Evaluation of the immediate impact of the Washington, D.C., smoke-free indoor air policy on bar employee environmental tobacco smoke exposure.

OBJECTIVE: On January 2, 2007, thw Washington, D. C., City Council banned smoking in restaurants and bars. We sought to determine the immediate impact of the ban on cotinine-confirmed environmental tobacco smoke (ETS) levels and respiratory symptom reports of a random sample of bar employees.
METHODS: We conducted an assessment of 66 employees from 41 randomly selected bars in December 2006, a month before the ban went into effect. After analyses of baseline data, 52 employees were eligible and 49 of them (94%) had a post-ban assessment in February 2007. Three participants were excluded due to high cotinine levels at the post-ban assessment, yielding a final sample size of 46 bar employees. ETS exposure levels were documented using saliva cotinine analyses by tandem liquid chromatography and mass spectrometry. Employee respiratory and sensory symptoms reports were assessed by a standardized, validated form: the International Union Against Tuberculosis and Lung Disease Bronchial Symptoms Questionnaire. Employee ETS exposure reports at work were eliminated after the ban.
RESULTS: Sensory symptoms reports (at < or = 4 weeks) declined significantly by 70% to 100% (p = 0.0016); respiratory symptoms results were inconclusive due to a lack of data. Saliva cotinine medians declined significantly by 70% (p < 0.0001), from a pre-ban mean of 2.11 nanograms per millileter (ng/mL) to a post-ban mean of 0.29 ng/mL, confirming reports of no ETS exposure at work.
CONCLUSION: We concluded that the indoor air law was effective, eliminating employee ETS exposure reports, dramatically reducing their cotinine levels, and almost eliminating reports of sensory symptoms.