Banning smokers in NY restaurants is having its intended effect:

The study found the reduction in illnesses among bar and restaurant workers is linked to the dramatic decline in employees' exposure to second-hand smoke. Prior to the smoking ban in 2003, employees reported being exposed to 12 hours of smoke over a four-day period. That figure dropped to 12 minutes in 2004.
This should be done worldwide.

("Study: NY's smoking ban decreasing second-hand smoke symptoms", WSTM.com, Jul.27)