In this short but forceful work pediatrician Ronald Glasser sounds the alarm against environmental carcinogens, ""the modern scourge."" The incidence of cancer in children and adults continues to rise. The risk of fetal malformation or malignancy in later years will also rise as long as pregnant women smoke or expose the fetus to carcinogenic drugs. Glasser argues that most cancer is environmentally caused. An invading substance interferes with cellular DNA creating a precancerous state. In time, perhaps aided by ""promoter"" substances, the cell becomes malignant at which point little can be done. Our inability to take preventive measures--eliminate the risks--stems largely from the time lag between exposure and onset of disease and from the impersonal it-won't-happen-to-me attitude that statistical studies elicit. Add to that the high economic stakes of the tobacco, food, drug, cosmetic, and power industries, and it's not hard to see why public policy flounders in a sea of wait-and-see. But the cautionary tales are abundant: thyroid cancer in adults exposed to radiation of tonsils or adenoids in infancy; lung cancers in asbestos workers; leukemia in Hiroshima victims years after the bomb; and many less familiar. As in his other writing Glasser is passionate, sparing none of the grim descriptions or sorry statistics. In this case the zeal seems warranted. Even if not all cancers are environmentally caused, the case for carefully screened tests of substances and for preventive measures is surely sound.