PANNA: U.S. EPA Approves Bt Corn Despite Lack of Testing


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U.S. EPA Approves Bt Corn Despite Lack of Testing
October 22, 2001

On October 15, 2001, the U.S. Environmental Protection Agency (EPA) announced approval of genetically engineered Bt corn for an additional seven years, despite serious questions about the dangers crops pose to human health or the environment. Genetically Engineered Food Alert (GE Food Alert) criticized the EPA for rushing to approve Bt corn without conducting necessary tests on human health effects and failing to investigate new concerns about environmental impacts.

Bt plants produce a type of insecticidal or Bt toxin, one of a family of related molecules produced by a soil bacterium, Bacillus thuringiensis (Bt). To develop these Bt crops, a company clones the insecticidal gene from the bacterium and inserts it into a crop plant. The plant then produces the toxin in most, if not all, parts of the plant through all or most of a growing season. There five varieties of Bt corn still on the market are made by Monsanto, Pioneer/DuPont, Dow and Syngenta. At least three types of Bt corn were previously taken off the market. Most Bt corn varieties were approved by EPA in 1995 with a federal registration that expired on September 30, 2001.

As we learned with the StarLink debacle, human allergenicity is a key issue related to Bt crops; however, during the re-registration process, EPA failed to take into account several recent studies showing that Bt toxins could act as possible human allergens. In July, EPA’s own scientific advisory panel, which included leading U.S. allergists, called for more tests to determine the potential allergenicity of Bt crops, yet the Agency approved the corn for planting before such tests were carried out.

The allergenicity studies that serve as the basis for EPA’s approval of Bt corn have several serious flaws. For example, the Agency has not required that biotechnology companies conduct toxicity and allergenicity tests on the pesticidal proteins actually produced in Bt crops and eaten by consumers. Instead, EPA accepts substandard tests conducted on surrogate proteins from bacteria, which can differ substantially from their plant-produced counterparts. (For more information visit the Friends of the Earth Web site at

In addition to human health research, studies on potential environmental impacts of Bt corn were inadequate. EPA ignored the concerns of researchers at Cornell University, Iowa State University and the University of Minnesota about impacts of Bt corn on monarch butterflies. Recently released studies leave open the possibility that exposure to Bt corn may have long-term, harmful effects on the butterflies. Biologists from the three schools, all of whom have been involved in related research, urged EPA to delay a decision, or grant a one-year provisional renewal, until more data were available on the risk for monarch caterpillars exposed to Bt corn. (For more information see Ag Biotech Infonet at

Organic farmers were also disappointed with EPA’s decision. Bt sprays are an important pest management tool for many organic and some conventional farmers, but continued use of Bt crops may reduce their effectiveness. Toxins in Bt sprays break down rapidly in the environment as opposed to the Bt in genetically engineered crops, which breaks down very slowly. With widespread use of Bt crops, there is increased insect exposure to the toxin, and insect resistance is much more likely to develop resulting in the loss of Bt sprays as a valuable tool.

EPA announced that to ensure that Bt continues to be a safe and effective form of pest management for farmers, the Agency has mandated several provisions “to strengthen insect resistance management, to increase research data on potential environmental effects and to improve grower education and stewardship.” Whether these mandates will be successfully implemented is doubtful when one examines implementation of such requirements in the past. A biotechnology industry survey published in January 2001 showed that nearly 30% of farmers who grew Bt corn in 2000 did not follow the resistance management guidelines.

Lack of implementation and enforcement of Bt corn guidelines was also clearly evident during the StarLink corn disaster. In 2000, GE Food Alert found that StarLink corn, a type of Bt corn approved only for animal feed, had contaminated the human food supply. In the resulting investigation, it was found that many farmers had not followed the guidelines for growing StarLink, and had not segregated the corn after harvest. Regulations and guidelines agreed to by Aventis, the corporation that produced the StarLink seed, were not passed on to farmers, and little if any follow up by the corporation or EPA was done to see if the plans were being implemented.

Genetically Engineered Food Alert supports the removal of genetically engineered ingredients from grocery store shelves unless they are adequately safety tested and labeled. Genetically Engineered Food Alert founding members include: Pesticide Action Network North America, Center for Food Safety, Friends of the Earth, Institute for Agriculture and Trade Policy, National Environmental Trust, Organic Consumers Association, and the State Public Interest Research Groups. The campaign is endorsed by more than 200 scientists, religious leaders, doctors, chefs, environmental and health leaders, as well as farm groups. Find out more about the campaign at

Sources: GE Food Alert press releases, July 24 and October 12, 2001. EPA Pesticide Program Update, October 18, 2001. “Farmers violating biotech corn rules,” Associated Press, January 31, 2001.

Contact: PANNA.

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