Too much ultraviolet (UV) radiation exposure can have damaging effects on the skin, eyes, and immune system.
What is Ultraviolet Radiation?
Radiation is the emission (sending out) of energy from any source and ultraviolet (UV) radiation is a form of electromagnetic radiation.
How are people exposed to UV radiation?
Sunlight is the main source of UV radiation, however there are artificial sources like tanning beds and welding torches.
What affects UV exposure?
The strength of the sun’s UV rays reaching the ground depends on a number of factors, such as:
- Time of day: UV rays are strongest in the middle of the day, between 10 am and 4 pm.
- Season of the year: UV rays are stronger during spring and summer months. This is less of a factor near the equator.
- Distance from the equator (latitude): UV exposure goes down as you get further from the equator.
- Altitude: More UV rays reach the ground at higher elevations.
- Cloud cover: The effect of clouds can vary, but it’s important to know that UV rays can get through to the ground, even on a cloudy day.
- Reflection off surfaces: UV rays can bounce off surfaces like water, sand, snow, or pavement, leading to an increase in UV exposure.
- Type of UV ray: UV radiation is divided into 3 main groups: UVA, UVB, and UVC rays
The main types of UV rays that can affect your skin include UVA rays and UVB rays.
- UVA rays have the least energy among UV rays. These rays can cause skin cells to age and can cause some indirect damage to cells’ DNA. UVA rays are mainly linked to long-term skin damage such as wrinkles, but they are also thought to play a role in some skin cancers.
- UVB rays have slightly more energy than UVA rays. They can damage the DNA in skin cells directly, and are the main rays that cause sunburns. They are also thought to cause most skin cancers.
- UVC rays have more energy than the other types of UV rays. Fortunately, because of this, they react with ozone high in our atmosphere and don’t reach the ground, so they are not normally a risk factor for skin cancer. But UVC rays can also come from some man-made sources, such as arc welding torches, mercury lamps, and UV sanitizing bulbs used to kill bacteria and other germs (such as in water, air, food, or on surfaces).
UVB rays have more energy and are a more potent cause of at least some skin cancers, but both UVA and UVB rays can damage skin and cause skin cancer. There are no safe UV rays. (To learn more about the different types of UV rays, see Ultraviolet (UV) Radiation.)
Tips to protect yourself from the sun
Some people think about sun protection only when they spend a day at the lake, beach, or pool. But sun exposure adds up day after day, and it happens every time you are in the sun. Even though sunlight is the main source of UV rays, you don’t have to avoid the sun completely. And it would be unwise to stay inside if it would keep you from being active, because physical activity is important for good health. But getting too much sun can be harmful. There are some simple steps you can take to help ensure you’re not getting too much sun:
- If you’re going to be outside, simply staying in the shade, especially during midday hours, is one of the best ways to limit your UV exposure from sunlight.
- Protect your skin with clothing that covers your arms and legs.
- Wear a hat to protect your head, face, and neck.
- Wear sunglasses that block UV rays to protect your eyes and the skin around them.
- Use sunscreen to help protect skin that isn’t covered with clothing.
Tips to protect children from the sun
Children need special attention. They tend to spend more time outdoors, can burn more easily, and may not be aware of the dangers. Parents and other caregivers should protect children from excess sun exposure by using the steps above. It’s important, particularly in sunnier parts of the world, to cover your children as fully as is reasonable. You should develop the habit of using sunscreen on exposed skin for yourself and your children whenever you go outdoors and may be exposed to large amounts of sunlight. Children need to be taught about the dangers of too much sun exposure as they become more independent. If you or your child burns easily, be extra careful to cover up, limit exposure, and apply sunscreen.
Babies younger than 6 months should be kept out of direct sunlight and protected from the sun using hats and protective clothing. Sunscreen may be used on small areas of exposed skin only if adequate clothing and shade are not available.
Are there any health issues related to UV radiation?
- Most skin cancers are caused by too much exposure to ultraviolet (UV) rays. Most of this exposure comes from the sun, but some can come from man-made sources, such as indoor tanning beds and sun lamps. People who get a lot of exposure to UV rays are at greater risk for skin cancer.
- UV rays, either from the sun or from artificial sources like tanning beds, can cause sunburn.
- Exposure to UV rays can cause premature aging of the skin and signs of sun damage such as wrinkles, leathery skin, liver spots, actinic keratosis, and solar elastosis.
- UV rays can also cause eye problems. They can cause the cornea (on the front of the eye) to become inflamed or burned. They can also lead to the formation of cataracts (clouding of the lens of the eye) and pterygium (tissue growth on the surface of the eye), both of which can impair vision.
- Exposure to UV rays can also weaken the immune system, so that the body has a harder time fending off infections. This can lead to problems such as reactivation of herpes triggered by exposure to the sun or other sources of UV rays. It can also cause vaccines to be less effective.
For more information, visit: https://www.cancer.org/healthy/be-safe-in-sun.html