YONKERS, N.Y., May 8 (UPI) -- Organic foods do indeed contain less pesticide residues, a study published Wednesday in the journal Food Additives and Contaminants revealed.
However, researchers found up to 23 percent of organic food contained some pesticide residue, including DDT.
"It's not a surprise to me because organic food never claimed to have no pesticide residue it claimed to be grown using no chemical pesticides or fertilizers," said Edward Groth III, senior scientist at Consumer Union in Yonkers, N.Y., and one of the paper's co-authors. "We found that if persistence pesticides such as DDT which have been banned for 30 years were excluded, the number dropped to 13 percent."
Most pesticides in organic foods can be explained by past pesticide use -- the half-life of DDT is 30 years, so in another 30 years there still will be one-quarter of the DDT present in soil -- or "drift" of pesticide sprays from neighboring fields or mislabeling of food, according to Groth.
The study team included analysts from Consumers Union, the publisher of Consumer Reports magazine, and the Organic Materials Research Institute, an independent research, education and evaluation organization in Eugene, Ore.
"While organic food is something we have studied, this paper was more outside of what we do in our organizations, but we wanted to take advantage of the data collected by the federal government to see if organic food had less pesticide residues because the issue has been surprisingly controversial," Groth said. "Some groups, such as Dennis Avery, director of Global Food Issues have claimed organic foods have just as many residues as foods grown conventionally so that organic food is a fraud.
"The paper is the first published analysis of pesticide residue data in foods grown organically and conventionally and we wanted it published in a peer-reviewed journal," Groth added.
The authors obtained and analyzed test data on pesticide residues in organic and non-organic foods from three independent sources: tests done on selected foods by Consumers Union in 1997; surveys of residues in a wide array of foods on the U.S. market conducted by the Pesticide Data Program of the U.S. Department of Agriculture in 1994 through 1999; and surveys of residues in foods sold in California, tested by the California Department of Pesticide Regulation in 1989 through 1998.
The combined residue data sets covered more than 94,000 food samples from more than 20 different crops. Of those samples, 1,291 were organically grown.
"We've pulled together the best available data on residues in organic produce to generate a clear picture of the category as a whole," said co-author Karen Benbrook, who carried out much of the data analysis for CU. "The USDA data showed that 73 percent of conventionally grown foods had at least one pesticide residue, while 23 percent of organically grown samples of the same crops had any residues."
The researchers found more than 90 percent of the USDA's samples of conventionally grown apples, peaches, pears, strawberries and celery had residues, and conventionally grown crops were six times as likely as organic to contain multiple pesticide residues, Groth said.
"The California data, based on tests with less sensitive detection limits, found residues in 31 percent of conventionally grown foods and only 6.5 percent of organic samples, and found multiple residues nine times as often in conventional samples," Groth explained. "CU tests found residues in 79 percent of conventionally grown samples and 27 percent of organically grown samples, with multiple residues 10 times as common in the former."
The levels of residues found in organic samples were also consistently lower than levels of the same pesticides found in conventional samples in all three sets of residue data. Overall, the data were consistent in all three programs, Groth said.
"I never said I thought organic foods contained pesticide residues. I said that in today's world where food is safer and more abundant that pesticide residues should not alarm anyone," Avery told UPI. "We are so rich and so safe and if we don't smoke, use seatbelts and don't smoke crack, what will kill us?"
Avery continued, "We can't all go organic because according to one Canadian researcher, there would be no room for growing food in the United States if we had enough cattle to produce the manure necessary to grow food organically because a cow needs two acres of feed or 30 acres of land for forage."
Since the Food Quality Protection Act was passed in 1996, the federal government has been trying in to remove the most persistent chemical pesticides such as methylparathion, according to Ken Cook of the Environmental Working Group in Washington, D.C.
"The reasoning for organic food, besides the obvious environmental benefits, is less pesticides residues and therefore the less risk for cancer, neurological problems in children, the less risk of endocrine disrupters in adults or the very reasons the federal government is regulating these chemical pesticides in the first place," Cook told UPI.
(Reported by Alex Cukan in Albany, N.Y.)