Impact of an indoor smoking ban on bar workers' exposure to secondhand smoke.

Abstract

To evaluate the impact of an indoor smoke-free bylaw in Toronto, Ontario, implemented June 2004. We used a pre-post comparison design to assess secondhand smoke (SHS) exposure among 79 eligible bar workers in Toronto, Ontario (bylaw enacted), and 49 eligible bar workers in a control community, Windsor, Ontario (no bylaw change), at four times: preban, and 1, 2, and 9 months postban. SHS exposure time and urinary cotinine level were substantially reduced in Toronto bar workers immediately after the ban by 94% (from 7.8 to 0.5 hours) and 68% (from 24.2 to 7.8 ng/mL), respectively. The reduction was sustained throughout follow-up. There was no change among Windsor bar workers before and after the ban. Compliance with the ban was high, and the ban led to a substantial reduction in SHS exposure.