passed a year ago
, goes into effect tomorrow -- July 1.
The law prohibits smoking indoors in all the city's restaurants and bars and 80 percent of its hotel rooms.
Less restrictive bans in St. Louis County and St. Louis go into effect in January 2011. In the county, the ban exempts casinos and establishments that derive 75 percent of their business from alcohol sales
. The city also exempts casinos as well as bars under 2,000 square feet
A Clayton smoking ban,