Health With a Capital H

App Happy and Sun Safe

July 8, 2011

By Sarah Byrnes, Health Communications Associate II

UV Safety Month

During my childhood in Tucson, Arizona, which boasts more than 350 days of sunshine per year, sun safety was always a part of my health education. From a very young age, my friends and I learned to protect ourselves with sunscreen, sunglasses, long-sleeved shirts, and wide-brimmed hats. I knew from experience (multiple stubborn experiences, in fact) that sunburn was painful, and that was reason enough to prevent prolonged sun exposure. 

However, it wasn’t until I got older that I came to learn that repeated exposure to the sun’s ultraviolet (UV) radiation increased my risk for skin cancer and eye diseases. In honor of UV Safety Month, I want to share what I have learned about UV radiation, tools for tracking the UV Index, and how to protect yourself from excessive UV exposure.

Ultraviolet Radiation—Human Carcinogen

UV rays—UVA and UVB—are a form of radiation emitted by the sun that damages skin cells and eye tissue. Considered “environmental human carcinogens,” UV rays can cause changes and mutations to the skin’s cellular DNA that can lead to cancer. Skin cancer is the most common form of cancer in the United States, and 65 to 90 percent of melanomas are caused by ultraviolet rays.

Excessive UV radiation can also cause cortical cataracts and pterygia, and can suppress the immune system. The World Health Organization’s “Global Burden of Disease From Solar Ultraviolet Radiation” report estimates that 600,000 lives were lost in 2000 due to excessive UV exposure (though the report warns against completely avoiding the sun because zero exposure would create a huge burden of skeletal disease from vitamin D deficiency).

All Days Are Not Created Equal

Knowing how much UV radiation is reaching the Earth each day will help you plan effective sun safety strategies. The Environment Protection Agency’s (EPA’s) UV Index predicts the amount of UV radiation reaching the ground, providing a daily forecast of the expected risk of sun exposure. The National Weather Service calculates the UV Index using a formula that weighs ozone concentration, ground-level strength of solar UV radiation, the ground elevation, and forecasted cloud coverage for each geographic location. The higher the UV Index number, the higher the risk of harmful sun exposure.

You can view the UV Index for all U.S. locations by visiting the EPA SunWise program website and searching by city and state or ZIP code (to view the UV Index for locations outside of the U.S., visit UV Awareness). You can also download a gadget that will display your local UV Index on your iGoogle page.

UV Index at Your Fingertips

Mobile technology makes it easy to keep track of the daily UV index.

  • UV Index Smartphone App (for Blackberry or Android)—EPA adapted its UV Index search functionality into a smartphone app. Simple and to the point, this geo-aware app will retrieve your current location or allow you to search by ZIP code.
  • Sun Safe and UV Index (for iPhone or iPad)—In addition to retrieving the UV Index for your location, these apps allow you to enter your skin type, environment type, weather conditions, and sunscreen level to calculate a safe time for you to be in the sun and alert you when you need more protection.
  • iSunBurnHD (for iPad)—This app gives you the UV Index for your current location or any U.S. city and displays a 4-day national forecast map.

There are also UV Index indicator apps sponsored by skin care companies such Nivea and Coppertone that provide customized suggestions for sun care lotions and send you coupons for their products.

Protect Your Skin and Eyes

  • The efficacy of sunscreen against UVB rays is rated by its sun protection factor (SPF). The National Cancer Institute recommends using a sunscreen with at least SPF 15. Here are some tips for practicing sun safety:
  • Find a broad-spectrum sunscreen that protects against both UVA and UVB rays.
  • In June 2011, the Food and Drug Administration (FDA) announced new rules that go into effect next year for labeling sunscreen to help consumers find products that protect against UVA rays. When choosing a sunscreen, look for FDA-approved, UVA-blocking ingredients such as avobenzone, Mexoryl, oxybenzone, titanium dioxide, and zinc oxide.
  • To find the best rated sunscreen—as well as those you should avoid—search the Environment Working Group’s database of 1,700 sunscreens, SPF lip balms, moisturizers, and makeup (also available as an iPhone app).
  • For those with higher sensitivity to sun exposure, or for those that will be out on days with a high UV Index, wearing sun-protective clothing another way to limit your skin’s exposure to UV rays.

Always wear sunglasses that offer 100-percent UV protection.

For more information on how to reduce your exposure to UV rays, read these tip sheets from FDA, the American Cancer Society, and the Skin Cancer Foundation. Have your own sun safety strategies to share? Let us know in comments.