In a unanimous decision, members of the San Rafael City Council have approved the strictest type of smoking ordinance in the country. Effective last week, Assembly Bill 746 bans residents of apartments, condos, duplexes, and multi-family houses from smoking cigarettes and "tobacco products" inside their homes.

Introduced by Assembly Member Marc Levine and pushed by the Smoke-Free Marin Coalition for over seven years, the ordinance applies to owners and renters in all buildings that house wall-sharing units for three or more families. The purpose is to prevent second-hand smoke from travelling through doors, windows, floorboards, crawl spaces, or ventilation systems (i.e. any conceivable opening) into neighboring units.

San Rafael has joined a growing number of cities, such as Belmont, CA, that have implemented similar bans.*

Levine said the bill is motivated by his desire to ensure that "Californians [can] breathe clean air in their own homes." He continued, "In apartments or condominiums, whenever a neighbor lights up, everyone in the building smokes with them."

Rebecca Woodbury, an analyst at the City Manager's office who helped write the ordinance, explained some of the bill's specifics to ABC News. "It doesn't matter if it's owner-occupied or renter-occupied," she said. "We didn't want to discriminate. The distinguishing feature is the shared wall…I'm not aware of any ordinance that's stronger."

The bill's proponents cited scientific evidence that shows cigarette smoke is able to travel through the ventilation systems of apartments. Some of this evidence was produced by two CDC studies, which found that roughly 45 percent of apartment dwellers claimed to have been exposed to second-hand smoke in their homes in the past year.

Some anti-smoking groups, like the American Lung Association, have expressed their support for the legislation. The President and CEO of California's division said the ordinance is "groundbreaking" and called for a state-wide ban.

The ordinance is not without its detractors, however.

A researcher at the Heartland Institute, a free-market policy think tank in Chicago, said the ban is part of a larger, disturbing trend of government encroachment on personal freedoms. As he told ABC News:

I don't like cigarettes, and I've never taken a puff. My sympathies aren't with smokers because I am one, it's because of the huge growth in laws and punishments and government restricting people more and more. Illinois' criminal code was 72 pages long in 1965; today it's more than 1,300 pages long.

Brian Augusta, of the Western Center on Law and Poverty, said that targeting multifamily units disproportionately affects low-income families and workers. According to the Sacramento Bee, Augusta said, "If smoking is an addiction, and it clearly is, are we telling people that they have to quit smoking—without support—or leave their homes?"

George Koodray, New Jersey state coordinator for Citizens Freedom Alliance and the Smoker's Club, decried the evidence linking apartment-dwelling to second-hand smoke exposure as weak. "The science for that is spurious at best," he said.

The California Apartment Association has not taken an official position on the issue, but has stated its doubts as to how the ordinance will be enforced and by whom. As it stands, AB 746 levies rule-breakers with fines but does not identify who will respond to complaints or write tickets.

Levine said that he hopes the ordinance will be "self-enforcing," but it's clear that landlords are being prodded to take up the torch. In an informational pamphlet published by the city, landlords are advised to threaten rule-breaking tenants with eviction.

*This was added to the article to make it clear that San Rafael is not the first city to implement this type of smoking ordinance.