Most of us are all too familiar with the itch, and even pain, that comes from mosquito bites. The annoying sensation lingers for days and is hard to ignore.
But mosquitoes also present very real threats to public health. With Zika virus cases expanding in the United States, causing birth defects, and with risks of encephalitis, malaria and West Nile virus, mosquitoes are more than just a nuisance. Their threat of disease transmission should be taken seriously, and mosquito prevention should be an important part of everybody’s outdoor excursions.
Why Do Mosquitoes Bite Humans?
Mosquitoes are drawn to the carbon dioxide we release when we breathe. In addition, they’re quite fond of certain odors of our skin. Basically, we’re walking food magnets for the annoying, and sometimes deadly, pest.
No wonder we all want to reach for a can of bug spray any time we’re exposed to mosquitoes. But not all mosquito repellents are created equal. And not all are safe.
Not All Repellents Are Good for the Skin
DEET was originally developed to protect American soldiers from mosquitoes in tropical climates during World War II, and the chemical has become the go-to ingredient in many repellents.
But DEET is a chemical, and some repellents containing DEET can cause rashes and skin irritations. Frequent use can even cause blisters and scarring.
Not All Repellents Are Good for Your Health
While the EPA has deemed DEET to be to be safe in certain concentrations, the EPA made its assumption based on the fact that most people don’t use repellents regularly. They actually placed DEET in Category 3 of a four-category ranking system, meaning they deem DEET to be “slightly toxic.”
In 2002, Duke University published a study that recommended caution when using DEET because it was found that “the chemical causes diffuse brain cell death and behavioral changes in rats after frequent and prolonged use.”
Health Canada has even banned products with more than 30 percent of the chemical. If you are someone who needs to use repellent regularly, the risks of DEET entering your bloodstream and potentially harming your brain or organs is terrifying.
And most of us would rather use products with natural ingredients that don’t pose those kinds of risks. Period.
Effective… For Now
One study showed that DEET may be losing its effectiveness. Researchers from the London School of Hygiene and Tropical Medicine tested A. aegypti mosquitoes, exposing them to DEET. The first exposure worked, and the scent caused the mosquitoes to stay away from a potential meal. However, a few hours later, when the meal was brought back, the DEET was less effective.
“There is something about being exposed to the chemical that first time that changes their olfactory system – changes their sense of smell – and their ability to smell DEET, which makes it less effective,” said Dr. James Logan from the London School of Hygiene and Tropical Medicine.
The Benefits of Natural Repellents
Natural mosquito repellents, on the other hand, do not need to register with the EPA as their active ingredients were evaluated in the 1990s and found to pose “minimal risk to human health in the percentages found on the market.” Some of the ingredients they evaluated were citronella oil, cedar oil, geranium oil, peppermint oil, and soybean oil.
Also, soybean and other oils have been shown to be as effective as some concentrations of DEET. The bonus? They’ve also been shown to be non-irritating to the skin.
For those searching for natural, non-toxic insect repellents, you can also read up on a company to see if they have conducted any tests of the effectiveness of their repellent. The good news is that there are natural repellents that have been shown in independent tests to be as effective as DEET.