The Science of Sun Exposure for Your Skin

Sun-exposed skin, regardless of our age, can gradually lose moisture and essential oils. Avoid long-term damage in your outdoor work.

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Barbara Jackson

When there’s no alternative to working outside during summer while the sun is at its peak, exposed skin, regardless of the level of pigment, is most susceptible to sun damage between the hours of 10 a.m. and 4 p.m. Over a lifetime, sunburn and unprotected sun exposure can significantly increase a person’s risk of malignant melanoma and other forms of skin cancer.

Sun-exposed skin, regardless of our age, can gradually lose moisture and essential oils, making it appear dry, flaky, and prematurely wrinkled. Sunburn is a common name for skin injury that appears immediately after skin is exposed to UV radiation. In mild cases, sunburn causes only painful reddening of the skin. In more severe cases, tiny fluid-filled bumps (vesicles) or larger blisters appear.

Actinic Keratosis and Longer-Term Sun Damage

Over time, actinic keratosis may develop. This is a tiny bump that feels like sandpaper or a small, scaly patch of sun-damaged skin that has a pink, red, yellow or brownish tint.

Actinic keratosis doesn’t generally go away unless it’s frozen, chemically treated or removed by a physician. This condition may develop in areas of skin that have undergone repeated or long-term UV sunlight exposure. Approximately 10% to 15% of these cases change into squamous cell cancers of the skin.

As a rule, persons with fair skin and light eyes are at greater risk of sun-related skin damage and skin cancers. That’s due to the fact that their skin contains less melanin (a pigment). Melanin helps protect skin from the effects of UV radiation.

Protect Skin from the Effects of Ultraviolet Radiation

  1. Apply sunscreen before going outdoors. Select a water-resistant sunscreen with a sun protection factor (SPF) of 30 or above. The product should have a broad spectrum of protection against both UV-A and UV-B rays. To avoid sweating off or washing off the sunscreen, reapply it often.
  2. Use sunblock product on your lips that has been especially formulated to protect lips and has a SPF factor of 20 or more.
  3. As much as possible, limit your time outdoors when the sun is at its peak (10 a.m. to 4 p.m.) in most parts of the continental U.S.
  4. Wear sunglasses that provide 99% – 100% UV protection. Wraparound sunglasses provide an extra measure of protection
  5. Wear long pants, a shirt with long sleeves and a wide-brimmed hat.
  6. Be aware that some medicines and skin care products can increase the risk of UV damage to your skin. These include certain antibiotics as well as some prescriptions used to treat psychiatric illness, high blood pressure, heart failure, acne and allergies. If you take prescription drugs and normally spend a great deal of time out of doors, ask your health care professional whether you need to take additional precautions to avoid sun exposure. Certain nonprescription skincare products containing alpha-hydroxy acids can make skin more vulnerable to sunlight damage.

For additional sun protection details, visit this informative article from and the CDC’s guidance.

Loretta Sorensen writes from her home in southeast South Dakota, where she regularly develops agricultural safety and health articles for the Central States Center for Agricultural Safety and Health (CS-CASH) at the University of Nebraska Medical Center. Connect with Loretta on Facebook and Twitter.

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