Mexican Maize Contaminated with Engineered Genes

By Cat Lazaroff

WASHINGTON, DC, October 18, 2001 (ENS) - Testing of maize varieties from 22 communities in the Oaxaca, Mexico areas have revealed genetic contamination in 15 of them. The findings raise questions about the potential for genetic pollution in a region considered the world's best repository of maize genetic diversity, and about American policies of exporting engineered crops.


Mexico has more varieties of native maize, or corn, than anywhere else on Earth (Photo courtesy Greenpeace)
This week, the international conservation group Greenpeace marked World Food Day by demanding an emergency ban on all U.S. maize imports to Mexico until their purity from genetically engineered (GE) compounds can be guaranteed.

The Mexican embassies in the United States, at the European Union and at the United Nations Food and Agriculture Organization (FAO) were told by Greenpeace that the US imports were the most likely source of genetic pollution now contaminating maize - one of the world's most important food crops - in a vital area of diversity in Mexico.

"The world is at risk of losing unique diversity of maize to genetic pollution. Mexico is the steward of the global maize diversity. It is Mexico's responsibility to take all necessary measures to protect this crop," said Raul Benet, executive director of Greenpeace Mexico. "This diversity ensures global food security now and in the future. As Jack Harlan, the pioneering American botanist and plant breeder has stated, genetic diversity 'stands between us and catastrophic starvation on a scale we cannot imagine'. We cannot afford any more delays. "

Testing of maize varieties from 22 communities in the state of Oaxaca, Puebla and Guanajuato, Mexico, revealed genetic contamination in 15 of them. Thirteen samples showed up to 10 percent levels of contamination. In two others, Greenpeace says the contamination level is known to be even higher, but no details have been published yet.


Greenpeace occupies a maize field near Mexico City on October 14 (Photo courtesy Greenpeace)
On Sunday in Mexico, Greenpeace occupied a maize field near Mexico City highlighting it as an example of one of the 300 local varieties at risk of being genetically contaminated.

Greenpeace, supported by the National Farmer Trade Association (ANEC), stressed that there is no need to continue U.S. maize imports to Mexico as the country already has a 630 thousand metric tons of home grown GE free maize stored in warehouses. About the same amount of maize is still due to be imported from the United States by the end of the year.

The Mexican government has prevented the sale of domestic maize in order to maintain the market price, which is threatened by cheap U.S. imports.

"The Mexican government's policy is insane both environmentally and economically. We already have large amounts of maize rotting away in storage but 783 thousand tons are still scheduled to come in from the U.S. by the end of this year without any guarantees that it is GE free," said Benet. "These imports risk further polluting 300 cultivated and indigenous maize varieties existing in Mexico. This would not only be a loss for Mexican environment and culture but this area is essential to maintain food security globally."

The Mexican government has so far failed to take measures to protect the maize in the affected areas located in at least 15 communities in the states of Oaxaca, Puebla and Guanajuato. The International Maize and Wheat Improvement Center (CIMMYT) in Mexico recently described the contamination as a serious development and offered its expertise to the appropriate Mexican institutions.

Since the North American Free Trade Agreement (NAFTA) came into force in 1994, the maize imports from the United States to Mexico have doubled from three million tons to six million tons. One fourth of the maize produced in the United States is genetically engineered.


Some engineered corn makes its own pesticides to combat plant pests like this maize weevil (Photo by Peggy Greb courtesy U.S. Dept. of Agriculture)
The GE grains are imported from the U.S. without labelling which increases the risk of contaminating both the environment and the food chain, Greenpeace warns.

Even a low level of genetic contamination is significant in a center of diversity and origin, some biologists say. The genetic contamination could multiply through pollen flow and spread further to other traditional varieties and wild relatives growing in the area.

Crop diversity is considered essential in the continuing pursuit of food crop varieties resistant to new pests, diseases, changing climatic and environmental conditions.

The tests on Mexican maize from Oaxaca have shown the presence of genes for the soil bacteria toxin Bt (Bacillus thuringiensis). Plants engineered to produce the Bt toxin make their own pesticide, killing insect pests that try to eat the crops.

home grown

Mexican home grown maize, free of engineered genes (Photo courtesy Greenpeace)
The contaminated varieties in Mexico may now produce this Bt toxin, potentially affecting beneficial insects.

"This contamination will not disappear by itself but spread further. It is likely to be only the tip of the iceberg of contamination in traditional varieties, as the plants in other parts of Mexico have not yet been investigated, " said Dr. Doreen Stabinsky from Greenpeace USA. "Mexico may need support to set up an infrastructure for testing plants. All maize affected by genetic contamination, including wild plants, needs to be identified. It also goes without saying that the source of contamination needs to be sealed by banning all imports of GE and GE contaminated maize to the centre of diversity."

The United Nations Biosafety Protocol recognizes the crucial importance to humankind of biological centers of diversity. But the treaty is still ineffective, as the ratification process has been at a standstill for almost two years, halting real progress in implementation.

"The international community must now agree on immediate preventative measures to avoid further outbreaks of contamination into other centers of diversity by banning all imports and releases of genetically modified organisms into these areas," said Stabinsky.