Ultraviolet Radiation

HealthLinkBC File Number: 
11
Last Updated: 
May 2015

What is ultraviolet radiation?

Ultraviolet (UV) radiation comes mainly from the sun as part of the electromagnetic (light) spectrum. Ultraviolet rays have wavelengths shorter than visible rays, so we cannot see or feel them. Artificial sources of UV radiation include tanning beds and welding equipment.

How damaging is UV radiation?

When exposed to UV radiation, your body produces and releases more melanin (a skin pigment) to absorb the UV. This makes your skin darken and is a sign of skin damage.

There are two types of UV radiation, UVA and UVB. Both are a serious health concern as UVA and UVB radiation can affect your skin, eyes, and immune system.

UVA causes immediate tanning (the darkening of the melanin in your skin). Repeated exposure to UVA can lead to premature skin aging, such as wrinkles, age spots, and sagging. It can also lead to some skin cancers.

UVB is more harmful than UVA. It causes delayed tanning by making your skin produce more melanin. UVB is responsible for sunburns and most skin cancers, along with cataracts and eye cancers.

Each tan or sunburn damages your skin cells and DNA. It can take years for the effects of repeated sun exposure to show.

Who is most at risk from UV radiation?

Children who are frequently in the sun are vulnerable to the effects of UV radiation. Young people who use tanning beds are also at risk. In British Columbia, children under the age of 18 are banned from using tanning beds.

When and where am I most at risk?

Direct sunlight is the strongest in summer, with about 80 percent of the UV occurring between 11 a.m. and 4 p.m. UV is more intense closer to the equator and at higher altitudes. Be aware of that when you travel. Clouds, haze and fog do not protect you from UV radiation. The reflection of sunlight from water, sand, snow and concrete can intensify the amount of UV exposure. For example, reflection off fresh snow nearly doubles UV radiation.

How can I protect myself and my family?

Make a plan

Plan your outdoor activity before 11 a.m. or after 4 p.m. Stay in the shade as much as possible and use an umbrella at the beach or park. Do not expose babies under 1 year old to any intense, direct sunlight.

Wear protective clothing

Wear light-coloured, long-sleeved shirt and pants, UV-protective sunglasses, and a broad-brimmed hat. Avoid baseball caps that do not shade the ears or back of the neck. If you can see through your clothing, UV can get through. Sun-protective suits specially made for swimming and playing outside are helpful.

Know your skin type

Your sensitivity to UV radiation depends on the amount of pigment in your skin and your skin's ability to tan. People with fair skin and light-coloured eyes, who usually burn, are at the highest risk of skin damage. For more information, visit The Ministry of Health – Protecting Yourself from Ultraviolet (UV) Radiation at www2.gov.bc.ca/gov/topic.page?id=CD0704E713B64EB5A81BFB57D076F053

If you have sun sensitivity due to a medical condition or medication, you can develop a skin rash or severe burn even from limited UV exposure.

Avoid tanning beds

Avoid using tanning beds. The World Health Organization has found that UV radiation from tanning beds causes skin cancer. The risk of melanoma (the most serious skin cancer) increases by 75 percent when tanning bed use starts before 35 years of age. For more information, visit the Ministry of Health – Tanning Beds at www2.gov.bc.ca/gov/topic.page?id=9C74F650BE41467BB2E646A83EE7ED1C.

Will sunscreen protect me against UV radiation?

The best protection against UV radiation is to stay out of the sun. If you need to be out in the sun, sunscreen is your best protection against UV radiation.

Sunscreen reduces the amount of UV radiation absorbed by your skin. It will allow you to be in the sun longer than you could without sunscreen.

A sunscreen’s Sun Protection Factor (SPF) shows how long you can be exposed to sunlight before sunburn occurs. The Canadian Dermatology Association recommends an SPF 30, which blocks 97 percent of UVB – the "burning" rays. SPF 50 blocks 98 percent and SPF 100 blocks 99 percent.

The product should be "broad spectrum," which means it screens both UVA and UVB. Use a minimum SPF 30 lip balm and reapply it every hour.

How much sunscreen should I apply?

To get the best protection, you need to completely cover all of your exposed skin. Apply sunscreen 30 minutes before you go outside, so your skin has time to absorb it. Reapply the sunscreen after you have been swimming or sweating to keep it effective.

If your baby must be in the sun, you can apply sunscreen to small areas of skin that are not covered by clothing or a hat. Use sunscreen on children older than 6 months. Use a sunscreen approved by the Canadian Dermatology Association.

How can I protect my eyes?

Sunglasses should provide at least 90 percent protection from UVA and 95 percent from UVB. Sunglasses for babies and children should provide 99 to 100 percent of both and UVA and UVB protection. Large lenses and a wrap-around design can help shield the eyes.

What is the UV Index?

The UV Index reports on the current strength of UV radiation in your area. When it is 3 or higher, make sure you are well protected. To see the daily UV Index Forecast, go to https://weather.gc.ca/forecast/public_bulletins_e.html?Bulletin=fpcn48.cwao.

For More Information

For more information on sun safety, see HealthLinkBC File #26 Sun Safety for Children

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Is it an emergency?

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