Presented in this preliminary report is one of seven assessments conducted by a special task force of Project Clean Air, the Human Health Effects Task Force. The reports summarize assessments of the state of knowledge on various air pollution problems, particularly in California, and make tentative recommendations as to what the University of California can do through Project Clean Air to alleviate those problems. In this report biomedical effects of air pollution are evaluated from epidemiological evidence and from experimental studies. Human hazards are emphasized to establish whether enough evidence exists to set air quality standards because of demonstrated human health effects. Section I provides a review of the findings and suggests basic and applied research that is needed. Section II enumerates: (1) the biomedical effects of fossil fuel combustion, (2) effects of individual pollutants, (3) effects of inherited metabolic patterns on air pollutant susceptibility, and (4) environmental carcenogens, mutagens, and teratogens. The last section offers tasks recommended for the Project in the nature of mission-oriented programs. Literature cited is listed. A related document from the Automobile Engine Development Task Force is ED 052 938. (BL)