A threat to human and environmental health, and an indicator of changes in atmospheric composition. Cancers can be caused, some fatal. Recent attention to the changes in stratospheric ozone has generated considerable interest in UV radiation, because as ozone levels decrease the amount of UV reaching the surface will certainly increase.
Ozone is a highly efficient absorber of UV radiation.
In fact, detailed measurements of UV are one method by which scientists keep track of the total amount of ozone contained in the atmosphere. There are many reasons for monitoring UV at the surface, corresponding to the concerns about health and the environment. Different instruments suit different applications. Questions about variations in human exposure are conveniently answered using broad-band instruments. Narrow band instruments sometimes constitute an optimal practical solution to the desire to satisfy both communities, but these are recent developments that are not yet thoroughly proven in field situations.