Cancer is most often thought of as a spontaneous process in which no known inciting agent has been identified. This does not mean that known causes do not exist. There is an extensive literature dealing with carcinogenic agents, and Dr. McDonald has succinctly defined those related to chronic industrial exposures in bladder tumorigenesis. Despite the known relationship between certain chemical carcinogens and bladder cancer, the translation of scientific facts into effective legislation is slow and virtually nonexistent in the United States. It should be emphasized that despite the facts that cancer of the bladder has been produced in workers in chemical, rubber, cable, and a number of other industries, and that its incidence is on the increase, to date—with the exception of the Commonwealth of Pennsylvania— no federal or state legislation exists in the United States for the regulation of the manufacture, use, or importation of these chemicals.