How does UV radiation affect my skin? What are the risks?
UV radiation, a known carcinogen, can have a number of harmful effects on the skin. The two types of UV radiation that can affect the skin — UVA and UVB — have both been linked to skin cancer and a weakening of the immune system. They also contribute to premature aging of the skin and cataracts (a condition that impairs eyesight), and cause skin color changes.
- UVA Rays: UVA rays, which are not absorbed by the ozone layer, penetrate deep into the skin and heavily contribute to premature aging. Up to 90% of the visible skin changes commonly attributed to aging are caused by sun exposure.1
- UVB Rays: These powerful rays, which are partially absorbed by the ozone layer, mostly affect the surface of the skin and are the primary cause of sunburn. Because of the thinning of the ozone layer, the effects of UVB radiation will pose an increased threat until the layer is restored in the latter half of the 21st century.
What are the effects of sun exposure?
The same people who are most likely to burn are also most vulnerable to skin cancer. Studies have shown that individuals with large numbers of freckles and moles also have a higher risk of developing skin cancer. Although people with higher-number skin types have a lower incidence of skin cancer, they should still take action to protect their skin and eyes from overexposure to the sun — since cases of skin cancer in people with darker skin are often not detected until later stages, when it is more dangerous.
Additional Factors
Certain diseases, such as lupus, can also make a person more sensitive to sun exposure. Some medications, such as antibiotics, antihistamines and even certain herbal remedies, can cause extra sensitivity to the sun’s rays. Discuss these issues with your physician.
How does the outside environment influence exposure?
In general, UV strength is greatest from 10 a.m. to 4 p.m. during sunny summer days. Up to 80% of UV rays pass through clouds, however, meaning that sunburn is possible on cloudy days as well. UV exposure is greater at low latitudes (nearer to the equator) and/or high altitudes. Snow, water and sand also increase sun exposure by reflecting incoming UV rays, making it especially important for skiers, boaters and beachcombers to wear clothing and hats and apply sunscreen.
Is a suntan healthy?
There is no such thing as a healthy suntan. Any change in your natural skin color is a sign of skin damage. Every time your skin color changes after sun exposure, your risk of developing sun-related ailments increases.
Will sun protection deprive me of vitamin D?
Most people get an adequate amount of vitamin D in their diets. If you are concerned about not getting enough vitamin D, consult your physician and consider taking a multivitamin supplement, and consuming foods and beverages fortified with vitamin D daily.2
Can I get a tan without UV?
Sunless tanners and bronzers are applied to the skin like a cream and can provide a temporary, artificial tan. The only color additive currently approved by FDA for this purpose is dihydroxyacetone (DHA). Application can be difficult, and areas of the skin can react differently, resulting in an uneven appearance.
Bronzers stain the skin temporarily, and they can generally be removed with soap and water. They may streak after application and can stain clothes. Sunless tanners and bronzers might not contain active sunscreen ingredients. Read their labels to find out if they provide any sun protection.
1Taylor, C.R. et al, Photoaging / Photodamageand Photoprotection, J Am Acad Dermatol,1990: 22: 1-15.
2Wolpowitz, D. and B.A. Gilchrest, The vitamin D questions: How much do you need and how should you get it?, J Am Acad Dermatol, 2006: 54:301-317.
Content provided by U.S. Environmental Protection Agency's SunWise program. The U.S. Environmental Protection Agency does not endorse or recommend commercial products, processes or services.
