A smoking ban in San Francisco could soon mean cleaner skies over The City by the Bay, but only a portion of the people that light up in Northern California will be affected. Lawmakers want to ban outdoor smoking - but not for medical pot patients.

San Francisco Supervisor Eric Mar is asking the city's Board to wrap their brains around a ban that would prohibit people from smoking cigarettes at outdoor events held on city property, such as street fairs, festivals and other open-air events that require permits. If the proposal is passed in its current form, though, those wanting to take a match to marijuana joints won't be pressed with penalties.

Mar says that the proposal is necessary to nix the dangerous toll that comes from inhaling secondhand cigarette smoking. As far as marijuana goes - which is legal for medicinal purposes in parts of the US, such as San Francisco - the supervisor doesn't see a problem.

"It's widely known that secondhand smoke is responsible for as many as 73,000 deaths among non-smokers each year in the United States, and there is no safe level of exposure," Mar tells the media.

The supervisor adds that "This is another step forward to protect the public's health from the dangers of second-hand smoke," which he calls "a critical public health danger with no safe level of exposure."

Since medical marijuana prescriptions are signed off by physicians, though, he says the city should look the other way.

Asked about the exemption for weed, Mar tells the Huffington Post, "My hope is that people wouldn't light up at community festivals."

"But if it's something medical and prescribed by a doctor," he adds, "that should be permitted."

The proposal is currently being considered by the San Francisco Board of Supervisors. A state-wide ban on indoor smoking was enacted back in 1994, and earlier this month lawmakers in Santa Monica, California extended city legislation to legalize cigarette smoking in some apartments and condos.