Potential Adverse Effects of Pesticides Used to Combat West Nile Virus
From: Robina Suwol
Date: 02 Jun 2003
Time: 05:56:03
Remote Name: 65.66.172.255
Comments
Maryland Pesticide Network
544 Epping Forest Road, Annapolis, Maryland, 21401,
410-849-3909,
info@mdpestnet.org
Duke University Medical Center Professor Warns Maryland About the Potential Adverse Effects of Pesticides Used to Combat West Nile Virus.
Public exposure to two pesticides commonly used to manage nuisance mosquitoes
and combat West Nile virus may be creating a dramatic public health problem
larger than the insects themselves. In a letter to Maryland state officials,
Duke University Medical Center professor of pharmocology, cancer biology and
neurobiology, Mohamed B. Abou-Donia, Ph.D. warns of the dangers of prolonged
use of high dose N,N-Diethyl m-Toluamide (DEET), used in over the counter
mosquito repellents, and a magnification effect when used in combination with
the insecticide permethrin (used to kill adult mosquitoes). In research
conducted by Dr. Abou-Donia, profuse brain cell death and behavioral changes
were found in rats exposed to DEET. A magnification effect occurred when DEET
was applied to rats also exposed to the pesticide permethrin, used for
mosquito control in Maryland. Rats dermally exposed to a combination of DEET
and permethrin had tremendous reductions in muscle control, strength, memory
and coordination.
"Since the recent outbreak of West Nile Virus (WNV), Maryland state officials
have been recommending the use of DEET products/mosquito repellents. Maryland
state officials are also planning to apply the insecticide permethrin for
protection against the WNV. The liberal and unrestricted use of these
chemicals and consequent exposure to the public, concerns me, considering the
results of our research on the neurotoxic effects of these chemicals", wrote
Abou-Donia in a recent letter to Maryland County health officers forwarded to
the health officers by the Maryland Pesticide Network.
Abou-Donia warns Maryland state officials and the public to be cautious in
recommending and using DEET products, and suggests DEET never be used on
infants or combined with other insecticides, sunscreens, or even over the
counter drugs such as antihistamines. In the U.S. many insect repellents
contain up to 100 percent DEET, but doctors have recommended using products
that contain no more than thirty percent DEET, and recently all products
containing a higher dose were outlawed in Canada.
In general, WNV is a mild disease. It only becomes serious encephalitis if the
virus can cross the blood-brain barrier. Among the agents that have been shown
to impair the blood-brain barrier are in the pyrethroid chemical family, of
which permethrin is a member. Therefore exposure to permethrin may have the
potential to worsen the process of WNV infection.
Permethrin is also considered a possible carcinogen and possible endocrine
disruptor by the US EPA. Short- term adverse effects include exacerbation of
respiratory illnesses such as asthma, and effects on the nervous system such
as itching, numbing, burning or tingling.
Last changed: March 14, 2006