The impact of Michigan's Dr Ron Davis smoke-free air law on levels of cotinine, tobacco-specific lung carcinogen and severity of self-reported respiratory symptoms among non-smoking bar employees

Tob Control. 2012 Nov;21(6):593-5. doi: 10.1136/tobaccocontrol-2011-050328. Epub 2012 Jun 15.


Objective: To determine the impact on bar employee's health and exposure to secondhand smoke (SHS) before and after the implementation of Michigan's Dr Ron Davis smoke-free air law that went into effect on 1 May 2010, prohibiting smoking in places of work, including bars.

Methods: This study used a pre/postintervention experimental design. The setting was bars in 12 Michigan counties. Subjects were bar employees, recruited through flyers and individual discussions with local health department staff. Participants completed a screening questionnaire to determine eligibility. A total of 40 eligible employees completed a demographic survey, provided urine samples for analysis of cotinine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and completed questionnaires on respiratory and general health status 6 weeks before and 6-10 weeks after the law went into effect. The main outcome measures were urine samples for total cotinine and total NNAL and data from a self-administered respiratory and general health status questionnaire collected during the pre-law and post-law study periods.

Results: There was a significant decrease in the mean cotinine levels from 35.9 ng/ml to a non-quantifiable value (p<0.001), and there was a significant reduction in the mean NNAL level from 0.086 pmol/ml to 0.034 pmol/ml (p<0.001) 2 months after implementation of the law. There was also a significant improvement in all six self-reported respiratory symptoms (p<0.001) and general health status (p<0.001).

Conclusions: The reduction in the SHS biomarkers cotinine and NNAL and reported improvement in respiratory health demonstrates that the Michigan smoke-free workplace law is protecting bar employee health.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Cotinine / urine
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Michigan
  • Middle Aged
  • Nitrosamines / urine
  • Occupational Diseases / epidemiology
  • Occupational Diseases / physiopathology
  • Occupational Diseases / prevention & control
  • Occupational Exposure / legislation & jurisprudence
  • Occupational Exposure / prevention & control*
  • Occupational Health / legislation & jurisprudence
  • Pyridines / urine
  • Respiratory Tract Diseases / epidemiology
  • Respiratory Tract Diseases / physiopathology
  • Restaurants / legislation & jurisprudence*
  • Severity of Illness Index
  • Smoking / adverse effects
  • Smoking / legislation & jurisprudence
  • Smoking Prevention*
  • Surveys and Questionnaires
  • Tobacco Smoke Pollution / adverse effects
  • Tobacco Smoke Pollution / legislation & jurisprudence
  • Tobacco Smoke Pollution / prevention & control*
  • Young Adult


  • Nitrosamines
  • Pyridines
  • Tobacco Smoke Pollution
  • 4-(methylnitrosamino)-1-(3-pyridyl)-1-butan-1-ol
  • Cotinine