UVA & UVB Rays: What's The Difference?

by / Friday, 06 July 2012 / Published in Uncategorized

I have not used a tanning bed since before my Air-Tan days – thank goodness. The amount of people I see with scars from melanoma and scary moles is alot higher than I ever imagined it would be. Last night, I looked at a local tanning company’s website to check out what is new in the tanning bed world – since it has been so long since I have been in that world. WOW, they have some crazy looking contraptions they call tanning beds…

All of the moderate level beds emit mostly UVB rays. One that caught my eye was their “instant” tanning bed. Sounds like instant skin cancer to me, so of course I wanted to learn more about this crazy bed. It emits only UVA rays which give skin a golden glow, instead of redness. I thought, “WOW! A bed that guarantees no burning?! What is the catch?!” I just didn’t understand how someone could get an instant tan from a tanning bed that won’t burn. So then I did some research into the difference between UVA and UVB rays. If UVA rays don’t burn your skin, they must be a lot better for your skin, right? After all, people get skin cancer from being burned, right?!

WRONG!! Thanks to skincancer.org, I educated myself on UVA and UVB rays and what exactly the difference is. They are both extremely harmful and even though UVA rays don’t burn your skin, they actually are FAR more dangerous than UVB rays. Here is what the website had to say…

“The center of this confusion is the sun’s ultraviolet A (long-wave) and ultraviolet B (shortwave) rays. Our understanding of exactly what kinds of damage each causes to the skin, and how best to protect ourselves, seems to shift every year as new research comes out. For example, it was once thought that only UVB was of concern, but we keep learning more and more about the damage caused by UVA. And new, improved forms of protection against UVA keep emerging. Keeping up with these new developments is a worthwhile challenge that can help all of us prevent sun damage.

UV radiation is part of the electromagnetic (light) spectrum that reaches the earth from the sun. It has wavelengths shorter than visible light, making it invisible to the naked eye. These wavelengths are classified as UVA, UVB, or UVC, with UVA the longest of the three at 320-400 nanometers (nm, or billionths of a meter). UVA is further divided into two wave ranges, UVA I, which measures 340-400 nanometers (nm, or billionths of a meter), and UVA II which extends from 320-400 nanometers. UVB ranges from 290 to 320 nm. With even shorter rays, most UVC is absorbed by the ozone layer and does not reach the earth.

Both UVA and UVB, however, penetrate the atmosphere and play an important role in conditions such as premature skin aging, eye damage (including cataracts), and skin cancers. They also suppress the immune system, reducing your ability to fight off these and other maladies.

By damaging the skin’s cellular DNA, excessive UV radiation produces genetic mutations that can lead to skin cancer. Both the U.S. Department of Health and Human Services and the World Health Organization have identified UV as a proven human carcinogen. UV radiation is considered the main cause of nonmelanoma skin cancers (NMSC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). These cancers strike more than a million and more than 250,000 Americans, respectively, each year. Many experts believe that, especially for fair-skinned people, UV radiation also frequently plays a key role in melanoma, the deadliest form of skin cancer, which kills more than 8,000 Americans each year.

Most of us are exposed to large amounts of UVA throughout our lifetime. UVA rays account for up to 95 percent of the UV radiation reaching the Earth’s surface. Although they are less intense than UVB, UVA rays are 30 to 50 times more prevalent. They are present with relatively equal intensity during all daylight hours throughout the year, and can penetrate clouds and glass.

UVA, which penetrates the skin more deeply than UVB, has long been known to play a major part in skin aging and wrinkling (photoaging), but until recently scientists believed it did not cause significant damage in areas of the epidermis (outermost skin layer) where most skin cancers occur. Studies over the past two decades, however, show that UVA damages skin cells called keratinocytes in the basal layer of the epidermis, where most skin cancers occur. (Basal and squamous cells are types of keratinocytes.) UVA contributes to and may even initiate the development of skin cancers.

UVA is the dominant tanning ray, and we now know that tanning, whether outdoors or in a salon, causes cumulative damage over time. A tan results from injury to the skin’s DNA; the skin darkens in an imperfect attempt to prevent further DNA damage. These imperfections, or mutations, can lead to skin cancer.

Tanning booths primarily emit UVA. The high-pressure sunlamps used in tanning salons emit doses of UVA as much as 12 times that of the sun. Not surprisingly, people who use tanning salons are 2.5 times more likely to develop squamous cell carcinoma, and 1.5 times more likely to develop basal cell carcinoma. According to recent research, first exposure to tanning beds in youth increases melanoma risk by 75 percent.

UVB, the chief cause of skin reddening and sunburn, tends to damage the skin’s more superficial epidermal layers. It plays a key role in the development of skin cancer and a contributory role in tanning and photoaging. Its intensity varies by season, location, and time of day. The most significant amount of UVB hits the U.S. between 10 AM and 4 PM from April to October. However, UVB rays can burn and damage your skin year-round, especially at high altitudes and on reflective surfaces such as snow or ice, which bounce back up to 80 percent of the rays so that they hit the skin twice. UVB rays do not significantly penetrate glass.”

WOW. Right??? I thought I knew a lot about sun safety and skin cancer, but I learned alot. It was amazing how glorious that “UVA-only, instant, no-burn” tanning bed seemed on the tanning company’s website. I felt almost tricked once I did my research on what UVA rays actually are. Despite what tanning bed companies tell you…there is NO such thing as a SAFE tan from a tanning bed. Our perceptions of burning, tanning, and how those relate to skin cancer aren’t always accurate and the only way to really practice sun safety and protect ourselves from cancer is to either stay out of the sun or use SPF 15 or higher – and as we all know here at Air-Tan, you will never get skin cancer with an Air-Tan! Be safe. Be smart. Get sprayed!