Advances in Controlled Clinical Inhalation Studies represents scientific work presented at the 3rd International Inhalation Symposium held 1991 in Hannover, FRG. The symposium covered the new developments in this field of research. The main pollutants of interest were acid aerosols, fog, and indoor pollutants, while with regard to biological effects, an emphasis was placed on immunotoxicological and biochemical parameters. Tests on high risk groups were also considered. Initial chapters describe the outdoor environment as well as indoor air, measurement and quality - both at home and in the workplace. Besides methods for clinical inhalation and assessing personal exposure, new methodologies are particularly presented. Further chapters focus on the relevance of clinical data for regulatory decisions.