by Dr. Mark Moore
The sun is the source of all life on earth, however, too much of a good thing can kill you. Sun exposure is the primary cause of skin cancer, which affects an astounding 1million people in the U.S. each year. Melanoma, the most deadly form of skin cancer, afflicts 50,000 of the U.S. population, while the most common skin cancers are basal cell carcinoma and squamous cell carcinoma.
The sun is everywhere, but it's cancer-causing UV rays (ultra-violet rays) are stronger in the southern states, and most intense during mid-day. It is estimated that fair skin will burn within 5 minutes in the Florida noon-day sun. Interestingly, the majority of our lifetime exposure occurs during our childhood.
Protecting your child's skin during the first 18 years of their life can reduce their skin cancer risk by 78%. Even the law is getting in on the act -- a women in Ohio was arrested and charged with a felony when she let her three children get so severely sunburned, they had to be treated for second-degree burns at a local hospital.
The sun gives off different types of ultraviolet rays. UV-A, UV-B rays penetrate deep into the skin and cause sunburn, wrinkling of skin, premature aging, and skin cancer. UV-B rays can, over time, cause clouding of the substance of the eye, called cataracts. UV-C rays are strong but get filtered by the ozone layer of the atmosphere.
Surprisingly, a cloudy day can be the worst exposure day -- it's not sunny or hot so people forget their hats and sunscreen. Yet 80% of the suns harmful rays penetrate clouds and fog. The suns strongest UV rays occur between 10am and 3 pm. Sit in a sunny room or a screened in porch, you are exposed to UV rays. Drive in an air-conditioned car, the sun's rays can reach you, too -- they penetrate clear glass. If your body leaves a shadow on the ground, then your skin is absorbing the sun's rays. Of course, convertibles with the top down don't afford much sun protection.
SPF Sun Protection Factor -- a multiplication of the amount of time you can have sun exposure without burning. Example: if you normally burn after 10 minutes in direct sunlight, an SPF 30 would give you 300 minutes (10 x 30 ). However, most sunscreens should be reapplied every 2 hours because of sweating and after swimming or exercise. My personal recommendation: forget all the numbers. Apply the highest one you can find, SPF 50 (sunblock), and reapply every 2 hours.
One of the hotbeds of scrutiny (no pun intended) is the tanning beds controversy. Are the use of tanning bed associated with an increase in skin cancers among children, teens and adults? It makes sense based on the etiology of skin cancer and melanoma coupled with the alarming statistics of increasing skin cancer cases (any type of UV exposure can cause skin cancer and UV rays from tanning lights are the tanning element of tanning beds).
Though medical research will take time to evaluate this, majority of the states of the U.S. are already proposing and passing legislation which restrict children and teens access to tanning beds. The hypothesis is that kid's skin, up to age 18 years of age, is even more susceptible to the harmful effects of these UV rays, causing more disruption of their DNA and making it more likely they may develop skin cancer later on in life.
Should one be encouraged to go to a tanning bed to get a "base tan" so you don't get burned later on vacation? I would not recommend it. The problem is sun exposure and although a gradual tan does lower the incidence of sunburn, it is still UV exposure, and in a way, may encourage more sunning. The solution is liberal use of sunblock and sunscreen.
Each week, I care for people with the diagnosis of skin cancer. It came even closer to home when a friend of the family was diagnosed with melanoma on her abdomen, necessitating a wide excision of tissue. She is only 20 years old. But every surgeon will tell you, this is not an unusual case.