Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 18 November 1977:
Vol. 198. no. 4318, pp. 693 - 699
DOI: 10.1126/science.910152
Prev | Table of Contents | Next

Articles

Science, Vol 198, Issue 4318, 693-699
Copyright © 1977 by American Association for the Advancement of Science

articles

Carcinogenic risk assessment

J Cornfield

Carcinogenic risk assessment involves a mixture of statistical, scientific, and public policy considerations. Concepts in current use, such as "no observed effect levels" and "virtual safety," and the problems in implementing them by means of dose-response models, particularly the probit-log dose and linear models are reviewed. The upper limits to risk provided by some conservative procedures are inconsistent with coherent balancing of risks and benefits. A common basis to the dose-response curves describing both carcinogenic and noncarcinogenic effects is to be found in deactivating reactions. A simplified model in which a toxic substance is activated and deactivated in separate and simultaneous reactions is presented and the dose response curve implied by the model is deduced. This curve has the general form of a hockey stick, with the striking part flat or nearly flat until the dose administered saturates the deactivation system, after which the probability of a response rises rapidly. Such a curve describes the Bryan-Shimkin methylcholanthrene-tumor incidence dose response curve as well as the probit log-dose model. The concept of a saturation dose is relevant to risk assessments for carcinogenic and noncarcinogenic substances alike.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
A true threshold dose in chemical carcinogenesis cannot be defined for a population, irrespective of the mode of action.
W K Lutz (2000)
Human and Experimental Toxicology 19, 566-568
   Abstract »    PDF »
A cancer risk model with adaptive repair.
T. Downs and R. Frankowski (1998)
Human and Experimental Toxicology 17, 697-700
   PDF »
A Selected Review of Risk Models: One Hit, Multihit, Multistage, Probit, Weibull, and Pharmacokinetic.
B. Hanes and T. Wedel (1985)
International Journal of Toxicology 4, 271-278
   Abstract »    PDF »
Process and Outcome in Regulatory Decision-Making.
G. Majone (1979)
American Behavioral Scientist 22, 561-583
Old problems, new challenges.
V Mike and R. Good (1977)
Science 198, 677-678
   PDF »
Acquiring new information while retaining old ethics.
V Herbert (1977)
Science 198, 690-693
   PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)