More than 100 people packed a forum at the Louisville Metro Department of Public Health and Wellness Wednesday night to hear from public health officials and scientists on the possible health effects of e-cigarettes and the impetus for a ban by the city.

In 2008, Louisville enacted a smoke-free ordinance in workplaces and indoor public spaces. The proposed ban would add e-cigarettes and hookah to that ordinance. Thirteen other communities in Kentucky have already done so.

Aruni Bathangar, a professor of medicine at the University of Louisville, said there’s solid research showing people exposed to e-cigarette vapor inhale the same amount of nicotine and other ingredients as the user.

He said it’s difficult to enforce any rules related to the use of e-cigarettes because the lines are blurred.

“Most places don’t have explicit legislation, so if you want to go to some people and say ‘you can’t use e-cigarettes indoors,’ we don’t have a law for that,” Bathangar said. “Some people have argued that there’s no law to stop us.”

But critics of the proposed ban, mostly e-cigarette store owners and manufacturers, said e-cigarettes are a critical tool for people trying to quit tobacco. Some argue that cigarette smokers use e-cigarettes as a bridge to eventually move down to using very-low or no level of nicotine.

Other supporters said the ban is unnecessary and could lead to more restrictions later. Christopher Kellums, who works at a vape shop in Louisville, said most vapers understand the unwritten rule of not vaping where you wouldn’t smoke.

Billy Bryant, owner of e-cigarette juice manufacturer Weird Vapes, echoed that sentiment.

“Why can’t we let a business decide if we want to subject my employees or patrons to this,” Bryant said. “Give them the information, make them aware of the studies. If a business wants to allow it, why can’t they allow it for a healthier alternative?”

The American Cancer Society, the American Heart Association and other public health organizations issued guidance to cities and states in 2011 supporting the addition of e-cigarette bans to smoke-free laws.

Metro Government officials are asking the public to comment on the proposed ban. The deadline to submit comments is Friday, Oct. 28. Details are here.

Lisa Gillespie is WFPL's Health and Innovation Reporter.