The sun’s rays contain essential Vitamin D, which is required for formation of bones in the body. But overexposure to sun can cause enough damage to our skin. The skin’s outer layer consists of melanin. This chemical protects our skin from the sun’s ultraviolet rays. Over time, these rays burn the skin and cause wrinkles and age spots. The skin loses its elasticity and can even cause premature aging. Too much exposure to sun can cause sunburn. The tan obtained from the sun actually accelerates the aging process. UV rays pass through the outer skin layer and penetrate into the deeper layers of the skin killing the skin cells. People with less melanin in their bodies are subject to a lot of sunburn and should cover themselves whilst going out in the sun. Prolonged exposure to UV rays over the years has also been related to skin cancers.
Effects of sun on the skin
Exposure to sun is known to cause:
- Mottled pigmentation
- Sallowness – yellow discolouration of skin
- Tumors – benign
- Coarse and fine wrinkles
- Elastosis – breakdown of elastic and collagen tissue
- Telangiectasias – dilation of small blood vessels in the skin
- Skin cancer: There are three types of skin cancers – melanoma, basal cell and squamous cell carcinoma. There are also non-melanoma skin cancers which can be cured if detected early. Abnormal skin pigment cells called melanocytes are the primary cause of melanoma. Exposure to UV rays during summer or winter is equally harmful. Prolonged exposure to sun usually causes squamous cell and basal cell carcinoma.
There are two kinds of UV rays – ultraviolet A and ultraviolet B. It is UVB that is responsible for the cause of squamous cell and basal cell carcinomas. UVA penetrates the skin and causes premature aging and wrinkling of the skin. People with fairer skins have less melanin and hence are less protected by UV rays.