September 26, 2006, updatedJune 12, 2007, Longmont, CO, Dr. Anne Maziar, Ph.D. 


This document may be seen on my website at  under

II.Permethrin + Piperonyl Butoxide + ? : Fogging Trucks






On August 29, 2006 Longmont was sprayed by 10 trucks using Aqualuer 20-20.  It passed within one half block of my house around 11:00 p.m. when the temperature was 56.0 degrees F. ( Temperature: [North Longmont, Horizon Park]. Time and location from my neighbor who was returning from work.  I had fled and was 50 miles away until August 31, 2006).  We live in the oldest part of Longmont and there is much foliage including 130 year old trees which are very tall (Ash, Elm).


The label of Aqualuer 20-20 states :   “Where dense vegetation is present, use higher rates of application and/or a slower speed for best results.  All applications should be conducted when temperatures are greater than 50 F.”  ( )


The temperature was barely above 50 F.  At this colder temperature, Aqualuer 20-20 is much more toxic:  “DDT and pyrethroids are some of the few insecticides with toxicities that increase at lower temperatures.3,10”  (Toxicology and Environmental Fate of Synthetic Pyrethroids , Doria Mueller-Beilschmidt / Journal of pesticide Reform v.10,n.3 Fall 1990.  Doria Mueller Beilschmidt is the information services coordinator at the North American regional center of the Pesticide Action Network International (PAN).

(  )  )


THERE WAS NEVER ANY REASON TO USE WIDESPREAD MOSQUITO SPRAYING!          The weather never got hot again, not surprising for the altitude of 5040 ft. at this time of the year, except that it did reach 92.5 degrees very briefly on Aug 30..   (  Go to  Go to the bottom of the page to “Browse Archive Records.  Enter the date.  Click on “Browse Day Records”.  For August:   and September:  ) There was a frost advisory for Sept. 24, 2006.  (        ).  They only found one mosquito with West Nile Fever.


There is a public record of all the mosquito traps set and mosquitos caught by Colorado Mosquito Control, Inc. with dates from 4/1/2006 to 6/2/2006, but no public record after that.  (  .


The Longmont Daily Times-Call reported on 8/25/2006 that 68 female mosquitoes were caught on Tuesday and that 2.4 percent were infected with West Nile Virus.  That works out to 1.6 mosquitoes.  On the basis of these figures it was determined that there was a public health crisis.  According to Ted Williams in the Audubon Magazine it is the field technicians who are reporting the necessity to fog residential neighborhoods with pesticides, technicians whose average education is high school.  (  )..


The public health officials who urged the City of Longmont to order fogging do not work or live in Lingmont, but work in the cities of Boulder and Fort Collins.  Neither of those two cities’ residents or workers had to undergo the trauma or aftermath either environmental or medical of being sprayed with lethal pesticides.


The answer was not widespread fogging of neurotoxins and carcinogens, endocrine disrupters and hormone replicators.  The EPA rates synthetic pyrethroids as “among the most dangerous to children of all pesticides in common use.    (  )..  That same newspaper article reported that spraying would start about 8:30 p.m., by at least 10 fogging trucks that would cover 377 miles of city streets, along with a buffer zone around Longmont, in about four hours.


The only warning ever issued was in the newspaper which many cannot afford to buy.: “Residents can close their windows if they’re concerned about breathing the spray, but ‘unless you are chemically sensitive, there’s really no reason to do that.’”   This statement is both inaccurate and illegal according to Federal law.  Residents were also told that they could contact CMC to have the trucks avoid spraying directly in front of their homes.


I was phoned that Thursday by Colorado Mosquito Control so that I could flee the city, because I contacted CMC weeks earlier to tell them that I have asthma and that I am growing an organic garden.  However, they sprayed down 9th Ave., one half block away, and the spray drifts 400-400 feet.  There is an alley at the back of my property.  I can see the very thick, grey residue of pesticide on all my six plum trees, both by the front street, and on the alley, and in the back yard.  It is still there todey.  The half-life for permethrin is from 30 days to 42 days outside.  It is years inside out of the sun for the pesticide that drifts inside and is tracked inside.  No one knows the half-life of Aqualuer 20 20 which includes also piperonyl butoxide and other lethal and secret so-called “inert” ingredients.


In 1999 a producer faced fines up to #10,000 per violation and other fines for illegally applying a permethrin to 5 acres of basil:


This summer, an investigation conducted by the FDACS's Pesticide Compliance Section determined that a producer was illegally applying Ambush (permethrin) to his five acre basil crop. No tolerance has ever been established for permethrin on basil, so this user is in violation of the label. To aggravate the problem further, Ambush is a restricted use pesticide, for retail sale and use only by certified applicators or persons under their direct supervision. The producer did not posses a restricted-use pesticide applicator's license, and admitted that he borrowed the Ambush Insecticide from a friend and used it without any direct supervision.


Added to this, the producer had not even taken the first step toward training his agricultural workers in accordance with the Worker Protection Standard (WPS). None of his workers possessed an approved Worker Protection worker training certificate.


