"On February 25, 1990, the "no-smoking" sign was permanently lit on U.S. domestic airline flights - for the health of flight attendants and passengers. This eventually led to smokefree air on all flights to and from the U.S. and to smokefree policies for airlines worldwide."
"Exposure to secondhand smoke (SHS) from burning tobacco causes disease and death in nonsmoking children and adults. No risk-free level of SHS exposure exists...Overall, SHS exposure in the United States has been reduced by half since 1999–2000. However, 58 million persons were still exposed to SHS during 2011–2012, and exposure remains higher among children, non-Hispanic blacks, those living in poverty, and those who rent their housing."