Thursday marks the Great American Smokeout, a day when the American Cancer Society encourages smokers to quit smoking for at least 24 hours.
Wednesday, health officials took the opportunity to point out the dangers of secondhand smoke in apartment buildings.
Some California communities including Calabasas have already passed laws that regulate smoking inside apartments and other buildings that contain more than one residence. Health officials are pushing for even more cities to follow suit.
At a news conference at Children's Hospital Wednesday morning, officials spelled out the dangers of secondhand smoke. It's considered a Group A carcinogen with hundreds of toxic chemicals, 70 of which can cause cancer.
One particular problem officials emphasized was that secondhand smoke is not contained by closed doors or windows. It seeps through the thousands of cracks and seams in most apartments and is dispersed through other units by ventilation systems.
"The evidence is alarming. Dangerously high levels of tobacco smoke particles are being found in non-smokers' apartments. These levels are comparable to what you would find in what used to be a smoky bar or in today's casinos," said L.A. County Public Health Director Dr. Jonathan Fielding.
Health officials say some 336,000 kids in L.A. County are exposed to secondhand smoke.