ATLANTA – Today the Department of Health and Human Services released the Report on Carcinogens 9th edition. Prepared by the National Toxicology Program, which is headquartered at the National Institute of Environmental Health Sciences, the Report identifies substances — such as metals, pesticides, drugs, and natural and synthetic chemicals — and mixtures or exposure circumstances that are “known” or are “reasonably anticipated” to cause cancer, and to which a significant number of Americans are exposed. The Report is published every two years.

An agent, substance, mixture or exposure circumstance can be listed in the Report either as “known to be a human carcinogen” or as “reasonably anticipated to be a human carcinogen.”

The “known” category is reserved for those substances for which there is sufficient evidence of carcinogenicity from studies in humans that indicates a cause and effect relationship between the exposure and human cancer.

The “reasonably anticipated” category includes those substances for which there is limited evidence of carcinogenicity in humans and/or sufficient evidence of carcinogenicity in experimental animals.

Conclusions regarding carcinogenicity in humans or experimental animals are based on expert, scientific judgment, with consideration given to all relevant information.

The following briefly describes a change made to the 9th edition of the Report:

Saccharin – Saccharin has been removed from the 9th edition. The Calorie Control Council nominated saccharin for delisting, which led to a new review of the carcinogenicity data for saccharin. Saccharin had been listed in the Report as “reasonably anticipated to be a human carcinogen” since 1981. The basis for this listing was “sufficient evidence of carcinogenicity in experimental animals.” Saccharin was removed from the Report after this extensive review determined that the rodent cancer data are not sufficient to meet the current criteria to list saccharin in the Report as a “reasonably anticipated human carcinogen.” This is based on the determination that the observed bladder tumors in rats arose from a mechanism that is not relevant to humans.

Dr. Kenneth Olden, Director of the National Institute of Environmental Health Sciences and the National Toxicology Program, said, “Two decades ago, when saccharin was shown to produce bladder tumors in rats, it was a prudent, protective step to consider the sweetener to be a likely human carcinogen. However, our understanding of the science has advanced and allows us to make finer distinctions today. Studies now indicate that the rat bladder tumors arise from mechanisms that are not relevant to the human situation. In addition, we have decades more data from observations of humans using saccharin that adds to our confidence. In other words, with better science we can now make a better call.”

[ Public policy support for artificial sweetener Saccharin. ]