A new study published in the journal Circulation reveals an up to 36 percent reduction in heart attacks after smoking bans were enacted. Researchers studied the rate of heart attacks in US, Canadian and European cities immediately after smoking bans became effective and noted a 17 percent reduction the first year of the ban, followed by the 36 percent reduction after three years. They used the data to call for increased bans on public smoking to reduce the affects of secondhand smoke which lead to heart attacks, and noted that the bans should result in reduced health care costs as well.