What is the difference between the ozone layer and ground-level ozone?
Ozone is also present in the lower levels of the atmosphere (i.e. the troposphere), but at even lower concentrations than in the stratosphere. Close to the Earths surface, most of the Suns high-energy UV radiation has already been filtered out by the stratospheric ozone layer, so the main natural mechanism for ozone formation does not operate at this low level. However, elevated concentrations of ozone at ground level are found in some regions, mainly at the result of pollution. Burning fossil fuels and biomass releases compounds, such as nitrogen oxides and organic compounds, which react with Sunlight to form Ozone. This ground level Ozone is a component of urban smog and can cause respiratory problems in humans and damage to plants. There is little connection between ground level Ozone and the stratospheric ozone layer. Whereas stratospheric ozone shield the Earth from the Suns harmful rays, ground level Ozone is a pollutant. Though the downward movement of Ozone rich air from the st
