Smoking in public places which has been banned has also reduced the rate of people being hospitalized for heart attacks, strokes and respiratory diseases like asthma and emphysema.

Richard D. Hurt, MD, of the Nicotine Dependence Center at the Mayo Clinic in Rochester, Minn., and colleagues found that by implementing the law against smoking in public places such as restaurants, bars and workplace has reduced Myocardial infarction (MI) incidence.

A study published in the Circulation also said people being hospitalized due to strokes has dropped by 16 percent and respiratory disease dropped by 24 percent. The 2007 law had more impact than the one which was implemented in 2002, was just to ban smoking in restaurants.

"We should prioritize the enforcement of smoke-free policies, eliminating loopholes in existing policies as well as encouraging the expansion of smoke-free policies," UC San Francisco physicians Sara Kalkhoran and Pamela M. Ling wrote. The law should enforce and include apartments, cars, casinos which remain untouched by the new law as of now.

Dr. Richard Hurt said to Reuters Health about the ban on smoking: "There have been lingering doubts among some people about whether or not this was a real finding. We think we have produced the most definitive results that anyone can produce related to smoke-free laws and heart attacks."

Hurt also studied that secondhand smoke forms a change in the lining of aorta, which results in making the blood platelets stickier, which could form a dangerous blood clot.

While Dr. Michael Siegel, a tobacco control researcher from the Boston University School of Public Health, finds this study just a co incidence as it took place just in one county. "The main problem with this study is that there's no control group or comparison group. This is a look only at what happened before and after an ordinance went into effect in one particular county," he said.

"We have no idea whether heart attacks may also have gone down in other counties in Minnesota that didn't have this smoke-free law. Without knowing that, I don't see how you can make the conclusion that this (decline) was due to the law," Siegel said.