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Big Ag's "Celery Calculator" Lowballs Pesticide Risk

Thursday, December 16, 2010

By Chris Campbell, Brett Lorenzen and Elaine Shannon

Big agribusiness is up in arms over The Dirty Dozen, Environmental Working Group's list of fresh fruits and vegetables that are most likely to carry pesticide residues.

The Dirty Dozen is based on testing of residue levels conducted by the U.S. Department of Agriculture and the Food and Drug Administration. EWG compiles the results into a user-friendly Shopper's Guide to Pesticides in produce, because we think people have a right to know what's in their food.

A lot of people evidently agree. The Shopper's Guide gets more than 100,000 page views a month -- and it's now become the target of a slick, well-heeled attack campaign by the conventional produce lobby.

The industry's latest counter-offensive, spearheaded by the California-based Alliance for Food and Farming representing major produce trade groups and agricultural chemical vendors, is a pro-pesticide website that goes by the faux-green name, Safe Fruits and Veggies.com. The website asserts:


"The mere 'presence' of pesticide residue does not mean that the food is harmful in any way. Use the calculation tool below to see how many servings a man, woman, teen or child could consume and still not have any adverse effects from pesticide residues."


The "calculation tool" is a real head-scratcher. Take celery, which ranks first - meaning worst - on EWG's Dirty Dozen list. The industry calculator tells us that a child between ages two and five could eat 98,412 "servings" of celery without consuming a dangerous amount of chlorothalonil, the most abundant pesticide found on celery.

Since few small kids want to tuck into a bathtub-size batch of crudités, the website's message is one of reassurance. But a few facts underscore the absurdity of the Alliance's argument. The pesticide lobby makes the false assumptions that:

  • Every child is identical and that children are no more sensitive to toxic chemicals than adults -- or laboratory rats.
  • A child eating a piece of celery has no other exposures to pesticides and no other fruits and vegetables get dosed with pesticides.
  • Pesticides don't interact in the body, potentially bolstering or multiplying one another's toxic effects.
  • The pesticide industry and health agencies know everything there is to know about pesticide toxicity.
  • A child's serving of celery is a two-inch, seven-gram bit from the end of the stalk - when the CDC says it's more like 60 grams.

So here's the real story.

Kids need extra protection. Luckily, the Environmental Protection Agency, not the industry, sets pesticide safety standards. The agency starts with the highest pesticide dose found to be safe for a group of laboratory animals, usually around 50 rats. But then it builds in standard safety margins that take into account "inter-species" differences (rats vs. humans), "intra-species" differences among individuals, data gaps and, unless the agency has data proving it's unnecessary, an additional 10-fold safety factor to protect children's developing bodies. By ignoring these factors, the industry's calculation lowballs the risk by a factor of at least 100 and sometimes 1,000. The effect is enormous. People encounter lots of pesticides, not just one Kids get exposed to pesticides in lots of ways. Another whopper in the industry's pesticide calculator is the assumption that a child will encounter any one pesticide residue in just one kind of fruit or vegetable and that it isn't used on anything else. Not true.

As just one example, the pesticide chlorothalonil (the chemical on celery singled out by the industry calculator) turns up in around 10 to 20 percent of the green beans, tomatoes, winter squash and cranberries we eat, according to the test data. It has non-food uses, too. Altogether, at least 57 pesticides (or their breakdown products) have each been found in 10 or more kinds of fruits and vegetables. Moreover, pesticides commonly contaminate drinking water. Think about how many pesticides people encounter on any given day, and you can see why federal law requires that pesticide safety standards take into account aggregate exposures from all sources. That bite of celery is just the beginning.

Many pesticides do compound one another's effects. EPA has found that chlorothalonil is unique in the way it damages the stomach and kidneys. At the moment, the EPA safety standard for chlorothalonil assumes that no other pesticide -- and, implicitly, none of the hundreds of other chemicals known to pollute our bodies -- amplifies its harm.

