Compiled by Young Lee
Most consumers wonder whether the pesticide residues on produce cause cancer and other health problems. The popular perception is that the residues must be dangerous to health because pesticides are formulated to be highly toxic. Certain types of insects, plants and fungi are killed, and the toxic effects may extend to humans also.
There are also those who trust government regulation of food, and feel that the produce we buy is safe, or believe that the amount of pesticide residue is negligible.
Where does the truth lie? In a recent Vegetarian Times article "Pesticides: Pro and Con," two opposing view points were presented.
The pro pesticide argument
Summary of arguments by Bruce Ames Ph.D., Director of the National Institute of Environmental Health Sciences Centre at UC-Berkeley. He has studied naturally occurring chemicals in foods, and has co-authored many studies on pesticides and their cancer-causing effects.
· There is a great difference between the dose which is toxic to insects and that which is toxic to humans, so a great safety factor exists.
· A chemical is labelled a probable carcinogen based upon high-dose rodent tests, and those results cannot be extended to a human receiving a small dose.
· The world's leading scientific authorities on the causes of cancer do not think that synthetic pesticide residues are a significant cause of cancer. Inadequate fruit and vegetable consumption and smoking are more important causes. To eliminate pesticides would increase the prices of produce and threaten public health.
· EPA risk assessments are based upon enormous overestimates of human exposure and carcinogenic hazard.
· Safety factors are already great, and even if child exposure to pesticides is greater than for adults, they fall well within safe levels.
· Synthetic pesticides consumed represent only 0.01% of total ingested pesticide. The remaining 99.99% consists of natural Ôpesticides' occurring in food. For example, coffee contains vastly more potential carcinogens, natural or produced by roasting, than a person is likely to ingest in the form of synthetic pesticide residues each year. Coffee is still consumed. Therefore, natural safety factors exist, because the dose required to cause a significant cancer risk is so high that the risk becomes negligible.
Ames concludes by saying that there are more significant risks to be concerned with, and that resources would be better put towards other environmental issues.
The anti pesticide argument
Summary of arguments by Richard Wiles, Director of the Agricultural Pollution Prevention Project of the Environmental Working Group in Washington D.C. He is co-author of "Pesticides in Children's Food."
· Phasing out the highest risk pesticides would in fact have a negligible effect on the price of fruits and vegetables in the United States. The twelve most consumed fruits and vegetables did not change from 1985 to 1993, despite the EPA's cancellation of 200 pesticides during this period.
· Per capita fruit and vegetable consumption has doubled since 1975, but cancer rates (age adjusted) have increased by 25%. The risk of cancer due to synthetic pesticide consumption may be a greater factor than the cancer-fighting effect of eating more produce.
· A review by the National Toxicology Program showed that 94% of chemicals that cause cancer at high doses also cause cancer at low doses.
· Coffee is poor support for the high-dose-equals-high-risk theory, he writes, because none of the many studies conducted has linked coffee consumption with increases in cancer.
· Cancer is only one of the toxic effects of pesticides. The National Academy of Sciences claims neurotoxic compounds may cause brain function loss for children at the same dose which is deemed safe for adults.
· Pesticides are deliberately toxic to insects and cause toxic effects in animals including cancer, nervous system damage, birth defects and interference with immune and endocrine systems.
· Not every pesticide poses a great risk, but some of the more heavily used are very toxic. Fifteen pesticides commonly found in food are said to be named as probable human carcinogens by the EPA.
· Government regulations are based upon averages which do not accurately represent individuals, particularly children and vegetarians. Furthermore, the standards assume exposure to one pesticide at a time, an unrealistic scenario given the multitude of pesticides used.
Wiles concludes that the health benefit of fruits and vegetables is unnecessarily compromised by use of pesticides.