Ground level ozone, known as smog, is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC). This happens when these pollutants. emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources, chemically react in the presence of sunlight.
Climate Change to Bring More Smoggy Days
More smoggy days will be in our future, thanks to climate change. Cities like Pittsburgh could see the number bad air days double by 2050.
