by Chrysann Rudig

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Summer is here in full glory, and what a beautiful one it is! Mother Nature has been generous to Coastsiders this year; the many days of sunny blue skies have been a welcome departure from our customary fog. But fog or sun, it’s important to be wise about the risks of sun exposure and savvy to smart solutions. How much do you know about effective sun protection?

Five percent of the solar rays that reach the earth are ultraviolet. Sunscreen products were first developed to protect us from UVB rays, which are responsible for sunburn. But the longer UVA rays, which make up the largest percentage of UV radiation, penetrate deeply into the dermal layer; these are the rays primarily responsible for wrinkling and accelerated aging of the skin. And both UVA and UVB rays can contribute to the development of skin cancers.

Sun Protection Factor is a metric relating to a product’s ability to protect against UVB rays, but an SPF rating provides no information about how well a product protects against UVA rays. A sunscreen is referred to as “broad spectrum” when it contains ingredients that block both UVA and UVB rays, although there is no metric for measuring protection against UVA.

When using a sunscreen with an SPF rating of 15, a person who would typically sunburn in 10 minutes can stay out 15 times longer without burning, or approximately 150 minutes. However, this is just an estimate; the actual times will be influenced by a person’s skin type, the intensity of the sun, and the type of activities performed in the sun. Also, the SPF scale is not linear; the difference between SPF 30 and SPF 50 is not significant. According to the Environmental Working Group, a sunscreen rated SPF 50 only blocks about 1.3 percent more UVB radiation than one rated SPF 30.

Sunscreen products generally fall into two categories: chemical sunscreens and physical sunscreens. Chemical sunscreens penetrate the epidermis; the UV rays also penetrate the skin, and are then absorbed by the chemicals. The active ingredients in chemical sunscreens are toxic and many are known to cause damage to DNA. In addition, chemical sunscreens raise the temperature of the skin, which may exacerbate skin conditions such as rosacea, causing increased inflammation due to chemical irritation and increasing redness by expanding already enlarged blood vessels.

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Physical sunscreens contain minerals such as zinc oxide or titanium dioxide, which form a reflective barrier on the skin, thereby protecting the skin from both UVA and UVB rays, as well as heat and chemicals. Physical sunscreens are preferred because of their ability to protect the skin. Physical sunscreens may be water resistant, but chemicals are required to make a sunscreen truly waterproof.

The American Cancer Society recommends using a sunscreen with an SPF of at least 15. To improve your sunscreen’s protection, increase both the frequency of application and the volume of product applied. It is estimated that most Americans use only one-fourth to two-thirds of the amount of sunscreen required to achieve the SPF rating printed on the product’s package. The FDA recommends applying one ounce — about a palmful — evenly to all exposed skin. Sunscreen is one instance where more is definitely better.

According to the American Cancer Society, sunscreen should be applied early, regularly and generously. The first application should be 30 minutes prior to sun exposure. At least one study suggests that sunscreen works more effectively when applied again 15-30 minutes after sun exposure begins. Regardless of the SPF rating, all sunscreens must be reapplied every two hours, or immediately after water activities, heavy perspiration or toweling off.

Children have special sunscreen needs, as they are more vulnerable to chemicals and the sun. It is generally advisable to avoid using sunscreen on children under 6 months unless sun exposure cannot be completely avoided through the use of shade or clothing (including hats).

It is important to remember that the best sun protection program begins by minimizing sun exposure during the sun’s most intensive hours — between 10 a.m. and 4 p.m. — and by wearing adequate protective clothing. Add to that a consistent daily physical sunscreen habit — yes, even on those foggy and cloudy days — and you will enjoy the sun while slowing the aging process and protecting your health and immunity.

On the Web:

www.ewg.org/newsrelease/which  sunscreenssafest

www.cosmeticsdatabase.com/faq.php

Chrysann Rudig is a licensed  esthetician and the owner of  Abundance, a skin care studio in Half Moon Bay. You can reach her at 650-560-9600, or e-mail chrysann@abundanceSKINcare.com.