Washington, Nov 27 (ANI): One in four of the largest U.S. airports still allows smoking indoors, potentially exposing travelers and workers to disease-causing secondhand smoke, according to a report by the Centers for Disease Control and Prevention.

The findings reveal an unnecessary risk, according to CDC director Thomas Friedan. Secondhand smoke has been linked to heart attacks, lung cancer and asthma attacks, among other ailments.

"Every year, millions of people who travel through and work at these airports are unnecessarily exposed to secondhand smoke," Live Science quoted Friedan as saying in a statement.

"Even ventilated smoking rooms do not eliminate secondhand smoke exposure. Eliminating smoking at airports is the only way to fully eliminate exposure."

According to the report, more airports prohibit smoking today than in 2002, when 42 percent of the 31 largest U.S. airports were smoke-free. Of the 29 largest airports examined in the current study, 76 percent were smoke-free indoors.

But seven of the nation's largest airports still allow indoor smoking in designated areas, the CDC reports. That includes Hartsfield-Jackson Atlanta International Airport, Dallas Fort Worth International Airport, and Denver International Airport, three of the five busiest airports in the country. The other four large airports that allow indoor smoking are: Las Vegas McCarran International Airport, Charlotte Douglas International Airport, Washington Dulles International Airport, and Salt Lake City International Airport.

These airports don't allow people to light up willy-nilly; specially ventilated enclosed areas are set aside for smokers. But CDC officials argue that these rooms don't do enough to protect passersby and workers.

The findings have been published in the CDC's Morbidity and Mortality Weekly Report. (ANI)