November
28th meeting
Questions were raised about the mosquito problem,
a new elementary school being built, and the new Home Depot.
First issue was the
mosquito problem:
It was reported that the
Board of Supervisors instructed staff to look at a countywide spray program.
1.
What is
the status/findings of the Health Department's research in this area?
2.
What type
(name) of pestacide and/or larvaecide will be used?
From: Eidem,
Roy
Sent: Thursday, November 30, 2000 12:30 PM
To: Lambert, Rose
Cc: Smith, Glenn L.
Subject: FW: SPRAY PROGRAM
Rose, I hope this is helpful. As you can see there is not a simple
answer to
this complex issue. Roy
The
question of spraying for adult mosquitoes is often focal in the minds
of the
public and press. We do not recommend
spraying for mosquitoes in
Fairfax
County at this time. Spraying to kill
adult mosquitoes will not
eliminate
the West Nile virus. Spraying, under
the best of conditions
has only a
very short-term knock down effect on the mosquito population in
the
immediate area treated. Unless the
actual mosquito breeding sites
are
identified and controlled, that is, areas of standing water,
mosquitoes
will return. Spraying for adult
mosquitoes is a single tool
in
mosquito management and control, but it is not the overall most
long-term
effective or first action of choice.
When
should we spray in Fairfax County? The
simple answer is when the
weight of
the protection of the public health outweighs the risks
associated
with the application of a pesticide into the environment. The
public
health risk is human illness and death; the use of pesticides
places at
risk: those with respiratory illness and asthma and chemical
sensitivities, fish and aquatic invertebrates, and non-target
beneficial
insects
such as honey bees.
The most
effective way to reduce risk of exposure to West Nile virus is
public
education and reduction of the types of water breeding sites the
mosquitoes
prefer. The public needs to know that there are things they can
do to
reduce exposure: wear long-sleeved shirts and pants, use insect
repellants
when necessary, reduce outside activities at dusk when most
bites
occur, use yellow "bug-lights" around your home, and most
importantly eliminate any standing water around your home. The mosquito
species
that most frequently are carriers of West Nile virus are
artificial
container breeders. Open bodies of
water (lakes and farm
ponds) are
not good mosquito-breeding sites as these areas have fish and
other
insect life that eat mosquitoes. It is
the little cups and
containers
of water that stand for 7-10 days around your home, where other
hungry
wildlife are not present, in which mosquitoes are most likely to be
able to
complete a breeding cycle. Mosquitoes
are not strong fliers. If
you are
being bitten around you home, the breeding site is nearby. Some
favorite
breeding sites for mosquitoes are: rain gutters, tarps or covers,
toys,
buckets, cans, bottles, flower pots, wagons, unused hot tubs, tires
without
rims, open boats and canoes, unattended pet bowls, wheel barrows,
and
stagnant bird baths. (This information
is on the Health Department's
new web
site (www.co.fairfax.va.us/service/hd)
and new mosquito
information phamplet.
Fairfax County Cable channel 16 also ran a series
of
programs on West Nile virus and mosquito control.)
The next
course of action is to identify roadside ditches and small areas
of
ponding/puddling water and if at all possible, to permanitely fill in
or drain
these areas. If backfilling or
draining is not possible, the
water may
be treated with a larvaciding agent. Larviciding treatment is
more
effective in long-term reduction of the mosquito population and does
not carry
the same level of risks associated with spraying. The
predominately used larvaciding agents come in three general types:
bacterial,
hormonal, and suffocating. An example
of a hormonal control is
the
placement in the water a juvenile growth hormone that is specific for
mosquitoes. The hormone causes the mosquito larva to stay as a
larva and
never
mature into a flying, biting adult.
Some of these hormone,
time-released tablets can last up to 150 days in the water.
The
pesticides that have recently been used to spray for the West Nile
virus are
synthetic pyrethroids -- Sumithrin (Anvil(tm)) and resmithrin
(Scourge(tm)). These
are synthetic formulations of a naturally
occurring
pesticide in the chrysanthemum flower.
When applied correctly
they have
a quick knockdown effect and biodegrade quickly in the
environment. They are,
however, toxic to fish, water invertebrates, and
especially
to honey bees. Restrictions in their
use are not to use over
or within
100 feet of lakes, streams and other bodies of water. The
pesticide
is only effective on warm, non-breezy evenings when the
mosquitoes
are out. Pyrethroids are a
"contact" pesticide, that is, a
droplet
must land on the mosquito to be effective.
Also, the pesticide
will
quickly move away on a breezy evening to non-target areas that could
cause
other public health and environmental concerns. Public response to
spraying
can be emotionally charged and polar.
Some will want their
neighborhood sprayed on a regular basis all summer long as a
preventative
basis,
some will never want any chemical sprayed into the environment
under any
circumstances.
In summary
then, the Health Department:
* Continues to monitor for the
arrival of the West Nile virus through
avian
(bird) surveillance.
* Concurs with the CDC and COG
guidance to initiate of a mosquito
capture
and analysis program. (New staffing
will be needed -- the
previous
Health Department Mosquito Control Program was abolished under
the FY'92
budget cuts).
* Continues to educate the public in
things they can do to reduce
their risk
from mosquito bites and the West Nile virus.
* Does not recommend spraying for
mosquitoes at this time.
Roy W.
Eidem, R.E.H.S.
Environmental Health Supervisor
Community
Health & Safety Section
Fairfax
County Division of Environmental Health
Phone:
(703) 246-3561
FAX: (703)
278-8157
1.. The
Island Creek Elementary School (off Beulah Street) is in the next
bond
issuance and may be constructed as soon as 2003. It is getting
expeditious review as a result of the massive over-crowding in the
Kingstowne
area and because the site was donated.
There was also talk
about a
piece of property that the School Board owns near Pinewood Lake
and the
possibility of building a school there - the community rejected
that idea
and it is now dead (especially in light of the uncertainty
surrounding the ISA's future).
2. Home Depot keeps getting delayed because of
asbestos removal problems.
The
shopping center owner tells me the hope to demolish by the end of
December
about want to be open next fall. I am
somewhat optimistic, but
the date
does keep sliding. Last time I spoke
with the owner was three
weeks ago,
Becky may have chatted more recently.
See you
Monday. Have a great weekend.
Jeffrey C.
McKay,
Chief of
Staff
Office of
Supervisor T. Dana Kauffman
Fairfax
County Government, Board of Supervisors
6121
Franconia Road
Alexandria, VA 22310
(703)
971-6262 Phone
(703)
971-3032 Facsimile