SMOKING BAN CITED IN HEALTH SUCCESS.(MAIN)

Byline: DANIEL Q. HANEY Associated Press

CHICAGO -- Heart attacks in Helena, Mont., fell by more than half last summer after voters passed a broad indoor smoking ban, suggesting that cleaning up the air in bars and restaurants quickly improves health for everyone, a study found.

Doctors said their study is the first to examine what happens to public health when people stop smoking -- and breathing secondhand smoke -- in public places.

The doctors, themselves backers of the ban, acknowledged the effects need to be demonstrated in a larger locale. But they said Helena's experience offers a clear hint that the change reduces the risk of heart attacks …