Ground Level Ozone

When a lot of people hear the word “ozone” in conjunction with environmental concerns they only think of the ozone layer which is a layer of the Earth’s atmosphere that is situated approximately 8 25 miles above the ground. But did you know there is also ground-level ozone (or tropospheric ozone) which is actually located closer to ground level and therefore a contender in daily widespread health threats.The EPA has published this overview of ground-level ozone:

  • Ground-level ozone is a primary component of smog
  • Repeated exposure to ozone can make people more susceptible to respiratory infections and lung inflammation. It also can aggravate pre-existing respiratory diseases, such as asthma
  • Children are at risk from ozone pollution because they are outside, playing and exercising, during the summer days when ozone levels are at their highest
  • The two types of chemicals that are the main ingredients in forming ground-level ozone are called volatile organic compounds (VOCs) and nitrogen oxides (NOx)
  • Nitrogen oxides (NOx) are produced when cars and other sources like power plants and industrial boilers burn fuels such as gasoline, coal, or oil
  • The reddish-brown color you sometimes see when it is smoggy comes from the nitrogen oxides
  • Weather and the lay of the land (for example, hills around a valley, high mountains between a big industrial city and suburban or rural areas) help determine where ground-level ozone goes and how bad it gets
  • As traffic and other sources add more ozone-forming pollutants to the air, the ground-level ozone gets worse
  • Many of the clean-up requirements for particle pollution and ground-level ozone involve large industrial sources (power plants, chemical producers, and petroleum refineries), as well as motor vehicles (cars, trucks, and buses). Also, in nonattainment areas, controls are generally required for smaller pollution sources, such as gasoline stations and paint shops

Another thing to keep in mind is that there is not a current threshold that has been identified in which health is deemed affected (since different individuals respond differently to exposure) so unless you know your specific tolerance level (which is unlikely) it’s best to be aware and evoke change.