Makeup Down Under

As I mentioned in the answer to Marlene Ward’s question on Monday, the ozone layer and clothing does help in protecting us from the sun’s damaging rays. The degree to which these two “sunscreens” help depends on location and composition.

The ozone is thickest at the north and south poles and is the thinnest at the equator. Ultraviolet ray intensity increases about 10% with every 1,000 feet of elevation above sea level. Therefore, Denver, the Mile High City, 5,280 feet above sea level, has a higher intensity of UV rays due to its altitude versus New Orleans, which is at sea level.

The sunscreen benefit of clothing is related to the thickness, type of fiber, weave, stretch, color, and other factors. A point of interest is the fact that nylon stockings have an SPF of only 2 to 3.

It is important to remember that fog and clouds only reduce UV intensity about 30% and that UV protection is needed even on cloudy days.

Don’t be fooled by window glass and sunglasses. UVB rays (the sunburn rays) are blocked by glass, but the UVA rays (the longer wavelength UV rays) pass through window glass and sunglasses and can damage the skin and eyes.

All the news is not bad. There have been advances. Environmental regulations have improved the thickness of the ozone layer. Clothing has been manufactured to provide sun protection, some chemically treated with sunscreen agents. Glass has been thickened, polarized, and tinted to increase its sun protective properties. Many cosmetic products contain pigment and sunscreen ingredients, which increase their sun protection ability to an SPF 3-15, based on the product.

When you are preparing to go out in the sun and applying your sunscreen products and/or apparel, keep in mind a couple places that some people neglect and then suffer the consequences later. The scalp can definitely burn…and I’m not just speaking of those with no hair. The sun can penetrate your hair and melanomas could occur yet be hidden under your hair. It’s best to wear a hat made from a tightly woven fabric or even a hair product with SPF in it.

Another overlooked spot is the rims of your ears. According to the Skin Cancer Foundation, the two most common forms of skin cancer (basal and squamous-cell carcinoma) are primarily found on ears. Be sure to apply your sunscreen to your ears as part of your application routine.

Now that spring…and soon summer…is upon us, be sure you are diligent in protecting yourself from the damage that can be done by UVB and UVA rays. Use your sunscreen each and every day!

Hello, Dr. Samuels. I am very confused about sunscreens. Is the SPF of the sunscreen more important than the ingredients or is there something else I should know about sunscreens? (Marlene Ward)

Marlene, as I’m sure you already understand, ultraviolet rays from the sun or tanning beds are what cause photo-damage to your skin (rough texture, blotchy skin color, brown spots and wrinkles), as well as skin cancer. UVB rays damage the surface of your skin, while the UVA rays are those that penetrate below to damage elastin and collagen, contributing to premature aging from within. No matter what SPF or sunscreen you decide on, I want to emphasize the need for sunscreen application every day. This is where prevention begins.

Let me first mention that screening of UVB rays is done not only by topical sunscreens, but also is aided by the ozone layer and clothing, as well. (For more detailed and interesting information on UVB and UVA protection, watch for my next blog post on Thursday.)

SPF (Sun Protection Factor) is a value given to a sunscreen which indicates its ability to block UVB rays. The higher the SPF, the greater the protection from damaging UVB rays…but not UVA rays. However, it is important to note that an SPF 35 absorbs 97-98% of the UVB rays; and an SPF 50 absorbs 98-99% of the UVB rays. The bottom line becomes that there is not much extra protection beyond an SPF of 35. To this end, there are broad spectrum sunscreens on the market for everyday use that can provide adequate protection.

The sunscreen ingredients that block UVA rays only work for a short time when applied to the skin. However, micronized zinc oxide and titanium dioxide are both stable UVA blockers and have excellent reflective properties to help prevent UVA rays from penetrating and causing damage beneath your skin’s surface.

So the answer to your question, Marlene, is that the SPF and the ingredients are equally important. An effective sunscreen should have an SPF of at least 35 for the face and contain several sunscreen ingredients including zinc oxide or titanium dioxide. Our Facial Moisturizer SPF 35 with transparent zinc oxide, additional sunscreen ingredients, and antioxidants is an example of this type of product.

If you have any other questions about sunscreens or sun damage, please comment below or visit my Facebook page and ask your question there. I will answer it here on my blog as soon as I can.