The Effects of Sun
On Your Body

Learn more about UV exposure
and the effects on your skin.

Click on the arrows below to learn more.

The Effects of Sun On Your Body

  • It seems odd that sunlight, which is essential for life, can also be extremely dangerous to our health, but it's true.
  • Sunlight is made up of electromagnetic energy, which is transmitted through the air as electromagnetic waves.


U.V Exposure

  • Too much exposure to ultraviolet radiation (UV rays), which is invisible to the eye, increases the risk for a host of problems including:
    • Skin cancer
    • Moles
    • Premature wrinkling and sagging of the skin
    • Cataracts and other eye diseases
  • UV rays can also weaken the immune system, making us vulnerable to other health problems
  • Too much exposure to infrared radiation (another type of invisible wave) may result in heat stroke and similar reactions.


The UV Index

The UV index was developed in 1994 to estimate UV intensity as a way of helping people assess the type of precautions they need to take when going outdoors. The index is based on the amount of time spent in the sun that it would take for a fair-skinned person to burn.

UV Index
0 – 2
3 – 4
5 – 6
7 – 9
10 and over
Risk
Minimal
Low
Moderate
High
Extreme
Estimated time for a fair-skinned person to burn
1 hour
less than 20 minutes
less than 15 minutes
less than 10 minutes
less than 5 minutes





Understanding UV Rays

  • The electromagnetic wavelengths that make up UV rays are classified as UVA, UVB, and UVC.


UVC Rays

  • The UVC rays from the sun are completely filtered by the ozone layer surrounding the earth and, therefore, don’t have much effect on us.


UVB and UVA Rays

  • Both of these types of UV rays can cause us quite a bit of trouble.
  • The amount of UVA and UVB rays that reach your body is affected by many factors such as:
    • Where you are on the earth
    • Your altitude
    • The season and time of day
    • Cloudiness, and the condition of the ozone layer
  • Other factors for exposure:
    • Reflections from sand, pavement, snow, and water increase UV exposure.


UVB Risks

  • UVB rays are mostly to blame for sunburn, and they increase risk for melanoma (the most serious form of skin cancer) more than the other types of radiation.
  • Even in amounts too low to even cause skin reddening, UVB may impair the immune system, damage DNA, and increase the risk for skin cancer.
  • Direct sunlight can be harmful to your eyes. Make sure you wear sunglasses that block at least 95% of UVB, 60% of UVA, and 60% to 90% of visible light.