People need to wear sunscreen in order to protect the skin from the powerful rays of the sun. The two types of ultraviolet rays that can affect a person's skin are UVB and UVA. Although both cause different types of skin problems, such as photo-aging and wrinkling, these rays also can increase a person's risk for skin cancer.
Everyone 6 months of age or older needs a sun cream or sunscreen, according to the American Academy of Dermatology, and anyone younger than that should be kept out of the sun. The type of sunscreen used should be a broad-spectrum variety, have an SPF higher than 30 and be impervious to water. A broad-spectrum SPF can protect the skin against both types of ultraviolet rays.
It is beneficial for someone to use sunscreen when he or she is outdoors and exposed to the sun. The application of sunscreen should be done about 30 minutes prior to going outside. One needs to apply at least 1 ounce of sunscreen to make sure that the skin gets the full effect of the SPF in the sunscreen. However, more frequent sunscreen application is necessary if one is out in the sun for prolonged periods of time, such as being at the beach.
Although the sun's ultraviolet rays are a major risk for skin cancer, ultraviolet light exposure from the use of tanning beds or other artificial sources can also be a risk factor, according to the Centers for Disease Control and Prevention.