May is Skin Cancer Awareness Month: How protected are you from the sun’s rays?

It’s estimated that more than 58 million Americans—nearly 20 percent—have had precancerous growths removed from their skin, commonly by cryotherapy (freezing). The reality is that we must be diligent to avoid excess sun exposure.

Without getting too technical in this article, I review the basic types of skin cancer, discuss what SPF is, explain the different damage done by UVA and UVB sun rays, and review the characteristics and importance of broad spectrum products.

When you are done reading it, you will be able to evaluate your current sunscreen and understand just what level protection you have taken.

What are the types of skin cancers?

Per Wikipedia, “Skin cancers… are due to the development of abnormal cells that have the ability to invade or spread to other parts of the body.

“There are three main types of skin cancers: basal-cell skin cancer (BCC), squamous-cell skin cancer (SCC) and melanoma.  The first two, along with a number of less common skin cancers, are known as nonmelanoma skin cancer (NMSC).

“Basal-cell cancer grows slowly and can damage the tissue around it but is unlikely to spread to distant areas or result in death.  It often appears as a painless raised area of skin that may be shiny with small blood vessels running over it or may present as a raised area with an ulcer.

“Squamous-cell skin cancer is more likely to spread.  It usually presents as a hard lump with a scaly top but may also form an ulcer.

“Melanomas are the most aggressive. Signs include a mole that has changed in size, shape, color, has irregular edges, has more than one color, is itchy or bleeds.

More than 90% of cases are caused by exposure to ultraviolet radiation from the sun.

The Skin Cancer Foundation answers some basic questions regarding sun protection. You can learn more at https://www.skincancer.org.

SPF (sun protection factor) is a relative measure of how long a sunscreen will protect you from ultraviolet (UV) B rays. The chief cause of reddening and sunburn, UVB rays tend to damage the epidermis, the skin’s outer layer, where the most common (and least dangerous) forms of skin cancer occur.

Does a sunscreen with a high SPF (sun protection factor) protect skin better than one with a lower SPF? How high should I go?

Ultraviolet light is invisible to humans, because it has shorter wavelengths than the light we can see. Within the UV spectrum, there are two types of rays that can damage the DNA in your skin cells and lead to skin cancer. It’s important to protect your skin from both types:

• UVB rays cause sunburn and play a key role in developing skin cancer. A sunscreen’s SPF number refers mainly to the amount of UVB protection it provides.
• UVA rays cause skin damage that leads to tanning as well as skin aging and wrinkles. The shortest wavelengths of UVA rays also contribute to sunburn. It’s important to look for the words “broad spectrum” on the label, which means the product has ingredients that can protect you from UVA as well as UVB rays.

What Does the SPF Number Mean?

The SPF number tells you how long the sun’s UV radiation would take to redden your skin when using the product exactly as directed versus the amount of time without any sunscreen. So ideally, with SPF 30 it would take you 30 times longer to burn than if you weren’t wearing sunscreen.

An SPF 30 allows about 3 percent of UVB rays to hit your skin. An SPF of 50 allows about 2 percent of those rays through. That may seem like a small difference until you realize that the SPF 30 is allowing 50 percent more UV radiation onto your skin.

Under ideal conditions (like in a laboratory), a sunscreen with higher SPF protection and broad-spectrum coverage offers more protection against sunburn, UVA damage and DNA damage than comparable products with lower SPF values.

But, real life is not like a lab. In real life, products with high SPFs often create a false sense of security. People who use them tend to stay out in the sun much longer. They may skip reapplying. And they may think they don’t need to seek shade, wear a hat or cover up with clothing. They end up getting a lot more UV damage, which, of course, defeats the purpose.

For people who have a history or high risk of skin cancer, genetic diseases such as albinism or xeroderma pigmentosum or certain immune disorders, SPF 50 may not be enough. Same goes for certain scenarios, such as hiking or skiing at high altitude or vacationing near the equator.

The Skin Cancer Foundation recommends a water-resistant, broad-spectrum sunscreen with an SPF of 30 or higher for any extended outdoor activity. Regardless of the SPF, though, it’s important to apply one ounce (two tablespoons) 30 minutes before going outside and reapply it every two hours or immediately after swimming or sweating.

What is the best overall strategy to protect my skin?

Here’s the answer: It’s important not to rely on high-SPF sunscreens alone. No single method of sun defense can protect you perfectly. Sunscreen is just one vital part of a strategy that should also include seeking shade and covering up with clothing, including wide-brimmed hats and UV-blocking sunglasses.