(WAND) - Many people are still being exposed to secondhand smoke while at work.

CDC researchers studied data from a 2015 National Health Survey. It found nearly a fifth of non-smoking employees were exposed to secondhand smoke at the workplace.

Those working in industries that have outdoor workplaces, like construction, had the highest rate of exposure.

Previous studies have shown that exposure to secondhand smoke could increase the risk for developing heart disease, lung cancer and stroke.