Samuel Epstein writes an exceedingly persuasive and comprehensive text on environmentally-caused cancer--the majority of all cancers. As a doctor with a thorough grounding in industrial medicine, he speaks with authority on the nature of tests to determine whether a given chemical or intermediate by-product is a carcinogen or a mutagen, and on matters of threshold values, sample sizes, controls, and duration of testing. He follows with illustrations of major carcinogens in the workplace, in consumer products, and in the community at large. His targets include such well-known culprits as tobacco, asbestos, vinyl chloride, DES, the red dyes, certain pesticides, and benzene. He is especially illuminating in discussing the weight of evidence against saccharin and how popular distortion of the Canadian findings has led to widespread confusion. One tends to regard works published by consumer-advocate organizations as special pleading. But Epstein's voice is never shrill, and his clear presentation of individual case histories--along with the arguments for or against the chemical involved--are all the more effective for that reason. Moreover, while clearly assigning blame to industry, agribusiness, and their academic and government links (including the National Cancer Institute and the American Cancer Society), he is the first to note the winds of change. Accordingly, he has good marks for Donald Kennedy of FDA, for example, and Arthur Upton, the new director of the National Cancer Institute. Indeed the message is plain--change is possible inside and outside the government. In the past, such change has mainly reflected the work of consumer groups and labor unions. Epstein stresses how the reader can take action (and also how best to live). He insists, further, on the need for broader linkages between groups which often form about a single issue only. A positive outlook at an opportune moment.