by Patricia Wen
Boston Globe
June 16, 1997

Joan Marshall, 33, had never worried about the safety of fruits and vegetables. Scoffing at the concerns of the organic food crowd, she happily grabbed a box of fresh strawberries at an Allston supermarket earlier this spring, without giving a thought to pesticides. But when she was told the Globe would be testing the same batch of strawberries for pesticide residues, Marshall admitted she was curious.

And when she heard the results last week, even Marshall was slightly rattled. On her strawberries were four pesticides -- captan, iprodione, malathion, and carbaryl -- two of which are known to cause cancer. All residues, however, were at levels far below the current federal limits. While the account executive from Medford says she isn't ready to switch to expensive organic produce, she confessed the results "make you think a little bit."

Marshall joins the ranks of confused Americans who are trying to sort out whether pesticides on produce are a trivial concern or a potentially serious health hazard. Nobody wants to worry all the time, but scientists increasingly suspect unknown environmental causes may explain the rise in certain types of cancer. And if people have a hard time controlling environmental factors such as air, water, or soil quality, they can at least control what food they put in their mouths. But how can they determine that their produce is safe?

Even federal regulators concede that current standards for amounts of pesticides on produce are out of date, and they are now working to revise them.

The current rules focus mostly on potential cancer risks, though pesticides can injure people in other ways. At lower levels, the chemicals may damage the nervous system or they may be "endocrine disruptors," affecting the human hormonal system and possibly impairing fertility.

And current tolerance limits are geared toward adults, not children, who eat proportionately more fruits and vegetables. Children, with their small, developing bodies, may be more susceptible than adults to pesticides' ill effects. The standards will get tougher under a law enacted last summer that requires the Environmental Protection Agency to revise tolerance limits on 9,000 pesticides used on crops.

"The new numbers have to be protective of the most vulnerable in the population, which is often infants and children," said James Aidala, deputy assistant administrator for EPA's office of prevention, pesticides, and toxic substances. But until the new standards take effect, at least several years from now, consumers must choose whether to trust today's standards as good enough, or spend the extra money for organic produce.

Some are attacking the problem with a scrub brush and water -- or the paring knife. Pesticide specialists say vigorous washing of produce may remove from 25 to 50 percent of pesticide residues, though it will do nothing for chemicals that penetrate the fruit. Many people stick with domestic produce. Imported produce generally shows slightly higher pesticide levels than domestic, and a somewhat higher rate of pesticide violations. It is smart to take precautions, but concerns about pesticides should not inhibit people from eating plenty of fresh fruits and vegetables, said Graham Colditz, director of the Center for Cancer Prevention at the Harvard School of Public Health.

If the hazards of pesticides are unclear, the benefits of fruits and vegetables couldn't be more clear, he said. Studies repeatedly show those with diets high in fruits and vegetables have lower rates of cancer, whether the produce is organic, conventional, domestic, or imported. "If we choose to avoid some fruits and vegetables because we'll allow them only in the strictest and most controlled way, it's clearly the wrong choice," Colditz said.

Meanwhile, federal officials say consumers should take comfort in the fact that random tests show only a 1 to 2 percent rate of violations of pesticide limits for domestic produce, and a 2 to 4 percent rate for imported fruits and vegetables. "When we look at the levels in the foods, the average levels are probably 10 times lower than the set tolerances," said Terry Troxell, director of the division of program and enforcement policy for the US Food and Drug Administration. "The actual exposure is extremely low."

Federal law limits the amount of pesticides that can remain on each kind of produce when it leaves the farm, measured in "parts per million" of the total fruit or vegetable. The limit is based on calculations of how much pesticide a person is likely to ingest with a varied diet in a 70-year lifetime, and is set well below the level that would be expected to cause cancer or other serious health problems. Indeed, the strawberries tested by the Globe had very low levels of the pesticides detected. Captan, considered an endocrine disruptor as well as a carcinogen, was 0.35 parts per million, while the legal tolerance level is 25 ppm, about 70 times that amount. Iprodione was found at 0.51 ppm, while the limit is 15 ppm, or 29 times that amount.

But some say these figures only seem low because the current limits are set so high. "The speed limit is set at 1,000 miles an hour," said Richard Wiles, vice president for research for the Environmental Working Group, a nonprofit environmental research organization based in Washington, D.C. "It's not safe for anyone." Besides being set at adult levels, Wiles says, the limits ignore many non-cancer effects of pesticides and assume a person is not exposed to pesticides in the environment in other ways.

The new EPA standards, he said, must take into account the cumulative effects over a lifetime of multiple sources of pesticides, not just from food, but also from air and water. And they must also consider the levels at which pesticide residues may interfere with the hormonal or nervous system. A 1993 report by the Environmental Working Group concluded that the average American child, by age 5, has accumulated 35 percent of the federally permitted lifetime exposure to captan and similar percentages of the allowed 70-year exposures to other carcinogenic pesticides.

While federal officials are quick to act on produce contaminated with bacteria, such as last week's suspected contamination of Guatemalan raspberries, they are only starting to educate consumers on health issues involving produce and pesticides. Starting next summer, the EPA is required to give all major grocery stores a copy of a consumer brochure that will attempt to explain these issues.

Fearful of all the unknowns about pesticides, consumers are driving a healthy $3.5 billion organic food industry. Though organic fruits and vegetables can cost up to twice as much as conventional produce, organic produce sales have grown by about 20 percent a year in the past decade. To strengthen standards in the industry, the organic food industry pushed for stronger certification requirements. In 1990, the federal government passed the Organic Food Production Act, which required that anything with the label "certified organic" had to pass standards of an approved state or regional program.

Federal officials also set up a national board that is in the midst of setting uniform standards for organic produce throughout the country. All organic farms -- which produce about 2 percent of the nation's produce -- must be "free of all toxic and persistent pesticides and fertilizers" for the past three years, said Katherine DiMatteo, executive director of the Organic Trade Association, a national trade group for organic growers.

She said organic growers are allowed to use natural pesticides, such as rotenone, which are safer because they deterioriate quickly and often are simply repellents that have no toxic impact. And organic produce is allowed to have some low level of synthetic pesticides -- current recommendation is 5 percent of the EPA tolerances -- to take into account the fact that pesticides in the air and water may spread to organic fields.

The overwhelming amount of organic produce tested, DiMatteo said, comes up with no pesticides. Indeed the Globe's random tests of some organic apples and carrots found no synthetic pesticides.