Some of this absorption causes breakdown to NO and atomic oxygen:

NO + O

The NO can be reoxidized to , and the oxygen atom goes on to do further damage. If you add the two preceding reactions, you will see that the oxides of nitrogen are really only the cyclic machinery for using photons of visible light to tear oxygen molecules apart into atoms:

2O

Free oxygen atoms are damaging because they combine with to form ozone ():

+ O

Ozone is an excellent oxidant that attacks organic matter, including hydrocarbon pollutants, rubber, paint and plastics, and the lining of our lungs.