Avoid Mosquito Bites, West Nile and Toxins This Summer

The mosquito — that annoying harbinger of warm weather — is back. And increasingly, the blood-sucking pests aren’t just taking our blood and leaving itchy bumps behind, they are also leaving viruses and spreading panic in an easily panicked population.

With the mysterious SARS shocker still in our collective memory, people are now preparing for the return of the West Nile Virus (WNV), which killed 17 people in Ontario last year.

And much like SARS, people should maintain a little perspective about the illness. Many more people will die as a result of poor air quality in Toronto this year than will die from WNV. But that doesn’t stop people from worrying and besides, mosquitoes are annoying at the best of times. Avoiding bites is now a healthcare concern.

What should be avoided when it comes to mosquitoes is allowing repellant measures to be worse than the illness — or the risk of the illness. One should be aware of the risks of the disease and balance those against the risks of the almost universally touted DEET, (diethyl-meta-toluamide).

There are alternatives — and ones that work — without the toxicity. DEET clearly works better than any other insect repellant tested but the toxic effects of this compound created by the U.S. Department of Agriculture in the 1950s for military use are undeniable.


There is a massive campaign pushing DEET as the only way to repel insects. Organizations such as the U.S. Center for Disease Control and Health Canada are not only giving timid warnings about DEET’s toxicity but they are in fact pushing DEET as a healthcare option in the prevention of WNV.

This is being done despite Health Canada’s move to ban products containing more than 30% DEET by December, 2004. While they are banning the stronger concentrations of DEET out of one side of their mouth, Health Canada is suggesting that the product can be used on babies as young as six months.

I can tell you first hand from years of working in the bush that this is a substance that melts plastic, disintegrates most fabrics, and leaves nasty rashes on exposed skin. I have personally seen a treeplanter evacuated off a clearcut with toxic shock syndrome as a result of over-applying 95% DEET. Incidentally, it has been suggested that the lower percentage DEET repellants may actually be worse because the alcohol increases absorption (not to mention that people reapply them more often).

DEET has been positively linked to dermal and neurological problems, and several cases of toxic encephalopathy (brain damage) associated with the use of DEET have been reported in the medical literature. Generalized seizures have been also associated with the use of DEET. In addition, DEET is linked — in combination with other chemicals — to the Gulf War Syndrome that affected U.S. soldiers in the 1990s.

Duke University Medical Center pharmacologist, Mohamed Abou-Donia, made the link between DEET and Gulf War Syndrome and has studied it closely. In 2002 Abou-Donia said that frequent and prolonged applications of DEET cause neurons to die in the region of the brain that control muscle movement, learning, memory, and concentration.

Children in particular are at risk for subtle brain changes because of their developing nervous systems and because their skin more readily absorbs chemicals.

“Never use insect repellants on infants, and be wary of using them on children in general,” Abou-Donia said. “Even so simple a drug as an antihistamine could interact with DEET to cause toxic side effects … Until we have more data on potential interactions in humans, safe is better than sorry.”

And safe does not mean using DEET to stop bug bites, it means not using DEET at all.

Michael Downey reported on DEET in Vitality last year and quoted Dr. Hebert from the University of Texas Medical School in Houston. Hebert has said that children who absorb high amounts of DEET have developed seizures, slurred speech, hypotension (low blood pressure), and bradycardia (slowing down of the heart rate). And adults don’t fare much better.

When you combine all the indictments of DEET and its effect on children with the fact that none of the 17 people who died in Ontario last year — or any of the 201 who died in U.S. — were younger than 20, it looks pretty irresponsible to use the product on kids and just plain silly to use it on yourself.


The biggest knock on essential oils as insect repellants — and consequently the argument in favour of DEET — is not that they don’t work, but rather that they don’t last as long as DEET. But as Jane Sheppard Harris, editor of says, “Reapplying the essential oils is a small price to pay for keeping a child protected from insects while free from potentially harmful insecticides.”

Clinical Herbalist Michael Vertolli says that essential oils with insect repellant properties come in three general categories: lemony scented oils such as citronella, lemon grass, lemon and lemon verbana; conifer oils like pine, fir, spruce, cedar and cypress; and general aromatics like basil, lavender, eucalyptus and geranium.

“I prefer to mix one or two items from each of these three categories,” Vertolli writes. “In total, use 15-20 drops of all essential oils for every 25 ml of your base (do not use 15-20 drops of each oil.)”

