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from Natural Life Magazine
July/August, 2008 Q: I’m worried about the dangers of sun exposure and the diseases that are carried by biting bugs. But I’m also worried about how to protect myself and my family without exposing us to equal or greater dangers from sunscreens and bug repellants. What should I do? A: You’re right to be concerned. Both conventional sunscreen products and bug repellants have been shown to have health and environmental problems. Sunscreens Getting a little sunshine (experts say that just 10 to 20 minutes a day is enough) is important for helping our bodies generate Vitamin D, which is hugely important to our health. However, too much sun exposure can cause sunburn and skin cancer. Sunburn is caused by Ultraviolet B (UVB) rays, which are partially absorbed by the ozone layer and don’t penetrate our skin very deeply . However, 90 percent of the sun’s ultraviolet radiation is in the form of Ultraviolet A (UVA) rays, which are not absorbed by the ozone layer and penetrate deep into our skin. Both types can cause skin cancer. Most sunscreens do fairly well at absorbing UVB radiation but many don’t screen UVA rays at all, although new chemicals are being developed to that end. Sunblocks provide a barrier to both types of rays. The Sun Protection Factor (SPF) that you see on packaging measures only UVB protection, creating a false sense of protection for those who feel they can bask for hours in the sun without worrying about skin cancer. According to the Environmental Working Group (EWG), which has studied the issue in depth, most of the commercially available products do not provide adequate protection and may also contain chemicals with questionable safety records. In recent research, EWG reviewed nearly 400 scientific studies, industry models of sunscreen efficacy, and toxicity and regulatory information from nearly 60 government, academic and industry databases. They also tested 831 sunscreen products, finding health and environmental problems with 84 percent. Many contained potentially harmful chemicals like benzophenone, homosalate and octyl methoxycinnamate, which are known to mimic estrogen. Some also contained padimate-0 and avobenzone, which are suspected of causing DNA damage when exposed to sunlight. Several are strongly linked to allergic reactions and still others may build up in the body or the environment. As far back as the late 1970s, scientists have known that these substances are absorbed by the skin. After research funded by the U.S. Food and Drug Administration, University of California Professor Howard Maibach warned in a 1978 report that up to 35 percent of sunscreen can pass through the skin and enter the bloodstream. As we reported in our March/April feature about nanotechnology, many sun products contain nano-scale ingredients like zinc oxide and titanium dioxide. While these minute ingredients do not penetrate healthy skin, there have been concerns raised about the lack of research into the health and environment issues surrounding nanotechnology. Insect Repellants Insect bites are the other issue that sparks debate over which risk is greater – in this case, the risk of the potentially deadly West Nile Virus and other infections like Lyme Disease or the risk posed by toxic chemicals in insect repellants. Since there is no vaccination or cure for West Nile Virus, prevention is crucial. The most effective repellant is said to be DEET (N,N-diethyl-m-toluamide, diethyltoluamide), which is the active ingredient in many bug sprays and lotions. It is a registered pesticide – one of the few applied directly to human skin – and a member of the toluene chemical family. Toluene is an organic solvent used in rubber and pastic cements and paint removers. And yes, DEET can melt plastic and certain synthetic fibers. DEET is absorbed through the skin and passes into the blood. According to some research, up to 56 percent of DEET applied topically penetrates intact human skin and 17 percent is absorbed into the bloodstream. It can cause skin irritation, but the most serious concerns about DEET involve its potential effects on the central nervous system. Dr. Mohammed Abou-Donia of Duke University studied lab animals’ performance of neuro-behavioral tasks requiring muscle co-ordination. He found that lab animals exposed to the equivalent of average human doses of DEET performed far worse than untreated animals. He also found that combined exposure to DEET and permethrin, a mosquito spray ingredient, can lead to motor deficits and learning and memory dysfunction. There are also a few studies pointing to toxicity in rats, rabbits and other animals. However, those who favor the use of DEET because of the West Nile threat point out that the number of human case reports is relatively small. Between 1961 and 2002, according to researchers, there were only 23 reported cases of possible neurological symptoms associated with DEET use in the U.S. and six were deliberate ingestions. In a 1994 report reviewing 9,086 cases of DEET exposure from 71 poison control centers in the United States, the most severe reactions to DEET were found to be caused by inhalation or eye contact, not skin application. In reality, most of the