Skin cancer rates have been on a steadily incline over the last decade. Sunscreen manufacturers have insisted that sunscreen use can prevent skin cancer and promote health. Paradoxically, studies indicate that sunscreen may partially be to blame for escalating skin cancer rates. There are two major forms of sunscreen, chemical and mineral. Chemical sunscreens come in various formulations with esoteric components such as oxybenzone. Mineral based sunscreens contain zinc and titanium dioxide.
There is a small body of evidence indicating that some components of both mineral and chemical based sunscreens may themselves be carcinogenic. However, these studies have had conflicting results and the body of evidence in support of these accusations is limited. A comprehensive review by the US Preventive Services Task Force and a follow up study in Australia indicates that appropriate use of sunscreen reduces the risk of developing melanoma. Given these confirmatory results, what is the issue?
Sunscreen is not effective unless it is applied repeatedly and in significant quantities to all sun exposed areas. However, as a study published in 2002 in the Archives of Dermatology indicates, most consumers don’t apply the recommended 2 mg/cm2 of sunscreen. The average adult should use roughly one third of a bottle of sunscreen whenever it is applied. A failure to meet these standards increases the risk of developing sunburn and promoting skin cancer. Compounding this issue is evidence from the same study that shows that sunscreen use compels consumers to increase the amount of time they spend exposed to the sun. Sunscreen use may be increasing skin cancer rates through the additive risk of inadequate application and sun overexposure.
The issue of sunscreen labeling practices is also of considerable concern. The sun protection factor(SPF) refers to the amount of protection provided against ultraviolet B(UVB) radiation but not ultraviolet A(UVA) radiation. 95 percent of the UV radiation that blankets the earth is UVA. Therefore, as indicated in a 1996 study in the Boston Medic Journal, extended periods of sun exposure may provide some protection from UVB radiation but allow for an increased exposure to UVA radiation, promoting skin cancer development. Exacerbating these concerns is a perpetual increase in the SPF values marketed to consumers. The Environmental Working Group(EWG) believes this grants consumers with an inflated sense of protection compelling them to spend extended periods exposed to the suns harmful rays. As reported by the EWG “,People apply about a quarter of the recommended amount. So in everyday practice, a product labeled SPF 100 really performs like SPF 3.2, an SPF 30 rating equates to a 2.3 and an SPF 15 translates to 2.” The best protection lies in covering exposed areas with clothing.