EDITOR'S NOTE: This is the second of two columns on organic fruits and vegetables. Last week, we talked about the nutritional content and other purported advantages of organic foods; this week is a look at organic food's safety issues.

Q. Am I avoiding dangerous chemicals by eating organic?

A. "There are absolutely fewer pesticides used on organic foods," says Urvashi Rangan, an environmental scientist at Consumers Union. "Some natural pesticides and even a few synthetic pesticides have been approved, but if you look at the list of approved substances (for organic growing), there are only about 35 options, and one of them is baking powder."

In fact, many organic proponents claim that the major benefit of organics is avoiding toxic contaminants, particularly carcinogenic and neurotoxic pesticides.

"These are certainly a concern to healthy people, but more so to the unhealthy, and even more so to toddlers and infants, who are extremely sensitive to carcinogens," says Dr. Samuel S. Epstein, a professor emeritus of Environmental and Occupational Medicine at the University of Illinois School of Public Health and chairman of the Cancer Prevention Coalition.

However, not everyone agrees.

"Yes, some agricultural chemicals are dangerous, but humans do not ingest enough to threaten their health," argues Joseph Rosen, a professor of food science at Rutgers University in New Jersey.

Nevertheless, the effects of these chemicals on agricultural workers may make you want to reduce exposure as much as possible. One analysis in Reviews on Environmental Health determined that workers exposed to pesticides are at high risk for cancer.

Q. Do government regulations protect our food from harmful chemicals?

A. In this country, Rangan says, "We tend to believe that something is safe until it's proven otherwise. In Europe, they work the other way: They don't believe anything is safe until they see proof that it is. Right now, we don't have a lot of hard proof demonstrating that conventionally grown foods could be considered dangerous. But just because we don't have all the evidence to explain the danger doesn't mean the danger isn't there." The bottom line: Eating organic food is a way to be "safer than safe."

According to Epstein, "The USDA and FDA have a statutory obligation to inform the public of risks from carcinogens and contaminated foods, but both have abysmally failed to do so. Both agencies are more protective of agribusiness industry interests than consumer safety interests."

The FDA disagrees. According to a spokesperson, "The FDA has an extensive program and commitment to protect the public health from chemical contaminants, which includes setting action and guidance levels, action plans aimed to minimize exposure to harmful contaminants, public meetings both to inform the public and solicit input, food advisory committee meetings, surveillance, consumer advice and enforcement actions."

Some would say that eating organic isn't necessarily better because natural pesticides can be as bad as synthetic ones. "There is a common assumption that natural chemicals are somehow safe to eat, whereas synthetic chemicals are dangerous. That is completely untrue," says Anthony Trewavas, a professor and plant scientist at the Institute of Cell and Molecular Biology in Edinburgh, Scotland.

"In fact, some natural pesticides kill insects by precisely the same chemical mechanism as synthetic pesticides. And there is no difference in the overall toxicological stability of natural and synthetic chemicals in the human body. But while the daily consumption of natural pesticide is equivalent to about a quarter of a teaspoon, the synthetic pesticide trace is the equivalent of one-quarter of a grain of salt — about 10,000-fold lower. That amount of synthetic chemicals is toxicologically irrelevant."

Nevertheless, even die-hard cynics like Rosen agree that if you can afford to buy organic, "Why not do it?"

Q. Do I need to buy organic fruits and vegetables for my children?

According to Rangan: "It's a value judgment. If you want to reduce the pesticides and chemicals your children are exposed to, it makes sense to avoid conventionally grown foods." Ask yourself: Would you like to err on the side of caution? Can you afford it?

Q. Should you avoid all nonorganic foods even if you're on a tight budget?

A. Not necessarily. According to Rosen, a family of four would probably spend 50 percent to 300 percent more to be completely "organic." However, there is a middle ground. Not only do the amounts of pesticides used on different kinds of produce differ, but the physical makeups of the fruits and veggies themselves change the level of pesticides you're likely to ingest, says Kathleen Merrigan, a professor of nutrition at Tufts University.

If you're concerned about contamination but don't want to go completely organic, here are the "Dirty Dozen," the 12 foods with the highest chemical levels, according to a USDA analysis on pesticide residue: peaches, strawberries, apples, nectarines, pears, cherries, red raspberries, imported grapes, spinach, celery, potatoes and bell peppers.

According to the Environmental Working Group, the six fruits least likely to have pesticide residues are pineapples, mangoes, bananas, kiwis, avocado and papayas. And the vegetables least likely to have pesticide residue are corn, avocado, cauliflower, asparagus, onions, peas and broccoli. To find out the level of pesticides on your produce, go to food news.org.

Q. Can't you simply rinse off pesticides, fertilizers and other allegedly harmful chemicals?

A. Washing can substantially reduce the amount of pesticides on the skins of fruits and vegetables. Your best bet is a 30-second rinse, a 15-second soak and then a final rinse.

Charles Stuart Platkin is a nutrition and public-health advocate. Write to info@thedietdetective.com.