Killer Rays: Sunscreens, sun glasses Can't Fully Protect You
The first hot day of summer sends Lorry Harrison and her three young children enthusiastically to the crowded shores of Venice Beach. Standing in front of a sunglass stand along Ocean Front Walk, Harrison's four-year-old son picks out a pair of goofy, oversized sunglasses for his tiny pale face, while the two girls and their mother choose other cool-looking shades. Soon, they trudge to the beach for a day in the sun. After her children enjoy a quick frolic in the water, Harrison takes out the sunscreen and applies some to each child. She knows that the sunscreen and the sunglasses are important for protection against the sun, and is confident she's doing everything she can. But like most consumers, Harrison does not know about the inadequacies of the protection afforded by sunglasses and sunscreens, or that the thinning of the earth's protective ozone layer may subtly be wreaking immunological havoc on her children, leaving them vulnerable to cancer and other diseases. Some 20 to 50 kilometers above the earth's surface, ultraviolet radiation splits oxygen molecules into two reactive atoms. When one of these atoms encounters another oxygen molecule, an ozone molecule (O3) is formed. This thin layer of ozone in the stratosphere absorbs the sun's ultraviolet radiation, protecting plants and animals from its adverse effects. Indeed, if it weren't for stratospheric ozone, all flora and fauna would become fried dumplings. The problem is that industrial pollutants, such as chlorofluorocarbons from aerosols and refrigerants, have been diffusing into the stratosphere, producing free chloride ions that break down ozone. Since 1985, scientists have been documenting the resulting ozone gaps. In addition to the large hole over Antarctica, the ozone layer is increasingly thinning over the heavily populated mid- latitudes of the Northern Hemisphere. The result is that more ultraviolet (UV) radiation is penetrating the earth's atmosphere. Moreover, ozone depletion is now occurring in the spring and summer, when the sun's rays hit the earth's Northern Hemisphere most directly and are thus capable of doing the most damage, noted Connecticut Senator Joseph L. Lieberman at a June 5, 1992, hearing of the Subcommittee on Consumer and Environmental Affairs. "If ozone loss reaches 10 percent by the year 2000, as expected, there will be about a quarter of a million additional cases of skin cancer annually and an estimated 4,000 more deaths," said Lieberman. "More than a million additional cases of cataracts will occur by the end of this decade." What's more, newly emerging evidence suggests that the sun's UV radiation may profoundly damage the immune system, the body's main defense against infectious diseases. Thus, consumers must ask whether sunscreens and sunglasses can sufficiently protect their immune function from the increasingly large doses of UV radiation to which they are being exposed.Lieberman noted that even those sunglasses labeled "UV protection" provide consumers with inadequate information "about how much ultraviolet light is actually reaching their eyes, and unfortunately there is no oversight by the government to test the truthfulness of the specific numbers that do appear on some sunglasses. We are left to trust those who produce the glasses." The Sunglass Association of America (SAA), working with the FDA, has developed a voluntary program of labeling to inform consumers about how much UV-radiation protection a pair of sunglasses provides. Yet "manufacturers represented in that group...cover only about 40 percent of the market," said Lieberman. Testifying at the Senate subcommittee hearing, Edward C. De Fabo of the Department of Dermatology at George Washington University Medical Center declared that reliance on sunscreens "to prevent the potentially deleterious immunosuppressive effects of [ultraviolet radiation] cannot be recommended, given the large amount of data in the scientific literature on their inability to protect against immunosuppression. Thus, although sunscreens do indeed help protect against the initiation of new skin tumors [and] sunburn, if they do not protect against [solar radiation]-induced immunosuppression, then they may not protect against the growth of tumors which may have been initiated previously, perhaps even in early childhood."In the early 1980s, De Fabo found that UV-radiation-related immune suppression is triggered by urocanic acid (UCA), which is found in natural abundance in the outermost layer of skin. When UCA absorbs UVB radiation, it literally "bends" and changes shape into a form that is immunologically very active and damaging, warned De Fabo in his testimony before the Senate subcommittee. Since UCA "virtually sits on the surface of skin," it is of "considerable importance in trying to understand the role of sunscreens and immune suppression." Beyond its effects on UCA, solar radiation damages the skin's Langerhans cells, which help the body recognize foreign "invaders," enabling it to mount positive immune responses, noted David H. Lynch in the May 1981 issue of the Journal of Immunology. Animal studies have shown that "under the right conditions of ultraviolet exposure with the right timing of the infection, we can actually decrease immunity to infectious agents, such as the