Basic Chemistry and Sources

As we have learned, volatile Organic Compounds (Hydrocarbons) combine with nitrogen oxides (NOx) in the presence of sunlight to form ozone.

VOCs + NO x  sunlight   Ozone 

In turn, sunlight and hot weather cause ground-level ozone to form in harmful concentrations in the air. As a result, it is known as a summertime air pollutant.

Ozone  +  NO  sunlight   Photochemical  Smog  (Haze) 

Many urban areas tend to have high levels of "bad" ozone, but even rural areas are also subject to increased ozone levels because wind carries ozone and pollutants that form it hundreds of miles away from their original sources.

View the graph below to compare the major sources of NOx and VOC that help to form ozone.

Major sources of NOx and VOC's including: Industrial, utilities, motor vehicles, consumer solvents, and other sources. Refer to text description below.

Major sources of NO and VOC's.

Sources of NOx and VOC
SourceAmount of NOxAmount of VOC
Industrial18%50%
Utilities24%0%
Motor Vehicles55%45%
Consumer Solvents0%5%
Other5%0%
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