Exposure of restaurant personnel to environmental tobacco smoke was assessed in 23 restaurants in 2002-2003 after the Finnish Tobacco Act--including restrictions on smoking at bar desks and demands on non-smoking sections--had been extended to restaurants. Air samples were collected using passive samplers from the breathing zone of non-smoking workers during entire work shifts. 3-ethenylpyridine (3-EP) was used as a tobacco-specific vapour-phase marker. The overall median concentration of airborne 3-EP for 97 workers was 1.2 microg/m3, the individual concentrations ranging from <0.06 to 9.4 microg/m3 (n=292). Higher concentrations were measured for staff working in smoking areas or at bar counters than that recorded for those working in non-smoking areas or across different areas. Area samples were collected by passive sampling of 3-EP on organic vapour monitors and by active sampling of 3-EP and nicotine in charcoal tubes. The median concentrations of 3-EP and nicotine were 1.5 microg/m3 (n=292) and 11 microg/m3 (n=92), respectively. In non-smoking areas and at the bar, 3-EP concentrations were 41% and 69% of those measured in smoking areas, with a third of the restaurants having concentrations below 20% in their non-smoking areas.
Practical implications: The method applied here--based on diffusive sampling of 3-ethenylpyridine--proved adequate even at low environmental tobacco smoke (ETS) levels. The easy-to-use sampler is thus well suited to detect whether a non-smoking room or area is actually smoke-free or contaminated by smoke drifting from a smoking area. Only a third of the restaurants participating in this study achieved low concentrations of 3-ethenylpyridine in their non-smoking areas. In these cases, the non-smoking area was usually strictly separated from the smoking area. Despite the ban on smoking at bar counters in most restaurants, the drifting smoke was usually a problem if the counter was located in the middle of the smoking area. However, exposure to ETS behind the bar desk was reduced if the counter was located in a non-smoking area.