Columbia subject headings:
Chemicals--Health aspects.
Industrial hygiene--United States.
Industrial safety--United States.
Working class--United States--Attitudes.
Harvard subject headings:
Chemicals--Health aspects.
Industrial hygiene--United States
Industrial safety--United States
Working class--United States--Attitudes
Princeton subject headings:
Chemicals--Hygienic aspects.
Industrial hygiene--United States.
Industrial safety--United States.
Working class--United States--Attitudes.