ABSTRACT
There is consensus among the scientific and medical communities that exposure to
sunlight is a major factor in the etiology of the progressive unwanted changes in the
appearance of skin, i.e., photoaging, and in the risk of skin cancers (1-3). The evidence
supportive of this view comes from epidemiology, clinical studies, and experimental
studies in humans, laboratory animals, and in vitro systems. It is well established that acute
exposure of unprotected skin to ultraviolet (UV) radiation in sunlight produces numerous
physiological effects beyond the most obvious which is sunburn (4). Such insults or
damage following repeated, lifetime exposure to solar UV lead to skin cancers (5-8), and
as presented in Table 1, a myriad of degenerative events responsible for the visible signs of
skin aging (10,11). Recent years have seen a very rapid increase in knowledge concerning
the etiology and prevention of solar damage (12-14). Since exposure to UV radiation in
sunlight is associated with deleterious dermatological events, it is logical that reducing
solar UV exposure will diminish such damage to the skin.
