What Causes Skin Cancer?
Sunburn and Sunlight
Very simply, sunburn and UV light  can damage your skin, and this
damage can lead to skin cancer. There are of course other determining
factors, including your heredity and the environment you live in.
However, both the total amount of sun received over the years, and
overexposure resulting in sunburn can cause skin cancer. Most people
receive 80% of their lifetime exposure to the sun by 18 years of age.
The message to parents from this is to protect your children.
Tanning  is your skin's response to UV light. It is a protective
reaction to prevent further injury to your skin from the sun. However,
it does not prevent skin cancer.
Remember, skin cancer is very slow to develop. The sunburn you receive
this week may take 20 years or more to become skin cancer.
Heredity
If there is a history of skin cancer in your family, you are probably
at a higher risk. People with fair skin, with a northern European
heritage appear to be most susceptible.
Environment
The level of UV light today is higher than it was 50 or 100 years ago.
This is due to a reduction of ozone in the earth's atmosphere (the
Ozone Hole). Ozone serves as a filter to screen out and reduce the
amount of UV light that we are exposed to. With less atmospheric
ozone, a higher level of UV light reaches the earth's surface.
Other influencing factors include elevation, latitude, and cloud
cover. Ultra Violet light is stronger as elevation increases. The
thinner atmosphere at higher altitudes cannot filter UV as effectively
as it can at sea level. The rays of the sun are also strongest near
the equator, as you might guess. But even in Antarctica, Chile, and
New Zealand, the UV level is much higher than normal especially in the
springtime  due to the ozone hole in the southern hemisphere.
One factor that actually reduces UV is cloud cover. Climates and micro-
climates with regular cloud cover may have a 50% lower level of UV
light. The actual amount is affected by the density of the clouds.
What is Skin Cancer?
(From the National Cancer Institute PDQ Statement)
Skin cancer is a disease in which cancer (malignant) cells are found
in the outer layers of your skin. Your skin protects your body against
heat, light, infection, and injury. It also stores water, fat, and
vitamin D.
The skin has two main layers and

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