An increase in solar ultraviolet-B (UVB) radiation reaching the earth's surface is an important consequence of stratospheric ozone depletion. UVB has important effects on human health, both beneficial and harmful. Recent research has found that solar UVB reduces the risk of over 20 types of cancer, respiratory diseases caused by viruses, autoimmune diseases, and, likely, several other diseases, in addition to the well-known effects on bone diseases. On the other hand, solar UVB is an important risk factor for non-melanoma skin cancer and cataracts. Human epidemiological studies have provided evidence that solar UVA may be a more important risk factor for melanoma than UVB. If this result is correct, melanoma risk is not related to ozone depletion. We consider the net effect of solar UVB on human health to be beneficial at or near current levels.