But that's the exception. More typical is the insecticide Dursban. EPA restricted use of this popular bug-killer when it found that its class of pesticides, organophosphates, poses risks to childhood brain development by blocking chemicals that help transmit signals through nerves.

Children are often exposed to many of these pesticides at once. Again, take celery: on average, samples were polluted with residues of four different pesticides. (In 2008, one particular batch of celery tested positive for 13 pesticides.) Since people eat a variety of foods, the chemicals on a bite of celery represent a small fraction of an individual's daily exposures to industrial chemicals. As testing of umbilical cord blood by EWG and others has shown, babies are exposed to a huge array of industrial chemicals in the womb, including substances that can cause cancer, damage the brain and nervous system and cause birth defects or abnormal development. When you pile up even more exposures from food, water and air, the risks can inch up and reach a tipping point. What we don't know just might hurt us. Since November 2009, EPA has amended, stopped or suspended the use of about one of every three of the 22,122 pesticide uses it has reviewed. Some fell out of use because when more effective or safer agricultural chemicals came online, but others were shelved over health concerns uncovered by recent research.

The more we test, the more we find. Take lead, for example. Once an ingredient in pesticides for fruit orchards, it is still a common contaminant in tap water and old house paint. The government's "safe" blood lead level for children has dropped six-fold over the past 40 years, with each decrease driven by new studies revealing risks to brain development at ever-lower doses. New science regularly turns up previously unknown pesticide toxicities, and the standard test protocols in rodents can miss health risks for people. The pesticide industry itself conducts most safety tests for its products, submits them to EPA and then defends the product tooth and nail. It might be anything but safe. You call this a serving? In coming up with its estimate that a child could eat 98,412 "servings" of celery without running a safety risk from pesticides (leaving aside the issue of a massive stomach ache), the industry's celery calculator assumes that a serving is 7 grams, basically a thin, two-inch slice of a stalk. The CDC says it's more like 60 grams. If your kids are anything like ours, they don't stop after at two inches, especially when there's a scoop of peanut butter or ranch dressing on it.

Dr. Philip J. Landrigan, professor and chairman of the Preventive Medicine Department at Mt. Sinai School of Medicine, helped persuade Congress to pass the 1996 pesticide law. He contends that even a 1000-fold safety factor is inadequate for some chemicals, such as organophosphates, that have been linked to developmental disorders of the brain and nervous system. Says Landrigan:

"There appears to be no safe limit for the organophosphates. Exposure in early development, exposure during pregnancy lead to effects on brain development that are quite profound and qualitatively quite different from the toxicity produced by these chemicals in adult animals. The early development of the human brain is probably one of the most complex phenomena in all of nature.

The price we play for that great complexity is great vulnerability. There's not much chance to go back and get it right because the whole thing is such a precisely orchestrated dance. That's why exposures even to small doses of chemicals can have devastating effects."

People don't want to gamble with their health and their children's futures. As they become more aware of the consequences of food pollution, they are voting with their pocketbooks. It's no coincidence that organic produce sales have been climbing rapidly, even during a recession. At the end of the day, young families and children - the audience the AFF seems to feel is most affected by EWG's message - are not only eating their vegetables, they are eating more of them, and they are increasingly choosing to buy pesticide-free products. This is the exact result EWG had in mind when it created Dirty Dozen.

If people mistrust the conventional produce and pesticide industries, it's not because of the Dirty Dozen. It's because of the industry's long, sorry history. People don't refuse to eat vegetables because of EWG. They refuse to buy vegetables, if they actually refuse at all, from people they don't trust -- and EWG's Shopper's Guide makes it easier for them to weigh that decision.

Big Ag would do better to spend its money to fix its trust problem ... instead of making it worse by engaging in nonsensical distractions, like the celery calculation. Turning to public relations campaigns as a "solution" only encourages people to distrust them more.


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