To Screeen or NOT TO Screen, That is the questions or The Life and Legend of UVB

by  Leonard Marks, MD

Dear sweet innocent sunlight – warming the sole, making plants grow, a wonderful source on energy.  Also, burning skin and causing cancer.

Depending on which studies you read people get 50 to 80 percent of their lifetime exposure to sunlight before the age of 18 to 20 years.  Of course this does not apply to soccer coaches and probably is lower in today’s Video Game and TV oriented society.  Usually redness and skin tenderness (i.e. pain) begins 30 minutes after exposure to the sun, peaks at 24 hours (you can get blistering) and lasts up to 72 to 96 hours.  This varies with the intensity of the exposure and the person’s natural coloring (see table below).  Anywhere between two and 8 days after heavy exposure layers of skin will peel.

It is the ultraviolet spectrum that causes the damage and lest we forget this sunlight is actual solar or ultraviolet radiation (OOOOOOOOOOooooooooooooooh a bad word).  Ultraviolet A or UVA is the lesser of two evils causing immediate darkening from existing melanin (the chemical in the skin responsible for pigmentation) in the skin.  This lasts a few hours and is not protective from burning.  While heavy concentrations of UVA can also cause redness and burning, the primary culprit is ultraviolet B or UVB which causes the red, tender, swollen, blistering skin.  UVB also causes delayed melanin formation and tanning starting in 2 to 3 days and lasting for several weeks.  This latter tanning decreases the skin sensitivity to UVB several fold.

Of far more long term concern than the burning are the delayed effects of sun exposure and burning.  It is well documented and (after you have read this) common knowledge that prolonged or continued exposure to solar radiation (there, I have used that bad word again) will have several effects.  These effects are rarely seen in kids but manifest themselves in adults, the age depends on the exposure.  They are:

  1. Early aging with wrinkles with a good deal of wrinkling in the exposed skin.  This is due to the effect of the radiation on the skin’s elasticity.
  2. Multiple scaly red patches called actinic keratosis.
  3. Skin cancer with a significant increase in the rate of squamous and basal cell carcinoma associated.
  4. Significantly increased number of melanocytic nevi which form the usually fatal malignant melanoma in adults is correlated with sunburns during childhood.

To summarize the above:  The more exposure to sun you have as a child correlates with significant problems with skin cancer as an adult including death (that could have a detrimental effect on your soccer career).

TABLE 1 – sun reactive skin typer (From Nelson’s textbook of Pediatrics)

               Type    demographics                          sunburn/tanning history

I           Red hair, freckles, Cletic origin           Always burns easily – no tanning

II       Fair skin, fair hair, blue eyed, white    Usualy burns, minimal tanning

III        Darker skinned white                           Sometimes burns, gradual light brown tan

 IV      Mediterranaen background                  Minimal to no burning, always tans

V        Middle eastern white, Mexican            Rarely burns, tans profusely dark brown

VI      Blacks                                                  Never burns, pigmented black

Prevention is easy – avoid the sun and use sun screen or sunblock.

Regarding the sun:  wear clothing with a tight weave and darker colors.  If you are a follicular impaired (bald) coach, use a hat.  In the summer 60% of the UVB rays reach the earth between 10AM and 3PM – as a general rule, if your shadow is shorter then your height, you are more likely to burn.  Find shade for team chats and discussions.

There is a whole batch of stuff you can put on your skin.  First you have the sunblocks like Zinc oxide and Titanium dioxide.  These used to be the thick white goop that physically blocked the sun’s rays from hitting the skin.  It blocked UVA and UVB.  Today’s technology has permitted scientists to create smaller particles dissolved in the application vehicle so they are now colorless.

By far the most popular are the chemical sunscreens.   Many of us remember PABA which filtered primarily UVB.  This has been replaced by the “benzophenones” and “dibenzoylmethanes” which protect against both UVA and UVB.  The companies rate the protection by using a “sun protection factor” or SPF which is a ration as follows:

SPF = minimal dose of sunlight required to produce redness after application of the sunscreen divided by the minimal dose of sunlight require to produce redness with no sunscreen

In other words, an SPF of 30 will take 30 times longer to burn as compared to no sunscreen.   It is rarely necessary to go above SPF 30.  For those engineers, if you apply a second coat of SPF 30, you do not get SPF 60.

The use of higher SPF screens does not mean the sunscreen will stay on the skin longer, just that it filters more radiation.  Indeed, sunscreens should usually be reapplied every two hours and initially should be applied ½ hour in advance of sun exposure (to permit it to absorb or bond).  The duration of the sunscreen will depend on physical activity, swimming, sweating and rubbing.  Some of sunscreens advertise that they actually bond to the skin, having longer duration and being sweat resistance.  These sunscreens do last longer and I recommend them.  The protection also varies with skin type and I again refer the reader to Table 1.

All of us who have used sunscreens know that if you apply sunscreens to the forehead or around the eyes, some will either directly get in the eye or will leach into the eyes when we sweat.  This causes intense burning and discomfort.  While the newer sweat resistant sunscreens are sweat resistant, no matter what they say they are not sweat proof and will still get in the eyes and burn.  The burning is not from the sunscreen but from the vehicle the sunscreen is dissolved in.  This vehicle is an alcohol base, and it is the alcohol that will burn the eyes.  Sunscreen sticks are not an alcohol base and will not burn the eyes.  While I would not apply them directly to the eye (that’s why we have sunglasses), I would use them on the face and forehead.  Be prepared to hunt around.   Sunscreen sticks are harder to find in stores.  In addition, they are a little greasier then the lotions and sprays.

To summarize, use a waterproof, sweat resistant SPF 30 sunscreen, applying ½ hour prior to exposure and reapplying every two hours.  On the face and around the eyes use a sunscreen stick.  As a coach, I would emphasize this to the players.  A small amount of sunscreen can prevent a significant amount of wrinkles and cancer.

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