The Sun: Friend and Foe
The sun is both our friend and our foe. Life on earth would not exist without the sun. It provides light and warmth, and sustains all living things.
BUT – within that warm sunlight is an invisible enemy: Ultraviolet (UV) Radiation. Too much exposure to the UV Radiation in sunlight can cause harm to people.
Have you ever had a sunburn from staying out too long in the sun without protecting your skin? That’s one way too much sun can harm you.
Too much exposure to UV Radiation damages the skin. This damage causes
premature aging or wrinkling of the skin, which makes people appear old before
their time. Other damaging effects of UV Radiation are cataracts (clouding of the
lens of the eye), weakening of the immune system, and SKIN CANCER.
Types of UV Radiation
UVA and UVB are the two types of Ultraviolet Radiation emitted by the sun, which penetrate the earth’s atmosphere. UVC rays are absorbed by the earth’s atmosphere
and do not reach earth.
UVA rays – are longer rays, which penetrate the skin deeply and cause wrinkling and tanning of the skin.
UVB rays – are the shorter rays which cause burning
of the skin.
When is UV Radiation most intense?
- In the middle of the day (Between 10am and 4pm)
- During the summer months
- At higher altitudes
- In regions of the earth closer to the equator
Click here to see the UV Index in your area. Then get your personalized sun safety recommendation based on your skin type, chosen activity, and time of day.
Diagram of the Skin
The skin is your body’s largest organ. It protects your internal organs and guards you from infections. The skin has 2 layers: the outer layer called the epidermis and the dermis.
There are three main types of skin cells in the epidermis: basal cells, squamous cells and melanocytes. Your skin color depends on the activity level of the melanocytes.
How Does UV Radiation Affect Your Skin?
UV radiation from the sun (or tanning beds) causes the skin cells (melanocytes) in the epidermis to become more active, releasing pigment (melanin), which shows up on your skin as freckles, sunburns or suntans.
When melanocytes are changed by UV radiation they sometimes start to grow and divide rapidly, causing growths or tumors, which may be skin cancer.
Many people think a tan is a sign of health and that they look better with a tan, but a tan is really a sign of damaged skin. There is no such thing as a healthy tan!
Did You Know?
UV Radiation can penetrate through 3 feet of water. UV-A Radiation can reach your skin through glass.
Visit Related Links to see where you can learn more about UV Radiation.