milder reactions probably go undetected and unreported due to their vague nature. Of the cases studied, most were children under eight, and some were due to accidental ingestion. The effects ranged from irritability, lethargy, headaches and muscle or joint pain to seizures and convulsions; a few were fatal. DEET should not be used for children under six months of age. Health Canada currently recommends that “on children aged six months to two years the use of one application per day may be considered in situations where a high risk of complications from insect bites exist – the product be applied sparingly and not be applied to the face and hands; only the least concentrated product (10 percent DEET or less) should be used; prolonged use be avoided.” For children over two, DEET-containing products shouldn’t be used more than three times a day. The Children’s Health Environmental Coalition recommends that you avoid exposure to DEET altogether. Oddly enough, there are few reports about DEET’s effect on pregnant women. However, a review of its safety published in 2003 in the Canadian Medical Association Journal found a few studies showing it can cross the placenta and expose babies in the womb to possible damage. While there was no evidence found of health effects resulting from exposure during the second and third trimesters, the study, headed by Dr. Gideon Koren of the Hospital for Sick Children in Toronto, recommended that pregnant women avoid the use of DEET during their first trimester. Neither is there much information about DEET’s environmental effects. Its registration category doesn’t require ecological assessments, but it has commonly been detected in aquatic water samples from around the world, indicating that it is both mobile and persistent, despite earlier assumptions that it was unlikely to enter aquatic ecosystems. It has been found to have a slight toxicity for coldwater fish such as rainbow trout and tilapia and to be toxic for some species of freshwater zooplankton. Experts also advise avoiding other controversial repellents such as permethrin or malathion, which are stronger pesticides and should not be applied to the skin, especially children’s. Malathion is used as a treatment for head lice and scabies and sometimes aerial sprayed as part of West Nile Virus campaigns. Alternatives Unless you’re hiking the desert or the Amazon, you should be able to reduce if not avoid excessive sun exposure and insect bites without the use of chemical sunscreens and insect repellants. First of all, there is avoidance. Stay out of the sun when it is the most intense. Use shade, hats, sunglasses and clothing to protect yourself and your children from the sun. Mosquitoes are active at dusk and near standing water, situations which can usually be avoided. Wear light colored clothing, which heats the skin less, minimizing insect-attracting perspiration. Long-sleeved shirts and pants, or even specially designed “bug wear,” reduce the amount of exposed skin. Socks and closed shoes or boots, and pant legs tucked into socks are also helpful. Avoid using scented soaps or other fragranced products. And avoid outdoor activity at dusk when mosquitoes are most active. If you have pets that live both indoors and out, check their fur frequently for crawling or embedded ticks that may be carried into your home. Eating more fresh vegetables and berries will increase antioxidant levels, which helps protect skin from sun damage. Studies on vitamin C and grape seed extract have demonstrated that they offer protection from UVA radiation by combating free radicals. Merely growing a plant beside your deck will not repel insects. But there are a number of plants whose leaves contain essential oils that, when crushed and applied to the skin or made into homemade concoctions, do repel mosquitoes. Plants whose essential oils have been reported to have repellent activity include citronella, cedar, verbena, geranium, lavender, pine, catnip, cinnamon, rosemary, basil, thyme, allspice, garlic, lemon eucalyptus, lemon balm, peppermint and even soy. Calendula ointment is also an excellent insect repellent. Most of these essential oils give short-lasting protection, usually less than two hours. Health Canada states that citronella and oil of lavender should not be used on children under two years of age. Neem oil is a highly effective, non-toxic, child-safe bug repellent that can also be used on open sores and wounds. Neem heals wounds, cuts, sores, poison oak or ivy, and has anti-bacterial, anti-fungal and anti-viral properties. The National Research Council of Canada has found that neem affects more than 200 species of insects, including mosquitoes, biting flies, sand fleas and ticks. You can locate natural sunscreens or discover the ingredients in your favorite brand by consulting the Skin Deep database at www.cosmeticsdatabase.com. And you can find out if DEET is an ingredient in a particular insect repellant on the Pesticide Action Network’s Pesticide Database at www.pesticideinfo.org. Have a natural summer! Author Wendy Priesnitz is the Editor of Natural Life Magazine and a journalist with over 30 years of experience. She has also authored nine books. Read her blog. |
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