The current lack of empirical data on outdoor tobacco smoke (OTS) levels impedes OTS exposure and risk assessments. We sought to measure peak and time-averaged OTS concentrations in common outdoor settings near smokers and to explore the determinants of time-varying OTS levels, including the effects of source proximity and wind. Using five types of real-time airborne particle monitoring devices, we obtained more than 8000 min worth of continuous monitoring data, during which there were measurable OTS levels. Measurement intervals ranged from 2 sec to 1 min for the different instruments. We monitored OTS levels during 15 on-site visits to 10 outdoor public places where active cigar and cigarette smokers were present, including parks, sidewalk cafés, and restaurant and pub patios. For three of the visits and during 4 additional days of monitoring outdoors and indoors at a private residence, we controlled smoking activity at precise distances from monitored positions. The overall average OTS respirable particle concentration for the surveys of public places during smoking was approximately 30 g m 3. OTS exhibited sharp spikes in particle mass concentration during smoking that sometimes exceeded 1000 g m 3 at distances within
Secondhand tobacco smoke (SHS), also called environmental tobacco smoke (ETS) or passive smoke, is defined as diluted and dispersed air pollutant emissions generated from the consumption of tobacco products. Emissions may be exhaled by a smoker (mainstream) or by leaving the burning tip of a cigarette or cigar (sidestream). When occurring outdoors, SHS is called outdoor tobacco smoke (OTS).
Indoor SHS has an established connection to adverse health outcomes in adults and children, such as asthma, respiratory infection, and lung cancer. More recent work has shown an association between SHS exposure and reduced cognitive ability in children, increased respiratory disease in adults from work exposure and increased cancer for people exposed at home as children, increased coronary heart disease in women exposed at home or work, and a general increase in mortality for persons living with smokers. The U.S. Surgeon General’s Report titled “The Health Consequences of Involuntary Exposure to Tobacco Smoke” concludes that there is no level of exposure to SHS without some associated risk, and the California Air Resources Board (CARB) recently designated SHS as a “toxic agent,” a classification also given to pure compounds such as arsenic or benzene.