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Environmental and Health Concerns

The Hazards of DEET

EHANS Spring, 2003  

DEET is a registered pesticide. It is a member of the toluene chemical family, a solvent used in rubber and plastic cements and paint removers. DEET is absorbed through the skin and passes into the blood. The Medical Sciences Bulletin, published by Pharmaceutical Information Associates Ltd. reports, "Up to 56% of DEET applied topically penetrates intact human skin and 17% is absorbed into the bloodstream." Blood concentrations of about 3 mg per liter have been reported several hours after  DEET repellent was applied to skin in the prescribed fashion. DEET is also absorbed by the gut.


The most serious concerns about DEET are its effects on the central nervous system. Dr. Mohammed Abou-Donia of Duke University studied lab animals' performance of neuro-behavioral tasks requiring muscle co-ordination. He found that lab animals exposed to the equivalent of average human doses of DEET performed far worse than untreated animals. Abou-Donia also found that combined exposure to DEET and permethrin, a mosquito spray ingredient, can lead to motor deficits and learning and memory dysfunction. DEET repellents should not be inhaled. Repellent-treated clothes should be washed, or kept outside living areas to reduce exposure. Following all these precautions reduces risk, but does not eliminate it.


An emergency medicine bulletin notes that DEET may have significantly greater toxicity when combined with ethyl and isopropyl alcohols and freon which are components of some DEET repellents.  In 1998, the US EPA made it illegal for any product containing DEET to make any child safety claims.  Products with DEET are required to carry instructions that they should not be used at all for children under 6 months.  


Health Canada has now banned products with DEET concentrations over 30%, citing health risks.Health Canada has also banned two-in-one products which combine sunscreen and DEET.


Products containing DEET are now required to carry labels which specify:

  • Do not apply over cuts, wounds, or irritated skin. 

  • Do not apply to hands or near eyes and mouth of young children. 

  • Do not spray in enclosed areas.


Aerial Application of Mosquito Killer Linked to Higher Rates of Autism  June 07, 2016

Up to this point, the warfare against pests has involved chemicals, and this too has been shown to have devastating side-effects. According to recent research, higher rates of autism are found in areas exposed to annual aerial spraying of pyrethroids, a type of larvicide that kills mosquitoes, compared to areas where mosquito control is done primarily through pellets distributed on the ground.


"The authors report that kids living in areas where the spraying was done each summer had around a 25 percent higher risk of an autism diagnosis or developmental problem compared to kids living in areas without the aerial spraying," Time Magazine20 writes. 


According to Dr. Steve Hicks, assistant professor of pediatrics at Penn State College of Medicine: "Several studies have previously reported links between pesticide and autism risk. Our data suggests the way in which pesticides are applied might play some role."


Previous research has found that pregnant women who are exposed to pyrethroids in their third     trimester are more likely to give birth to autistic children, and animal studies suggest it causes neurological, immune, and reproductive damage. Some pyrethroids also act as endocrine disruptors by mimicking estrogen. Such hormone-disrupting chemicals can raise your levels of estrogen, thereby promoting the growth of estrogen-sensitive cancers such as breast cancer.


Besides the occasional aerial disbursement by your local mosquito control, there are more than 3,500 commercial products containing this insecticide. This includes items like roach sprays, flea bombs, and dog flea or tick collars and medicated shampoos. (Compounds that end in "thrin," such as bifenthrin, permethrin and cypermethrin, are all pyrethroids.) As noted in a recent article by The Atlantic, history is rife with pest control experiments gone terribly wrong.

Government Programs are Failing

Controlling Zika Mosquitoes May Be ‘Lost Cause 

USA Today  May 3, 2016

The female Aedes aegypti — the ones that bite — hang out in your house, preferably under your bed. If door and window screens block her entrance into your house, she will settle down under your patio furniture. And unlike the mosquitoes that most cities target for destruction each summer, the Aedes aegypti doesn't swarm or bite at night. With the prospect of Zika spreading the continental U.S. this summer, experts say the country must map exactly where the species lives and urgently rethink its standard operating procedures for controlling mosquitoes.


"There is no good method for killing these mosquitoes that's being used on a widespread basis," said Michael Doyle,  executive director of the Florida Keys Mosquito Control District. 


Recent efforts to kill the Aedes aegypti, which also transmits the viral diseases dengue and chikungunya, "don't give us much reason for optimism," said Scott Weaver, director of the Institute for Human Infections and Immunity at the University of Texas Medical Branch in Galveston. "In the near term, it's a lost cause.”  Many communities are using mosquito-killing methods that don't work on the Aedes aegypti, Doyle said.


While aerial spraying or fogging from a truck after can kill the Culex mosquitoes that can spread West Nile virus and or the "nuisance" mosquitoes that annoy people but don't spread disease, these methods have no effect on the Aedes aegypti, Doyle said.


“We cannot spray our way out of this," said Shah, executive director of Harris County, Texas, Public Health and Environmental Services, at a national summit on Zika preparedness in April. Aerial spraying won't "get to the mosquito that's sitting on the wall of your bedroom," said David Dyjack, executive director of the National Environmental Health Association.

In Brazil, which is contending with a widespread outbreak of Zika, officials have tried a number of approaches to controlling the Aedes aegypti, said Mauro Martins Teixeira of the Federal University of Minas Gerais. ”We haven't done anything to dramatically change their numbers," he said. So what's the best way to kill the Aedes aegypti? "The bottom line is that we don't know how," said Peter Hotez, dean of the National School of Tropical Medicine at Houston's Baylor College of Medicine. 


  • Almost one million deaths per year are related to mosquito-borne diseases; that number is expected to increase as the warming global climate broadens the habitats of these disease vectors. 


  • Given ALL insect repellents wear off after a few hours, repeated applications are necessary to ensure protection. A safe, natural formula solution offers continued repellency with no toxicity over time, unlike DEET or other toxic chemicals that are absorbed through the skin into the bloodstream. 


  • DEET and other toxic chemicals are showing up in our drinking water abroad and in the US and is now being looked at as posing a health risk. Hawkeye Global formulas integrate with the environment and pose no threat and naturally become part of the environment. Botanicals offer additional healing benefits beyond repellency as they are used by ancient cultures.


  • Broad band spraying and DEET based products are a short-term solution to show the public action is being taken without addressing the dramatic consequences of environmental pollution of air, ground, water, people and destruction of pollinating insect populations. Current formulas do not affect the Zika mosquito.

Additional Articles:

DEET in Our Waterways, a Billion Dollar Clean-Up Opportunity

Zika Virus: More than Two Billion People Live in “At-Risk” Areas

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