Another element that needs consideration, as described by Brudnoy, is the question of cell duplication rates. In any case, however, there are sound methods to evaluate human cancer risks. It is intriguing that there is so much intellectual discussion on cancer risks when the removal or modification of the documented known cancer risks--namely, tobacco use and nutritional excesses (especially in regard to fat intake)--that overall account for about 90 percent of the current cancer burden in the Western world, receives so little attention and readily implemented control measures.
JOHN H. WEISBURGER
Director Emeritus
American Health Foundation
Valhalla, N.Y.
