Passive smoking does cause lung cancer, do not let them fool you.
D002986:Clinical Trials as Topic; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000453:epidemiology / Q000209:etiology*; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D014944:World Health Organization
D014028:Tobacco Smoke Pollution