Ultraviolet Radiation and Your Health

How Can Ultraviolet Radiation (UVR) Affect Health?

Our skin, eyes and immune systems are all affected by exposure to UVR both natural (sun) and artificial (tanning devices):

Skin

• Short-term exposure results in sunburn.
• Excessive exposure over time leads to premature aging and skin cancer.

• One in seven Canadians will experience skin cancer in their lifetime (Canadian Cancer Society).

Eyes

• UVR can cause damage to the eye.
• Excessive exposure over time can lead to the development of cataracts. 
• Cataracts are the leading cause of blindness worldwide.

Immune system -Increasing evidence shows that UVR affects our immune system:

• Over-exposure to UVR suppresses the immune system, which may reduce our body’s ability to fight infections. 

What is the UV Index (UVI) and why is it so important to understand?

The UVI is a measure of the intensity of the UVR on the earth’s surface as it relates to the health effects on human skin.  The UVI for Canada can be found in radio and television weather forecasts, in newspapers, and on the Ministry of the Environment’s web site.

UV Index           Category                  Sun Protection Actions

0-2                     Low                            Mimimal protection required for normal activities

3-5                      Moderate                   Cover up.  Wear hat, sunglasses, and sunscreen if

                                                              outside for 30 minutes or more. 

6-7                      High                            Protection required.  Reduce time in sun between

                                                              10 a.m. to 4 p.m.

8-10                    Very High                   Take full precautions and avoid sun between

                                                               10 a.m. and 4 p.m.

11+                      Extreme                      Take full precautions and avoid sun between

                                                               10 a.m. to 4 p.m.              

Environment  Canada,  modiffiedby: Windsor Essex County Health Unit Mar 2005

To protect yourself from the harmful effects of UVR, follow these tips:

• Reduce exposure to the sun during peak ultraviolet times – 10 a.m. to 4 p.m.
• Seek shade or make your own shade.
• Wear a wide-brimmed hat or a French foreign legion type hat to protect your face, head, neck, and ears.
• Protect arms and legs with tightly woven, dark, loose fitting clothing.
• Use a broad-spectrum (protects against ultraviolet A and B rays) sunscreen with an SPF of 15 or higher.  Apply 15-30 minutes before going outdoors.  Re-apply often, at least every 2 hours and after being in the water or doing vigorous activity and sweating.
• Wear UV protective sunglasses.
• Do not get tans from tanning salons that use ultraviolet rays

Sources:

World Health Organization.  2003.  Climate Change and Human Health-Risks and Responses. Retrieved May 2, 2005, from http://www.euro.who.int/document/gch/climchsum0903e.pdf   

World Health Organization. 2003.  Guidelines for Safe Recreational Water Environments, Sun, Heat & Cold.  Retrieved May 2, 2005, from http://www.who.int/water_sanitation_health/bathing/srwe1-chap3.pdf 

Cancer Care Ontario. 2002.  Skin Cancer is the Most Common Cancer.  Retrieved May 2, 2005, from http://www.cancercare.on.ca/documents/CF-May2002-skinmostcommonca.pdf