Smog, a form of air pollution strongly associated with asthma hospitalizations, forms from both volatile organic and nitrogen oxide (VOC and NOx) pollutants. The ratio and relative significance of these two pollutants vary from city to city. Please choose your location below to learn which affects your area.

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Read the report and learn about how cars contribute to America's asthma epidemic. Smog causes lifelong damage to our children's lungs.