The 2012 edition of The Skin Cancer Foundation Journal features medically reviewed, reader-friendly articles such as tanning, the increasing incidence of skin cancer diagnoses among young women, & the prevalence of melanoma among white males over 50.
Issue link: http://skincancer.epubxp.com/i/526209
A s if worrying about sun exposure weren't enough, today we have to consider what air pollution is doing to our skin. It's a sub- ject of growing interest to scientists, the cos- metics industry, the media and consumers. Recent research shows that common envi- ronmental pollutants interact with and amplify the effects of the sun's ultraviolet radiation (UVR) to increase skin damage and the risk of skin cancer. 1,2 The combination, it turns out, can be a virulent double whammy. Like the sun's UVR, air pollution is an environmental phenomenon most of us encounter every day. If, say, you live near a factory or an active volcano spewing sulfur dioxide into the air (parts of Hawaii come to mind), you and your skin are significantly ex- posed to air pollution. Living in the mountains or near the sea is no guarantee of protection, and neither is having billions to spend. Los Angeles, San Francisco and the San Joaquin Valley in California are all notorious for their poor air quality, and Silicon Valley billionaires and Hollywood movie stars may slog through polluted air just as the rest of us do, just as UVA and UVB rays beat down on all of us. D O U B L E D A M A G E The harmful effects of UVA and UVB rays on the skin are well known. The most serious risk, of course, is skin cancer, whose incidence has been skyrocketing for decades. Nearly 5 million people will be treated for skin cancer in the US this year, 3 and almost 74,000 will be diagnosed with melanoma. 4 Sun exposure is also by far the greatest cause of skin aging; it leads to mottled, thickened skin, discol- oration, sagginess, wrinkles, and creases. Meanwhile, environmental pollutants are damaging our skin on multiple levels. First and foremost, thinning of the stratospheric ozone layer due to pollution (especially indus- trial chemicals such as halons and chlorofluo- rocarbons) has led to more UVR reaching the earth, increasing our risk of skin damage and skin cancers. 5 Recent lab and animal research show that pollution from fossil fuels (power plants, car exhaust, heaters and even ciga- rette smoke) in combination with UVR also increases visible photodamage and the risk of skin cancer. Several studies have found that mice exposed to benzo[a]pyrene (BaP)—a common pollutant in air, food and water— and UVA had more skin tumors than those exposed to BaP or UVA alone. 1 A study with human skin cells found that BaP interacts with UVA to generate cellular DNA damage that increases the risk of skin cancer. 1 Another recent study, presented at the American Academy of Dermatology annual meeting in 2011 but still not peer-reviewed, found that skin cells exposed to air pollution and UVR had more than double the sun- damage compared to UVR exposure alone. 2 Smoking and extreme weather also increased the UV damage. 2 F U R T H E R M A Y H E M In addition to exacerbating the effects of UVR, environmental contaminants have their own negative impacts on the skin. Like UVA rays, air pollution generates free radicals, highly reactive molecules that can attack collagen and elastic tissue, the major structural supports for the skin. Factories, incinerators, power plants, construction sites, even cars idling in traffic spew particles that settle on the skin, or if tiny enough, actually penetrate the skin. These particles appear to accelerate skin aging and skin discoloration, especially producing brown patches. Polycyclic aromatic hydrocarbons, a com- mon byproduct of combustion, not only age and darken the skin, but have been reported to cause skin cancers (as well as lung and bladder cancers) in their own right. 6 Anybody chronically exposed to cigarette smoke, auto- mobile exhaust fumes, and even wood-burn- ing fireplaces is being exposed to polycyclic aromatic hydrocarbons. W H A T C A N Y O U D O ? How can you protect your skin from the combined effects of UV and environmental pollution? Cleanliness is a good start. Wash well when you come in from outside to remove any traces of pollutants from your skin surface. The most effective way to clean both face and body is with a sonic cleans- ing system. A low-tech alternative is to use a clean washcloth, a loofah, or a cotton pad to exfoliate your face and a nylon scrub puff on your body. Bonus: exfoliation can also elimi- nate some abnormal cells caused by sun dam- age that could develop into precancers and skin cancers. It's especially important to cleanse before you go to bed, so the pollutants don't stay on your skin for hours while you sleep. At the very least, wash your face, the most exposed area of the body and the one that ages most rapidly. Another good strategy is to eat colorful fruits and vegetables, which are rich in free radical-fighting antioxidants. Red beans, blueberries, kidney beans, pinto beans, cranberries, artichoke hearts, blackberries, raspberries and strawberries are all high in antioxidants. Get into the habit of drinking green tea and nibbling dark chocolate. Antioxidants can also go on the face and body. Topical serums and creams containing antioxidants such as green tea, resveratrol, pomegranate extract, grapeseed extract, coenzyme Q10, and vitamins C and E all benefit the skin. There is evidence that some of these antioxidants, like vitamin E, may degrade quickly when exposed to air and sun- light, so products containing them are proba- bly best used at night, after pollutants have been washed off. Retinol, the vitamin A derivative, not only helps repair UV damage, but can also help mitigate the effects of air pollution on the skin. Since retinol-containing products make your skin sensitive to sunlight, they should be used only at night. Be especially careful in the sun for 48 hours after using them. Finally, DNA-repair enzymes, compounds often derived from seaweed and plankton, appear to be effective at enhancing the body's natu- ral mechanisms for repairing DNA damage caused by sun exposure and air pollution. Almost every major skin care line now has sunscreens and skin treatment products with DNA-repair ingredients. The bottom line is that while it is not possible to eliminate the sun's rays and air pol- lution, we can do a lot to prevent and mitigate their harmful effects. First, we must make a daily habit of sun protection: shade, sun-safe clothing (including a wide-brimmed hat and UV-filtering sunglasses), and a sunscreen of SPF 30 or higher whenever we leave the house. In addition, thorough skin cleansing, diet, and the use of well-formulated skin products may reduce some of the damage from environmental pollution. DEBRA JALIMAN, MD, is a dermatologist with a private practice in New York City. Internationally recognized for her research and work in clinical and cosmetic dermatology, Dr. Jaliman has a reputation for using cutting-edge technology and the latest in skin care, as well as for being the "last stop" doc- tor who fixes what others can't. She is an assistant professor of dermatology at Mount Sinai School of Medicine and a member of the American Society of Dermatologic Surgery. A spokesperson for the American Academy of Dermatology, she is consid- ered an authority in her field by journalists and the cosmetics industry, appearing frequently on televi- sion and in publications such as the Wall Street Jour- nal, The New York Times, Allure, Glamour, Self, and InStyle. Dr. Jaliman's book Skin Rules: Trade Secrets from a Top New York Dermatologist was released in 2012 by St. Martin's Press. References on pages 105-107. 23