Cal. Health and Safety Code § 118920

(a) The Legislature hereby finds and declares that the United States Surgeon General’s 1986 Report on the Health Consequences of Involuntary Smoking conclude all of the following: (1) Involuntary smoking is a cause of disease, including lung cancer, in healthy nonsmokers. (2) The children of parents who smoke compared with the children of nonsmoking parents have an increased frequency of respiratory infections, increased respiratory symptoms, and slightly smaller rates of increase in lung function as the lungs mature. (3) The simple separation of smokers and nonsmokers within the same air space may reduce, but does not eliminate, the exposure of nonsmokers to environmental tobacco smoke. (b) The Legislature further finds and declares the following: (1) Nonsmokers have no adequate means to protect themselves from the damage inflicted upon them when they involuntarily inhale tobacco smoke. (2) Regulation of smoking in public places is necessary to protect the health, safety, welfare, comfort, and environment of nonsmokers. (c) It is, therefore, the intent of the Legislature, in enacting this article, to eliminate smoking on public transportation vehicles.