BALTIMORE - The level of cancer-causing particles is much higher in the air of smoke-filled bars and casinos than on truck-choked highways and city streets, according to a published comparison of indoor air quality before and after smoke-free workplace legislation. The study, conducted in a casino, six bars, and a pool hall in Wilmington, Del., is published in the September 2004Journal of Occupational & Environmental Medicine.

"This research clearly shows that it is far worse for your health to be a bartender or casino dealer in a smoking-permitted establishment than it is to be a turnpike toll collector," said James L. Repace, MSc., the study's author. "These workers breathe an average of 90 percent cleaner air after a smoke-free workplace law." Repace, a health physicist, is visiting assistant clinical professor at Boston's Tufts University School of Medicine and a secondhand smoke consultant based in Bowie, Md.

Repace assessed air quality in the eight hospitality venues on Friday evenings in November 2002 - before Delaware's smoking ban - and again in January 2003, two months after the ban took effect. Using state-of-the art monitoring equipment, he measured respirable particulate air pollution (RSP) and particulate polycyclic aromatic hydrocarbons (PPAH), pollutants shown to increase risk of respiratory disease, cancer, heart disease, and stroke.

Repace's findings demonstrate the effect of Delaware's smoking ban: Except for residual chalk dust in the pool hall - at 17 percent of pre-ban levels - air quality levels post-ban in all venues were indistinguishable from those measured out-of-doors.

Prior to the smoking ban, however, Repace found all eight venues to be heavily polluted. Indoor RSP levels averaged 20 times those in the outdoors and were 4.6 times higher than the level permissible under the U.S. Environmental Protection Agency's (EPA's) National Ambient Air Quality Standard (NAAQS). The hospitality workers were exposed to RSP levels 2.6 times higher than those Repace measured on diesel-exhaust polluted streets in Boston and on Interstate-95 in Delaware. Carcinogenic PPAH levels pre-ban were five times higher than outdoor levels in Wilmington, and exceeded those measured at an I-95 tollbooth at the heavily trafficked Baltimore Harbor Tunnel.

"Before the ban, secondhand smoke contributed 90 percent to 95 percent of the RSP air pollution in the studied venues, and 85 percent to 95 percent of the carcinogenic PPAH," said Repace. "This demonstrates conclusively that ventilation does not control the life-threatening pollutants inherent to a smoking environment. Only a smoke-free workplace law can protect the health of these workers."

According to the federal Agency for Toxic Substances and Disease Registry, people exposed to polycyclic aromatic hydrocarbons (PAHs) for prolonged periods can develop cancer. Ten carcinogenic particulate phase PAHs have been identified in tobacco smoke, representing one-sixth of all known tobacco smoke carcinogens.

Repace has conducted research on indoor air pollution from secondhand smoke for 28 years, and has published more than 60 scientific papers on the topic.

Publication date: 09/20/2004