Indoor air pollution (PM2.5) due to secondhand smoke in selected hospitality and entertainment venues of Karachi, Pakistan.

OBJECTIVE To determine particulate matter smaller than 2.5 μm (PM(2.5)) levels at various hospitality and entertainment venues of Karachi, Pakistan. METHODS This was a descriptive cross-sectional study conducted at various locations in Karachi, during July 2009. Sampling was performed at 20 enclosed public places, including hospitality (restaurants and cafés) and entertainment (snooker/billiard clubs and gaming zones) venues. PM(2.5) levels were measured using an aerosol monitor. RESULTS All entertainment venues had higher indoor PM(2.5) levels as compared to the immediate outdoors. The indoor PM(2.5) levels ranged from 25 to 390 μg/m(3) and the outdoor PM(2.5) levels ranged from 18 to 96 μg/m(3). The overall mean indoor PM(2.5) level was 138.8 μg/m(3) (± 112.8). Among the four types of venues, the highest mean indoor PM(2.5) level was reported from snooker/billiard clubs: 264.7 μg/m(3) (± 85.4) and the lowest from restaurants: 66.4 μg/m(3) (± 57.6) while the indoor/outdoor ratio ranged from 0.97 to 10.2, highest being at the snooker/billiard clubs. The smoking density ranged from 0.21 to 0.57, highest being at gaming zones. The indoor PM(2.5) concentration and smoking density were not significantly correlated (Spearman's correlation coefficient = 0.113; p = 0.636). CONCLUSIONS This study demonstrates unacceptably high levels of PM(2.5) exposure associated with secondhand smoke (SHS) at various entertainment venues of Karachi even after 8 years since the promulgation of smoke-free ordinance (2002) in Pakistan; however, better compliance may be evident at hospitality venues. The results of this study call for effective implementation and enforcement of smoke-free environment at public places in the country.