Web site for the National Institute of Environmental Health and Sciences
Center (NIEHS) at the University of California at Berkeley. Contains updated
information on the Salmonella Tester Strains program.
A new web page of Gold, Ames & Slone presents a graphic that uses a Margin of Exposure index to provide a broad perspective on possible cancer hazards from human exposures to chemicals that cause cancer in high dose rodent cancer tests. Exposures include high historical exposures to workers, pharmaceuticals, natural chemicals in the average diet (e.g., natural pesticides that plants produce to defend themselves), air pollutants, food additives, and pesticide residues. Human exposure levels range from close to the rodent carcinogenic dose for a few historical exposures in the workplace to a billion times less the rodent carcinogenic dose for some pesticide residues. Human consumption of the background of natural chemicals in food is usually closer to the rodent carcinogenic dose than pesticide residues or pollutants, and half the natural chemicals tested are carcinogenic in high dose tests. Recent risk assessment methods indicate that for some chemicals the mechanism of carcinogenesis in rodents at high dose is not relevant to humans.
April 16, 2020 2:28 PM