Understand how to benefit from sunlight — and protect yourself from it
By Mark A. Mahoney
I recently returned from a wonderful backpacking trip to California and will be writing soon on the benefits of physical activity relative to my sense of well-being and mental health. The serenity produced by hiking and camping within the Ansel Adams Wilderness of the high Sierra Nevada mountains post-pandemic produced some significant benefits.
However the focus of today’s column is a precautionary on focusing on ultraviolet radiation (UV) as I returned with slight sunburn on the front side of my body.
Ultraviolet (UV) radiation is a form of non-ionizing radiation that is emitted by the sun and artificial sources, such as tanning beds. While it has some benefits for people, including the creation of Vitamin D, it also can cause health risks.
Our natural source of UV radiation is the sun.
Some artificial sources of UV radiation include:
- Tanning beds
- Mercury vapor lighting (often found in stadiums and school gyms)
- Some halogen, fluorescent, and incandescent lights
- Some types of lasers
Different types of UV radiation rays
UV radiation is classified into three primary types: ultraviolet A (UVA), ultraviolet B (UVB), and ultraviolet C (UVC).
All of the UVC and most of the UVB radiation is absorbed by the earth’s ozone layer, so nearly all of the ultraviolet radiation received on Earth is UVA. UVA and UVB radiation can both affect health.
Even though UVA radiation is weaker than UVB, it penetrates deeper into the skin and is more constant throughout the year.
Benefits and risks of UV radiation
Beneficial effects of UV radiation include the production of vitamin D, a vitamin essential to human health. Vitamin D helps the body absorb calcium and phosphorus from food and assists bone development. There is also evidence it helps prevent or mderate disease, duch as the Covid-19 virus.
To maintain healthy blood levels, aim to get 10 to 30 minutes of midday sunlight, several times per week.
Risks of overexposure to UV radiation include:
- Sunburn is a sign of short-term overexposure, while premature aging and skin cancer are side effects of prolonged UV exposure.
- Some oral and topical medicines, such as antibiotics, birth control pills, and benzoyl peroxide products, as well as some cosmetics, may increase skin and eye sensitivity to UV in all skin types.
- UV exposure increases the risk of potentially blinding eye diseases, if eye protection is not used.
- Overexposure to UV radiation can lead to serious health issues, including cancer.
Skin cancer is the most common cancer in the United States. The two most common types of skin cancer are basal cell cancer and squamous cell cancer. Typically, they form on the head, face, neck, hands, and arms because these body parts are the most exposed to UV radiation.
Most cases of melanoma, the deadliest kind of skin cancer, are caused by exposure to UV radiation.
Anyone can get skin cancer, but it is more common in people who:
- Spend a lot of time in the sun or have been sunburned.
- Have light-color skin, hair, and eyes.
- Have a family member with skin cancer.
- Are over age 50.
Recommendations for protection from UV radiation
- Stay in the shade, especially during midday hours.
- Wear clothes that cover your arms and legs.
- Consider options to protect your children.
- Wear a wide brim hat to shade your face, head, ears, and neck.
- Wear wraparound sunglasses that block both UVA and UVB rays.
- Use sunscreen with sun protection factor (SPF) 15 or higher, for both UVA and UVB protection.
For an explanation of ionizing (and non-ionizing) radiation and additional sun safety tips: www.cdc.gov.
Check out tips out provided by the Food and Drug Administration, Tips to Stay Safe in the Sun: From Sunscreen to Sunglasses.
Focus on having a healthy sunburn-free summer. Don’t forget your eyes by taking appropriate actions to protect them. Thanks to the Centers for Disease Control and Prevention for much of the content provided here.
Mark A. Mahoney, Ph.D. has been a Registered Dietitian/Nutritionist for over 35 years and completed graduate studies in Nutrition & Public Health at Columbia University.
Credit: Tallahassee Democrat