Mass-Spraying for Mosquito
Control – The Great Experiment by Christopher Lepisto, ND
This summer my hometown of Grand Junction, CO was gripped by the concern over
West Nile Virus. “Mosquito season” was upon us and the county responded by
initiating a series of three aerial pesticide sprays over Mesa County (known locally as The Grand
Now completed, how necessary was the spraying for an “epidemic” of 125 cases
and 3 deaths? My county is likely to consider further spraying next year, yet
for comparison, how many more deaths does the county see monthly from
And most importantly, what are the potentially disastrous health effects to
humans, especially pregnant women and children who are breastfeeding? This is
a side of the mosquito story that you may never have heard before.
Naled - A Very Toxic Chemical
Naled (Dibrom) is an organophosphate pesticide designed to kill adult
mosquitos. It is the only adulticide whose label reads, “Do not breathe vapor
or spray mist.
Causes irreversible eye and skin damage,” and is listed as a Class 1, highly
toxic pesticide by the U.S. Environmental Protection Agency (EPA).1 According
to the EPA, naled can cause cholinesterase inhibition in humans: that is, it
can over stimulate the nervous system causing nausea, dizziness, confusion,
and at high exposures, can cause respiratory paralysis and death.2
Naled is more toxic when exposure occurs by breathing contaminated air than
through other kinds of exposure.3,4 Clear research also demonstrates that
naled causes headaches and diarrhea in exposed people.5
In my practice I have seen multiple patients with these symptoms occurring
directly after the sprayings. Often these are patients who have never had
these symptoms before. But of most concern are the laboratory tests
demonstrating that exposure to naled's breakdown product dichlorvos caused
increased aggressiveness and a deterioration of memory and learning,6,7 and interference with prenatal brain development.8
Naled is also classified as a cancer-causing chemical by the International
Agency for Research on Cancer.9 This is not a safe chemical, especially for
the unborn, infants and children with developing nervous systems.
The Canary in the Coal Mine
Unfortunately, naled is only one many chemicals being sprayed, applied or
consumed in many areas like The Grand Valley. While an individual application
is unlikely to outright kill anyone, it is the total accumulation of
environmental toxins (from the air, food, water, etc.) that will cause
anyone’s barrel to spill over and for symptoms to develop.
The coal miners knew very well that canaries had “small barrels” and used
this to their advantage when descending into the dangerous mines. When the
level of toxic gases rose too high, the canaries would fall ill or die and
the men knew they would have to get out immediately.
Unfortunately, the unborn, infants and children are our modern-day canaries.
Remember that animals higher in the food chain concentrate the chemicals
consumed from those lower down, which means that breastfeeding infants are at
the top end of this chain.
They are the unwitting subjects of a world-wide experiment of toxic
The Great Experiment
No-one really knows what full effect the three mass-sprayings will have on
the population and environment of the Grand Valley. What we do know is that
Mesa County has one of the highest cancer rates in the states.10
It will be the combined exposure from uranium mill-tailings, agricultural
pesticides, and overall food, air and water contamination, as well as
individual choices in diet and lifestyle that will determine the health of
this population in the years to come.
General Valuable Facts to Understand the Pesticide Problem
1. In the past the CDC (Center for Disease Control) has stated that aerial
spraying is the least effective way to control mosquitoes.
2. Aerial spraying can blow the chemical 22 or more miles away from
3. Miscalculations in spray preparations are a common cause of tragic health
4. Spraying is only 30 % effective in killing mosquitoes according to well
documented Florida studies.
5. Most people who are exposed to an infected mosquito will not become ill. A
few will have a mild flu-like illness. In NYC, for example, it was estimated
that 1 person per 6 million would die of the illness.
6. It is estimated that it takes a million drops to hit a mosquito with a
spray and at least 2-3 drops to kill a mosquito. Realistically, is it worth
millions of dollars for aerial spraying that can do more harm to people than
to the mosquito?
7. The spray will pollute the water and at 1 ppb it can kill up to 40% of
fish before ending up in your water supply. In parts per quadrillion these
chemicals are reported to damage the unborn of animals. It also pollutes the
soil and any crops grown on polluted ground.
8. Sprays wipe out natural predators of mosquitoes (like dragonflies) and
tend to make those that live, more aggressive in nature.11
. What you Can Do 1. Get informed. Educate yourself on pesticide dangers and
alternatives at www.beyondpesticides.org and
2. Join a local the coalition through Beyond Pesticides.
3. Call your local Health Department and tell them you are opposed to
4. If you or your family are still experiencing
symptoms you suspect are related to pesticides, and would like consultation,
you may contact Dr. Lepisto at 970-250-4104.
About Christopher Lepisto, ND:
Dr. Lepisto is a graduate of Bastyr University of Natural Health Sciences and
a practicing Naturopathic Doctor at The Alderwood Center for Natural Health
in Grand Junction, Colorado. He specializes in environmental medicine,
cleansing and detoxification. He can be reached at firstname.lastname@example.org
1. Washington State Naled Use Summary. March 2004.
2. Myers, Tom, 1999. Organophosphate pesticide information, Naled Summary.
3. Berteau, P.A. and W.A. Dean. 1978. A comparison of oral and inhalation
toxicities of four insecticides to mice and rats. Bull. Environ. Contam.
Toxicol. 19: 113-120.
4. U.S. EPA. Office of Pesticide Programs. Health Effects Division. 1999.
Human health risk assessment: Naled. www.epa.gov/pesticides/op/ status.htm.
5. Reigart, J.R. and J.R. Roberts. 1999. Recognition and management of
pesticide poisonings. Fifth edition. U.S. EPA. Office of Pesticide Programs.
6. Sarin, S. and K.D. Gill. 1998. Biochemical and behavioral deficits in
adult rat following chronic dichlorvos exposure. Pharmacol. Biochem. Behavior
7. Sarin, S. and K.D. Gill. 1999. Dichlorvos induced alterations in glucose
homeostasis: Possible implications on the state of neuronal function in rats.
Mol. Cell. Biochem. 199:97-92.
8. Mehl, A. et al. 1994. The effect of trichlorfon and other organophosphates
on prenatal brain development in the guinea pig. Neurochem. Res. 19:569-574.
9. International Agency for Research on Carcinogens. 1991. Occupational
exposures in insecticide applications, and some pesticides. IARC Monographs
10. Finch, J., MS and Bol, K, BS. Cancer in Colorado, 1990-2000, Incidence
and Mortality by County. Dec. 2002 p.14.
11. Rapp, Doris, MD. 2004. West Nile Virus Information Center. p.2