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    Sunday, July 16, 2006

    Article: Are You a Mosquito Magnet?

    In this time of increasing outdoor fun, a lot of people want to know how to beat the becoming dinner blues. I have reposted the article in it's entirety, but give SERIOUS WARNING to anyone who considers using DEET-containing repellants. DEET is effective, but deadly. I forget where I saw it, but catnip oil is just as effective as DEET (yes there are scientific studies). I am currently in the process of developing a Snake Oil based, chemical free, mosquito repellant that is applied via a stick-type applicator so that your hands don't end up covered in repellant-goo. You'll just have to bear with me in waiting for that one to come to fruition. *chuckle*)

    Experts try to crack the code behind why mosquitoes like some humans more
    than others.
    By Elizabeth Heubeck, M.A.
    WebMD Feature

    You're flipping burgers for the neighborhood barbecue, and the mosquitoes
    have already begun their feast -- on you. As you swat madly at the pests, you
    notice other folks seem completely unfazed. Could it be that mosquitoes prefer
    dining on some humans over others? This may clear up the mystery.
    It's true. Mosquitoes do exhibit blood-sucking preferences, say the experts.
    "One in 10 people are highly attractive to mosquitoes," reports Jerry
    Butler, PhD, professor emeritus at the University of Florida. Incidentally, it's
    not dinner they're sucking out of you. Female mosquitoes -- males do not bite
    people -- need human blood to develop fertile eggs. And apparently, not just
    Who Mosquitoes Like Best
    While researchers have yet to pinpoint what mosquitoes consider an ideal
    hunk of human flesh, the hunt is on. "There's a tremendous amount of research
    being conducted on what compounds and odors people exude that might be
    attractive to mosquitoes," says Joe Conlon, PhD, technical advisor to the American
    Mosquito Control Association. With 400 different compounds to examine, it's an
    extremely laborious process. "Researchers are just beginning to scratch the
    surface," he says.
    Scientists do know that genetics account for a whopping 85% of our
    susceptibility to mosquito bites. They've also identified certain elements of our body
    chemistry that, when found in excess on the skin's surface, make mosquitoes
    swarm closer.
    "People with high concentrations of steroids or cholesterol on their skin
    surface attract mosquitoes," Butler tells WebMD. That doesn't necessarily mean
    that mosquitoes prey on people with higher overall levels of cholesterol,
    Butler explains. These people simply may be more efficient at processing
    cholesterol, the byproducts of which remain on the skin's surface.
    Mosquitoes also target people who produce excess amounts of certain acids,
    such as uric acid, explains entomologist John Edman, PhD, spokesman for the
    Entomological Society of America. These substances can trigger the mosquitoes'
    olfactory sensations, or sense of smell, causing them to launch their
    "landing" onto unsuspecting victims.
    But the process of attraction begins long before the landing. Mosquitoes can
    smell their dinner from an impressive distance of up to 50 meters, explains
    Edman. This doesn't bode well for people who emit large quantities of carbon
    "Any type of carbon dioxide is attractive, even over a long distance,"
    Conlon says. Larger people tend to give off more carbon dioxide, which is why
    mosquitoes typically prefer munching on adults to small children. Pregnant women
    are also at increased risk, as they produce a greater-than-normal amount of
    exhaled carbon dioxide. Movement and heat also attract mosquitoes.
    So if you want to avoid an onslaught of mosquito bites at your next outdoor
    gathering, stake out a chaise lounge rather than a spot on the volleyball
    team. Here's why. As you run around the volleyball court, the mosquitoes sense
    your movement and head toward you. When you pant from exertion, the smell of
    carbon dioxide from your heavy breathing draws them closer. So does the lactic
    acid pouring from your sweat glands. And then -- gotcha.
    Where Mosquitoes Lurk
    Even if your body chemistry doesn't attract mosquitoes, where you're located
    Some of the worst mosquito populations exist along coastal areas, Conlon
    tells WebMD. And being several miles inland does not guarantee your safety from
    the pests. "They'll fly 40 miles for a meal," Conlon says.
    Are You a Mosquito Magnet?
    While any water source is potential breeding grounds for mosquitoes, they
    much prefer stagnant water. So if you crave a mosquito-free water oasis on your
    property, forego the backyard pond and seek out a babbling brook instead.
    "Even in a desert area, mosquito biting tends to be intense around a water
    source," Conlon says.
    Can you find respite high in the mountains? Don't count on it. Although
    they're generally not active below 55 degrees Fahrenheit, mosquitoes have been
    sighted in the Himalayan Mountains, Conlon tells WebMD.
    How about cold climates in places such as Alaska? You're safe for most of
    the year. But, says Conlon, mosquitoes flock there for a brief, three-week
    period between July and August. "The Arctic National Refuge is one big bog,"
    Conlon explains, making the mosquito population there second only to that in the
    Florida Everglades.
    With a long track record -- mosquitoes have been around for 170 million
    years -- and more than 175 known species in the U.S., these shrewd summertime
    pests clearly aren't going to disappear any time soon. But you can minimize
    their impact.
    Keeping the Bite at Bay -- Chemical-Based Repellents
    Plenty of mosquito repellents line the shelves of drug stores and
    supermarkets each summer, but they're not all created equally.
    The majority of available mosquito repellents derive their effectiveness
    from chemicals. Protecting the public from mosquitoes since 1957, DEET continues
    to be the chemical of choice used in repellents. In repeated studies, it's
    been proven the most effective chemical repellent on the market. Repellents
    with 23.8% DEET (most formulas contain between 10% and 30%) protect wearers for
    about five hours, according to a recent study led by Mark Fradin, PhD,
    researcher with Chapel Hill Dermatology. The American Academy of Pediatrics and
    other experts suggest that it is safe to apply repellent with low
    concentrations of DEET (10% or less) to infants over 2 months old.
    In 2005, the CDC began recommending alternatives to DEET for repelling
    mosquitoes. Picaridin, which is new to the U.S., has been used worldwide since
    1998. It has proven to be as effective as DEET but is more pleasant to use
    because it has a light, clean feel and is virtually odorless. Picaridin is safe
    for children older than 2 months. This substance is marketed as Cutter Advanced.