The use of the Ambush inconsistent with its label issue is unlawful under Section 487.031(10) of the Florida Statutes. The use of a restricted-use pesticide without a license is unlawful under Section 487.031(9) of the Statutes, and the WPS problem is a violation of Title 40 of the Code of Federal Regulations, Parts 170.130 and 170.230. Therefore, this producer is subject to administrative action, including fines up to $10,000 per violation. Additionally, he may be subject to additional penalty provisions of FIFRA, which are administered by EPA.

FDACS Communication; July 28, 1999  (  ).


I don’t understand how anyone could illegally apply Aqualuer 20-20 to my organic vegetables and fruits and not face similar penalties.


Two CSU professors issued the following warning about illegal spraying of food crops in home gardens by residential spraying for mosquitoes:


“Caution: Adulticides may not be registered for use on food Crops.  Applications in residential areas can result in illegal residues on produce from home Gardens.”  This information comes from Colorado State University Cooperative Extension – Horticulture bulletin no. 5.526, entitled Mosquito Management by F.B. Peairs and W.S. Cranshaw (Colorado State University Cooperative Extension entomologists and professors, bioagricultural sciences and pest management. 6/98. Reviewed 11/03.  Updated Friday, June 23, 2006.)  This bulletin is found on the following website:


The label of Aqualuer 20-20 contains the following warning:


“Do not allow spray treatment to drift on pastureland, cropland (other than crops listed), or  water supplies.  In treatment of corrals, feedlots, animal confinements/houses, wine lots and zoos, cover any exposed drinking water, drinking fountains and animal feed before application.”   

( ). 


Crops NOT registered for use of Aqualuer spraying or listed on the label include: plums, brassica leafy vegetables including collard greens and mustard greens, bok choi, corn on the cob, green onions, peppers (except for bell peppers), all root vegetables including beets, carrots, turnips, summer squash, winter squash, peas, beans, berries, grapes, hazelnuts., herbs  If  you are growing any of these vegetables, fruits, herbs, or nuts  no amount of washing of THESE vegetables, fruit, herbs and nuts will make this food safe for consumption after application of this pesticide illegal for this food..


I made a phone call to the Pesticide Hotline in Oregon (Oregon State Univ.) and learned that fogging or spraying Aqualuer 20-20 from a truck is an illegal application for ALL vegetables and fruits.  This product is approved for only SOME vegetables and fruits when it is sprayed by an individual with a hand carried sprayer.  Otherwise, the pesticide drifts and this results in poisonous concentrations illegal on crops making it illegal for human consumption.


Permethrin has been a Restricted Use Product since December, 2002.  (  ).  “The U.S. EPA (1) restricts use of some pesticide products because they are acutely toxic to humans or beneficial insects; have been shown to cause worker illnesses, groundwater contamination, bird or fish kills; or their drift damages other crops”  (  ).


West Nile Virus doesn’t claim many victims unless their immune systems are comprised by, among other things, pesticide spraying and DEET.  In 1999 West Nile virus killed seven New Yorkers; in 2000 it killed two.  The vast majority of people who get it recover with no damage.  I don’t mean to have no sympathy, but there are safer, more effective ways to deal with the problem.  The more deadly enemy is not WNV, but cancer and the lasting damage done to children and future generations.  40,000 women will die of breast cancer this year in the U.S.  Pesticides, including permethrin and piperonyl butoxide are each separately strongly indicated as a cause of breast cancer.   (  ).


 The risk of having cancer in one’s lifetime in the U.S. rises every year.  In my youth it was a one in four chance.  Now it is almost a one in two chance and the lifetime cancer rate rises every year:

“Based on rates from 2001-2003, 41.28% of men and women born today will be diagnosed with cancer of all sites at some time during their lifetime. This number can also be expressed as 1 in 2 men and women will be diagnosed with cancer of all sites during their lifetime. These statistics are called the lifetime risk of developing cancer. “  From:

Ted William reports in his article “Out of Control”  in the Audubon Magazine that:


The Audubon Society, which had worked with New York State to hatch a reasonable response plan, was horrified. "The only peer-reviewed professional science on this issue says there is no correlation between use of adulticides [pesticides for adult mosquitoes] and reducing disease," declares Bill Cooke, director of government relations for Audubon New York. "What we have are B.S. field studies put out by the pesticide companies. Decisions were being made on junk science….

Mosquito controllers who depend on this type of "source reduction," as they call it, and on chemical pesticides can never succeed because, along with a few mosquitoes, they take out whole ecosystems, including such natural controls as frogs, toads, salamanders, fish, damselflies, dragonflies, and birds. If birds aren't killed directly, hatchlings may starve when insects are poisoned off, and exhausted migrants may not be able to fuel up for the next leg of their journey.

But sometimes birds are killed directly. …

When the Collier Mosquito Control District, which has five helicopters, three turbo-prop Sky Vans, and a DC-3, was criticized for killing fiddler crabs, it began spraying fenthion in "ultra-low volume." But though the dose was reduced, it was delivered in finer drops that hung in the air far longer, drifting as far as five miles…

Moreover, Krimsky and other public-health authorities warn that routine, pesticide-based mosquito projects, ongoing in most states, may impede real disease control, should it ever become necessary, by creating chemical resistance in local mosquito populations.

