UVB rays are the middle of the spectrum. They are responsible for delayed tanning, burning and aging the skin, and causing skin cancer. At the longest wavelength range, UVA causes immediate tanning, as well as aging and wrinkling of the skin. It also adds to the carcinogenic effect of UVB . Nowadays UVA is likely to be prevalent in tanning parlors.
Children spend more time in the sun than most adults, specially in the summer.
The skin can suffer a lot of damage in childhood. In fact, one of the conditions that puts people most at risk for skin cancer is two or more blistering sunburns as a child or adolescent. Environment Canada's Daily UV-Index Environment Canada issues information on UV levels to Canadians as part of the daily weather. The UV -index gives the amount of UV you would receive on a clear sunny day. You get less UV under thick, heavy cloud, or more if you're on a bright surface, like snow or sand.