Good Fruit Grower

August 2012

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PESTICIDE RISK? E What's the real ach year, the Environmental Working Group issues its annual list of the "Dirty Dozen" produce items as part of its "Shopper's Guide to Pesticides in Produce." This year, apples topped its list of the most pesticide-contaminated fruits and vegetables, with peaches at number four. But Dr. Charles Benbrook, chief science consultant at The Organic U.S. producers have dramatically reduced pesticide residues, but we are still importing foods with high pesticide risk, says pesticide policy expert Charles Benbrook. by Geraldine Warner Center, based in Troy, Oregon, takes issue with how the EWG compiles its list and says apples probably shouldn't be on the list at all. If Benbrook were to compile a Dirty Dozen list, he would put hot peppers in the number-one slot and include no domestic tree fruits. However, he would include imported peaches, plums, nectarines, and cher- ries. In June this year, Benbrook, a national pesticide policy expert, joined the faculty at Washington State University's Center for Sustaining Agriculture and Natural Resources. The new position enables him to work with analytical sys- tems and bring to bear the best scientific thinking to study the safety and nutritional quality of food and agriculture's impact on the environment. Benbrook said the U.S. Environmental Protection Agency has a rich database relating to pesticide residues in food that can be used to understand where the real risks are in the food supply. The latest pesticide residue data, issued this summer by the U.S. Department of Agriculture's Pesticide Data Program, show that apples have on average 5.9 different pesticide residues—which contributed to the EWG number-one ranking. Four postharvest fungicides (diphenylamine, thiabendazole, pyrimethanil, and chlo- rantraniliprole) accounted for more than half of the residues detected on apples. Those are not very toxic compounds, the residue levels were not high, and the risk they pose is relatively low, Benbrook said. Criteria The criteria used by the EWG in compiling their Dirty Dozen and Clean 15 lists are heavily weighted to the number of different pesticide residues detected on samples, rather than the amount of residues and the toxicity of the pesticides, he pointed out. Pesticide residues on apples Each year, the U.S. Department of Agriculture tests samples of foods for pesticide residues. This summary shows the number of pesticide residues found on samples from different origins based on 2010 data. Very few of the residues were above legal tolerances. Origin Domestic Chile New Zealand Combined imports SOURCE: Charles Benbrook, WSU 20 AUGUST 2012 GOOD FRUIT GROWER Number Average positive Dietary risk index of samples residues per sample for food supply 685 27 23 57 5.37 4.78 3.22 3.84 0.28 0.42 0.015 0.21 The dietary risk index is the average residue level in the food divided by the maximum amount that can be in the food based on the U.S. Environmental Protection Agency's assessment of each pesticide's toxicity. "There is often much greater real risk with some foods that might only have 1.5 residues or 2 residues, when the residue happens to be a hot organophosphate. I think the EWG needs to revisit the criteria that it uses in making this list, and, also, it should be more deliberate in distinguishing risks between imports and domestically grown fruit. "What troubles me about the current EWG list is failure to distinguish between domestically grown and imported food when big differences exist in risk levels," he said. "For example, EWG has peaches on the Dirty Dozen list. American peach growers have reduced risk dramatically, to a level that it's questionable whether they belong on anybody's Dirty Dozen list, but risks remain very high in imported peaches." EPA's most recent data show that of the 100 peach samples with the highest residues, 98 came from Chile. U.S. samples accounted for 99 of the 100 lowest-residue samples, and the other came from Argentina. Chilean fruit is consistently the most contaminated and poses the highest risk, yet the EWG list makes no distinction, he said. Apples EPA data show that the dietary risk for domestic apples has dropped by 90 percent as since the 1996 Food Quality Protection Act. Lower residue levels have been achieved through changes to U.S. pesticide labels that resulted in lower application rates, longer reentry intervals and preharvest intervals, and the phasing out of some organophosphates and other broad-spectrum active ingredients on certain crops. The dietary risk for imported apples has dropped by 94 percent in the same time frame, but the risks vary greatly depending on where they were produced. EPA found the highest-risk residues on Chilean apples, while New Zealand apples had very few residues and posed only a slightly higher risk than organic apples. The risk for organic fruit is 50- to 200-fold lower than the risks associated with conventional fruit. Overall, imports represent 80 percent of the total dietary risk in the U.S. food supply today, while domestic produce represents only 20 percent of the risk. Before 1996, it was the other way round. "EPA has helped farmers bring about this substantial reduction of risk, but mostly on the backs of U.S. farmers," Benbrook said. "Farmers abroad have really gotten a pass." The FQPA did not affect overseas producers, who simply need to meet the maximum residue tolerance in the United States. Maximum residue levels have not been changed because, for the most part, they are aligned with international standards, such as Codex, and to lower them could be construed by other countries as a nontariff trade barrier, Benbrook said. When tolerance levels were set for pesticides that came on the market 50 or 60 years ago, a wide margin was built in between the residue levels thought to be present at harvest following a legal application of the pes- ticide and the residue levels allowed by the tolerance. This is why over- tolerance residues are so rare for many older pesticides. For example, the tolerance for diazinon on apples is 0.5 parts per million, a level that would overexpose a child after one or two bites. "There's no way the EPA would say diazinon residues at 0.5 ppm are safe, but because there's not that much diazinon used on apples in the United States, the agency feels it's just not worth it to lower the tolerance, Benbrook said. "The problem is, though, that the tolerance applies to farmers all over the world." After the FQPA passed, EPA did lower the tolerance for chlorpyrifos on grapes and apples 100-fold and restricted its use mostly to the dormant season, which greatly reduced the risks posed by that chemical. But EPA should have lowered the tolerance on all organophosphate food uses by 100 fold in one action, he suggests. www.goodfruit.com

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