“West Nile Virus and Mosquito Control Practices, Survey of Mosquito Control Practices and Less-Toxic Alternatives, December 2002 – Update” reports that routine and widespread spraying can actually in the long run lead to many more mosquitoes:


It has been found that routine and widespread spraying can lead to more mosquitoes in the long-term. This result occurs since the mosquito’s natural predators are killed by the sprays, and do not reproduce as rapidly, leaving more favorable conditions for mosquitoes to increase their numbers. 


An example of this produced a 15-fold increase in mosquitoes at Cicero swamp in NY State, after an 11-year period of routine spraying.  One report stated “Putting too much faith in mosquito adulticides may have contributed to the West Nile outbreaks in New York.  For years, aerial spray in the swamps was the only control measure.” 


Increased Risks of West Nile Encephalitis from Sprays


The Immunity Paradox

Ironically, use of adulticide sprays for West Nile  mosquito control could actually end up suppressing human and avian immune systems in the areas sprayed, resulting in greater risk of contracting or becoming seriously ill from West Nile virus.  (Three-state report [“Overkill”])

Encephalitis is mainly a risk to individuals who currently have a weak functioning immune system.  This can include the elderly, sick and very young.  However, a paradox arises since the use of many pesticides have shown the side-effect of weakening the human immune system. Since our immune system defends us from contracting encephalitis after being bitten by an encephalitis-carrying mosquito, the use of pesticide sprays can potentially create further risks of encephalitis by creating greater numbers of people whose immune systems are impaired below the threshold necessary to protect against encephalitis. In other words, the spraying intended to protect sensitive groups of people can increase the potential for encephalitis, making matters worse.

    /  Dr. Wayne Sinclair, MD,  Richard Pressinger, M.Ed


Same Immunity Warning from Canada: 

Stop the Indiscriminate Spraying of “Friendly Fire” Pesticides. 

In Quebec, 26  doctors and scientists have signed a report expressing opposition to mosquito spraying, and analyzing the health problems.   This study concludes that adulticide spraying is like the battlefield terminology of “friendly fire” - killing one’s own friends while intending to shoot an enemy.

“There is a widely accepted erroneous belief that mass spraying of adulticides protects the population against mosquitoes. In fact, the opposite is true: the mass spraying will result in a deterioration of public health by exposing millions of people to “friendly fire” pesticides. Ironically, such spraying is especially dangerous to those with impaired immunity for whose “protection” such spraying is mainly being done.”    


Insecticide risks to the brain-blood barrier

Dr Dennis Goode, Department of Biology, University of Maryland, says West Nile Virus, in general, is a mild disease unless it crosses the blood-brain barrier. He warns that pesticides (mosquito adulticides) can damage the blood-brain barrier making entry of WNV more possible.  Among the agents that impair the blood-brain barrier in tests on young rats are pyrethroid, organophosphate, and organochlorine pesticides. He concludes that insecticide spraying for mosquitoes has the potential to worsen the process of WNV infection.


Encephalitis risks in mosquitoes

Adulticide chemicals may be putting mosquitoes that are sprayed, but not killed, into an immuno-compromised state, thereby allowing them to accumulate and spread more West Nile virus than healthy mosquitoes.  Pesticide researcher Richard Pressinger has theorized that the chemicals cause subtle genetic damage in the mosquito population, increasing the number of mosquitoes with genetic flaws which could, in theory, allow the encephalitis virus to take hold and grow more rapidly.  (Three-state report)


Spraying is Ineffective

Much spray does not reach its intended target, the mosquitoes.   Dr. David Pimentel , professor of entomology at Cornell University and a longtime pesticide researcher said,  “I doubt that more than one-tenth of 1 percent of the poison is actually hitting its target. And you have to put out a lot of material to get that one-tenth of a percent onto the mosquito."  Thus for every droplet that reaches a mosquito,  thousands more droplets circulate pointlessly in the environment. 

This question seems the most important. If the efficacy of spraying approaches zero, what's the point of exposing our bodies, ecosystems, and wildlife to toxic chemicals in the first place?  (Three-state report)


Centers for Disease Control (CDC)  within its guidelines for control of  West Nile Virus has recognized that adulticide spraying is the least efficient mosquito control technique (as discussed earlier.)…


Widespread Spraying Impacts Agriculture

The success of agriculture depends in large measure on pollination, a necessary step in the production of most fruits and vegetables and in the production of many forage crops utilized by livestock. It is estimated that domestic honey bees pollinate only 15% of these crops, while the remainder are pollinated by wild bees and other wildlife, principally insects. 


        Widespread spraying of mosquito adulticides can adversely impact a broad  range of  honey  bees, other insects and wildlife, as these pesticides are broad-based killers.  Loss of crop  productivity could occur from loss of pollinating species resulting from widespread adulticide spraying.  Organic farms could lose their status and their market if exposed to the mosquito pesticides.  Widespread spraying is a poor choice, and should be avoided where agriculture is at risk.   



