Columbia subject headings:
Employees--Health and hygiene--United States.
Indoor air pollution--United States--Prevention.
Passive smoking--Health aspects--United States.
Smoking in the workplace--United States--Prevention.
Harvard subject headings:
Indoor air pollution--United States--Prevention.
Industrial hygiene--United States
Passive smoking--Health aspects--United States.
Smoking in the workplace--United States--Prevention.
Princeton subject headings: