EFFECT OF STRATOSPHERIC OZONE DEPLETION ON TERRESTRIAL ULTRAVIOLET-RADIATION - A REVIEW AND ANALYSIS IN RELATION TO POLYMER PHOTODEGRADATION

Current satellite and ground-based data indicate a long-term decrease in global ozone levels of 2.7 +/- 1.4% per decade, although recently t he rate may have increased to about 4% per decade outside of the tropi cs. There is yet little evidence of an accompanying wide-spread increa se in terrestrial UV levers, but calculations predict increases of a s imilar magnitude in coming years. The manifestation of increased UV wi ll be as a broad band centered about 310 nm with only very little abso lute increase in wavelengths shorter than 295 nm. Unless sustained ozo ne losses exceed 15% during the summer months, the effect should be in consequential for most polymers. The effects of sun position on daily and seasonal variations in UVB are discussed.