Widespread Spraying Impacts Mosquito’s Natural Predators    


Widespread spraying for mosquito control can increase mosquito populations by killing off natural predators (dragonflies, fish, birds, bats, amphibians, wasps, etc.) of the mosquitoes and their larvae, thereby removing natural control of mosquito population levels. The fewer mosquito predators there are, the more mosquitoes there will be.  The results at Cicero swamp in NY State (discussed earlier) indicated that mosquitoes increased 15-fold when the natural predators were impacted by routine adulticiding.

Dragonflies are important predators as the adults eat adult mosquitoes and the nymphs feed on mosquito larvae and pupae.  Other natural predators such as bats and birds (Purple Martins and Tree Swallows) eat adult mosquitoes and can help reduce their numbers in an area. Communities and residents have maintained bird and bat houses as another natural method of control.  Goldfish serve as natural predators in ornamental water gardens and ponds, but the feeding of fish food should be limited if residents expect the fish to eat mosquito larvae.  Gambusia fish are used by some jurisdictions, adding these fish to drainage holding ponds and other freshwater ponds.  Guppies, sunfish and killies have also been successfully used as natural predators of mosquito larvae.  By avoiding adulticide spraying, the natural predators will benefit.  (  ).


This report also list a number of non-toxic alternatives to widespread spraying and list many communities who have used alternative methods successfully for years to control mosquito populations.


The city of Bryan, Texas, also finds widespread spraying for mosquitoes unproductive and the wrong approach to mosquito control:




8 reasons why spraying pesticides is not the solution to West Nile virus

(excerpted from UPdate, Spring 2003, by Rebecca Watson)


The so-called "solution" of spraying pesticides to kill mosquitoes actually leads to bigger problems. Here are eight compelling reasons why spraying pesticides is not the answer to West Nile virus, or WNV.


Least-Effective Measure

The U.S. Center for Disease Control and other experts say that spraying or fogging is the least-effective means for slowing the spread of WNV-carrying mosquitoes. For fogging to have maximum effect, a mosquito has to be flying. Estimates are that fogging kills only about 10% of adult mosquitoes. A federal-provincial task force on WNV admits there is little evidence for the efficacy of insecticide spraying. Adult mosquitoes live only about two weeks, with new larvae hatching constantly. This means that spraying cannot be a one-shot operation, but needs to be repeated frequently if chosen as a means of control.


Predators Harmed, Mosquitoes Thrive

Aerial spraying or fogging is more harmful to mosquito predators than to mosquitoes. Since predators are farther up the food chain, they will take in higher amounts of pesticide. By decreasing mosquito predator populations, aerial spraying actually leads to increases in mosquito populations. Data from a study in New York State published in the Journal for Mosquito Control found that, after 11 years of insecticide spraying, the mosquito population increased 15 times.


Pesticide exposure also results in immune suppression in birds, which serve as the hosts for WNV. Birds exposed to organophosphate pesticides tend to suffer immune suppression, as do mammals, amphibians and other animals. This makes them less able to fight off viral and bacterial infections — the very opposite of what is needed. Once infected with WNV, birds are more likely to develop symptoms and to remain ill longer than if they had not been exposed. Thus, pesticide spraying leads to more frequent and longer infections and higher viral loads in birds, making it more likely they will spread the disease to mosquitoes. This increases the possibility of mosquitoes transmitting the virus to humans and other mammals.


Super Mosquitoes, Sicker Mosquitoes

For some reason, as yet unknown, mosquitoes exposed to pesticides are more likely to have WNV in their salivary glands and develop a damaged gut lining that becomes more porous, allowing WNV to pass through. Over a decade of insecticide spraying to control encephalitis in Florida has not been effective, and mosquitoes are now 15 times more likely to pass the disease. Mosquitoes, which have short life spans, go through many generations in a single year. Mosquitoes that survive pesticides are more likely to develop resistance to them. So aerial spraying contributes to the development of "super mosquitoes" that can only be killed by using higher amounts or different types of pesticides.


Immediate Human Health Effects

Immediate health effects on humans from exposure to sprayed pesticides are considerable. A letter from 26 prominent physicians and scientists in Quebec states, "Indiscriminate spraying of pesticides, especially in heavily populated urban areas, is far more dangerous to human health and the natural environment than a relatively small risk of West Nile Virus... Ironically, such spraying is especially dangerous to those with impaired immunity for whose 'protection' such spraying is mainly being done. Those individuals who are most vulnerable in this chemical action against mosquitoes include children, pregnant women, the elderly, chemically sensitive and immuno-suppressed individuals, such as patients with AIDS and cancer, and people suffering with asthma and other allergies.".


