Secondhand smoke contains at least 250 chemicals that are toxic or carcinogenic and is itself a human carcinogen (1). Exposure to secondhand smoke causes cardiovascular disease, respiratory illness, and lung cancer, and is responsible for an estimated 40,000 deaths in nonsmokers annually (2,3). Even short-term exposures to secondhand smoke may increase the risk of heart attack (4). The 2006 US Surgeon General's report The Health Consequences of Involuntary Exposure to Tobacco Smoke concluded that secondhand smoke causes long-term and short-term health risks, that no levels of secondhand smoke are safe, and that secondhand smoke should be eliminated in all public places (3). The report states, "Eliminating smoking in indoor spaces fully protects nonsmokers from exposure to secondhand smoke. Separating smokers from nonsmokers, cleaning the air, and ventilating buildings cannot eliminate exposures of nonsmokers to secondhand smoke" (3).

The Surgeon General's Report and the Guide to Community Preventive Services (3,5,6) state that secondhand smoke exposure and its adverse health effects are preventable. Preventing such exposure is most effectively done by enacting policies requiring smoke-free facilities (3,6). In North Carolina, legislation was introduced that allowed for smoking in "separately ventilated" areas as a way to protect public health. The North Carolina Alliance for Health, the North Carolina Association of Local Health Directors, and the state health department had a goal to make all North Carolina workplaces and public places smoke-free and to exclude exemptions for separately ventilated areas. To that end, they developed criteria for any pending legislation that would meet the public health evidence-based standard outlined by the Guide to Community Preventive Services to eliminate all potential secondhand smoke exposures. The challenge was to demonstrate to decision makers why the exemption for separately ventilated areas jeopardized public health.

North Carolina and other states with historic, political, economic, and agricultural ties to tobacco have remained behind the rest of the nation with respect to worker protection from secondhand smoke (7). In North Carolina, 77% of adults report that their workplaces are smoke-free, but differences exist among subpopulations. When examined by subpopulation, among adults with less than a high school education or annual incomes less than $15,000, the proportion with smoke-free workplaces drops substantially (58% among those with less than a high school education and 61% among those with annual incomes less than $15,000). According to Current Population Survey Tobacco Use Supplement data, blue collar (55%) and service industry workers (61%) have less protection from secondhand smoke in their workplaces than do white-collar workers (73%) (8,9).

Support for statewide smoke-free indoor air regulations has been weaker in tobacco farming and manufacturing states than in those with fewer economic ties to tobacco. For example, a 2001 Centers for Disease Control and Prevention (CDC) report assessing policies and attitudes about a ban on smoking in restaurants in 20 states found North Carolina to have the lowest level of support for policy change (10). To move policy forward, health risks must be recognized and quantified. Although many now consider secondhand smoke a serious health hazard, the extent and level of exposure often seemed to be underestimated or misunderstood by decision makers. In the North Carolina General Assembly House Judiciary I Committee hearings on March 21 and April 18, 2006, decision makers raised questions that made it clear they were not aware that simply separating smokers and nonsmokers was not effective in eliminating the health risk.

North Carolina has had a law since 1993 that sets a weak standard at the state level and prevents adoption of stronger ordinances at the local level. This law has been a barrier to comprehensive smoke-free policies at the state level (Smoking in Public Places, General Statute 143-595-601). As of March 2009, 12 states have preemptive state laws prohibiting most new local smoke-free regulations or preventing passage of strong state legislation (11). The strategy in North Carolina has been to reduce these barriers by gaining support for and passing incremental legislation that either bans smoking in certain venues (such as public schools) or permits the passage of smoke-free policies in certain venues (such as public universities). The North Carolina Alliance for Health served as an umbrella group for all tobacco control policy efforts. North Carolina has no regulations on smoking in private workplaces, restaurants and bars, retail stores, or recreational or cultural facilities. Indoor air monitoring has become a tool used by many states to demonstrate the rapid reduction in harmful particulate matter following the passage of city or statewide smoking bans (12-14). These post-policy analyses have demonstrated the effectiveness of the policy, but few studies to date have used this technology as a way to build support for policy change.

CDC focuses on 4 major goal areas, including eliminating nonsmoker exposure to secondhand smoke (15). Tobacco control advocates in North Carolina thought that indoor air monitoring might be a tool to use in efforts to attain this goal. Indoor air monitoring would not only clarify the effect of existing policies but also raise awareness about the levels of secondhand smoke exposure among workers and the general public, increase advocacy on the need for the state to develop stronger secondhand smoke policies, and ultimately attain the goal of smoke-free workplaces and public places with comprehensive legislation. Air monitoring provides a way to illustrate the high levels of hazardous exposure to secondhand smoke in restaurants and increase public policy debate.

