The sun is wonderful – it promotes life, improves our mood and allows us to make vitamin D. But this comes at a cost. Sunlight contains ultraviolet radiation, which results in damage to the skin and DNA leading to burns, color changes and cancer.
There are two types of UV radiation from the sun – UVA and UVB. Nearly 95% of the radiation reaching the earth is UVA (UVA1 + UVA2), which causes increased pigmentation (sun spots) and aging (wrinkles) in skin as well as may be involved in the processes leading to skin cancers. UVB radiation, while less of the overall radiation, has been found to be responsible for burning, inflammation and cancers of the skin.
Protecting your skin from sun now can prevent cancerous changes in the future. In addition, you can keep your skin smoother and reduce sun-related dark spots by being diligent with the protection now.
SPF (Sun Protection Factor) – This measures the sunblock’s effectiveness in protection against UVB only when compared to not wearing sunblock. Theoretically, the SPF is a measure of how much longer you can stay in the sun before burning. But, people in real life don’t apply the sunblock in the same way it was applied in the actual studies – real people actually use approximately 1/3 the amount expected. Also, real people sweat, and go in the ocean / pool or wipe the water off their face taking some of the sunblock with it. And, remember the SPF only measures the protection against UVB.
So, while the SPF does matter, it also is important to pick out the right sunblock and apply it correctly. An SPF of 15 will protect against 93% of UVB radiation, SPF of 30 against 97%, SPF of 50 against 98%. So that SPF of 100, which sticks to your skin for days is not really getting you any more protection than the SPF 50, and providing much more irritation to your skin than likely necessary.
Spectrum – This tells whether the sunblock protects against UVA and/or UVB radiation. Remember that the SPF already tells you that there is UVB protection. Now, you need to make sure there is UVA protection as well. Only three ingredients will protect against UVA1: avobenzone, zinc oxide, titanium dioxide. Avobenzo will come combined with other ingredients to ensure entire UV spectrum protection, as it does not provide full coverage alone. Zinc and titanium are mineral compounds that reflect a wide range of UV wavelengths and are considered broad spectrum independently, however they are often combined with other ingredients, both for efficacy and cosmetic reasons (remember the lifeguards with white noses?). But if you tend to sensitive skin, limiting the chemical components can be helpful and a sunblock containing just zinc oxide or titanium dioxide would be a good choice for broad spectrum coverage with a single ingredient.
Form – If you wear it, it will work. It doesn’t work sitting in your beach bag. Spray, cream, lotion, stick, whatever. Put it on.
Application – Apply 20 minutes prior to the sun exposure and every two hours thereafter. Also reapply if you’ve been in water or wiped off water or sweat. The SPF is tested at 2 mg/sq cm, but no reasonable person knows how much that is when applying sunblock. An adult should use approximately a fully a shot glass full to cover his/her body (more relatable?).
Water-resistant – In order to be labeled as “water-resistant” the sunblock has to stay strong for 40 minutes in the water. That’s it. How many of you go to the beach and spend 40 minutes in the water? Make sure you reapply! The “very water-resistant” sunblock gets 80 minutes.
Is sunblock safe?
Sunblocks have an excellent safety profile. Most of the issues related to sunblock are skin irritation and / or allergic reactions. Fortunately, since there are so many formulations available, a person with sensitive skin can find a manufacturer they can handle.
More recent concerns have been raised with the use of titanium dioxide and zinc oxide nanoparticles (for cosmetic reasons) in sunblock and the possible absorption through the skin. Studies show that use of these components do not cause toxicity and the nanoparticles do not penetrate the outer layer of skin, which is composed of dead cells.
With sunblock use, your body will be unable to synthesize its own vitamin D. Fortunately, vitamin D is readily available as a supplement at your local pharmacy, grocery store, big box store and likely gas station these days.
Ultraviolet protection factor (UPF) – This is an international classification system to identify how well a fabric blocks out ultraviolet radiation. The UPF depends on several factors: type of material, tightness of weave (most important), color, stretch, moisture, conditions, additional treatments. Garments marked with UPF have built in photo-protection.
Laundry additive – Make your own UPF clothing by adding a package of sun blocking agent such as “SunGuard®” to your washer.
The Skin Cancer Foundation has a seal of recommendation on products they have reviewed and tested for sun protection. http://www.skincancer.org/prevention/seal-of-recommendation
Shade – Shade is better than direct sunlight, but remember that UV radiation can reach the skin indirectly as well. UV radiation can scatter and bounce through clouds, off sand, off concrete, etc.
Hats – Stylish and protective.
Sunglasses – Don’t forget sun can damage your eyes too.
We live on a beautiful island. With occasional beautiful weather. Enjoy the sun safely now and avoid skin biopsies later!