There are three types of ultraviolet (UV) radiation: UVA, UVB and UVC.

UVA rays, while not as powerful as UVB, penetrate more deeply into the skin and cause wrinkling of the skin, premature aging, and skin cancer. UVA can be found in tanning salons, where tanning equipment can emit two to five times more UVA than is found in natural sunlight.

UVB rays are shorter than UVA. UVB primarily affects the skin’s outer layers and is thought to be the primary cause of sunburn, skin aging and skin cancer. UVB rays tend to be more intense during summer months, at higher altitudes, and in areas closer to the equator. Continuous exposure to UVB over a lifetime can cause skin cancer and alter the immune system.

UVC rays are filtered by the ozone layer and do not reach the earth’s surface.


The UV Index: “A Weather Report for Skin”

For more information on the UV Index, visit Environment Canada's UV Index and Sun Protection website.

Indoor Tanning

Exposure to natural as well as artificial ultraviolet (UV) radiation (i.e. tanning beds) is a risk factor for skin cancer. Currently there is no evidence indicating that the exposure to artificial tanning is less harmful than sun exposure. Sun beds mainly produce UVA radiation, but have more recently been manufactured to produce higher levels of UVB radiation to mimic the sun and speed up the tanning process. As a result, people receive up to five times more UVA rays from using tanning beds than from the sun. There is growing evidence that UV radiation emitted by the lamps used in tanning beds many damage the skin and increase the risk of developing skin cancer.

A tan has the same protective effect as sunscreen with SPF 2 or 3. Therefore, a tan acquired through the use of a sun bed will not provide protection against sunburn. Both tanning and burning can increase an individual’s risk of skin cancer. A tan is evidence of skin damage that appears after UV rays have killed some cells and damaged others. Like the sun, tanning beds alter cells at the molecular level and these changes are believed to cause skin cancer. Exposure to UV radiation can also cause sunburns, premature aging of the skin and cataracts.

Vitamin D and the Sun

Vitamin D is obtained through diet, supplements and skin exposure to UVB radiation. The amount of sun exposure needed to make enough vitamin D is not the same for each person so health professionals are not able to give one general guideline. Factors such as latitude, season, and time of day influence the amount of exposure to ultraviolet B rays, and also impacts vitamin D production.

For most people small amounts of exposure to the sun and eating foods with vitamin D provides enough vitamin D throughout the year without long-term skin damage. If sunlight is used as a source of vitamin D, expose your skin for only a short amount of time (do not allow your skin to turn red). Intentional, increased sun exposure is not recommended to obtain vitamin D.

Insect Repellent and Sunscreen Use

People can use both sunscreen and insect repellents when they are outdoors to protect their health. Follow the instructions on the package for proper application of each product. In general, the recommendation is to apply sunscreen first, followed by repellent.

It is NOT recommended to use a single product that combines insect repellent containing DEET and sunscreen. While some personal insect repellent products contain sunscreen compounds, these products were phased out as of December 31, 2003, because of incompatible label instructions regarding methods of application of each component. If you still have sunscreen/DEET combination products, they may be disposed of in your regular household garbage.

While no recommendations are available at this time regarding products that combine other active ingredients and sunscreen, it is important to always follow the label on whatever product you use.

To protect from sun exposure and insect bites, you can also wear long sleeves and long pants. You can also apply insect repellent to your clothing, rather than directly to your skin.

In most situations, insect repellent does not need to be reapplied as frequently as sunscreen. Insect repellents should be applied sparingly while sunscreens should be applied liberally and frequently.

Apply the sunscreen first, wait 20 minutes, and then apply the insect repellent.

For more information, visit Health Canada’s website on personal insect repellents or visit Safe Summer Fun.