Minors (1) Origin (1) Sulfur dioxide (1) Respiratory organs--Diseases (1) Respiratory organs (1) Quarries and quarrying (1) Proportion (1) Production (Economic theory) (1) Pregnant women (1) Pregnancy (1) Pollution (1) Pollutants (1) Petroleum (1) Motors (1) Mortality (1) Mineral industries (1) Lungs--Diseases, Obstructive (1) Hydrocarbons (1) Health (1) Girls (1) Gases (1) Fountains (1) Force and energy (1) Diseases (1) Combustion (1) Cities and towns (1) Children (1) Chemical industry (1) Carbon monoxide (1) Benzene (1)