Sunlight and Wrinkles
Premature skin aging is caused by the effects of the ultraviolet light from sunlight. In fact, symptoms of skin aging can be attributed mostly to the damaging effects of UVA and UVB.
Depending on the wavelength off light, ultraviolet radiation can be divided into:
UVA-320 to 400nm
UVB-290 TO 320nm
UVC- 100 to 290nm
A major producer of skin damage, this type of ultra violet radiation is highly penetrative and efficient. It is not filtered by glass and travels more constantly that UVB. It’s harmful radiation effects are do not vary at particular times, days or seasons.
The epidermis is affected by UVB and appears in the form of a sunburn. It’s intensity is subject to time and is most damaging between 10am to 2pm, as well as the warmer seasons. Unlike UVA however, it does not penetrate through glass.
This type of radiation does not affect the layers of skin as it is 100% percent absorbed by the ozone layer. Artificial sources that contain UVC include germicidal lamps and mercury arc lamps.
In contrast to chronologic aging, UV radiation causes faster collagen breakdown.
Free radicals are caused by UV radiation. Instead of two electrons, they only have one and are unstable. As it must search for other molecules with two electrons, it can interfere with normal cell functions and consequently change genetic material. This damage causes wrinkles by activating metalloproteinases which destroy collagen.