Engineered Rice Cut Pesticides, Illnesses, Study Says

Brian Handwerk
for National Geographic News
April 29, 2005
Chinese farmers growing genetically modified rice reduced pesticide use
by 80 percent and saw pesticide-related health problems drop sharply, a
new independent study reports. The genetically modified rice seed also
boosted crop production by 6 to 9 percent.

No country has yet introduced a major, genetically modified (GM) food-grain crop—but the recent trials may signal a sea change. The tests are a final step before China decides on the commercial release of the GM rice.

"They've been doing this kind of research in China on a number of different GM products, like cotton. But this is the first one really focusing on human food, and it's of serious importance to China," said Martina Newell-McGloughlin, director of the University of California's Systemwide Biotechnology Research and Education Program.

China has invested the equivalent of hundreds of millions of U.S. dollars in biotech research and is outspent in the field only by the United States.

Two varieties of GM rice have been tested during years of regulatory trials. The tests in China measured food safety, growth effectiveness, and environmental impact. But the recent trials were the first to document the impact of genetically modified rice at the individual farm level.

"One of major reasons that commercialization has not proceeded is that there has been little independent evidence on whether GM food crops would really improve farmer income and rice productivity," said Jikun Huang, who led the study that appears today in Science.

Huang is both a professor and the director of the Center for Chinese Agricultural Policy at the Chinese Academy of Sciences in Beijing.

Fewer Pests, Better Health

Two rice strains were genetically altered to resist two insects, rice stem borers and leaf rollers, which sometimes require heavy use of pesticides to control.

Individual farmers in China cultivated the genetically modified rice crop on their own land. Subsidies enabled the farmers to purchase the GM seed at the same price as natural seed. But the farmers received no technical help during the crop cycle.

Farmers typically apply pesticides to combat rice stem borers and leaf rollers only if inspections show crops are infested. During the study farmers used smaller amounts pesticide because they saw less need. As a result, farmers' pesticide exposure dropped, and their health improved.

Pesticide exposure-related illness is a major problem in the agricultural communities of developing nations. Awareness and safety procedures lag far behind those in more developed economies. Manual labor is also more widespread, and, as a result, human-crop interactions occur much more closely and often.

"Annually more than 50,000 farmers are poisoned in farm fields, of which some 400 to 500 die," Huang said.

Regulation and Resistance

Not everyone agrees that GM food is risk free.

"There certainly is a package of benefits associated with [these] crops, and one might hope that those would be enjoyed by folks in China," said Margaret Mellon, director of the Food and Environment Program at the Union of Concerned Scientists in Washington, D.C.

"But there are also problems," she added. "The general question[s] one wants to ask [are], How good is the regulatory system in China? How rigorous is it? How rigorous will the enforcement be?"

Such measures are key to dealing with the potential challenges facing GM-food, from human allergic reactions to natural selection of pests resistant to the crops designed to thwart them.

Last month Swiss biotech firm Syngenta admitted that it had mistakenly sold U.S. farmers a genetically modified corn seed. The product has never been approved for use in the United States, although federal officials maintain that the crop is nearly identical to approved versions and poses no food safety or environmental threat.

Mellon says international regulation of GM agricultural products is a "looming problem" spotlighted by China's ambitious plans.

"Will it be possible for the Chinese to take the steps we've taken in the U.S. to mitigate [selective] resistance and other issues?" she said. "How much confidence do we have in the effectiveness of their regulatory system?"

Selective resistance is a phenomenon whereby a small number of individuals of a species with an inherent genetic resistence to a pesticide, antibiotic, or, in this case, a GM crop, survive and breed. Over time and successive breeding cycles, the population of GM-resistant "superpests" grows larger. This eventually makes the pesticide, antibiotic, or GM crop less effective.

No Panacea

If China approves GM rice for widespread cultivation, it is likely to represent only a fraction the total rice produced by the nation of 1.3 billion people.

"The stem bores are not a problem all over the country, so it's not like this is going to take over the whole country or something like that," said Carl Pray, a study co-author and professor of agricultural, food, and resource economics at Rutgers University in New Brunswick, New Jersey.

"[These pests] are a problem in specific areas, so we don't know how far this thing is gong to spread," he added. "Farmers will do what farmers do all over the world: They'll buy a bit of seed and test it in a corner of a field. If it yields a bigger return, they'll buy more the next year."

Newell-McGloughlin, the University of California biotechnology expert, said that such selective use is likely indicative of global demand for such modified crops.

"The notion that [genetically modified crops] are a panacea for all the world's ills is crazy. That's never said by real scientists," she said. "It's a useful tool to be used when it makes sense, when it can reduce the need for using chemical controls of those pests."

"I think [the study] is also a reflection of the value of using GM [crops] on small holdings," she added. "You often hear that the focus for GM is on large, industrial-scale production. In a country like China, where so much of agriculture is in small-scale holdings, to see this degree of potential impact is reassuring. You really can use it on any scale farm where it makes sense."

It's unclear when, or if, the Chinese government might release the rice crop for commercial use. If they do, it could be the beginning of a growing trend throughout the developing world.

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