The following research provides the strongest evidence to date linking pesticide applications with increasing the incidence of encephalitis carrying mosquitoes.
We will be ordering the complete article and placing a detailed summary on this site once it arrives. We are requesting that concerned citizens read through the article and write a letter to the editor to their local paper regarding this topic.
Impact of naled (Dibrom 14) on the mosquito vectors of eastern equine encephalitis virus.
SOURCE: Journal of the Am Mosquito Control Assoc, Dec;13(4):315-25, 1997
Howard JJ, Oliver
New York State Department of Health, SUNY-College ESF, Syracuse 13210, USA.
In central New York, aerial mosquito adulticide applications have been used in response to eastern equine encephalitis (EEE) outbreaks and have targeted the swamp habitats of the primary enzootic vector of EEE virus, Culiseta melanura (Coquillett). The organophosphate insecticide Naled (also called Dibrom) (1, 2, dibromo-2, 2-dichloroethyl dimethyl phosphate) has been the insecticide of choice in this region. This study reports on analyses of 11 years (1984-94) of mosquito collection data from Cicero and Toad Harbor swamps in relation to applications of naled. Naled applications were successful in achieving short-term reductions in mosquito abundance. However, despite repetitive applications, populations of the primary vector of EEE virus, Cs. melanura, have increased 15-fold at Cicero Swamp. Preventive applications had no noticeable impact on the enzootic amplification of EEE virus, and isolations of virus following preventive applications have resulted in additional spraying. The possibility that applications of naled contributed to increased populations of Cs. melanura discredits the rationale that preventive applications of naled reduce the risk of EEE.
1) Weakening of Wildlife Immune
2) Damage to the mosquito
Evidence Suggests a Possible Link
by Richard Pressinger
A new theory is coming to light which should be causing concern regarding the use of chemical pesticides for controlling mosquito populations in Florida and elsewhere. Because of the serious potential for irreparable widespread harm to human health regarding this potential problem, it is an issue that cannot be ignored and must be investigated immediately and thoroughly as it is based on the latest information we have regarding encephalitis carrying mosquitoes and human genetic function.
New Discovery Encourages New Theory
As scientists learn more about encephalitis, along with the effects of chemical pesticides on human health, we are now able to see connections between the two that suggests pesticide use may very well be increasing the encephalitis problem it was intended to reduce. Rates of encephalitis infection among "Sentinel Chickens" in Brevard County Florida have steadily increased from zero in 1990 to three around 1995 and are now up to seven in 1999. Other Florida counties are seeing similar increases as well. Hundreds of millions of dollars are being spent each year on mosquito control in Florida, yet, the encephalitis problem (at least according to our monitoring system), continues to worsen. A 15-fold increase in encephalitis carrying mosquitoes was found in one New York swamp habitat after beginning treatment with the pesticide Dibrom (Naled) over an 11 year period. This was reported in the Journal of Mosquito Control (1997, Vol. 13). This provides strong evidence demonstrating that current chemical treatment methods are actually making the situation worse in the long term. Common sense suggests if this trend continues - the likelihood of being bitten by an encephalitis carrying mosquito will increase dramatically as long as we choose to continue the use of chemical pesticide applications.
Theories are the 1st Step
In one of our opening class lectures, while a graduate student at the College of Public Health, University of South Florida in Tampa, our professor began his comments by stating - "Whenever you begin postulating circumstances related to the causes of illness - make sure it has one important denominator - Biological Plausibility").
What he meant by this is that, whenever we begin making theories on public health issues, we need to first make sure there is logic and common sense driving the points in our theories. I agree with this view completely and is the reasoning which underlies what you are about to read and why it should be setting off an alarm in anyone concerned about public health.
In early November, I met with University of Florida's new genetics viral/mosquito researcher, Dr. Walter Tabachnic, at the Florida Medical Entomology Lab in Vero Beach, Florida. While discussing the latest information regarding what is known about the encephalitis mosquito, Dr. Tabachnic said something which drew my attention because of other research I had come across on the harmful effects of chemical pesticides.
HOW ENCEPHALITIS BEGINS
Let me first address a few important points regarding encephalitis and mosquitoes as stated by Dr. Tabachnic: (Please note that this background information by Dr. Tabachnic is provided only to clarify understanding of the encephalitis process and does not suggest his views on this theory one way or another.)
1) Birds are the original carriers of viral encephalitis.
2) Mosquitoes bite infected birds which transfers the virus to the mosquito.
3) Somewhere between 7 and 14 days later, the mosquito can then transmit
the disease to humans, however, University of Florida researchers discovered that not all
mosquitoes get encephalitis, in fact, of the thousands of mosquitoes that do bite an
infected bird - only 1 or 2 even develop the disease. Interesting to say the least.
THE MOSQUITOES WHICH
What these specific
"abnormalities" are which allow the virus to leak through
EVIDENCE FOR GENETIC DAMAGE
Since every aspect of a living organism's life is controlled by the genes on its DNA molecule, it would be logical to assume that something would be genetically wrong with the genes controlling stomach lining function (in the mosquitoes susceptible tot encephalitis infection).
Before I go further, I was told by another entomologist at the UF Research Lab, Dr. Richard Baker, that it takes about 2 or 3 direct "droplet hits" from an airplane or spray truck pesticide mist to kill a mosquito. If the mosquito gets hit with only one droplet, which happens to millions of mosquitoes when the pesticides are sprayed - they will survive. However, as you could imagine, the insect wouldn't be the healthiest at this point, just like if you or I received half the dose necessary to kill us. Since both the pesticides malathion and dibrom have been found to cause genetic damage in tests of living cells (and malathion has been shown to cause premature gene loss) the mosquitoes could very likely be developing significant genetic hits due to this high level of sub-lethal pesticide exposure.
Here is the key point - When these genetically weakened mosquitoes reproduce, their offspring have a potential for being genetically inferior in many subtle ways themselves. Researchers found that the pesticide malathion was able to literally cause genes to break-off the DNA molecule - called gene "deletions" (Cancer Research, May, 1996). A quick biology lesson - our chromosomes are comprised of the DNA molecule which in itself is comprised of approximately 100,000 genes.
Like all living creatures, the mosquito has genes on his DNA which control everything from how well he flies to (yes) how well his stomach lining works. AS a quick note - Brevard County had been using malathion for mosquito spraying here for many years and only stopped this year and switched to another known (and considered even more toxic) pesticide - "Dibrom" (sometimes called Naled).
The Theory Showing How
Pesticides Could Be
The bottom line - every time a mosquito spray plane or truck sprays these
proven genetically damaging pesticides (dibrom and malathion) over the area, they are very
likely increasing the amount of subtle genetic damage in the mosquito population, and
hence, increasing the number of mosquitoes with genetic flaws which could in theory, allow
he encephalitis virus to take hold and grow more rapidly.
1) Mosquito Control sprays pesticides over the area - which
So while we are given warnings about wearing long sleeved shirts and plenty of bug repellant, there may now be one more prevention strategy we can use -
Impose an immediate moratorium on pesticide spray
The theory outlined is this article is that solely of the author and is not that of any scientists who contributed background information for the article.
Mr. Pressinger has been involved in Public Health Research for over 20
For more information on the health risks of mosquito control pesticides - dibrom - naled - and permethrins - please visit -http://www.chem-tox.com/brevard
For more information on health effects from the pesticide malathion -
For more information on the health effects from all pesticides - visit -