Major Air Pollutants:

Hydrocarbons, VOCs, and Ozone

Hydrocarbons and VOCs

     

      -hydrocarbons are composed of only hydrogen and carbon

      -react with nitrogen oxides and sunlight to produce ground-level ozone, a major

      component of smog result when fuel molecules in the engine do not burn or burn only

      partially

      -volatile organic compounds (VOCs) are composed of hydrogen and carbon, and may     

      also contain elements  such as oxygen, nitrogen, sulfur, chlorine, and fluorine.

      -these compounds take part in atmospheric photochemical processes (5)

 

The Sources

      -fossil fuel combustion

      -dry-cleaning operations

      -auto paint shops

      -chemical plants

      -service stations

      -waste facilities (4)

 

 

 

 

 

 

Ozone (O3)

 

 

 

 

 

 

 

 

-gas

-toxic, bluish, unstable, with pungent odor

-ground-level ozone is formed indirectly by the action of sunlight on volatile organic

compounds in the presence of nitrogen dioxide

-the interaction of primary pollutants (released directly from the source) makes ozone

a secondary pollutant (5)

 

-As ozone concentrations are particularly dependent on sunlight, episodes are always likely to develop following sustained periods of warmth and calm weather.