Long-Term Health Effects

Pesticides used in mosquito control can contribute to immune suppression in humans. A report from the World Resources Institute notes, "Impairment of the immune system by chemical pesticides can lead to allergies, auto immune disorders such as lupus and cancer. It may also lead to infections to which one may be normally resistant." People with weakened immune systems are the most vulnerable to WNV. Thus, in the long term, aerial spraying may actually increase the number of people who become seriously ill from WNV.


Long-Term Environmental Effects

Most of the pesticides presently used for mosquito control do not selectively target mosquitoes. Malathion, Naled and Resmethrin kill all insects. This includes hundreds of beneficial insect species that pollinate crops and keep pests under control. Malathion is known to contaminate water, and is classified as highly toxic to most species of fish. In 1999, 90% of adult lobsters in Long Island Sound were killed by malathion used on land. Fish kills in the thousands have been reported following mosquito spraying. Since some species of fish feed on mosquito larvae, this is doubly counterproductive.


Keep Risk in Perspective

West Nile virus is less dangerous than the flu. Only 1% of mosquitoes carry the WNV, even in places where WNV has been common for years. Less than 1% of people bitten by infected mosquitoes will have any symptoms, and most of those will be equivalent to a one-day flu or headache.


Taking a Long-Term Approach

We need a rational, long-term, problem-solving approach that is healthy for humans and the environment. Reducing mosquito breeding sites (standing water), known as source control, is the most-effective mosquito control method. Since adult mosquitoes seldom travel more than one kilometer, source control in a neighborhood can be extremely effective and quite non-toxic. Experts stress the value of source controls such as mechanical flushing of sewer catch basins, and introduction of dragonfly larvae in nearby ponds and lakes. Maintaining healthy mosquito predator populations is an important part of a mosquito control strategy. Eliminating mosquito larvae through predators and biological means and, if absolutely necessary, via pesticides, is far more effective than trying to kill adult mosquitoes. Ultimately, the most effective defense against WNV is a healthy ecosystem and a healthy immune system in humans, birds and other species.  (  )


WE ACTUALLY HAVE INCOMPLETE INFORMATION AS TO WHAT WE HAVE BEEN SPRAYED WITH.  The EPA has found “doctored” forms of  pesticides and the suppliers from a British chemical company are under investigation.  Cornell University reports:


EPA and Justice Department investigators are targeting a network of

pesticide manufacturers and suppliers in the United States and

overseas who allegedly have been selling counterfeit versions of

pesticides that are widely used to fight mosquitoes that may carry

the West Nile virus, sources say. The investigation is

one of the largest ever into the sale of alleged imitation

pesticides, according to one federal investigator, and sources say

the inquiry may prompt a rethinking of EPA policies aimed at

protecting the distribution of pesticides used for public health

purposes.  (  ).


            In addition, the label of Aqualuer 20-20 calls this product “A Synergized Permethrin Formulation”.  This means that other ingredients have been added to the 26% permethrin to made it much more lethal to the targeted animal.  The half life of insecticides made of chrysanthemums is a few hours.  The half life of permethrim is 10-30 days.  The half life of synergized permethrin was 42 days in Illinois.  Permethrim stays in the air 30 to 45 minutes.  Synergized Permethrim stays in the air 4 hours and drifts 400 to 500 feet. 


The label lists these ingredients:




**Piperonyl Butoxide Technical………..20.6%


            TOTAL            ………………….100.0%

*(3-phenoxyphenyl)methyl(+/-)Cis/trans 3-(2,2-dichlorethenyl)2,2-Dimethyl cyclopropanecarboxylate.

Cis/trans ration: min. 35%(+/-) cis and max. 65% (+/-) trans.

**Equivalent to 80% (butylcarbityl)(6-propylpiperonyl) ether and 20% related compounds

Contains 1.75 pounds of Permethrin and 1.75 pounds of Piperonyl Butoxide per gallon.


Apart from the dangers of these two ingredients separately, which I will list below, the Piperonyl Butoxide is added to the Permethrin to make it more lethal.  In addition, there is the problem of the “INERT INGREDIENTS” which are not “inert” but “other” ingredients added in a “secret” formulation to make the listed ingredients more lethal.  These secret ingredients are “trade secredts”.  The company will release the ingredients to emergency room doctors when someone is rushed to the emergency room if the doctors promise not to tell anyone what they are.  At least 8 ingredients used by pesticide companies are extremely dangerous to human health.


            One study finds that “inert ingredients” are often as toxic as the active ingredient or ingredients:


Despite their name, these ingredients are neither chemically, biologically or toxicologically inert. In general, inert ingredients are minimally tested, however, many are known to state, federal and international agencies to be hazardous to human health. For example, the U.S. government lists creosols as a “Hazardous Waste” under Superfund regulations, yet allows these chemicals to be listed as inert ingredients in pesticide products. Creosols are known to produce skin and eye irritations, burns, inflammation, blindness, pneumonia, pancreatitis, central nervous system depression and kidney failure. Some inert ingredients are even more toxic than the active ingredients;….   more than 200 chemicals used as inert ingredients are hazardous pollutants in federal environmental statutes governing air and water quality; and, of a 1995 list of inert ingredients, 394 chemicals were listed as active ingredients in other pesticide products….


