Chemical carcinogens: a review of the science and its associated principles. U.S. Interagency Staff Group on Carcinogens.

In order to articulate a view of chemical carcinogenesis that scientists generally hold in common today and to draw upon this understanding to compose guiding principles that can be used as a bases for the efforts of the regulatory agencies to establish guidelines for assessing carcinogenic risk to meet the specific requirements of the legislative acts they are charged to implement, the Office of Science and Technology Policy, Executive Office, the White House drew on the expertise of a number of regulatory agencies to elucidate present scientific views in critical areas of the major disciplines important to the process of risk assessment. The document is composed of two major sections, Principles and the State-of-the-Science. The latter consists of subsections on the mechanisms of carcinogenesis, short-term and long-term testing, and epidemiology, which are important components in the risk assessment step of hazard identification. These subsections are followed by one on exposure assessment, and a final section which includes analyses of dose-response (hazard) assessment and risk characterization. The principles are derived from considerations in each of the subsections. Because of present gaps in understanding, the principles contain judgmental (science policy) decisions on major unresolved issues as well as statements of what is generally accepted as fact. These judgments are basically assumptions which are responsible for much of the uncertainty in the process of risk assessment. There was an attempt to clearly distinguish policy and fact. The subsections of the State-of-the-Science portion provide the underlying support to the principles articulated, and to read the "Principles" section without a full appreciation of the State-of-the-Science section is to invite oversimplification and misinterpretation. Finally, suggestions are made for future research efforts which will improve the process of risk assessment.