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Indigenous Corn In Mexico Is Threatened by DNA from Genetically Modified Organisms


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 on Biodiversity (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% contamination rate. This means that between 1% and 35% of the indigenous kernels they sampled contained traces of DNA from genetically modified organisms (GMOs). In total, 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 2002, 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 of biodiversity.

There are over 20,000 varieties of corn in Mexico and Central America . In southern and central Mexico, approximately 5,000 varieties have been identified . In one village in Oaxaca, researchers found 17 different environments where 26 varieties of corn were growing . Each variety has evolved to adapt to elevation levels, soil acidity, sun exposure, soil type, and rainfall. When more varieties are grown in close proximity to each other, the corn is less 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 subsidies.

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 years.

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 were waved. 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 been 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 canola.

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 of contamination.

However, they do not solve the problem of cross-pollination, which will be difficult to eradicate. Testing corn is expensive and few labs exist in Oaxaca 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 of 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 of biodiversity. Stopping the production of genetically modified crops throughout the world is the most crucial long-term goal to help preserve the biodiversity of all crops and environments globally. Indigenous and campesino farming practices in Mexico and throughout the world must be preserved and encouraged. Free trade and capitalism through such institutions as the World Bank and the International Monetary Fund and free trade agreements, like NAFTA, must not 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 contamination of crops. This case should serve as a warning to farmers throughout the world to the potential contamination of their crops with DNA from genetically modified organisms.

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.