Smith Mountain Lake is a great place to get a suntan, and a sunburn too if you are not careful. We have all heard that sunburns are not good, but why exactly is that? What happens when a sunburn occurs? Here is my overview for the ordinary person (like myself who can’t quite wrap my mind around the scientific explanation).
The sun puts out ultraviolet (UV) radiation of 3 types, UVA, UVB and UVC. Because of the ozone layer in the atmosphere between the sun and earth, over 98% of the rays that reach us are of the UVA type. All types of radiation can cause damage to skin tissue (which speeds up the aging process), immune system, eyes, and in exteme cases skin cancer.
Type C (UVC) radiation is filtered out by the atmosphere before it reaches us.
Type B (UVB) radiation is responsible for some beneficial results such as the absorption of Vitamin D, a vitamin that plays an essential role in the prevention of many different diseases. Too little UVB rays and we become vitamin D deficient, too much and we risk serious consequences to our bodies.
Too much UVB radiation leads to direct damage of the living tissue that we call skin, in the form of a sunburn or worse. An appropriate amount of UVB (which depends on your skin color) leads to very little damage which your body repairs in part through the production of a brown pigment called melanin. The purpose of melanin in our skin is to protect us from UV radiation and the result of it’s activation is a darkening of the skin, commonly called a suntan. This tan is much less harmful and not as long lasting than the one obtained from UVA.
Type A (UVA) radiation can cause indirect damage (cellular stress and changes that do not happen immediately and do not result in sunburn or other warning signals of pain) to the cells of our skin. Studies have found that 92% of all melanoma (cancers) are caused by indirect damage and only 8% of the melanoma are caused by direct damage.
It was once thought that only UVB rays were harmful, but as you can see above, all types of the suns rays can become harmful with excess exposure. So the question we need to cover in Part 2 is how much exposure leads to damage and what can we do to protect ourselves further.