and Glantz 2003). In the same year, 14 other states passed new or amended clean indoor air laws (Emont et al. 1992).

As of July 1, 2006, 17 states have laws in effect that require 100 percent smoke-free workplaces and/or restaurants and/or bars (ANRF 2005a). Overall, 6,845 municipalities are covered by state or local laws requiring workplaces and/or restaurants and/or bars, to be 100 percent smoke-free, protecting 44.5 percent of the United States population (ANRF 2005b). Notably, 140 municipalities in the United States require workplaces, restaurants, and bars to be 100 percent smoke-free (ANRF 2005a). Additionally, many sites have voluntarily become smoke-free (Jacobson and Wasserman 1997).

A review by Serra and colleagues (2004) of interventions that prevent tobacco smoking in public places found that carefully planned and resourced, multicomponent strategies to implement policies banning smoking effectively reduce smoking in public places (Serra et al. 2004). Not surprisingly, less comprehensive strategies, such as posted warnings and educational material, were less effective.

Furthermore, the Centers for Disease Control and Prevention (CDC) Task Force conducted a systematic review of tobacco intervention studies (n = 10) and concluded that smoking bans or limits on tobacco smoking in workplaces and public areas are strongly recommended to reduce exposure to ETS based on the following key findings (CDC 2000b): First, smoking bans and restrictions effectively reduce workplace exposure to ETS in several different settings and populations. Second, following the implementation of smoking bans, decreases in daily tobacco consumption among smokers and increased rates of cessation were identified.

More stringent clean indoor air laws are associated with decreased smoking prevalence and cigarette consumption and a higher proportion of quitters. For example, Emont and colleagues (1992) found that the average smoking prevalence was 28 percent in states without clean indoor air laws and 24 percent in states with extensive clean indoor air laws (J * = 3.33, p < .001). Additionally, average cigarette consumption per head was about 119 packets in states without laws and 105 in states with laws (J * = 2.79, p < .005). Finally, the average proportion of quitters in states without laws was 44 percent and in states with laws was 50 percent (J * = 3.96, p < .00005) (Emont et al. 1992).

Comprehensive public clean air laws have the potential to reduce prevalence and consumption rates of the entire population (including nonworking and non–indoor-working smokers) by about 10 percent (Levy and Friend 2003). Additionally, clean air regulations may contribute to a changing social norm with regard to smoking by altering the perceived social acceptability of smoking (CDC 2000c). Because of changes in social attitudes and the need to smoke in less hospitable places, smokers may be induced to attempt to quit or not initiate (Levy and Friend 2001a).

Workplace smoking restrictions are likely to have the greatest impact on both ETS and smoking habits because of the number of hours that workers are subject to these restrictions. Worksite bans may include a total prohibition of smoking onsite, less stringent bans that limit smoking to separate ventilated areas, or smoking in designated areas only. A 1994 report by the EPA estimated that the net benefit of a nationwide, comprehensive clean indoor air law would exceed the estimated costs by $39 billion to $72 billion (EPA 1994). Cost savings to employers include an estimate $4 billion to $8 billion annually in operational and maintenance costs of buildings (EPA 1994).