The vast majority of all pesticide products registered for use by EPA and state governments have never been fully tested for the full range of potential human health effects, such as cancer, birth defects, genetic damage, reproductive effects and neurological disorders, and endocrine disruption. Indeed, pesticides can be registered even when they have been shown to cause adverse health effects….. There is no way to predict the effects in children solely based on toxicity testing in adult or even adolescent laboratory animals, which is EPA’s procedure for evaluating adverse effects.  (  ).


Doria Mueller-Beilschmidt lists some of the “inert” (secret) ingredients and contaminants used in pyrethrum formulations: 


"Inert" (secret) ingredients and contaminants can also affect the toxicity of a pyrethroid formulation, especially since the formulated product often contains more "inert" ingredients than active ingredients. Several "inerts" in pyrethroid formulations used in the U.S. are known or suspected carcinogens (such as silica, trimethylbenzenes, and ethyl benzene), or are chemicals which depress the central nervous system (such as xylenes). There are also hazardous contaminants, such as ethylene oxide, benzene, and arsenic, in several pyrethroid formulations.12-15  


Simultaneous contact with substances that inhibit detoxification processes, called synergists, can increase the acute toxic effects of a pyrethroid. High levels of some synergists (organophosphorus and carbamate compounds) can block esterases, enzymes that degrade pyrethroids by cleaving the molecule at the double bond between a carbon and an oxygen atom. Other synergists (piperonyl butoxide and sulfoxide) block the mixed function oxidases, enzymes which oxidize and detoxify a wide variety of compounds.10-16 Simultaneous exposure to pyrethroids and organophosphates has also been shown to increase the inhibition by the organophosphates of cholinesterase, an enzyme in the nervous system.17  (Toxicology and Environmental Fate of Synthetic Pyrethroids , Doria Mueller-Beilschmidt / Journal of pesticide Reform v.10,n.3 Fall 1990.  Doria Mueller Beilschmidt is the information services coordinator at the North American regional center of the Pesticide Action Network International (PAN).

(  )  )


Permethrim has been studied as a cause of Gulf War Syndrome.  Permethrim was added to military uniforms.   (  ).  It is also added to the material of other clothing:


            Permethrin is carcinogenic and mutagenic, so states Caroline Cox:


“PERMETHRIN – Insecticide Fact Sheet.  Read before using this poison.”


The insecticide permethrin (in the synthetic pyrethroid family) is widely used on cotton, wheat, corn, alfalfa, and other crops. In addition, over 100 million applications are made annually in and around U.S. homes.


Permethrin, like all synthetic pyrethroids, is a neurotoxin. Symptoms include tremors, incoordination, elevated body temperature, increased aggressive behavior, and disruption of learning. Laboratory tests suggest that permethrin is more acutely toxic to children than to adults.


The U.S. Environmental Protection Agency has classified permethrin as a carcinogen because it causes lung tumors in female mice and liver tumors in mice of both sexes. Permethrin inhibits the activity of the immune system in laboratory tests, and also binds to the receptors for a male sex hormone. It causes chromosome aberrations in human and hamster cells.


Permethrin is toxic to honey bees and other beneficial insects, fish, aquatic insects, crayfish, and shrimp. For many species, concentrations of less than one part per billion are lethal. Permethrin causes deformities and other developmental problems in tadpoles, and reduces the number of oxygen-carrying cells in the blood of birds.


Permethrin has been found in streams and rivers throughout the United States. It is also routinely found on produce, particularly spinach, tomatoes, celery, lettuce, and peaches.


A wide variety of insects have developed resistance to permethrin. High levels of resistance have been documented in cockroaches, head lice, and tobacco budworm.  (Journal of Pesticide Reform [Summer 1998] v. 18, no. 214, a copy of which is found at  .  The extensive bibliography is found at


Another study finds permethrin neurotoxic:


6 Neurotoxicity of Permethrin

Permethrin is neurotoxic at high doses. It produces a variety of clinical neurotoxic effects in animals. Some of those effects are tremors, salivation, paresthesia, splayed gait, depressed reflexes, and tiptoe gait; reversible axonal injury occurs at high doses (Brammer, 1989; Robinson, 1989a,b). These symptoms appear to be universal for pyrethroids.


The primary action of pyrethroids on the peripheral nervous system is to induce pronounced repetitive activity—i.e., continuous rather than single nerve impulses (van den Bercken, 1977; van den Bercken et al., 1979). Pyrethroids interact with a fraction of the voltage-dependent sodium channels in excitable membranes that produce a prolongation of the inward sodium current during excitation in which the channels remain open much longer than normal (see review by Vijverberg and van den Bercken, 1990). Membrane depolarization might also occur, resulting in enhanced neurotransmitter release and eventually blockage of excitation. Although postsynaptic neurotransmitter responses can be suppressed by pyrethroids, doses must be higher than those that produce effects on sodium channels. Pyrethroids also increase concentrations of β-glucuronidase and β-galactosidase, which are thought to be associated with repair process, in peripheral nerves (Aldridge, 1990).  (Health Effects of Permethrin-Impregnated Army Battle-Dress Uniforms (1994) (Commission on Life Sciences)  (  )


Permethrin is both mutagenic and carcinogenic:


Mutagenicity and Carcinogenicity In a number of separate Mutagenicity studies (studies of the ability to cause genetic amage), cypermethrin, allethrin, cismethrin, permethrin and fenpropathrin have shown some mutagenic effects.3,25,28 Only in the case of permethrin was the response (changes in mice bone marrow) found to be significant….. 


