Columbia subject headings:
Air--Pollution--Mexico--Mexico City--History.
Harvard subject headings:
Air--Pollution--Health aspects--Mexico--Mexico City--History--19th century.
Air--Pollution--Mexico--Mexico City--History--19th century.
Air--Pollution--Mexico--Mexico City--History.
Human ecology--Mexico--Mexico City--History--19th century.
Mexico City (Mexico)--Environmental conditions.
Odors--Mexico--Mexico City--History--19th century.
Public health--Mexico--Mexico City--History--19th century.
Princeton subject headings:
Air--Pollution--Health aspects--Mexico--Mexico City--History--19th century.
Urban health--Mexico--Mexico City--History--19th century.