Sail shades and canopies can help block UV radiation.

The summer of 2012 will likely go down as one of the harshest seasons in recent memory, thanks to record heat waves and droughts across much of the United States. And though the summer sun may seem punishing, the same techniques for preventing and treating sunburns still hold true. But avoiding sunburns effectively comes from knowing their causes.

What Is Ultraviolet B? Is It Helpful or Harmful to the Body?

The answer is actually more complicated than a simple “yes” or “no” response can provide.

Sunburns are caused by exposure to the ultraviolet radiation classified by scientists as Ultraviolet B (UVB.) Though possessing a smaller wavelength and remaining much less pervasive in our atmosphere than Ultraviolet A radiation (UVA), overexposure to UVB rays can cook the uppermost layers of skin tissue, producing reddening and sunburns. Prolonged overexposure to UVB rays can cause skin cancer, premature aging, and possibly contribute to even more serious health issues.

However, UVB intake helps the body synthesize Vitamin D from cholesterol. Vitamin D is a vital nutritional supplement that is shown to benefit the immune system and to help produce bone mass, among other important benefits.

What is Ultraviolet A? What Are Its Potential Risks?

Ultraviolet A radiation has a longer wavelength than UVB rays, and strikes in much greater amounts: UVA accounts for fully 95 percent of all ultraviolet radiation that reaches the Earth’s surface. UVA rays can penetrate windows and clouds, and are prevalent during daytime hours all year round.

Recent research suggests that UVA rays can suppress the immune system and even initiate some forms of skin cancer. UVA rays cause tanning, and the cumulative effects of tanning – itself the body’s flawed attempt to counteract exposure to UV radiation – produce mutations that can lead to skin cancer.

When Is the Risk of Sunburn Greatest?

The Earth’s surface experiences the most exposure to UVB rays between 10 AM and 4 PM each day, especially during the months of April through October. Snow and ice, especially at high elevations, can reflect up to 80% of UVB rays back into the atmosphere. Sand can also reflect ultraviolet light. Unlike UVA rays, Ultraviolet B radiation cannot penetrate glass. Canopies and tents that are treated against ultraviolet exposure can also help to deflect the rays from passing through their material.

Who Faces The Greatest Risks From UV Exposure?


Snow can reflect up to 80% of UVB rays back towards the atmosphere.

Everyone. The World Health Organization reports that, despite a common misconception that only fair-skinned people are at danger of damage from UV radiation exposure, people of all races are at risk for skin cancer. Skin problems among darker-skinned people are also often diagnosed much later, when the health risks have grown more serious.

Sunburns can often happen quite quickly. SunSmart, the Australian skin cancer education effort, reports that very fair-skinned people can burn in less than eleven minutes.

How Can I Monitor Ultraviolet Radiation Levels?

The United States Environmental Protection Agency publishes a daily index of ultraviolet radiation in local areas. It’s available at their UV Index Web page.

How Can I Protect Against Sunburn And Other Health Risks?

Skin care experts recommend wearing clothing and UV-blocking sunglasses, especially during the high-exposure times described above, and staying in shaded areas as much as possible. Bright-colored and more lustrous clothing better reflects sunlight, and loose-fitting, tightly woven clothes provide a better barrier between skin and sunlight.

Which Sunscreens Work Best?


Avoid direct sunlight during peak daylight hours.

The American Academy of Dermatology recommends using water-resistant sunscreens with a Sun Protection Factor (SPF) of 30 or greater. SPF classifications measure only UVB blockage; as yet, there’s no way to measure blockage of UVA rays. Nevertheless, the sunscreen should provide broad-spectrum protection, meaning it shields against both UVA and UVB rays. Sunscreen should even be applied on cloudy or semi-cloudy days, and when standing under shade or on sand.

Fair- and sensitive-skinned people should look for sunscreens with higher SPFs. They may also wish to use “inorganic sunscreens” that contain zinc oxide and titanium oxide; these mineral-based sunscreens protect the skin without penetrating it, which may cause irritation.

How Often Should Sunscreen Be Applied?

Apply liberal doses of sunscreen every two hours, beginning about fifteen minutes before going outdoors. Parents should consult a pediatrician before applying sunscreen to children under six months.

Extra sunscreen should be applied for prolonged periods of exposure. As a general guideline, sunscreens have a “shelf life” of three years.

How Can I Safely Treat Sunburn and Its Symptoms?

Most first-degree sunburns heal themselves within a few weeks; as the skin regenerates, old skin shells are shed off in flakes. Pain and discomfort from the burning can be managed with cold showers, aspirin and ibuprofen, lotions and ointments containing aloe vera, and by applying hydrocortisone cream. Experts also recommend drinking extra water to help the skin rehydrate.