Carcinogenicity studies of permethrin, resmethrin, fenvalerate and deltamethrin have hown increases in various kinds of cancers.3,27,29-32 Only permethrin has been determined to be a potential or weak carcinogen by the U.S. Environmental Protection Agency.29   (Toxicology and Environmental Fate of Synthetic Pyrethroids , Doria Mueller-Beilschmidt / Journal of pesticide Reform v.10,n.3 Fall 1990.  Doria Mueller Beilschmidt is the information services coordinator at the North American regional center of the Pesticide Action Network International (PAN).  (  )  )


Ms. Mueller-Beilschmidt explains the Pyrethroid mode of action:

Like DDT and many other insecticides, naturally occurring pyrethrins and the synthetic pyrethroids are nerve poisons. Pyrethroids' principal mechanism of action is believed to be disruption of the permeability of nerve membranes to sodium atoms. The site of action is not known, but pyrethroids and DDT probably act on both the central (the brain and spinal chord) and the peripheral nervous system (nerves in other parts of the body). Other major groups of insecticides (carbamates and organophosphates, for example) are nerve poisons but do not act on the peripheral nervous system.3,18

A study published 11/02/2005 measured levels of exposures of 127 Ohio preschool children in their everyday environments.  They found:


The metabolite, 3-PBA, was detected in 59% of the children's urine samples.,,,. Through inhalation, ingestion, and dermal routes of exposure, the median aggregate potential absorbed doses of cis- and trans-permethrin for these children were estimated at 2.1 and 1.7 ng/kg/day, respectively …The results showed that these children were potentially exposed to both cis- and trans-permethrin from several sources, and through several pathways and routes. The urinary biomarker of exposure, 3-PBA, confirms that these children were exposed to and absorbed one or more of the pyrethroids, likely including permethrin, into their bodies.  (MORGAN, M. K., L. S. SHELDON, C. W. CROGHAN, P. A. JONES, J. C. CHUANG, AND N. K. WILSON. EXPOSURES OF 127 OHIO PRESCHOOL CHILDREN TO CIS- AND TRANS-PERMETHRIN IN THEIR EVERYDAY ENVIRONMENTS. Presented at International Society of Exposure Analysis Conference, Tucson, AZ, October 30 - November 03, 2005.  An abstract of this report can be found at:  ).

Permethrin is much more toxic to babies and young children:

Infants and young children may distribute and metabolize certain toxicants differently from adults. Compared with adults, they have a higher proportion of total body water and less body fat in which to store lipophilic substances. This lesser ability to store toxicants in fat can lead to higher circulating levels. Renal clearance rates and activities of hepatic enzymes vary considerably during infancy and early childhood; as a result, a xenobiotic may exert greater or lesser toxicity. For example, a reduced capacity to metabolize organophosphate or carbamate insecticides might be beneficial because the metabolites are more toxic than the parent substances. Conversely, if metabolism of a toxicant typically converts it to a less active and more readily excreted metabolite, then reduced metabolism would result in a greater toxic effect. For example, permethrin is almost 5 times more acutely toxic in 8-day-old rats than in adult rats because the neonates lack permethrin-specific esterases…..32

The developing brain and central nervous system have pronounced vulnerability to neurotoxicants (eg, lead, mercury, alcohol) other than pesticides. As this special issue of Pediatrics confirms, threats to neurobehavioral development arising from chemicals in the environment must be a serious concern of pediatricians. The articles on lead, mercury, alcohol, and polychlorinated biphenyls all emphasize the special vulnerability of the developing brain to toxic challenges and, especially, how such vulnerability may be expressed in subtle disorders of function. The progression from encephalopathy to lowered IQ scores as criteria for excessive lead exposure or the similar progression from the overt signs of fetal alcohol syndrome to the subtle deficits of fetal alcohol effects offer a prototype for assessing the hazards of pesticides….

