New Study Finds State's Smoke Free Law Has Beneficial Health Impact
Significant Reduction in Unhealthy Air Quality Since Law was Implemented

Contact: Angela Minicuci (517) 241-2112
Dr. Theresa Wilson (517) 335-9124
Agency: Community Health

For Immediate Release:  October 4, 2011

LANSING - Results from an air monitoring study conducted before and after Michigan's Dr. Ron Davis Smoke Free Air Law took effect indicate a 93 percent reduction in the level of secondhand smoke air pollutants in restaurants after the law went into effect. 

The air monitoring study was conducted in the same 77 restaurants before and after the law took effect on May 1, 2010.  All 77 restaurants that allowed smoking before the law have been smoke-free since the law took effect. Prior to the law, 85 percent of the restaurants in the study had poor to dangerous air quality.  After enactment of the law, the venues' levels of secondhand smoke pollutants dropped by a median of 93 percent.

"Measuring the difference in air quality before and after the smoke-free air law went into effect helps the Michigan Department of Community Health determine the direct effectiveness of the law," said Olga Dazzo, Director of the MDCH. "We're thrilled to report that the air quality has dramatically improved. This study clearly demonstrates the health benefit of Michigan's smoke-free air law."

The MDCH Tobacco Section, with assistance from local health departments and other community agencies, recruited field investigators to measure the air quality in restaurants. Field investigators measured levels of fine particulate matter from secondhand smoke in restaurants before and after the statewide smoke-free air law was implemented to determine whether the law was effective in reducing air pollution from secondhand smoke. The study was conducted in 13 cities representing six major regions of the state that included Ann Arbor, Detroit, Flint, Grand Rapids, Kalamazoo, Lansing, Marquette, Midland, Novi, Saginaw, Sault Ste. Marie, Traverse City and West Branch.

Secondhand smoke is measured by PM2.5 which is a harmful combustion source air pollutant that is emitted in very large amounts by cigarettes, pipes and cigars.  Exposure to particulate matter of this size affects breathing and the cellular defenses of the lungs, aggravates existing respiratory and cardiovascular ailments, and causes adverse health effects on the respiratory and cardiovascular systems.  The entire population is affected, but susceptibility to PM2.5 pollution varies with age and health status. Persons with heart or lung disease, the elderly, and children are at the highest risk from exposure to PM2.5. 

The Air Quality Index (AQI), used by the Michigan Department of Environmental Quality to communicate health levels of outdoor air to the public, identifies air pollutant concentrations as one of six color-coded category levels ranging from good to hazardous. 

"When the before and after PM2.5 levels from the air monitoring study are plotted on the AQI, it is clear that the indoor air quality in the monitored restaurants markedly improved," said Dean Sienko, Interim Chief Medical Executive at the MDCH. "The results from this study provide clear evidence that the law has been highly effective in improving air quality in indoor environments and protecting workers and the public from the health harms of secondhand smoke exposure in Michigan workplaces."

To view a copy of the survey results or for more information about Michigan's smoke-free law, visit  View a copy of the Chart showing the 93% change in Air Quality. 

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