Sun Protection
Every year, the sun’s rays become stronger. The best that we can do to prevent skin damage from these rays is to avoid them and cover up when we are outside. Many people are confused about proper sun protection. This article will attempt to explain the main points of sun protection.
What causes sunburn?
Sunlight is made up of several kinds of ultraviolet (UV) rays. Ultraviolet B (UVB) rays have a very short wavelength and are blocked by most sunblocks. Even without sun protection, they only affect the very top surfaces of the skin. UVB rays cause the skin to burn and are associated with most skin cancers. Ultraviolet A (UVA) rays have a longer wavelength. They are responsible for aging of the skin, but there is evidence that they may also cause skin cancers. Most windows do not completely block UVA rays, meaning you must be cautious indoors and outdoors. Remember each type of UV ray with this mnemonic:
UVA causes Aging. UVB causes Burns.
What is SPF?
Sun Protection Factor (SPF) is a way to quantify and measure the ability of a material or substance to shield you from the sun. A sun protectant’s SPF is determined by applying a thick layer of the product to the skin and exposing the skin to sunlight. If the skin takes 30 minutes to get as red as unprotected skin would get in one minute, then the SPF of that sun protectant is 30. The main problem with the SPF measurement is that people generally don’t apply a thick layer of sun protection to their skin. Furthermore, the lotion may rub off or wash away after a short period of activity. Most people only apply about one quarter of the recommended amount of sun protectant.
Sunblock versus Sunscreen
A Sunblock is a physical substance (like zinc oxide or titanium oxide) that protects the skin by scattering or reflecting sunlight. A Sunscreen is a chemical (like avobenzone or homosalate) that binds with the skin to absorb light and turn it into heat. A typical sunscreen lotion will combine different types of sunscreen chemicals to improve efficacy and cover different UV ranges.
What is Broad Spectrum Protection?
If a sun protectant covers any part of both the UVA and UVB spectrums it is considered broad spectrum, multi-spectrum or UVA/UVB protection. Almost every sun protectant blocks UVB rays, but a sunscreen can still be called broad spectrum if it does not cover the entire UVA spectrum, as is often the case. Both sunblocks, zinc dioxide and titanium dioxide, cover the entire UVA and UVB spectrum, but to get an effective layer of protection, your skin will look white. Micronized zinc is less white but still visible. Dr. Bennett’s recommended sunscreen combination of avobenzone 3%, ecamsule, and octocrylene cover the majority of the UVA and UVB spectrum and will blend with the skin.
What about free radicals?
Exposure to the sun causes free radicals, which are known to contribute to skin cancer. There is some evidence that the sun hitting certain types of sun protectants may also cause free radicals. Limiting sun exposure is the best way to avoid sun-induced free radicals.
Should I use sunscreen that has an expired date?
No. The ability of a sunscreen to block the sun decreases over time. Similarly, mixing sunscreens can weaken the stability of the lotion. You can apply sunscreen and sunblock together for additional protection, but wait until the sunscreen dries before applying sunblock. Reapply your sun protectants every few hours, or after sweating or swimming.
What else can I do to protect myself?
Minimize your exposure to the sun during the peak sunlight hours of 10 AM to 4 PM). Clothing also provides some sun protection, so wear long-sleeved shirts, long pants, wide-brimmed hats, and polarized sunglasses whenever possible. There are also clothes and hats that are made with built-in sun protectant factors of 30 or more.
Do I need sun protection even if I’m just walking to work?
Absolutely! Even if you are only in the sun for 10 minutes per day, you are still clocking 60 hours of sun exposure every year. UVA rays are strong as long as the sun is up! Dr. Bennett recommends applying a broad spectrum sunscreen (SPF 30 to 55) on every area of your body that is exposed to sunlight, every morning. Let it dry for ten minutes. Neutrogena and other less expensive pharmacy brands should be fine, but look at the ingredients to make sure you are buying an effective sunscreen.
Sun Exposure