Sun Exposure

The sun gives off visible light as well as ultraviolet light (UVA, UVB, and UVC), which gives energy to all living things on earth. The energy it provides our body is used to convert inactivated 7-dehydrocholesterol into activated Vitamin D by absorbing UVB on our skin. Vitamin D contributes to the maintenance of normal levels of calcium and phosphorus in the blood. Though the sun is a necessary component of life on earth and it helps in the production of Vitamin D in humans, sun exposure can be a negative aspect as well.

Excessive exposure to the sun and its ultraviolet radiation can cause many different health problems. Some of these health problems are sunburns, damage to collagen fibers (contributing to premature aging of the skin), damage to eyes and surrounding tissue, damage to DNA, and even possibly causing skin cancer. With sunburn there is an acute period of excessive exposure to the sun, which is followed by redness, pain, and the exposed skin dying and peeling off. Sunburns can range from simple redness and tenderness to extreme sunburns, which can cause extreme pain that, requires hospitalization. The suns rays can cause damage to collagen fibers in human skin by breaking apart the connecting collagen fibers and causing premature aging of the skin leading to wrinkles (often called skin photodamage).

Too much sun exposure to the eyes has been linked to certain diseases like pterygium (benign growth of the conjunctiva) and cataract development (opacity of the crystalline lens of the eye). Excess exposure of the retina to the suns rays can also cause vision damage and even blindness.

Too much sun exposure can cause even worse damage to the human body at the molecular level. UVB light has been shown to have a direct cause on skin cancer in the human body. This type of radiation penetrates deep into skin cells causing DNA molecules to become excited and to form covalent bonds between adjacent tyamine bases, producing tymidine dimers. These changes in the normal DNA lead to mutations that can progress to cancerous growths.

Skin cancer is one of the most common forms of cancer in America. There are about 1 million new cases of skin cancer diagnosed each year. The majority of these skin cancers are basal and squamous type, which are less dangerous than melanoma, which has about 53 thousand new cases per year. Men are more prone than women in America to develop skin cancer, where men are 14 percent more likely to develop skin cancer.

The highest rate of skin cancer incidence in the world is in Australia. It is projected that one in three men and one in four women who live in Australia will be affected by skin cancer in their life. Skin cancer is the cause for 25 percent of the population's deaths in Australia each year. With sun exposure being such a major cause of skin cancer in the world, it is important to use the resources we have to try and prevent new cases of skin cancer from ever happening.

...