Exposure to secondhand smoke (SHS) from cigarettes causes an estimated 41,000 deaths among nonsmoking U.S. adults each year and an estimated $5.6 billion annually in lost productivity caused by premature death. In a 2006 report, the Surgeon General concluded that there is no risk-free level of exposure to SHS. Although an increasing proportion of the population is covered by state or local comprehensive smokefree laws that prohibit tobacco smoking in all indoor