Of the 50 busiest airports in the world, 23 have smoke-free policies indoors, according to the Atlanta-based Centers for Disease Control and Prevention.

In North America, 14 of the 18 busiest airports have smoke-free policies, while in Asia only 4 of 22 of the busiest airports have smoke-free policies.

Hartsfield-Jackson international Airport is one of the U.S. airports that allows smoking indoors, specifically in designated smoking lounges. The Atlanta airport also more than a year ago launched a plan to convert smoking rooms into cigar shops that would charge a fee to patrons who want to smoke.

The CDC said it conducted a study that showed secondhand smoke can migrate from designated smoking areas to nonsmoking areas, putting travelers and workers at risk.

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Hartsfield-Jackson to turn smoking rooms into cigar shops

Atlanta airport to convert smoking rooms into cigar shops, charge for entry to smoking areas