TROPOSPHERIC ozone is harmful, damaging plants and human health while ozone at the STRATOSPHERE level screen out mutagenic ultraviolet radiation. Ozone is principally found in two areas of the earth atmosphere, at the troposhere and at the stratosphere. The ozone found at the troposheric level is about 10% of the total ozone and is harmful to living organisms while the ozone found at the stratospheric level contributes about 90% of the total ozone and helps to screen out harmful ultraviolet radiations.