If you insist on using chemical laden insect repellents containing DEET, you may be getting more than you bargained for -- including damage to your central nervous system. In fact, scientists writing in the open access journal BMC Biology don't just say that more studies should be done to confirm DEET's potential neurotoxicity to humans. The researchers are calling for more investigations of the chemical to be conducted on an urgent basis. The reason? They suspect that the potential brain cell damaging effects of DEET could be particularly harmful if used in combination with other neurotoxic insecticides. And that's exactly the way DEET is normally used in products applied to both adults and kids in order to prevent mosquito bites.

French scientists Vincent Corbel from the Institut de Recherche pour le Developement in Montpellier and Bruno Lapied from the University of Angers headed a team of researchers who studied the mode of action and toxicity of DEET, also known by the chemical name N-Diethyl-3-methylbenzamide. "We've found that DEET is not simply a behavior-modifying chemical but also inhibits the activity of a key central nervous system enzyme, acetycholinesterase, in both insects and mammals," Corbel said in a statement to the media.

DEET has been in use since its discover in l953 and is now the most common ingredient found in insect repellent preparations. It is primarily hyped as a way to keep mosquitoes at bay and doctors and insect repellant manufacturers promote DEET's use through scare tactics, suggesting you are likely to get West Nile fever from mosquito bites unless you use the chemical.

Of course, not every mosquito bite spreads any kind of infection and West Nile fever is not always serious. What's more, a host of natural strategies, from wearing long sleeves and pants in areas plagued by mosquitoes to using a variety of herbal extracts and essential oils topically, can help you avoid bug bites and stings without chemicals. Yet DEET remains promoted by the mainstream media and medical establishment as the ingredient that protects adequately against mosquito bites and disease.

Consider this worrisome statistic: each year approximately one-third of all Americans spray and slather on insect repellents containing central nervous system toxin DEET. And this is in spite of the fact that previous studies have warned of DEET's dangers. For example, earlier research by Duke University Medical Center pharmacologist Mohamed Abou-Donia, who has spent 30 years studying the effects of pesticides, found that prolonged exposure to DEET can impair functioning in parts of the brain and could result in problems with muscle coordination, muscle weakness, walking or even memory and cognition.

In the new study, Corbel and his colleagues discovered that DEET inhibits the acetylcholinesterase enzyme. This is the exact effect organophosphate and carbamate insecticides have on the body, too. Alarmingly, these insecticides are often combined in products with DEET -- and the scientists found that DEET interacts especially well with carbamate insecticides, magnifying their toxicity. "These findings question the safety of DEET, particularly in combination with other chemicals, and they highlight the importance of a multidisciplinary approach to the development of safer insect repellents for use in public health," Corbel stated.

Another study published earlier this summer in the Journal of Agricultural and Food Chemistry, a peer-reviewed journal of the American Chemical Society, showed that a natural substance, cinnamon oil, shows promise as a great-smelling, environmentally friendly pesticide, with the ability to kill mosquito larvae. The researchers also believe that cinnamon oil could be a good mosquito repellant, though they have not yet tested it against adult mosquitoes. Historically, however, cinnamon oil has been used by natural health practitioners and traditional healers to repel mosquitoes and prevent their bites.