TUESDAY, March 17, 2020 (HealthDay News) -- For every 52 smokers, secondhand smoke claims the life of one nonsmoker, an international study reports.

"We hope that attributing harm directly to smokers will help influence public opinion against secondhand smoke exposure and enthuse governments to enforce stringent anti-tobacco control," said co-author Dr. Jagat Narula in a Mount Sinai news release. He is a professor of medicine at the Icahn School of Medicine at Mount Sinai in New York City.

The study found that in 2016, 52 smokers were tied to the death of one nonsmoker worldwide -- up from 1990, when 31 smokers were linked to the death of one nonsmoker. Researchers said this reflects effective measures such as smoking bans in public places.

For the study, researchers analyzed global data, calculating the number of smokers in each country along with premature deaths from secondhand smoke.

In North America, where public smoking bans are more widespread, about 90 smokers were associated with one death. That compared to a ratio of about 40 to 1 in the Middle East and Southeast Asia, where protective measures are more rare.

The researchers said these findings could help policymakers understand the harm inflicted by secondhand smoke and enact new ways to protect nonsmokers.

They said this is especially important where children are concerned, because exposure to secondhand smoke puts them at risk for sudden infant death syndrome (SIDS), respiratory infections and asthma.

Even a little secondhand smoke can damage the cardiovascular system, and long-term exposure can increase the risk for heart attack and lung cancer by 20% to 30%, the researchers noted.

"The problem is exaggerated in the rapidly developing economies which are lacking effective protection of nonsmokers," said lead author Dr. Leonard Hofstra, a professor of cardiology at VU University Medical Center in Amsterdam, the Netherlands.

"But this research demonstrates that even in modern states there is a lot to gain when it comes to strengthening policies to protect nonsmokers, especially children. For example, it should not be allowed for parents to smoke inside their cars with them," Hofstra said in the release.

The report was published online March 17 in the journal JAMA Network Open.

More information

To learn more about secondhand smoke, visit the U.S. Centers for Disease Control and Prevention.