An Update on Sunscreens and Sunblocks
Here is the latest information on Sunscreens. First a bit of information on ultraviolet (UV) sunlight. Sunlight is composed of UVA and UVB radiation. UVA radiation penetrates deep onto the skin and can affect skin structure and aging. UVB doesn't go as deep but is the primary cause of sunburn. Both UVA and UVB radiation can produce skin cancer, however. While most of the UV light reaching the ground is UVA, UVB is a bigger problem in the summer. Thus protecting you and your children from both UVA and UVB is very important.
Sunscreens presently use the SPF rating, which is related to the protection that a product will give related to sunburn only. The higher the SPF, the more protection from sunburn. It refers to the protection from UVB and not UVA radiation. By the way, an SPF of 30 does not mean you can stay in the sun 30 times longer than if you did not use sunscreen. These numbers should only be use to compare sunscreen products and not used to calculate how long you can be in the sun.
Sunscreens contain chemical agents that absorb UV radiation. These can degrade upon exposure to sunlight and therfore need to be reapplied frequently. Some sunscreens also have agents, such as Zinc Oxide that reflect UVA and UVB radiation and are called sunblocks.
So, what should you do? Alway get a high SPF sunscreen (at least 15), and make sure the label says it protects against UVA radiation as well. Remember SPF refers to only UVB protection. Apply the sunscreen liberally and generously and...frequently. Every two hours is best, and it should be applied 30 minutes prior to sun exposure to allow the product to be absorbed. Don't forget to reapply after swimming, and do not use sunscreens that also containing insect repellent as they can not be reapplied as often as sunscreens.
Proper understanding and use of sunscreen will provide protection from harmful UVA and UVB radiation for you and your children. Keeping children out of the sun between 10am and 4pm is best. Wide brimed hats, long-sleeved shirts and sunglasses help too.