Skin Cancer

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 several kinds of cells. The top layer of skin is called the epidermis. It contains three kinds of cells: flat, scaly cells on the surface called squamous cells; round cells called basal cells; and cells called melanocytes, which give your skin its color.