While there are some data, they point to minimal carcinogenic hazards from current levels of pesticides, he tells WebMD. However, the sheer number of toxins naturally occurring in the environment makes the issue complex.
However, "I haven't seen anything that made me think there's a big health risk from eating vegetables with pesticide residues in countries that have regulatory systems," Denison says. "I don't worry about pesticide residue in vegetables grown in the U.S. by conventional methods."
Also, "organic people" have concerns about bioengineered produce -- those fruits and vegetables that are genetically bred to have a "pesticide factory" in every cell, Lipson says. "Every cell in those crops is producing a pesticidal toxin -- which is different from being able to resist the effects of insect pests. That's the subtle difference that the propaganda of the seed industry glosses over."
Whether that's a problem, Denison says, is still being debated. "It's not that anybody made the determination that all those crops are dangerous to human health," he says. "The USDA just banned them from being used in organic production because people are skeptical about them."
As for fears about irradiation, "they remind me of the fuss over microwave ovens," says John Allred, PhD, professor of nutrition at Ohio State University in Columbus. "You don't want to crawl into a microwave oven and turn on the power, but eating food that comes from it doesn't harm you. It's a different form of energy; it would be hazardous if you were exposing yourself to the energy. But you're exposing the food. That doesn't make food radioactive."
The FDA approved food irradiation in the late 1970s to kill insects in spices. "It was designed to break up the DNA of bacteria so they don't reproduce," Allred tells WebMD. Since then, irradiation also has been approved for fruits and vegetables -- although very few are irradiated, and they have to be labeled if they are. "I've never seen a label like that," Allred says. "It just isn't done much. But that's just fresh produce. If it's a packaged product -- like canned strawberries -- I'm not sure they're required to put it on the label. "