The 13th World Conference on Tobacco OR Health

Objective: Many jurisdictions throughout the world have implemented legislation to protect workers and the public from tobacco smoke pollution (TSP), as called for by the Framework Convention on Tobacco Control. To date nearly all legislation has consisted of smoking bans in indoor environments. This study addressed two questions: Does TSP in outdoor settings reach hazardous levels? And can TSP in outdoor settings compromise indoor environments

Methods: Indoor and outdoor air quality was assessed at 6 bars with patios in Southwestern Ontario on the evening of July 15, 2005. Two portable air quality monitors recorded particulate matter at <=2.5 microns(PM2.5), an established proxy for TSP. Baseline PM2.5 readings were taken outdoors before and after each venue. Simultaneous indoor and outdoor (patio) measurements were taken. Outdoor researchers recorded the number of observed lit cigarettes every 4 minutes and estimated the distance to the closest cigarette.

Results: The findings demonstrate that TSP on outdoor patios represents a potentially significant health threat that, in some circumstances, may approach the levels of TSP in indoor settings (peaks > 200 micrograms/m3). PM2.5 levels inside a bar were related to PM2.5 readings on its patio. Average indoor readings over 90micrograms/m3 inside one bar location (3 times that of background readings) demonstrates that smoke from the outside can and does drift inside.

Implications: These results demonstrate that smoking on outdoor patios (1) represents a potential health hazard on those patios, and (2) leads to smoke exposure indoors that may compromise the protection against TSP intended by indoor smoke-free laws.