The connection between the Sun's powerful ultraviolet UVA and UVB rays and skin cancer is indisputable. Skin cancer is caused by a various number of external and internal factors. Basically it is the result of both visible layer damage or cellular level damage of the skin. This damage can initially be seen in the form of sunburn or tanning and can add up over the years causing skin cancer.

The various different causes of skin cancer are:-

• Sunburn
• Overexposure to sunlight.
• Heredity
• Environment

Sunburn:
Excess exposure to the Sun without proper protection causes damage to the skin in the form of sunburn. This is the visible damage caused by the Sun to the top layer of skin called the epidermis.

Over the years this damage to the skin adds up and presents itself in various forms such as wrinkles, age spots, and excess tanning. Over a long period of time this damage can culminate to present itself in the form of skin cancer.

The basic cause of sunburn is the harmful effects of the powerful Ultraviolet rays of the Sun. These are very powerful and actually burn the skin. The risk of UV radiation is higher where there is Ozone depletion.

Thus it is necessary that proper care is taken to prevent sunburn by adopting various safety measures as described in the prevention section.

Over Exposure to Sunlight:
The Sun's rays contain UVA and UVB rays which are capable of burning our skin cells. This can cause visible damage like sunburn and tanning. Along with this it can also cause invisible cellular damage that adds up over the years and can cause adverse effects such as wrinkles, age spots and skin cancer.

The UV rays of the Sun damage the various layers of the skin. The top layer or epidermis contains 3 types of cells, squamous cells, round basal cells and melanocytes. After being ravaged by the UVA and UVB rays from the Sun different types of skin cancer may form. It is thus necessary to prevent the overexposure of the skin to the Sun's rays.

Heredity:
It is known that people with a family history of cancer run a higher risk of getting skin cancer. This is mainly because of a type of geno-environmental interaction. As a result the chances of a person who has a family history of skin cancer and is exposed to various environmental factors like the Sun's rays are much higher.

The Environment:

German researchers reported in August 1998 that increases in the ozone-destroying chemical CFC-12 are slowing in the upper atmosphere. While this is good news precautions still need to be taken and the ozone layer protected.

Environmental factors play a huge role in governing the occurrence of skin cancer. In the past 50 years one of the major environmental factors which has caused much concern is the depletion of the ozone layer. The ozone layer is the layer of our atmosphere that filters out the harmful UV rays from the Sun's rays. Over the last few decades this layer has gotten depleted and as a result we are being exposed to more and more UV rays which can cause skin cancer.

Other environmental factors which can have an effect on the occurrence of skin cancer are elevation, latitude and cloud cover. At higher altitudes the UV radiation is much stronger and can cause skin damage at a faster rate. Also at higher altitudes the atmosphere is not able to filter out the UV rays as effectively as at sea level. At areas nearer to the equator the Sun's rays are much stronger and a higher incidence rate of skin cancer is found.

Another factor that can effect UV radiation is cloud cover. Places with a regular cloud cover have a much lower skin cancer incidence rate because they are exposed to lesser amounts of the harmful UV rays. The denser the cloud cover is the more the protection. However, unless the cloud cover is very dense steps should be taken to protect the skin as UV light penetrates clouds.

These are some of the more common causes of skin cancer and steps should be taken to protect yourself from it at all cost.