Like most concerns about consumer product safety, the public's emerging fears about sunscreen's possible dark side didn't come out of nowhere. The original source is a simple statistical observation: Since 1935, the average lifetime risk of melanoma has jumped from 1 in 500 to 1 in 5. During that time, both the use and SPF numbers of sunscreens have also soared. Sunscreen skeptics cite the simultaneous rise in these two trends as evidence that sunscreen may be carcinogenic. But while the appearance of a connection between these two trends may hint at a worthwhile avenue for scientist to explore, there's a big difference between an intriguing clue to a broader understanding of skin cancer risks and statistically significant evidence that sunscreens cause skin cancer. So if you're on the brink of swearing off sunscreen - don't. Although questions about how sunscreens actually work remain, the solid evidence needed to directly link their physical effects on the skin to cancerous cell mutations, or to rule out more logical causes for rising melanoma rates, just isn't there. Does that mean the apparent correlation between these statistics is pure coincidence? Not necessarily.

What the Skin Cancer Statistics May Be Telling Us

Most scientists attribute the ongoing climb of skin cancer to the interplay of a variety of changing social, public health, and environmental conditions. Many of these contributing factors, including longer life spans, the widespread popularity of suntans, the thinning ozone layer, and skimpy clothing styles, are totally unrelated to the effects of sunscreen on our skin. According to a National Institute of Science report, however, common misperceptions about sunscreen, also rank high on the current list of likely suspects.   Playing the SPF Numbers Game: Proceed with Caution While marketers continue to point to their high SPF sunscreens as effective skin cancer prevention, recent research suggests that these reassuring numbers may be endangering our health. To sun worshippers and tanning booth addicts, an SPF 50+ looks like green light to ramp up their risky behavior. If they see the long-term health implications of their habits at all, it's through a haze of misleading advertising claims and popular misconceptions. Part the problem is a widespread misunderstanding about sun protection factor (SPF) numbers. Many people, for instance, believe that a product SPF of 30 is twice as effective in preventing UV absorption as an SPF of 15. In fact, the difference in absorption rate is only about 3.4 to 4%. In fact, SPF numbers are supposed to serve as guide to the length of time an individual can stay in the sun without getting sunburned. Theoretically, then, a person whose unprotected skin burns in 10 minutes could extend that time to 150 minutes by using an SPF 15 sunscreen. However, these numbers are based on tests performed under ideal conditions. In practice, most of us only about half the amount of sunscreen required to achieve this degree of protection and seldom comply with recommendations to reapply it at least every 2 hours. Does Your Sun Protection Deliver Full Coverage? This dangerous overconfidence in sunscreen also comes from misleading marketing claims. Recent consumer research indicates that many so-called ultra-high SPF, "broad spectrum coverage" sunscreens actually provide little or no protection against the long-term damage cause by UVA radiation. Likewise manufacturers who label their products "waterproof" are overlooking the fact that all sunscreens degrade in water. Are All Sunscreens Ingredients Equally Safe? Some recent studies have raised doubts about the safety of several common sunscreen ingredients. Preliminary research data on oxybenzone, for instance, suggest it may be linked to increased risk of cancer and hormonal disorders. Natural: The Latest Word on Safe, Effective Sunscreens The fact that some brands of sunscreens fail to live up to their promises is no reason to dismiss them all as worthless or risky. A recent Environmental Working Group report rated natural mineral sun blocks as the best of all product options. Micronized particles of minerals such as zinc oxide physically shield the skin surface from UVA/UVB radiation without penetrating into deeper cell layers. In addition to providing safe, effective broad-spectrum coverage, zinc oxide helps reduce acne flares and heal skin irritations, maximizing the bright side of your sun protection routine.