A quick guide to UV radiation
As part of its essential place in our existence
on planet Earth, the sun fuels the process of plant photosynthesis that is the basis of the food chain that supports human life. The same plants that give us food also give us oxygen. Traveling 93,000,000 miles through space, the sun's rays create an endless supply of alternative energy while also keeping the earth's temperature from plummeting. It's also a source of vitamin D. And don't forget those beautiful sunrises and sunsets.
Let's hear it for the sun! But let's also remember that too much of a good thing can be a problem, particular when it comes to overexposure – and it's a problem that includes premature skin aging, skin cancer and skin growths, eye damage and suppression of the immune system.
The good news is that with some planning and a bit of close attention we can peacefully co-exist with the sun and enjoy its many gifts. Toward that objective, here are a few things to keep in mind.
What you should know
The difference between UVA and UVB radiation: Ultraviolet radiation is differentiated by its wave length and is designated as either UVA or UVB. There are also UVC rays but the ozone layer keeps them from reaching the surface of our planet. UVA and UVB rays, however, are only partially absorbed and otherwise make it all the way down to our bodies.
The UVA beams penetrate deeply into the skin, and are the type of ultraviolet radiation that causes sunspots, wrinkling or leathering of the skin, what we often refer to as photo aging. UVA rays are so powerful they can penetrate through some clothing and even glass. UVB is the type of radiation that causes sun burns and skin cancer. While large doses of UVA rays can also contribute to a higher risk for cancer, it's the UVB rays that do the most damage in that area. The important thing is to protect yourself against both forms of radiation.
When is UV radiation at its highest? UVA rays are the same strength year round. UVB radiation is more prevalent in the summer and is at its most dangerous levels when the sun's rays are strongest, usually from 11:00 am to 4:00 pm. Both forms of UV rays are also at high levels near surfaces that reflect light such as water, sand and snow and reflective light is even more intense.
UV risk factors: The damage from ultraviolet rays is related to everything from length of exposure, latitude and season to degree of skin pigmentation so some people are at higher risk than others. That higher risk contingent includes Caucasians who get sunburns easily or frequently. The fact is, however, that while the risk of skin cancer is not equal, everyone should take precautions and regardless of skin color, the potential for eye damage to overexposure is the same for everyone.
What you should do
Put on the sunscreen: Not all that long ago, just in time for last summer actually, the U.S. Food and Drug Administration created new sun protection factor (SPF) guidelines for products being used as sunscreens. These new guidelines are designed to help consumers reduce the risk of skin cancer as well as sunburn and premature skin aging. They also tighten the documentation requirements on the substitutes for creams or lotions, like sprays or wipes. Now that the packaging information on sunscreens is a little more accurate and straightforward, it's especially important to read it before making a selection.
Basically, sunscreens provide protection by prolonging the amount of time it takes for the sun's rays to adversely affect the skin. It is important to note that in the updated guidelines, sunscreen must be applied more frequently and doesn't have the same degree of "sweat proof" or "waterproof" qualities that the manufacturers once claimed. Regarding the SPF number, the longer the amount of time that you plan to spend outdoors, the higher your sunscreen's SPF should be. The best advice is to carefully read the guidelines and always use sunscreen – along with other sun protection measures – when you're spending anything other than a very short time outdoors.
Get in the shade: You've got to figure that getting out of the hot sunlight and into the cooler shade is the original strategy for protection from UV radiation, long before anyone knew what UV radiation was. After all the millennia of shade seeking, it still works. When natural shade is at a minimum create your own with pop-up shelters, umbrellas and wide-brimmed hats. And don't forget that pets need shade, too.
Wear your sunglasses: UV rays can damage your eyes as well as your skin, and even short periods of unprotected time in the sun can cause a problem. For more information, read the article in the month's My Healthy Lifestyle newsletter on the value of sunglasses and what to look for – it's called "For Your Eyes Only."
Check the UV index: The UV Index is a forecast that lets you know if you are at risk for overexposure to the sun. Index levels range from two to 11+, where level two is low risk and levels six and above are high risk. Check the UV index in your area before you go out so you can protect yourself accordingly. The index can be found online at www.epa.gov/sunwise/uvindex.
- Return to Newsletter Home