    The other new CDC recommendation is oil of lemon eucalyptus, which is
    available under the Repel brand name. This product offers protection similar to low
    concentrations of DEET. Lemon eucalyptus is safe for children older than 3
    The chemical IR3535, better known as Avon's Skin-So-Soft, has also been
    marketed as a repellent in the U.S. in recent years. To date, research shows it's
    much less effective than DEET.
    Safety of DEET Repellents
    Just how safe is it to coat yourself in a chemical-based product like DEET
    just to keep from getting bit by mosquitoes?
    "[DEET] has been in use for over 40 years and has a remarkable safety
    record. Only few hospitalizations have been reported, mainly due to gross overuse,"
    Conlon tells WebMD.
    The Environmental Protection Agency (EPA), after extensively assessing the
    safety of DEET, concluded that "as long as consumers follow label directions
    and take proper precautions, insect repellents containing DEET do not present
    a health concern." The agency does, however, offer the following safety
    strategies for DEET use:
    * Follow label directions and precautions.
    * Use sparingly.
    * Avoid spraying on or near open skin, eyes, mouth, and nose, under
    clothing, or near food.
    * Wash treated skin with soap and water.

    The American Academy of Pediatrics (AAP) provides these additional
    recommendations for DEET use on children:
    * Select the lowest concentration effective for the amount of time
    spent outdoors.
    * Avoid use on infants under 2 months of age.
    * Avoid repeated applications, which may increase the potential toxic
    effects of DEET.

    Alternative Repellents
    Want to avoid chemical-based repellents altogether? Alternatives do exist,
    with one or two showing promise.
    "Of the products we tested, the soybean oil-based repellent was able to
    protect from mosquito bites for about 1.5 hours," Fradin reports. He and fellow
    researchers found other oils -- citronella, cedar, peppermint, lemongrass, and
    geranium -- provide short-lived protection at best. Oil-of-eucalyptus
    products, however, may offer longer-lasting protection, preliminary studies show.
    Hate to spray or slather yourself with any product, either chemical- or
    plant-based? Mosquito traps, a relatively new product, may be the answer. They
    work by emitting substances that biting mosquitoes find attractive -- such as
    carbon dioxide, heat, moisture, and other mosquito-friendly byproducts. They
    attract, then trap or kill female mosquitoes. When placed strategically near
    breeding spots "they have knocked [mosquito] populations down," Conlon tells
    So, is it worth the effort it takes to prevent mosquitoes from nipping at
    your ankles? Yes, if you don't want to be bothered by bouts of mosquito-induced
    itching all summer long. Certainly, if you are one of the few unfortunate
    souls in whom mosquito bites result in severe allergic reactions. And most
    definitely if you believe you're likely to be exposed to potentially fatal
    mosquito-borne diseases, some of which are becoming increasingly common. Take the
    mosquito-transmitted West Nile virus, for instance which Conlon says "is
    probably here to stay." And with it, the age-old, ever-adaptable mosquito.
    Published July 12, 2004.
    Medically updated May 25, 2006.

    SOURCES: Jerry Butler, PhD, Professor Emeritus, University of Florida. Joe
    Conlon, PhD, technical advisor, American Mosquito Control Association. John
    Edman, PhD, Entomological Society of America; and Center for Vector-Borne
    Disease Research, University of California-Davis. Mark Fradin, PhD, Chapel Hill
    Dermatology, North Carolina. Environmental Protection Agency web site. The
    American Academy of Pediatrics Committee on Environmental Health web site.

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