Popular insect repellent deet affects nervous system: study

August 5, 2009

The active ingredient in many insect repellents, deet, has been found to be toxic to the central nervous system. Researchers writing in the open access journal BMC Biology say that more investigations are urgently needed to confirm or dismiss any potential neurotoxicity to humans, especially when deet-based repellents are used in combination with other neurotoxic insecticides.

Vincent Corbel from the Institut de Recherche pour le Développement in Montpellier, and Bruno Lapied from the University of Angers, France, led a team of researchers who investigated the mode of action and toxicity of deet (N,N-Diethyl-3-methylbenzamide). Corbel said, "We've found that deet is not simply a behavior-modifying chemical but also inhibits the activity of a key enzyme, acetycholinesterase, in both insects and mammals".

Discovered in 1953, deet is still the most common ingredient in insect repellent preparations. It is effective against a broad spectrum of medically important pests, including mosquitoes. Despite its widespread use, controversies remain concerning both the identification of its target sites at the molecular level and its mechanism of action in . In a series of experiments, Corbel and his colleagues found that deet inhibits the acetylcholinesterase enzyme - the same mode of action used by organophosphate and carbamate insecticides.

These insecticides are often used in combination with deet, and the researchers also found that deet interacts with carbamate insecticides to increase their toxicity. Corbel concludes, "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".

More information: Evidence for inhibition of cholinesterases in insect and mammalian nervous systems by the insect repellent deet, Vincent Corbel, Maria Stankiewicz, Cedric Pennetier, Didier Fournier, Jure Stojan, Emmanuelle Girard, Mitko Dimitrov, Jordi Molgo, Jean Marc Hougard and Bruno Lapied, BMC Biology (in press), http://www.biomedcentral.com/bmcbiol/

Source: BioMed Central (news : web)


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  • yyz - Aug 05, 2009
    • Rank: 4.5 / 5 (2)
    This looks like another cautionary tale concerning the apparent toxicity of deet, especially in combination with carbamate insecticides. For people already taking anticholinergic medications, this would seem to ratchet up concerns with using anticholinesterase inhibitors concurrently.
  • TaTom - Aug 05, 2009
    • Rank: 4.7 / 5 (3)
    I think for millions of people, the risk of getting malaria is far worse.
  • el_gramador - Aug 05, 2009
    • Rank: 3.7 / 5 (3)
    Okay TaTom. What would you rather have choose between:
    Malaria that destroyed your immune system?
    Or DEET which completely screws up your intracellular machinery?

    I can see the niceties of Malaria, but would you really rather your cells didn't work and that you became a unable to move because of a simple chemical compound called DEET?
  • sender - Aug 05, 2009
    • Rank: not rated yet
    industrial caffeine is a better alternative to DEET
  • korgo - Aug 07, 2009
    • Rank: not rated yet
    I used to spray this stuff everywhere! ugh


    Korgo
    http://www.eightforums.com
  • Geop - Aug 08, 2009
    • Rank: 4.5 / 5 (2)
    Nw slogan for insect repllelents:

    "Don't worry. We kill you more slowly than them."

    Look, I have always believed that you should never use products on yourself that kill other living things or that change some natural state of your body (like sunblock) no matter how safe or good someone is temporarily saying it is.

    If you had followed this rule you would not be having nervous system disorders from insect repellent and would not be suffering from vitamin D deficiency or sunblock related cancers now (sunblock ingredients have actually been found to cause cancer themselves).

    Just remember to keep the environment and food around your body as similar to what it evolved in as possible becuase that is what it is adapted to.



    Less weird chemicals- less extremes of food (less super colored flavored foods) - less extreme limitations on food (vegetarianism? no - all meat well maybe becuase it worked for the eskimos who ate the WHOLE animal not just muscle including the fats and organs which have the vitamins normally gotten from vegetables but probably not - no sugar (sugar didn't exist until europeans purified it from sugar beets and sugar canes - it's artificial even if natural)- no weird environments around your body like too much shade and never any sun or too much sun and never any shade.

    Anything else is likely to have bad effects and we don't NEED to wait for the studies to tell us.

    It's just common sense right?





  • Soylent - Aug 09, 2009
    • Rank: 5 / 5 (2)
    Bring back DDT. Small amounts effectively repels insects, it's safe and environmentally friendly.

    The ban on DDT is a travesty; political nonsense and fear mongering was allowed to override the science.

    The thinning egg shells nonsense is particularly pathetic. If you kill all the insects the birds eat, with indiscriminate spraying, what do you thing is going to happen?
  • Sean_W - Aug 09, 2009
    • Rank: 4.3 / 5 (3)
    Given the vast numbers of people twitching to death from DEET poisoning in the last fifty years, which totals 0 people /- 4 people compared with the significant death, damage and disability mosquito born pathogens cause, I'll take the DEET, thanks.
  • Ethelred - Aug 12, 2009
    • Rank: not rated yet
    Wow the AASPAMMER didn't say Wow or Dude it makes me wonder what he will lead his SPAM with in the future.

    And this time he conned at least two people into giving him something other than a one.

    WForWasteland | Egnite | ghidon. At least two of you need to be more aware of this twit. Flag it don't encourage it.

    This is its forth incarnation.

    Go away, just go away.

    Words and lyrics by Blondie

    Ethelred

August 5, 2009 all stories

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