James Repace, who published his results in the Journal of Occupational and Environmenal Medicine, was commissioned by the Delaware Tobacco Prevention Coalition to assess air quality in eight hospitality industry venues a casino, six bars, and a pool hall before and after Delaware amended its statewide Clean Indoor Air Act to ban smoking in restaurants, bars and casinos. The study measured respirable particle (RSP) air pollution and particulate polycyclic aromatic hydrocarbons (PPAH), two pollutants known to increase risk of respiratory disease, cancer, heart disease and stroke.
While most of the venues had average-to-very low smoking prevalence, the study found that preban indoor carcinogenic PPAH averaged 5 times higher than outdoor levels, tripling workers' daily PPAH exposure, and exceeding those measured at a tollbooth on a major U.S. Interstate highway during rush hour. Nearly all (96 percent) of the indoor RSP pollution and 84 percent of the indoor PPAH carcinogens were caused by secondhand smoke. By contrast, after the smoking ban was enacted, indoor air quality levels for both RSP and PPAH were except for RSP in one venue indistinguishable from outdoors.
According to Repace, the study "demonstrates conclusively that the health of hospitality workers and patrons is endangered by tobacco smoke pollution. Smoke-free workplace laws, such as the one enacted by Delaware, eliminate that hazard and provide health protection impossible to achieve through ventilation or air cleaning."
As an added benefit, the study found that the smoke-free law appears to have resulted in an 11 percent decline in statewide smoking after only 1 year, with a 25 percent decline among those 18 to 24 years old.