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Engineered DNA found in crop seeds
(Tuesday, Feb. 24, 2004 -- CropChoice news) -- Rick Weiss
Washington Post:
Much of the U.S. supply of ordinary crop seeds has become contaminated with strands of engineered DNA, suggesting that current methods for segregating gene-altered seed plants from traditional varieties are failing, according to a pilot study released yesterday.
More than two-thirds of 36 conventional corn, soy and canola seed batches contained traces of DNA from genetically engineered crop varieties in lab tests commissioned by the Union of Concerned Scientists, a Washington-based advocacy group.
The actual amount of foreign DNA present in U.S. seeds appears to be small, and most engineered genes getting into the seed supply are among those that regulators have deemed safe for consumption, the report acknowledges.
But if federal rules and farm practices are not tightened, it concludes, the United States may soon find it impossible to guarantee that any portion of its food supply is free of gene-altered elements, a situation that could seriously disrupt the export of U.S. foods, seeds and oils. Many believe it could also gravely harm the domestic market for organic food -- one of the fastest-growing and more lucrative segments of U.S. agriculture.
And with a growing number of crop varieties now being engineered to produce not just agricultural chemicals, but also potent pharmaceutical and industrial products in their leaves and stems, future incidents of cross-contamination may pose even more serious health and economic risks, the report warns.
"No one wants drugs or plastics in our cornflakes," said Margaret Mellon, director of the food and environment program at the Union of Concerned Scientists, an environmental and health group that has taken a skeptical stance toward agricultural biotechnology but is generally respected by experts for hewing to science. "Left unchecked, this is a problem that will hurt the U.S. economically, and perhaps even affect our health."
The 70-page report, "Gone to Seed," recommends that the agriculture department conduct a thorough assessment of the extent of genetic contamination of the U.S. seed industry.
The report also calls for tighter restrictions on the outdoor planting of crops engineered to make drugs and industrial products. It suggests that reservoirs of still-pure seed stocks for major crops be set aside immediately as an "insurance policy" in case gene-altered varieties prove to be environmentally or medically harmful.
Industry officials said the findings were predictable.
"We were not surprised by this report . . . knowing that pollen travels and commodity grains might commingle at various places and you may have some mixing in transport or storage," said Lisa Dry, communications director for the Biotechnology Industry Association.
Rather than pursue the unrealistic goal of trying to keep seeds completely free of genetic contaminants, she and other industry representatives said, the United States should work harder to get European and other nations -- many of which have balked at engineered crops and foods -- to be more accepting of the technology.
"It's important for countries around the world to adopt a uniform standard" of acceptable levels of contamination, Dry said.
Dick Crowder, president of the Alexandria-based American Seed Trade Association, agreed, saying he believes U.S. regulators are doing an adequate job of keeping the food supply safe.
The Food and Drug Administration and the Department of Agriculture have been developing standards to keep unwanted engineered products out of the food supply. Spokesmen from both agencies said yesterday they would review the report.
Whatever their significance, the findings indicate a remarkable degree of inadvertent DNA redistribution since American farmers started growing genetically engineered crops on a commercial scale eight years ago. Most of the varieties in use today have either a bacterial gene that helps the plant fight insect pests or a gene that makes the crop resistant to a popular weedkiller.
Hundreds of other varieties are in testing. The group could not search for many of those possible contaminants, because more than half of their DNA sequences are trade secrets.
Engineered crops remain highly restricted in Japan, Europe and other regions of the world, but they have become popular with American farmers and accepted by most U.S. consumers. In recent years, about 80 percent of all soy grown in this country has been genetically engineered, as is most canola and about 40 percent of all corn.
Non-engineered products are generally mixed with engineered varieties, except when they are aimed at certain foreign or specialty markets. But plants that are grown specifically to replenish the nation's supply of conventional seeds are carefully segregated to retain their purity and are used to produce "certified" commercial grade seed.
Mellon's group bought certified soy, corn and canola seeds and had six popular varieties of each tested for contaminating DNA sequences at two different laboratories that specialize in such tests -- GeneScan USA of Belle Chasse, La., and Biogenetic Services of Brookings, S.D.
The first lab found engineered DNA in half the corn and soy varieties and in all six of the canola. The second lab, which was given larger amounts with which to work, got positive results on five of six varieties for all three crops.
The molecular test used, known as PCR, is extremely sensitive and is a standard workhorse of molecular biology today, though its use in plant materials is still being perfected. Although PCR does not do a good job of estimating amounts, the scientists estimated that probably 0.05 percent to 1 percent of each batch's total DNA was engineered DNA.
It remains unclear to what extent the contamination is biological -- the result of pollen spread in the field -- or mechanical, from inadvertent commingling of conventional seeds with engineered seeds in farm equipment or in storage areas, Mellon said.
Source: http://www.washingtonpost.com/wp-dyn/articles/A486-2004Feb23.html | |
