Overexposure to ultraviolet radiation can cause skin damage. This can be immediate and long-term, with effects ranging from sunburn and premature wrinkling to carcinogenesis.
Sunscreens have been used for many years on exposed areas to protect the skin from the damaging effects of ultraviolet light. Although sunscreens are essential, some have adverse effects such as estrogenic activity
full text: http://medpublics.com/docs/choquenet2008.pdf