Skin cancer

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.

Symtoms

Nonmelanoma skin cancer may appear as a change in the skin, such as a growth, an irritation or sore that does not heal, or a change in a wart or mole.

Basal cell carcinoma usually affects the head, neck, back, chest, or shoulders. The nose is the most common site. Basal cell carcinoma occurs three times as often as squamous cell carcinoma.2 Signs of basal cell carcinoma can vary and may include skin changes such as a:

Firm, pearly bump with tiny blood vessels in a spiderlike appearance (telangiectasias).

Red, tender, flat spot that bleeds easily.

Small, fleshy bump with a smooth, pearly appearance, often with a depressed center.

Smooth, shiny bump that may look like a mole or cyst.

Scarlike patch of skin, especially on the face, that is firm to the touch.

Bump that itches, bleeds, crusts over, and then repeats the cycle and has not healed in 3 weeks.

Change in the size, shape, or color of a wart or mole

What Causes Skin Cancer?

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.

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.

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.

September 1995 Measurements of Antarctic Ozone The latest HALOE data in the form of a 100 mb surface cross section of column ozone (DU) is available. Please consult the data interpretation page for more information about the sampling pattern of HALOE.

United Nations World Meteorological Organization (WMO) Press Release Measurements of the Ozone Hole this year show it "was so far the most rapid depletion on record." An area the size of Europe received significantly higher levels of ultra violet exposure.

Environmental Protection Agency - Ozone Depletion Page This web site contains information about the science of ozone depletion, regulations in the US designed to protect the ozone layer, flyers about the UV index, information for consumers, and other topics.

How To Do a Skin Self-Exam

The best time to do a skin self-exam is after a shower or bath. Check your skin in a well-lighted room using a full-length mirror and a hand-held mirror.

Begin by learning where your birthmarks, moles, blemishes and freckles are and what they usually look and feel like. Check for anything new, especially a change in size, shape, texture or color. Also notice any area of scaliness, itching, bleeding, tenderness or pain.

Check yourself from head to toe. Don't forget the back, scalp, genital area, and between the buttocks.

Prevention

Minimizing sun exposure is the best way to prevent skin damage, including many types of skin cancer:

Protect your skin from the sun when you can -- wear protective clothing such as hats, long-sleeved shirts, long skirts, or pants.

Try to avoid exposure during midday, when the sun is most intense.

Use sunscreen with an SPF of at least 15. Apply sunscreen at least one-half hour before sun exposure, and reapply frequently.

Apply sunscreen during winter months as well.