As a base Vertolli says you can use vegetable oil, oil/ alcohol or water/alcohol/ glycerin.

Essential oil repellants are widely used and there are many alternatives to DEET available on your health food store shelves. There are also all kinds of folk remedies to avoid mosquito bites — almost as many as there are species of mosquitoes.

Through a polling of various experts on the topic it has been suggested that bugs are repelled by: garlic, elder leaves, catnip, tansy leaves, lavender, pennyroyal, sasafras, lemongrass, peppermint, marigolds, and the list goes on.

The most widely touted repellant amongst those I spoke with was neem oil. Neem is an East Indian herb used not only to repel bugs but to heal wounds. Registered herbalist Carol Little says she is a fan of a spreadable gel with a base of neem oil.

“Neem is a wonderful plant and recognized in many countries for its healing and insect repellant properties,” Little says. This is illustrated well in a quote she provided from a 1993 article in the Journal of the American Mosquito Control Association: “Two percent neem oil mixed in coconut oil, when applied to the exposed body parts of human volunteers, provided complete protection for 12 hours from the bites of all anopheline (mosquitoes that carry malaria) species. Application of neem oil is safe and can be used for protection from malaria in endemic countries.”

Jane Sheppard Harris also lauds neem for its beneficial qualities. “Neem oil is a higly effective, non-toxic, child safe bug repellant 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,” she says. “The National Research Council found that Neem is known to affect more than 200 species of insects.”

As they did with SARS, the Canadian Naturopathic Association (CNA) has released a handout on West Nile Virus. While the CNA is toeing the Health Canada line and suggesting that DEET should be used — albeit with caution — they do also offer some alternatives. The CNA handout suggests making an essential oil repellant consisting of: 20 drops eucalyptus oil, 20 drops cedar wood oil, 10 drops tea tree oil, 10 drops geranium oil mixed with 2 oz of carrier oil. Mix together and apply to skin avoiding the eye area.

Other options the CNA suggest include: planting marigolds around the yard or applying pure vanilla mixed half and half with water to the skin. They also suggest Avon ‘Skin-So-Soft’ hand cream, lavender oil and citronella oil.


One of the obvious ways of avoiding mosquito bites is to simply stay indoors. Not a great option for many but at least minimizing the time you spend outside at dusk and dawn helps. Also of course, covering your skin with long sleeves and even wearing a bug hat or bug shirt will simply keep the nasties away.

Those who have spent any significant time in the bush will say, the more you smell like something that doesn’t belong there, the more the bugs will get you.

Vitality editor Julia Woodford suggests that staying stinky is the way to go.

“I think the sweet smells of city slickers are very attractive to mosquitoes and the best way to pass under their radar is by getting naturally stinky,” she says. “So if you’re going into a bug-infested area, don’t use commercially-scented shampoos, soaps, deodorants, laundry soap, or toothpastes. If you don’t want to repel people too then use personal hygiene products containing good esssential oils that repel bugs. I like Thursday Plantation tea tree oil both for prevention and treatment of bug bites. Even better, if you’re in the bush camping, don’t wash with soap at all, and stand in the smoke of a campfire for a few minutes every day. Also, do yoga to calm your countenance, as an agitated mind will attract the notice of all the creatures of the forest.”

Avoiding mosquitoes is a good way of avoiding the diseases they carry but as with SARS, the CNA is suggesting that people don’t get sick because they didn’t use the right precautions — they get sick because their immune system is weakened and unable to fight the infection. Of those infected by WNV, about 70 to 80% will have no symptoms because of the health of their immune system and so they won’t even know they had the illness. There is less than a 1% chance that infections will result in severe illness or neurological disease and the most significant risk factor is advanced age and a compromised immune system.

There have been suggestions that, as with chicken pox and the mumps, WNV might be something that is not that dangerous to children and so they should be allowed to get bitten. They might then be protected for the rest of their lives. This has been the experience in endemic countries like Uganda.

That said, no one likes mosquitoes and no one really wants to get bitten anyway. If you do try to protect yourself this mosquito season make sure you keep WNV in perspective as a dangerous disease, try to maintain your overall health in the first place, pick your repellants carefully and use DEET at your peril.

• Neem products are available in health food stores and Indian groceries.
• Michael Vertolli is the director of Living Earth School of Natural Therapies (416) 591-0400.

Write a Comment

view all comments

Your e-mail address will not be published. Also other data will not be shared with third person. Required fields marked as *