What is UV Radiation?

Sunlight is the main source of ultraviolet (UV) radiation. UV rays come from the sun (and tanning beds among other sources) as radiation that you cannot see or feel. The sun gives off two types of harmful rays, UVA and UVB. About 95% of the sun’s UV radiation is UVA – and about 5% are UVB. UVA, or the sun’s long rays, penetrate into the inner layers of the skin and is known to play a major role in skin aging and wrinkling. UVB (sun’s shortwave) rays are the primary cause of skin reddening and sunburn, and is a key contributor to the development of skin cancer.

UV Index

It’s important to note that the intensity of the sun’s rays (or amount of UV radiation that you are exposed to) will depend on certain factors.

• Time of day – sun’s rays are most powerful between 10 AM and 4 PM
• Time of year – UV rays are strongest during summer
• Location – sun is strongest the closer you are to the sun’s equator or at higher altitudes
• Surface reflection – surfaces such as water, sand, snow and even some types of clouds can reflect UV rays causing increased exposure

The Environmental Protection Agency (EPA) wanted to give people an idea of how strong the UV light is in their area, and thus developed a scale system from 1 to 11+. The higher the number the greater the exposure to UV rays, and the higher your chances are for sun burn and skin damage. The UV Index is given daily throughout the US. UV Index forecasts are often provided in local newspapers, television and weather apps. Further information about your local UV Index can be found on the EPA’s website

Adverse Effects of the Sun

Sun exposure is unavoidable, especially when spending time outdoors for physical exercise or work-related activity, but it’s important to remember that unprotected skin exposed to UV radiation can also lead to several adverse health effects.

• Sunburn – this type of radiation burn occurs when the amount of UV exposure is more than the amount of melanin, the pigment in your skin that absorbs UV light. Those with lighter skin have less melanin to absorb UV radiation; however, people with more melanin are still susceptible to the negative effects of the sun. When a burn goes deeper, sunburn may be severe enough to cause pain and blistering
• Skin aging and wrinkling – occurs as skin is chronically exposed to the sun – as the skin loses its elasticity, the outer layer of the skin becomes thick, leathery and wrinkled
• Skin cancer – although largely preventable, it is the most common of all cancers in the US. There are 3 major types of skin cancer – basal cell carcinoma, squamous cell carcinoma and melanoma
• Eye damage – this occurs when the tissues of the eye are unprotected to UV radiation. The American Academy of Ophthalmology warns about the higher incidence of cataracts due to excess exposure to UV radiation
• Weakened immune system – this occurs as repeated overexposure to UV radiation inhibits the immune functions of the skin

Protect Yourself from UV Rays

About 2 million people in the US are diagnosed with skin cancer every year. And, ultraviolet (UV) rays from the sun contribute anywhere from 60-90% of skin cancers. By making sure to take on sun protection measures, you can reduce the risk for skin cancer and other adverse health effects. Here are a few simple tips to follow:

• Stay in the shade – seeking shade under an umbrella or tree can help protect you from UV exposure
• Cover up – protect your skin from UV rays with clothing; wear a wide brimmed hat to cover your face, neck and ears; wear sunglasses to protect your eyes
• Apply sunscreen – wear sunscreen on all exposed areas before going outside everyday regardless of it being sunny or cloudy, cool or hot; remember that sunscreen alone does not block out the entire spectrum of the sun’s rays
• Avoid tanning beds – these emit UV rays similar to the sun; remember that tanning indoors is not safer than tanning outdoors in the sun