The effects of ingesting pesticides in the very small amounts present in vegetation are unknown. Bruce Ames, Ph.D., director of the National Institute of Environmental Health Sciences Center at the University of California at Berkeley, who has devoted his career to examining this question, believes these minute amounts pose no risk at all.
He and other scientists support this view because humans and other animals are exposed to, small amounts of naturally occurring toxins with every mouthful of organically grown, natural food. The body normally breaks down self-produced metabolic wastes and naturally occurring carcinogens in foods, as well as pesticides, and excretes these harmful substances every minute. Since 99.99 percent of the potential carcinogenic chemicals consumed are naturally present in all food, reducing our exposure to the 0.01 percent that are synthetic will not reduce cancer rates.
These scientists argue that humans ingest thousands of natural chemicals that typically have a greater toxicity and are present at higher doses than the very minute amount of pesticide-residues that remain on food. Furthermore, animal studies on the carcinogenic potential of synthetic chemicals are done at doses a thousand fold higher than what is ingested in food. Ames argues that a high percentage of all chemicals, natural or not, are potentially toxic in high doses - "the dose makes the poison” - and that there is no evidence of possible cancer hazards from the tiny chemical residue remaining on produce.