Exposure of U.S. workers to environmental tobacco smoke.

The concentrations of environmental tobacco smoke (ETS) to which workers are exposed have been measured, using nicotine or other tracers, in diverse workplaces. Policies restricting workplace smoking to a few designated areas have been shown to reduce concentrations of ETS, although the effectiveness of such policies varies among work sites. Policies that ban smoking in the workplace are the most effective and generally lower all nicotine concentrations to less than 1 microg/m3; by contrast, mean concentrations measured in workplaces that allow smoking generally range from 2 to 6 microg/m3 in offices, from 3 to 8 microg/m3 in restaurants, and from 1 to 6 microg/m3 in the workplaces of blue-collar workers. Mean nicotine concentrations from 1 to 3 microg/m3 have been measured in the homes of smokers. Furthermore, workplace concentrations are highly variable, and some concentrations are more than 10 times higher than the average home levels, which have been established to cause lung cancer, heart disease, and other adverse health effects. For the approximately 30% of workers exposed to ETS in the workplace but not in the home, workplace exposure is the principal source of ETS. Among those with home exposures, exposures at work may exceed those resulting from home. We conclude that a significant number of U.S. workers are exposed to hazardous levels of ETS.