Sun Protection: Questions and Answers
Dr. Richard J. Ort, M.D.
Board Certified Dermatologist
Fellowship Trained - Harvard University
The most important step we can all take in skincare is protecting ourselves from the harmful effects of the sun's ultraviolet (UV) rays. Any dermatologist would agree that the smartest ways to protect yourself is to limit your intense sun exposure during the peak hours of 10am-2pm, wear protective clothing and hats when possible, wear sunglasses that block UV light, generously apply a broad-spectrum sunscreen to all our exposed skin, and avoid artificial tanning beds. Sun protection and sunscreen use can be an overwhelming subject, so here are the answers to some of our patients’ most common questions:
Why use sunscreen?
- Ultraviolet light from the sun and tanning beds cause skin cancer and age our skin
- 1 in 5 Americans will develop some form of skin cancer during their lifetime
- More than 3.5 million skin cancers are diagnosed in the United States every year
- Sun exposure and tanning bed use is the most preventable risk factor for skin cancer, including melanoma
What is Sunscreen?
- Sunscreen is a topical product that either absorbs or reflects the UV rays from the sun and thus prevents sunburn, sun damage, skin cancer, and photo-aging of the skin
- Sunscreen agents (or the “active ingredients” on any sunscreen product) fall into two major categories:
Sunscreens are further classified by how much or what type of UV light they absorb or reflect
Most sunscreen products contain 2 or more sunscreen agents
- Organic or Chemical sunscreens, which work by absorbing UV light
- Inorganic or Physical sunscreens, which work by reflecting or scattering UV light (titanium dioxide or zinc oxide)
What does “SPF” mean and does the number matter?
- SPF stands for "sun protection factor" and is a direct measurement of protection from the UVB rays, which are the UV rays that cause sunburn
- The higher the SPF, the more protection from UVB rays
- An SPF 15 sunscreen blocks 93% of the sun's UVB rays; SPF 30 blocks 97% and SPF 50 blocks 98%
- The American Academy of Dermatology (AAD) recommends the use of a sunscreen with a SPF of 30 or higher
What does "broad-spectrum" mean?
- UV radiation or light is classified into UVA, UVB and UVC rays by the wavelength of light
- UVC is absorbed by our ozone layer and does not reach the earth
- UVA (long-waves) and UVB (short rays) reach our skin and eyes and play a role in premature skin aging, eye damage (including cataracts), and skin cancers by directly damaging the DNA in our skin cells
- You need to choose a sunscreen that is labeled "Broad-spectrum" or "UVA/UVB protection" to be certain you are getting adequate UVA protection
- Be certain that your choice of sunscreen contains at least one of these UVA blockers: avobenzone, ecamsule (a.k.a. MexorylTM), titanium dioxide, and zinc oxide
- Zinc Oxide is the broadest spectrum sunscreen ingredient available!
How much and how often?
- Sunscreen should be applied 15-30 minutes before sun exposure since chemical sunscreens need to be absorbed before they can protect skin from UV light!
- Apply a generous layer of sunscreen to all exposed skin, but it is recommended that an adult use 1 ounce (or 2 tablespoons) of sunscreen for a full body application
- Apply sunscreen every 2 hours or immediately after swimming, excessive sweating or toweling off!
- Sunscreen should be applied to dry skin to allow for proper absorption
- Sunscreens are labeled as "water-resistant" or "very-water resistant" which means they are tested to maintain their effectiveness with 40 or 80 minutes of water exposure
Hats and sun protective clothing...what is the UPF rating?
- Clothing and hats are the BEST form of sun protection!
- Many clothing items marketed for sun protection are labeled with a UPF rating which stands for "UV protection factor"
- UPF indicates the fraction of the sun's UV rays that can penetrate the fabric
- A shirt with a UPF of 50 lets just 1/50th of the sun's UV rays reach the skin, (compared to a white cotton T-shirt, which has a UPF of about 5!)
Why are tanning beds so bad for you?
- Tanning beds primarily emit UVA rays, which are the dominant tanning ray, penetrate deeper into the skin, cause skin aging and wrinkling, and cause skin cancer
- UV light is a known carcinogen (cancer-causing agent)
- The sunlamps used in tanning salons emit doses of UVA as much as 12 times that of the sun
- 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, which are the two most common types of skin cancer
- People who use tanning salons are 74% more likely to develop melanoma than those who have never tanned indoors
Sun protection and your kids
- Babies and children are extra sensitive to the harmful effects of the sun's UV rays!
- Just one blistering sunburn in childhood more than doubles a person's risk of developing melanoma later in life!
- Like all healthy habits, it's best to start young and lead by example! Make sun protection an easy, daily habit for kids starting when they are babies and toddlers so that it doesn't have to interfere with a healthy, active lifestyle.
- Babies under 6 months should NEVER be exposed to the sun - when outside, keep their skin covered or shaded and avoid sunscreen use if possible since it is not tested in infants less than 6 months of age
- Sun protection can become more challenging in older infants and toddlers
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