Perhaps the best known example of endocrine-disrupting activity in early embryonic and fetal development is that of the synthetic estrogen diethylstilbestrol (DES). DES was used extensively in the 1950s to 1970s to maintain pregnancy in women threatening spontaneous premature delivery.59 Only decades later was it discovered that daughters born to DES-treated mothers experienced increased rates of vaginal clear cell adenocarcinoma, genital tract abnormalities, and abnormal pregnancies. Although not a pesticide, the DES model provides evidence for the effects of estrogen receptor agonists on the developing human reproductive system. Animal studies and cell-culture studies have shown that a variety of pesticides such as DDT/DDE, mirex, aldrin, dieldrin, atrazine, hexachlorocyclohexane, toxaphene, alachlor, chlordane, vinclozolin, and chlorpyrifos can interact with endocrine system components such as the estrogen, androgen, and thyroid receptors during critical periods of development and produce an equally varied spectrum of adverse developmental effects such as altered social skills, decreased intelligence, and reproductive difficulties or failures.6067 Thyroid function in pregnant women is a critical determinant of offspring IQ,68 and contaminants such as polychlorinated biphenyls and dioxins are known to disrupt thyroid function.69 Such findings demonstrate the special sensitivities of developing embryos and fetuses to chemical exposure levels that are safe and without effect in mature adults.  (Bernard Weiss, PhD [* Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York], Sherlita Amler, MD and Robert W. Amler, MD [US Department of Health and Human Services, Agency for Toxic Substances and Disease Registry, Atlanta, Georgia ]   Pesticides (   )

Piperonyl butoxide is mixed with permethrin to increase its toxicity:


piperonyl butoxide inhibits microsomal oxidation of a wide variety of compounds which are detoxified by hydroxylation reactions.  This effect can explain the ability of piperonyl butoxide to prolong the action of barbiturates and zoxazolamine, slow the metabolism of benzpyrene and enhance the toxicity of pyrethrins.  (  ).


            Colorado Mosquito Control, Inc. before 2006 used AquaReslin.  During 2006 it has changed to Aqualuer.  Residents of Longmont and surrounding communities have been sprayed numerous times between the spring of 2003 and fall of 2005.  There has been at least one supplier who sold “doctored” forms of AquaReslin and other pesticides:

            EPA (Environmental Protection Agency) and Justice Department personnel are investigating the Sierra Chemical and Supply Company, Anniston, Alabama, for allegedly distributing adulterated versions of mosquito-control insecticides. Apparently, these substances may have been distributed to municipalities in the southeastern and midwestern United States. ….

            Investigators are examining whether Sierra sold imitations of Aqua-Reslin and several other pesticides. Investigators are also examining whether Sierra doctored the formulations of brand-name pesticides…

Federal investigators are looking at whether Sierra made copies of Aqua-Reslin labels and placed them on canisters of Sierra's own pesticide formulation, which sources say was a rough approximation of Aqua-Reslin.Sources say Sierra sold pesticides carrying the Aqua-Reslin label to municipalities in states across the Southeast and parts of the Midwest, including Georgia, Alabama, Louisiana, Ohio, and Illinois, at prices well below the general market rate for the brand-name pesticide…..


Sources estimate Sierra may have ac-cumulated at least hundreds of thousands of dollars in revenue from the sale of these pesticides…..


Sources familiar with the investigation say that tests of Sierra's pesticides revealed chemical concentrations that were some-times too high and other times too low to match the concentrations of chemicals in Aqua-Reslin.


Investigators are also examining potential criminal violations in Sierra's supply chain, which sources say investigators have traced back to a British chemical company.


Sources say that investigators are also examining other suppliers, both domestic and international, to determine whether Sierra may have obtained raw materials from other facilities.  (Phil Nixon, “EPA Investigates Pesticide Distribution,” Illinois Pesticide Review, 16, 1 [January, 2003]. ).




When I asked Marshall Lipps two times on the phone who his supplier was, he wouldn’t tell me.


            March 5, 2003, the province of Québec bans use of permethrin as one of the most dangerous pesticides for health and the environment:


The ban covers 23 pesticide active ingredients that--according to the U.S. Environmental Protection Agency (EPA) and/or World Health Organization (WHO)--are known or possible carcinogens or endocrine disruptors, including lindane, malathion, MCPA, permethrin, benomyl, captan and 2,4-D.  (  ).


40,000 women will die of breast cancer this year in the U.S.  Pesticides are strongly indicated as a cause of breast cancer.



 The risk of having cancer in one’s lifetime in the U.S. rises every year.  In my youth it was a one in four chance.  Now it is almost a one in two chance.


“Based on rates from 2001-2003, 41.28% of men and women born today will be diagnosed with cancer of all sites at some time during their lifetime. This number can also be expressed as 1 in 2 men and women will be diagnosed with cancer of all sites during their lifetime. These statistics are called the lifetime risk of developing cancer. “  From:


All statistics involving encephalitis and meningitis caused by West Nile Virus are meaningless, because the county departments of health do not keep track of whether the patient was exposed to DEET or mosquito fogging before these conditions were contracted.  This would have to include nuisance fogging as well as fogging ordered by local governments and local departments of health, and would have to include careful records of fogging by the designated pesticide company such as Colorado Mosquito Control, because patients are not always or even usually aware of having been fogged.  IF PUBLIC HEALTH DEPARTMENTS REALLY WANT TO PROTECT CITIZENS, IT IS ESSENTIAL THAT THEY CAREFULLY KEEP THESE STATISTICS.  In my experience, the public health department points to these cases and says that they prevented many more.  But the fogging in fact actually caused these cases.


Dr. Anne Maziar, Ph.D.