Environmental tobacco smoke in an unrestricted smoking workplace: area andpersonal exposure monitoring

The objective of this investigation was to determine the extent of areal an d day-to-day variability of stationary environmental tobacco smoke (ETS) co ncentrations in a single large facility where smoking was both prevalent an d unrestricted, and to determine the degree of daily variation in the perso nal exposure levels of ETS constituents in the same facility. The subject f acility was a relatively new four-story office building with an approximate volume of 1.3 million ft. The exchange of outside air in the building was determined to be between 0.6 and 0.7 air changes per hour. Eighty-seven are a samples (excluding background) were collected at 29 locations over the co urse of 6 days of sampling. Locations included offices and cubicles occupie d by smokers and nonsmokers, common areas, and the computer and mail rooms. Twenty-four nonsmoking subjects wore personal sampling systems to collect breathing zone air samples on each of 3 days in succession. This generated a total of seventy-two 8-h time-weighted average (TWA) personal exposure sa mples. In all samples, respirable suspended particulate matter, ultraviolet light-absorbing and fluorescing particulate matter, solanesol, nicotine, a nd 3-ethenyl pyridine were determined. With the exception of a few location s, tobacco-specific airborne constituents were determined in all samples. N ot surprisingly, areas with the highest ETS constituent concentrations were offices and cubicles of smokers. Median and 95th percentile concentrations for all area samples, excluding background, were determined to be 1.5 and 8.7 mug/m(3) for nicotine, and 8.2 and 59 mug/m(3) for ETS-specific particl es (as solanesol-related particulate matter, Sol-PM), respectively. Persona l exposure concentrations of ETS components were similar to those levels fo und in the area samples (median nicotine and Sol-PM concentrations were 1.2 4 and 7.1 mug/m(3), respectively), but the range of concentrations was some what smaller. For example, the 95th percentile 8-h TWA nicotine and ETS-spe cific particle (as Sol-PM) concentrations were 3.58 and 21.9 mug/m(3), resp ectively. Intrasubject variation of daily concentrations ranged from 20% to 60%, depending on the component. Self-reported proximity to smokers was su pported by higher ETS concentrations determined from the personal monitors, but only to a modest extent. Although smoking was completely unrestricted inside the main office areas of the facility, ETS levels, either areal or f rom personal exposure measurements, were lower than those estimated by Occu pational Safety and Health Administration to be present in such facilities.