Indoor air monitoring data across North Carolina show that, in the absence of comprehensive public health protections at the state or local level, levels of RSPs remain unacceptably high in multiple hospitality establishments statewide. Restaurants with complete bans on indoor smoking have substantially lower RSPs than do venues with no or minor limitations on smoking. The data show that venues allowing smoking (separate or not) can substantially reduce indoor exposure to secondhand smoke among customers and staff by becoming smoke-free.

The effect of these data is unclear. However, the media coverage combined with several advocacy efforts seemed to have some effect with key stakeholders who had not previously publicly supported secondhand smoke policy restrictions, thus increasing support for statewide secondhand smoke policies. At the state level, the results helped educate policy makers considering the passage of House Bill 259: Act to Prohibit Smoking in Food and Lodging Establishments and State Government Buildings and Allow Local Governments to Prohibit Smoking in Public Places and Places of Employment. The act was narrowly defeated in the North Carolina House (61 to 55), but this bill provided the greatest health protection and was the best showing of support for the policy to date. A previous bill considered by the North Carolina General Assembly in 2005 was considerably weaker in public health terms by creating loopholes for separately ventilated areas and exempting certain venues. Support that might have come from the Senate and the governor's office is unknown as neither ever considered this or other bills, although historically the challenges to such legislation came from the House. These results illustrate that the use of indoor air monitoring has the potential not only to demonstrate effectiveness of policy change but also may play a role in building support for evidence-based policy change.

As of March 2009, only 13 states have enacted 100% smoke-free worksite laws that include restaurants and bars (20). Studies analyzing these policy changes have found significant reductions in secondhand smoke in every location tested (21). The North Carolina findings are consistent with these studies but differ in terms of how the data can be used. In Delaware, RSP levels declined similarly in 8 hospitality venues after state law prohibited smoking there (12). In New York, a study observed declining RSP levels in 20 hospitality venues after a smoking ban was put into place (14). However, previous studies of indoor air quality have largely ignored states with laws pre-empting stronger local controls and only examined changes before and after laws were implemented.

Several studies of the effects of smoking bans suggest that the long-term heath effects could be substantial as a result of these policies (13,22). Some indicate that respiratory health improved rapidly among workers after smoke-free workplace laws went into effect (22,23). A growing number of studies demonstrate reductions in acute myocardial infarctions from 8% to 40% in locations such as Helena, Montana; Pueblo, Colorado; Bowling Green, Ohio; northern Italy; and, most recently, New York State (24-29).

These findings are subject to several limitations. First, the venues chosen for this study may not be representative of all venues in North Carolina or elsewhere. However, we sampled a variety of sizes, types, and locations. Second, secondhand smoke is not the only source of indoor particulate matter. Although ambient particle concentrations and cooking smoke are additional sources of indoor particulate levels, secondhand smoke is the largest contributor to indoor RSP pollution (30). Additionally, air quality was monitored in public service areas where secondhand smoke is the most likely source for concentrations measured. Third, the popularity of hospitality venues and the number of customers varied from venue to venue. Therefore, the level of active smoking in any given area at a given time varied from place to place. For this reason, PM_2.5 concentrations may not accurately represent actual overall levels but be specific to that time. Fourth, although the testing times per venue were similar to those in prior studies, the testing time might not have been representative of a particular venue because of the range of hours that venues are open. Finally, this was an exploratory study looking at the possible effects of using indoor air monitoring to influence policy change. We have shown this type of research is feasible statewide, to generate publicity and data used in policy debates. We do not know, however, the exact role that the research can and would play with a more rigorous study design. Our work shows that additional research and evaluation are warranted.

Twenty-seven states lack comprehensive smoke-free legislation. Of these, 12 states face tough preemption laws that effectively limit local level and state level change (11). For an investment of $12,000 (4 machines at $3,000 each), we trained local county volunteers to collect data from their communities and then used that data to raise awareness and educate policy makers at both the local and state level. This study design can be readily replicated in all areas that face similar constraints. In cases where statewide laws cannot be easily achieved, air monitoring may be a valuable tool to assist tobacco control advocates in influencing policy change.

Nineteen states (Arizona, Delaware, Florida, Hawaii, Illinois, Iowa, Louisiana, Maryland, Massachusetts, Minnesota, Montana, Nevada, New Jersey, New York, Ohio, Oregon, Rhode Island, Utah, Washington) and Puerto Rico meet the national health objective for 2010 calling for implementation of statewide smoking bans in worksites, which includes hospitality venues (although 4 of those states have bans that do not cover bars). Comprehensive smoking bans will also take effect in Nebraska in June 2009 and in Montana in October 2009 (20). These states account for approximately 45% of the US population. To further reduce the nearly 40,000 deaths among never smokers caused by secondhand smoke each year, similar comprehensive laws are needed in the other 31 states and the District of Columbia.