Sun Protection
By Kimberly Royal, D.O.
Certified by the American Board of Internal Medicine
419-289-6357
We all enjoy getting outdoors for various activities, and with that, of course, comes the potential hazards of sun damage and burns from the sun’s ultraviolet rays. Ultraviolet A and B cause the most problem. Excess sun exposure has been shown to increase one’s risk of various skin cancers.
To prevent over exposure, it’s important to keep the following two things in mind; one’s susceptibility to sunburn which would include fair skin, light colored hair, history of sunburn with limited exposure to sunlight and the use of photosensitizing medications such as aspirin-like products, tetracyclines, certain diuretics, etc. One can check with the pharmacists whether any drugs they are taking increase sensitivity.
There are many ways to prevent damage from the ultraviolet rays which include seeking shade when appropriate, and trying to avoid the peak hours of the sun, which is 10 a.m. – 4 p.m. Also, shady days don’t necessarily provide less effect from the ultraviolet rays. Clothing can provide protection including the use of wide brimmed hats, sunglasses, and loose fitting clothing with long sleeves and pants. Darker fabrics tend to provide greater protection and some manufacturers have begun producing sun protective clothing with a minimum SPF, as well as UV absorbing agents that may be applied to clothing during laundering.
Sunscreen is also one of the main treatments for sunburn prevention. They protect the skin by absorbing or reflecting UV radiation. SPF, which stands for sun protection factor, in actually a measure of the ability of an intervention to prevent redness in response to sun exposure. The SPF can be multiplied by the time of exposure necessary to produce minimal redness in an unprotected individual. As an example, if an unprotected individual develops minimal redness after 20 minutes of sun exposure, then use of an SPF of 15 sunscreen would expect to reduce minimal redness after 300 minutes of sun exposure. One of the problems is that the SPF may not be fully protective if the individual is applying inadequate amounts of lotion or not applying it at frequent enough intervals.
Sunscreens are frequently classified as either physical/inorganic or chemical/organic sunscreens. Physical sunscreen typically contain large particulate substances which may include titanium dioxide, zinc oxide, talc, etc., which serve to reflect and scatter both physical and UV light. These sunscreens do a good job in protecting against broad spectrums of light, but they are aesthetically unappealing and may stain clothing.
Chemical sunscreens absorb rather than reflect UV radiation, and they typically have a limited spectrum of protection. In the past, chemical sunscreens have acted primarily to absorb only UVB radiation. More recently, increasing attention on the importance of protecting against UVA exposure has led to development of chemical sunscreens acting to absorb these wave lengths as well. Ideal sunscreen products protect against UVB and UVA.
Sunscreen should be uniformly and liberally applied approximately 15-30 minutes before sun exposure and using a liberal amount is important, as well as applying in all areas. While reapplication every 2-3 hours has traditionally been recommended, some evidence suggests that reapplication as soon as 20 minutes after initial application may offer greater protection. Of course, sunscreens that are not water resistant or waterproof require more frequent applications. Keep in mind that chemical sunscreens may degrade over time, and exposure to high temperatures (example, car and beach) may speed the process. Sunscreen manufacturers and others recommend not using sunscreen that is past the expiration date listed on the bottle. If a sunscreen does not have an expiration date, a typical recommendation is to dispose of the sunscreen after three years.
Finally, a word about tanning and tanning beds. It’s generally felt by the scientific community that these pose a threat and will increase the risk of skin damage and skin cancer over time.
