Summer means fun in the sun whether it is on the beach, in the garden, or on the go but that same summer sun can increase the risk of sunburn, premature wrinkles, and skin cancer. Sun exposure contributes to 90% of non-melanoma skin cancers and 60% of melanoma skin cancer. We know that sunscreen is an important part of sun protection but do you know how to use it?
First, the reality is that SPF 15 blocks out 93% of UVB rays while SPF 30 and SPF 50 blocks out 97% and 98% of UVB rays over two hours. So thinking you are getting twice the protection when you are actually only getting 4-5% extra protection can lead to poor choices. An SPF of 30 or above is recommended for everyone. Second, you need to reapply sunscreen every two hours because sunscreen breaks down, rubs off, rinses off, or is removed by sweat over that time. If you apply once and don’t reapply until you feel the burn; that is dangerous. This is why it is problematic to use sunscreen with insect repellent in it because you need to reapply the sunscreen more often than you should reapply the insect repellent. So if you are going this route, have the combination product for the initial application but also a product that is just a broad spectrum sunscreen for reapplication. Third, most people don’t use enough sunscreen, you need at least an ounce of sunscreen for an initial application before hitting the beach. Fourth, sunscreen also doesn’t start working right away, it can take a good 30 minutes before you are truly protected so don’t put it on and run immediately outside because you are not protected. Fifth, if you are using a sunscreen spray, remember that we do not know about the safety of inhaling the fumes so do not spray the product directly on your face. Either use a cream on your face or spray the sunscreen in your hands and apply it.
In the summertime even on cloudy days you can burn because up to 70% of the UVA and UVB rays can penetrate the clouds and because predicted cloudy days more often than not have breaks of sunshine where burns can occur in 15 to 30 minutes if you are not covered.
One of the problems with sunscreen, especially improperly used sunscreen, is that people feel like they are fully protected and frequently expose themselves to more sun than they should. If you can avoid of limit exposure to the sun during the 11 a.m. to 3 p.m. time frame when the UV rays are strongest, that is advisable. Combining sunscreen with physical barriers like a shirt or a shady tree is much better than relying on sunscreen alone. The top of the head, eyes, and lips don’t get sunscreen so hats, UV protection sunglasses, and SPF lip balm are also valuable.
Dr Michael White, UConn School of Pharmacy.