Multiple studies presented in Tables 3-2 and 3-3 observed reductions in number of cigarettes smoked per day that persisted for 12-18 months following implementation of a change in smoking policy. One study found a decline after 6 months, with a return to prior levels of consumption after 18 months. Emont demonstrated a nonsignificant, but suggestive, relationship between level of smoking restriction from state clean-indoor-air laws and number of cigarettes smoked per day using data from the 1989 CPS.
Analyses of data from a 5-year longitudinal follow-up of 8,271 employed adult smokers conducted as a part of the COMMIT trial examined the change in number of cigarettes smoked per day as reported by the same individuals in two surveys conducted 5 years apart. Using multiple linear regression techniques, they demonstrated a statistically significant greater reduction in number of cigarettes smoked per day over the 5-year period among those who worked in workplaces where smoking was restricted to designated areas (OR = -1.17), and an even greater
reduction for those who worked in workplaces where smoking was banned (OR = -2.78).
An internal tobacco industry study (Heironimus, 1992) of the effects of restrictions on smoking in the workplace using a tracking database of smokers demonstrated that smokers who work in smoke-free environments consumed 11-15 percent fewer cigarettes per day compared to smokers who work where there are no restrictions. Lesser restrictions, such as allowing smoking only in designated sections, had little effect on consumption.
The CPS did not ask a question on the number of cigarettes smoked per day 1 year prior to the survey, and therefore these analyses are limited to examination of the cross-sectional distribution of current number of cigarettes smoked per day in relation to workplace restrictions on smoking. As a result, the analyses in Table 3-4 cannot identify whether the difference in number of cigarettes smoked per day by smokers working under different workplace smoking restrictions is due to a reduction in number of cigarettes smoked per day produced by the workplace restriction or due to workplace restrictions being more difficult to implement where there are greater numbers
of heavy smokers.
The 1990 and 1996 California Tobacco Surveys (CTS) recorded the number of cigarettes smoked per day both at the time of the survey and for 1
year prior to the survey. Table 3-5 compares the current number of cigarettes smoked per day by those current cigarette smokers who work indoors with that reported for 1 year prior to the survey, and the results are stratified by the level of workplace restrictions on smoking. In the 1990 CTS, smokers who worked in workplaces with no restrictions on smoking were more likely to report smoking 25 or more cigarettes per day both at the time of the survey and for 12 months prior to the survey than were workers employed in workplaces where there were at least some restrictions.
Workers who smoked 25 or more cigarettes per day 1 year prior to the survey were also significantly more likely to report reducing the number of cigarettes that they currently smoked if they worked in areas where smoking was banned than if they worked in areas where there were no restrictions.