Yes, secondhand smoke can cause lung cancer
nonsmokers demonstrated that smoking limited the extent of differentiation of all three subclusters and altered SAM pointed domain-containing Ets transcription factor (SPDEF)-regulated transcription in the effector cell population leading to a change in the location of the branch point for mucous cell production, a potential explanation for the concomitant reduction in effector club cells and increase in mucous cells in smokers

Source: Centers for Disease Control and Prevention, State-Specific Prevalence of Current Cigarette Smoking Among Adults ---United States, 2002, MMWR , 52(53);1277-1280, January 9, 2004 Public Domain Table of Contents (TOC) Article: State-Specific Prevalence of Current Cigarette Smoking Among Adults ---United States, 2002 Editorial Note Tables References Cigarette smoking in the United States causes serious illnesses among an estimated 8.6 million persons1 and approximately 440,000 deaths annually,2 resulting in $157 billion in health-related economic costs.2 To reduce smoking prevalence, morbidity, mortality, and economic impact, state tobacco-control programs should include interventions to help persons stop smoking.3 To assess the prevalence of current cigarette smoking among adults, attempts to quit, and receipt of physician advice to quit during the preceding year, CDC analyzed data from the 2002 Behavioral Risk Factor Surveillance System (BRFSS) survey

Promoting smoke-free lifestyles and encouraging regular dental check-ups are crucial steps in preserving and enhancing oral health for both smokers and non-smokers alike