Environmental Considerations for Bio-Engineered Crops in U.S. Food Aid Donations

Foods produced with modern biotechnology, such as maize (corn) and soybeans, have been rapidly adopted by U.S. farmers since their introduction in 1996. In recent years, up to one-third of U.S. corn acreage and three-quarters of U.S. soybean acreage has been planted with bio-engineered varieties. In the U.S. commodity marketing system, harvested grain and oilseeds from many sources are commonly mixed at several points, and bio-engineered crops are not generally separated from non-bio-engineered crops. Systems to segregate non-bio-engineered crops from the field to the market are costly and have been implemented on a very limited scale in the United States. Approximately 1-2% of corn and 2% of soybean production are currently grown and marketed under such systems, for high-value products and markets. Commodity shipments for food aid, as well as product destined for domestic and export food and feed uses, may contain mixed bio-engineered and non-bio-engineered crops.

U.S. farmers have adopted crop varieties bio-engineered to be resistant to insects, tolerant to herbicides, or both. Insect resistance is derived from a soil bacterium, Bacillus thuringiensis (Bt). Crop plants have been engineered to produce Bt proteins that are toxic to certain insects but are safe for humans and other organisms. Sprayable Bt insecticides are commonly used by organic farmers. Herbicide tolerance is also derived from soil bacteria. Herbicide tolerant crops are engineered to withstand the use of very effective herbicides that would otherwise harm the crop.

The bio-engineered crops that are planted by U.S. farmers have been rigorously reviewed for environmental and food safety by all relevant U.S. regulatory agencies, including the U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service, the Environmental Protection Agency, and the Department of Health and Human Services’ Food and Drug Administration. The environmental issues considered in the regulatory review include the possibility of increased weediness of the crop plant, out-crossing (cross-pollinating)of bio-engineered crops with closely related wild or domesticated plant species, and impact on non-target organisms.

Currently, the only whole grain in U.S. food aid donations that might be bio-engineered is maize. While the maize in food aid is not intended for planting, the shipment of whole grain commodities has raised issues surrounding the potential environmental impacts, should the grain be planted in recipient countries.

Outside the United States, bio-engineered maize varieties have been approved for planting in several other countries, including Argentina, Canada, the European Union, and Japan. South Africa has conducted environmental reviews of bio-engineered maize and has approved both yellow and white maize varieties, which are now being planted.

There is no indication that bio-engineered maize varieties currently planted in the United States would become a weed. Cultivated maize is not considered a weed outside of agricultural fields and the insect and herbicide tolerance traits are not expected to convert maize into a weed. During domestication, maize lost the ability to survive in the wild, and cannot maintain itself outside of an agricultural environment.

Although whole kernel maize provided as food aid is not intended for planting, if it is planted, food aid maize will only out-cross (or cross-pollinate) with other maize varieties or closely related plants. Closely related plants are geographically restricted to the Americas, and maize cannot out-cross with wild plants in Africa or with other crop plants besides maize. The frequency of out-crossing to domestic maize in Africa will be low unless the food aid grain is planted close to or in fields with domestic maize. Maize pollen is relatively heavy and large, and most lands close to the parent plant. The pollen desiccates quickly, losing viability within two hours. Furthermore, bio-engineered maize varieties adapted for the U.S. climate and growing conditions will likely not grow well in Africa, limiting their ability to cross-pollinate with local maize varieties. In addition, U.S. food aid corn is comprised of hybrid varieties, which, if replanted, tend not to grow well due to loss of vigor.

The potential impacts of bio-engineered maize currently planted in the United States on non-target organisms, i.e. those not intended to be controlled by the newly introduced trait, were also assessed prior to commercialization. Testing was performed on several different organisms: honey bee, parasitic wasps, green lacewing, lady beetles, northern bobwhite quail, earthworm, spring tails, channel catfish and water fleas. These tests indicate that non-target organisms would not be at risk from Bt maize. Also, subsequent field studies have not shown any adverse effects to non-target organisms. After the commercialization of bio-engineered insect resistant maize in the United States, concern was raised about potential harm to certain butterfly populations, which are closely related to the target insects of bio-engineered insect resistant maize. Additional field studies were conducted to address these concerns. These studies indicated that there is no significant risk to monarch butterflies from environmental exposure to Bt maize currently planted in the United States.

In addition to the environmental safety assessments that are conducted by U.S. regulatory agencies prior to the commercialization of bio-engineered crops, other independent scientific committees have also conducted reviews of the environmental issues related to their release. The U.S. Environmental Protection Agency assembles Science Advisory Panels of independent scientists to address risk issues before and/or after commercialization of a bio-engineered crop. Such panels have been convened to address such issues as the potential impacts on butterfly populations.

The National Research Council, a private nonprofit institute operating under a congressional charter, has reviewed environmental risks and the U.S. regulatory review of risk issues in two separate reports. In both reports, the committees have concluded that no strict distinction exists between the health and environmental risks posed by plants bio-engineered through modern molecular techniques and those modified by conventional breeding practices.

The Council for Agricultural Science and Technology (CAST), a leading private research institute, recently published a report comparing the environmental impacts of biotechnology-derived and traditional crops. The report, a comprehensive review of a broad range of scientific literature on agriculture and environment, concludes that biotechnology-derived maize, soybeans, and cotton yield environmental benefits from reduced pesticide use and reduced soil erosion and pose no environmental concerns unique to or different from those associated with conventionally-developed crops.

On U.S. regulatory reviews:

On independent scientific reviews:

Also see fact sheets on:
--Food Safety Assessments for Bio-Engineered Crops in U.S. Food Aid Donations;
--Agricultural Development and Trade Issues for Bio-Engineered Crops in U.S. Food Aid Donations.