Indoor Air Quality in Hospitality Venues Before and After Implementation of a Clean Indoor Air Law

Secondhand smoke contains more than 50 carcinogens.1 Exposure to secondhand smoke exposure is responsible for an estimated 3,000 lung cancer deaths and more than 35,000 coronary heart disease deaths among “never smokers” in the United States each year,2 and for lower respiratory infections, asthma, sudden infant death syndrome, and chronic ear infections among children.3 Even short-term exposures to secondhand smoke, such as those that might be experienced by a patron in a restaurant or bar that allows smoking, can increase the risk of experiencing an acute cardiovascular event.4 Although population-based data indicate declining secondhand smoke exposure in the US over time,5 secondhand smoke exposure remains a common but preventable public health hazard. Policies requiring smoke-free environments are the most effective method of reducing secondhand smoke exposure.6 Effective July 24, 2003, New York implemented a comprehensive state law requiring almost all indoor workplaces and public places (e.g., restaurants, bars, and other hospitality venues) to be smoke-free. This report describes an assessment of changes in indoor air quality that occurred in 20 hospitality venues in western New York where smoking or indirect secondhand smoke exposure from an adjoining room was observed at baseline. The findings indicate that, on average, levels of respirable suspended particles (RSPs), an accepted marker for secondhand smoke levels, decreased 84% in these venues after the law took effect. Comprehensive clean indoor air policies can rapidly and effectively reduce secondhand smoke exposure in hospitality venues. The specific class of RSP monitored was PM2.5 (i.e., particulate matter that is less than 2.5 microns in diameter). Methods Particles of this size are released in substantial amounts from burning cigarettes and are easily inhaled deep into the lungs. Baseline measurements were made during July 11–23 in a purposeful sample of 22 hospitality venues in three counties in western New York. Sites were selected to provide a range of venue types, sizes, and locations. The sample consisted of seven bars, six bar/restaurants, five restaurants, two bowling alleys, a pool hall, and a bingo hall. The venues were located in popular downtown entertainment districts and suburban areas and ranged from small neighborhood bars to large bar/restaurant chains. At baseline, smoking was occurring in 14 bars and restaurants and four large recreation venues. Two bar/restaurant combinations allowed smoking in the bar section but not in the adjoining restaurant section. In these two venues, air quality was monitored separately in the restaurant and bar areas. In two restaurants, no smoking was occurring at baseline, because restaurants were already required to be smoke-free by local clean indoor air ordinances. Follow-up measurements of air quality were made in all 22 venues during September 9-November 1. The follow-up measurements were taken on the same day of the week and at approximately the same time of day as the measurements taken before the smoke-free law was implemented. The median time spent in each venue for all 44 baseline and follow-up observations combined was 38 minutes (range of 22 to 140 minutes). Measurements were taken at one-second intervals. The number of persons and the number of burning cigarettes in each venue were recorded every 10 minutes during sampling, and the average number of persons and the average number of burning cigarettes in each venue were calculated. The volume of each venue also was measured, and the cigarette density was calculated by dividing the average number of burning cigarettes by the room volume. An air monitor was used to sample and record RSP levels. The monitor was placed in a central location on a table or bar near the height at which a person breathes air. The monitor recorded continuous measurements, which were averaged over time. The first and last minute of logged data were removed, and the remaining data points were averaged to provide an average concentration of PM2.5 within the venue. The percentage change in PM2.5 levels was then determined by comparing average PM2.5 levels in each venue before the law went into effect with levels after the law was implemented. The Wilcoxon signed-rank test was used to assess changes between pre-law and post-law PM2.5 levels, stratified by type of venue. The average PM2.5 concentration was substantially lower after the law went into effect in every venue where smoking or indirect secondhand smoke exposure had been observed at baseline, with a grand mean reduction in PM2.5 concentration of 84% (324 µg/m3 to 25 µg/m3; p<0.001). When stratified by the type of venue sampled, the average PM2.5 concentration decreased 90% (412 to 27 µg/m3; p<0.001) in the 14 bars and restaurants in which smoking was occurring at baseline (including bar/restaurant J, which was the only venue where smoking was observed during the post-law sampling). The restaurant portions of the two bar/restaurants that allowed smoking in the bar section but not in the restaurant section experienced an average 58% decrease in PM2.5 concentrations (156 to 31 µg/m3; p<0.001) after the law was implemented, even though they had only indirect secondhand smoke exposure at baseline. In the four other large recreation venues, which had larger volumes and lower smoker densities, the average PM2.5 concentration decreased 76% (101 to 18 µg/m3). In contrast, the PM2.5 concentration remained low and virtually constant in the two restaurants that were already smoke-free at baseline; these venues were not included in the grand mean calculation. The findings in this report indicate that a statewide law to eliminate smoking in enclosed workplaces and public places substantially reduced RSP levels in western New York hospitality venues. RSP levels were reduced in every venue that permitted smoking before the law was implemented, including venues in which only secondhand smoke from an adjacent room was observed at baseline. These findings are consistent with those of previous studies. In Delaware, a similar decline in RSP levels was observed in eight hospitality venues after smoking was prohibited there by state law.7 Previous studies also have assessed the health effects of smoke-free laws. One study indicated that respiratory health improved rapidly among a sample of bartenders after a state smoke-free workplace law was implemented in California,8 and another study reported a 40% reduction in acute myocardial infarction admissions to a regional hospital during the six months that a local smoke-free ordinance was in effect in Helena, Montana.9 The results of these studies (both those assessing changes in indoor air quality and those assessing changes in health) suggest that improvements can occur within months of policy implementation. Limitations The findings in this report are subject to at least two limitations. First, the venues sampled were not necessarily representative of venues in western New York. However, they did provide a range of venue types, sizes, and locations. Second, secondhand smoke is not the only source of indoor particulate matter. However, although ambient particle concentrations and cooking are additional sources of indoor particle levels, secondhand smoke is the largest contributor to indoor RSP pollution3. Eliminating nonsmoker exposure to secondhand smoke is one of the four goals of comprehensive state tobacco-control programs, as set forth in CDC's Best Practices for Comprehensive Tobacco Control Programs.10 The results of the study described in this report indicate that a comprehensive statewide ban on smoking in indoor workplaces and public places can substantially reduce secondhand smoke exposure in these settings. Six states (California, Connecticut, Delaware, Maine, Massachusetts, and New York) currently meet the national health objective for 2010 calling for implementation of such laws. These six states account for approximately 23% of the US population. Rhode Island also has adopted such a law, but the law does not take full effect until 2006. To further reduce the nearly 40,000 deaths among never smokers caused by secondhand smoke exposure each year, similar comprehensive laws are needed in the other 43 states and the District of Columbia. Reprinted (slighted edited) from Morbidity and Mortality Weekly Report, 11/12/04, Vol. 53, No. 44, pp 1038–1041