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, homo- salate 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
article 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.
There has been some controversy about the use of sunscreens and the fact
that they can prevent our bodies from producing Vitamin D. Unfortunately,
there are conflicting studies about this. Some lab studies demonstrate that
sunscreens can reduce ultraviolet-radiation-generated vitamin D in the skin,
but on the other hand, several large, controlled studies have shown that
vitamin D deficiency does not result from regular sunscreen use. However,
since regular sun exposure can cause premature aging of the skin, the risk
of skin cancer, macular degeneration, and DNA abnormalities, you might want
to have your Vitamin D level checked and consider taking a supplement just
to be safe (and implement the other sun-safe behaviors later in this
article.)
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,” re duce 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.
Have a naturally safe summer!
Author Wendy Priesnitz is the Editor of
Natural Life Magazine and a journalist with over 40 years of
experience. She has also authored 13 books.
