What is UV?
Ultraviolet (UV) rays are a form of invisible energy given off by the sun. Ultraviolet radiation is divided into 3 wavelength ranges:
- UVA rays age skin cells and cause some damage to cells' DNA. UVA rays are mainly linked to long-term skin damage such as wrinkles, but are also thought to play a role in some skin cancers.
- UVB rays are the rays that cause sunburns. They are also thought to cause most skin cancers.
- UV C rays don't penetrate our atmosphere and therefore are not present in sunlight. They are not normally a risk factor for skin cancer.
UV rays also increase a person's risk of cataracts and certain other eye problems and can suppress their immune system.
What is SPF?
Sun Protection Factor or SPF is used to measure the amount of time a product protects the skin from reddening due to exposure to UVB rays.
A sunscreen with an SPF of 15 filters approximately 93% of the UVB and a SPF of 30 blocks about 97% of the UVB. Put another way, a sunscreen with an SPF of 15 will delay the onset of sunburn in a person who would otherwise burn in 10 minutes to burn in 150 minutes. The SPF 15 sunscreen allows a person to stay out in the sun 15 times longer before they would burn. There are a lot of variable that go into exactly how long a sunscreen will protect you from burning, so it is important to use these numbers as a guideline and not absolute.
There currently is no similar standard for UVA, however a broad spectrum sunscreen can provide protection from UVA and UVB radiation.
What is the difference between sunscreen and sunblock?
A sunscreen chemically absorbs the UV rays. A sunblock physically deflects those rays.
How often should sunscreen be applied?
Sunscreens should be applied generously 20 minutes before going outdoors and every two hours there after. More frequent reapplications should be made if you are sweating. Always reapply sunscreen immediately after swimming. Remember.
How do I protect myself from UV rays?
See our page titled Protect Yourself.
What are the different types of skin cancer?
Basal Cell Cancer
Basal cell carcinoma accounts for more than 90 percent of all skin cancers in the United States. It is a slow-growing cancer that seldom spreads to other parts of the body.
Basal cell cancer usually occurs on areas of a person's skin that have been exposed to the sun. Often, it appears as a small, raised bump that has a smooth, pearly appearance. However, it can also look like a scar and be firm to the touch.
Squamous Cell Cancer
Squamous cell cancer usually occurs on parts of a person's body that have been exposed to the sun. Often, it appears on the top of the nose, forehead, lower lip, and back of the hands. It also may appear on skin that has been severely sunburned, been exposed to carcinogenic chemicals, or had X-ray therapy.
Melanoma is one the most serious cancer of the skin. In some parts of the world, especially among Western countries, the number of people who develop melanoma is increasing faster than the number for any other cancer. In the United States, the incidence of melanoma has more than doubled in the past 20 years. One explanation for this trend is increased recreational exposure to the sun. That is why The Sun SafeTee Program is so important for golfers.