Ozone , on the other hand, is made up of three oxygen atoms. It comprises a thin layer in the upper atmosphere and protects animal and plant life from harmful solar ultraviolet radiation. Ozone is also found near the surface of the earth. But here, it can be a dangerous and unhealthy pollutant in high concentrations. Lower level ozone is caused by a variety of natural and human activities.
Aerosols are tiny and microscopic particles of dust, smoke and ash.
Volcanoes, deforestation, desert storms,and fires, both natural and man-made, may generate these aerosols. UV exposure has served as a focal point for most stories dealing with ozone depletion. Erythemal UV exposure is described as the daily amount of radiation that gets through the atmosphere to ground level. Measured by TOMS in terms of kilojoules per square meter, it is the intensity of solar ultraviolet radiation reaching plant and animal life after it has been filtered through stratospheric ozone, clouds and aerosols multiplied by its biological damage potential. Erythema is the scientific word for sunburn.