herpes simplex virus [or] mycobacteria, which are the causative agents of tuberculosis and leprosy in humans," testified Margaret L. Kripke, chairperson of the Department of Immunology, University of Texas M.D. Anderson Cancer Center. "Ultraviolet radiation not only can decrease the immune response against these organisms but can also increase the pathogenesis and the severity of diseases caused by these agents." Individuals vary considerably with regard to their sensitivity to this form of UV-induced immune suppression. "Some people are suppressed by very low doses of UV radiation; others require much higher doses," observed Kripke. Interestingly, the amount of pigment in the skin seems to be unrelated to one's relative degree of resistance to UV-induced immune suppression.The ultimate scenario is a horrific one. If global warming continues and the ozone layer is further depleted, UV suppression of the immune system may result in an increasingly lethal inability to fight off disease, wrote Dr. Alexander Leaf in the June 15, 1994, issue of Hospital Practice. Such immune suppression, combined with overcrowding caused by the displacement of people to geographic areas less affected by ozone depletion, would increase the spread of infectious diseases, he added. For now, the most obvious manifestation of immune suppression in the U.S. is the epidemic of skin cancer. One in six Americans will develop the disease in their lifetime, according to Dr. Jane M. Grant-Kels of the Division of Dermatology, University of Connecticut Health Center. Between 1950 and 1970, the death rate from melanoma, the most serious and potentially fatal type of skin cancer, doubled, she testified. "The incidence of melanoma is presently rising at a faster rate than that of any other cancer." In the meantime, people are lulled into a false sense of security when they use sunscreens. "We seem to lose protection against immunological effects before we lose protection against sunburn," Kripke said, adding that her research demonstrates that sunscreen products with the same sun-protection factor (SPF) "appear to have different abilities to protect against immunological damage." Consumers ought to be warned that such products "may not be protecting [the] immune system," De Fabo asserted. Still, he believes that people should continue using both sunscreens and sunglasses. The key to protecting oneself is to become more sun savvy, especially during spring and summer. Dermatologist Dr. Karen Burke, of the Cabrini Medical Center in New York, offers the following advice: *Guard against passive sun exposure. Those ten and twenty-minute spurts of unprotected sun exposure, running errands on a lunch break, for example, take a cumulatively destructive toll on the skin over the years. *Office "palefaces" should avoid quick-roasting themselves on their two-week vacations, as they end up with higher rates of melanoma. *Stay out of the sun during peak hours (10 a.m. to 2 p.m., or 11 a.m. to 3 p.m. during daylight savings time.) *When exposed to direct sunlight, cover up with a densely woven, wide-brimmed hat, as well as densely woven long-sleeved shirts and pants or a beach robe. Also consider using a protective beach umbrella. *Don't be fooled when it is cool, wet, or cloudy: under such conditions, one can still receive a hefty dose of UV radiation.Burke does recommend the use of sunscreens and offers the following cautionary guidelines: *During the summer, use a sunscreen with an SPF of 25 to 30. Those with an SPF over 30 are not the best choice, because they have many preservatives and are less moisturizing. Apply sunscreen liberally 15 to 30 minutes before exposure to allow the chemicals to penetrate and still leave a protective layer on the skin. *Read labels. Seek a sunscreen certified by the Skin Cancer Foundation as being protective against both UVA and UVB radiation. *Apply sunscreen frequently while in the sun. *Even if using a waterproof sunscreen, reapply it after getting wet or perspiring. *Use sunscreen during high-altitude activities, such as mountain climbing or skiing. *Be aware that reflective surfaces, including sand, snow, concrete, and water, will increase your exposure.For children, follow these additional guidelines: *Schedule playtime so that kids are indoors when UV radiation is most intense. *Keep kids under wraps. The tender skin of babies and young children is especially vulnerable to burns. Keep very young infants off the beach, and older babies covered up in the shade. Begin using sunscreen on children at six months, then allow only moderate sun exposure.As for sunglasses: *Find out how much UV radiation they block, and select only those that claim to block the most. *Wraparound sunglasses block out much more light than other styles.The phase-out of ozone-destroying pollutants is not expected to occur until the year 2000 and will not, according to Leaf, have an impact on human health for another century. Meanwhile, the immediate health problems must be addressed. The best solution would be for government and industry to provide uniform disclosure guidelines for all sunglass and sunscreen products. Then consumers like Harrison could make more informed choices about the products they buy to protect themselves from the sun -- and about the way they live their lives. Their long-term health depends on it.