Indoor fine particle (PM2.5) pollution exposure due to secondhand smoke in selected public places of Sri Lanka.

BACKGROUND: Secondhand smoke accounts for a considerable proportion of deaths due to tobacco smoke. Although the existing laws ban indoor smoking in public places in Sri Lanka, the level of compliance is unknown. METHODS: Fine particulate matter (PM(2.5)) levels in 20 public places in Colombo, Sri Lanka were measured by a PM monitor (Model AM510-SIDEPAK Personal Aerosol Monitor). Different types of businesses (restaurants, bars, cafés, and entertainment venues) were selected by purposive sampling. Only the places where smoking was permitted were considered. RESULTS: The average indoor PM(2.5) ranged from 33 to 299 µg/m(3). The average outdoor PM(2.5) ranged from 18 to 83 µg/m(3). The indoor to outdoor PM(2.5) ratio ranged from 1.05 to 14.93. In all venues, indoor PM(2.5) levels were higher than the Sri Lankan ambient PM(2.5) standard of 50 µg/m(3). All indoor locations had higher PM(2.5) levels as compared to their immediate outdoor surroundings. CONCLUSION: The study highlights the importance of improving ventilation and enforcing laws to stop smoking in public places.