Cigarette smoke in closed spaces.

For years it has been postulated that the cigarette smoker adversely affects the nonsmoker by contaminating the indoor atmosphere (2,3). Recently, the U.S. Surgeon General, J. L. Steinfeld, focused public attention on the question when he requested a ban on smoking in closed public spaces (4). The average person spends the great majority of his time, probably 80 to 90 percent, indoors (5);thus, there is widespread concern about the environmental conditions produced by indoor smoking. Experiments on mouse skin have indicated that the condensate tar of the smoke from the glowing end of the cigarette (sidestream) has a higher tumor-producing activity than condensate leaving the mouthpiece of the cigarette (mainstream) (6). Other experiments showed that air pollution extract and cigarette smoke condensate combined have more than additive tumor-producing potential (7,8). Previous studies on cigarette smoke in closed spaces suggest that the nonsmoker is exposed to considerable amounts of cigarette smoke in the course of his normal activities (9). Thus, the pollution of closed spaces by cigarette smoke possibly contributes to such otherwise unexplained phenomena as lung cancer in nonsmokers, differences in lung