UV light: not only make you ugly
Summer is the favorite season for some of us. The summer fantasy is all about ice cream, beach, bikini and sunbaths. But wait for a second, it seems that you have forgotten something very important. Yes, it is your sunscreen.
There are many pieces of research that have shown that UV light can damage our skin and cause sun bourn and photoaging. It is well known that the sunlight contains UV light while bringing the visible light. The UV light is an invisible light which has a short wavelength and high energy. The high content of energy in UV light enables it to damage the DNA of plants, animals and bacteria, therefore is it usually used for disinfection.
UVA, UVB and UVC
The UV light can be classified as UVA, UVB and UVC depend on the wavelength. UVC which has the shortest wavelength and the largest energy is the most dangerous UV light. Fortunately, we are protected by the ozone layer against 100% of UVC and most UVB. In our daily life, our skin is threatened by the UVB and UVA, but you may not know the difference between them.
UVB ray is responsible for the sunburn. It composes only 5% of the UV light we exposed to, however, it will be strong enough to make you feel itchy, pain and stinging after 1 to 2 hours direct contact. The lucky thing is, UVB is hard to pass through fabrics and glasses. In other words, avoiding direct contact with the sun can easily avoid sunburn.
The lowest energy UV light, UVA ray, is much harder to block compared to UVB and UVC. UVA composes 95% of the UV light on the earth’s surface. It arrives on our skin though direct contact and diffuse reflection, which means even you are under a shade or behind glasses, UVA can reach to you. UVA ray is responsible for the photoaging of the skin, which includes collagen breaking, dilated capillary and melanin production, then followed by wrinkles, rash and tanning. The dull and dry skin is not only about our appearance, but prolonged exposure to UVA rays can also cause the abnormalities of our tissue and therefore accelerate the toxic effect of UVB rays, proved by several experiments.
Protect our skin
Fortunately, we can count on the reliable sunscreens to protect our skin from UVA and UVB rays. The most usual scheme of our sunscreen is either reflecting the UVA and UVB rays, such as titanium dioxide, or absorbing the rays by breaking bonds, such as Benzophenone.
When we walk into a shop and look at the package of the sunscreens, you are able to see the SPF level on it. However, the SPF level only represents the blocking effect of UVB rays, which has nothing to do with UVA rays. For those who do not want as much as wrinkles and dark spots on the skin, you will need to look for the phrase ‘broad spectrum protection’ on the package to ensure the product is also blocking UAV rays effectively.
Stay safe and protected is another theme in summer. When the summertime arrives, don’t forget to bring your sunscreens with you before you are going out.