Laboratory animal tests and human cancer.

The use of the results of laboratory animal tests to predict human cancer is effective in identifying potential human carcinogens before human exposure, permitting measures to be taken to prevent that exposure, a foolproof way to prevent human cancer. The purported, and highly publicized, faults of these tests, when examined critically, are shown not to be significant. Most chemicals are not carcinogenic; only about 1 in 10 are truly carcinogenic. The high doses used to maximize sensitivity do not produce false positives. All human carcinogens are carcinogenic in laboratory animals, and almost all animal carcinogens for which there is human exposure, when analyzed by epidemiological studies, show responses that are not statistically different. Most carcinogens are not banned, some are regulated, but many are not. The claimed costs of these health regulations are typically overestimated, and often greatly overestimated. Using the results of laboratory animal studies is good science and good public health.