ground level ozone vs. stratospheric ozone
Ozone gas, O3, can be found in both the troposphere and in the stratosphere, but it has very different effects in each region. Ozone in the stratosphere is helpful; it absorbs harmful UV-B and UV-C waves from the sun, which are both known to cause sunburn and skin cancer. On the other hand, ozone in the troposphere is very damaging; it is a major component of photochemical smog, and it causes eye, nose, and lung irritation and aggravates asthma. Long-term exposure to tropospheric ozone can cause more serious conditions, such as chronic lung disease and reduced life expectancy. Stratospheric ozone is formed by oxygen in the presence of ultraviolet radiation. Tropospheric ozone is formed by a reaction between NOx, VOCs, and sunlight ("Ozone - Stratospheric and Ground-level," n.d.).