We have undertaken a study on 200 autopsy lung samples collected from subjects who lived in the Rome urban area and were not occupationally exposed to mineral dusts. The samples belonged to subjects who died aged between 15 and 65, both male and female. Subjects suffering from diseases and drug addicts were excluded. The purpose of this investigation was to determine whether any correlation existed between subjects' life-style, in particular smoking habits, and the presence of mineral fibres and dusts in their lungs. The data obtained were compared with those on airborne mineral dusts in the environment of the subjects themselves, particularly data on the concentration and types of mineral fibres present in that environment.