southern Mexico. The distinct genetic composition
could be lost in teosinte and other relatives of corn as they cross-pollinate
with corn that contains DNA from genetically engineered organisms.
Genetically engineered foods can transfer food allergies from one food to
another as genes from one species (a potential allergen) are placed into
another. When a gene from another plant/animal/bacteria is inserted into
our food, it is uncertain what kind of effect that will have on the human
body. New chemicals could be formed that are toxic to humans. Starlink corn
genetically engineered by Aventis, contained a bacterial protein Cry9C that
cannot break down in the human digestive system and is therefore a potential
allergen. The United States’ FDA only approved Starlink for cattle
feed. In September 2000, US activists publicized that Taco Bell tortillas
were contaminated with Starlink corn. The FDA and the Center for Disease
Control in the United States are investigating forty-cases of allergies induced
by Starlink corn. In March 2001, Aventis announced that 143 million tons
of corn were contaminated, forcing farmers, seed companies, processors and
food makers to spend over $1 billion to get rid of it.
Hundreds of lawsuits have been filed against US and Canadian farmers by Monsanto,
who claims that the farmers, are using proprietary seeds without Monsanto’s
permission. Percy Schmeiser from Saskatchewan had his fields of canola contaminated
with his neighbor’s GM canola when it cross-pollinated. Monsanto sued
Schmeiser for illegally planting their patented variety of GM canola without
a license, even though he never intended and never wanted to cultivate Monsanto
Farmers cultivating any crop that contains patented genes and have not signed
a contract with the corporation could risk legal repercussions from transnational
corporations whether the farmer knows her/his crops contain GM material or
not. The Mexican government does not currently honor Monsanto’s patents
but this could change under future trade agreements or with free trade agreements
that are already in place. If this were to occur, the multinational corporations
who own the GM genes could sue farmers who have indigenous corn varieties
that have cross-pollinated with genetically altered corn. Some industry scientists
even state that Mexican corn farmers are benefiting from the “free” DNA
transfer and should have to pay for it.
Solutions to Reverse the Genetic Pollution in Mexican Corn
A comprehensive plan to eradicate the contamination needs to be implemented
immediately. The campesinos, after being informed about the dangers of genetic
engineering, must make the ultimate decision of what actions should occur.
Many solutions have been discussed in Oaxaca to stop and reverse this pollution.
First, the direct source must be eliminated, by banning US imports of genetically
altered maize. This will be difficult since Mexico is subordinate in the
free trade hierarchy and is not in an economic position to dictate to the
US what imports they will or will not accept. However, with enough pressure
from around the world on both the Mexican and US governments, the imports
could be halted.
Diconsa needs to hang signs in their stores and warehouses immediately to
warn campesinos to not plant the corn; explicitly stating the corn may contain
genetic material from GMOs. Also Diconsa must take responsibility and inform
their workers about GMOs. There need to be education campaigns throughout
Oaxaca to inform farmers what genetic engineering is and its impacts. Education
and ending US imports are two solutions that address only the direct sources
However, they do not solve the problem of cross-pollination, which will
be difficult to eradicate. Testing corn is expensive and few labs exist
to analyze the maize. Several NGOs and grassroots organizations are trying
to fund labs and criollo seed saving projects. Establishing a seed bank
in Oaxaca controlled by the campesinos could serve as a secondary source
seed preservation. Cultivation in the fields should be the primary source
of conserving indigenous corn, since storage in seed banks does not permit
evolution to occur. However, seed banks can provide a backup copy for genetic
material of corn varieties that are GM-free.
These suggestions detailed above only address the immediate issue of the
corn contamination in Oaxaca. A long-term strategy must be discussed
to prevent further contamination of crops, especially in centers of origin
Stopping the production of genetically modified crops throughout the
is the most crucial long-term goal to help preserve the biodiversity
of all crops and environments globally. Indigenous and campesino farming
in Mexico and throughout the world must be preserved and encouraged.
Free trade and capitalism through such institutions as the World Bank
International Monetary Fund and free trade agreements, like NAFTA, must
be able to dictate what farmers should produce and export to meet the
needs of the industrialized countries
A critique of genetic engineering with a deeper understanding, addressing
capitalism and free trade must occur on a global scale so that people
comprehend the underlying causes of environmental disasters, like genetic
of crops. This case should serve as a warning to farmers throughout
the world to the potential contamination of their crops with DNA from
S’ra DeSantis recently finished her thesis on the case of Oaxacan
corn for the Environmental Studies Department at the University of Vermont.
She is an organic vegetable farmer in Burlington, VT. She also works with
ACERCA, Action for Community and Ecology in the Regions of Central America.
Danielle Rolli, a farmer advocate, was her research assistant in Mexico.