Q.
What are "larvicides" and "adulticides"?
A.
Larvicides are products used to kill immature mosquitoes before they become adults. They
can be either biological (such as toxin from specific bacteria
that is lethal to mosquito larvae but not to other organisms)
or chemical products, such as insect growth regulators, surface
films, or organophosphates. Larvicides are applied directly to
water sources that hold mosquito eggs or larvae. When used well,
larvicides can help to reduce the overall mosquito burden by limiting
the number of new mosquitoes that are produced.
Adulticides
are products used to kill adult mosquitoes. Adulticides can be
applied from hand-held sprayers, truck-mounted sprayers or using
airplanes. Adulticides, when used well, can have an immediate
impact to reduce the number of adult mosquitoes in an area, with
the goal of reducing the number of mosquitoes that can bite people
and possibly transmit West Nile virus.
Both
larvicides and adulticides are regulated by the US
Environmental Protection Agency.
Q.
What is CDC's position regarding the use of chemical mosquito
control?
A. Chemical control measures are one part of a comprehensive
and integrated mosquito management program. An integrated program
is the most effective way to prevent and control mosquito-borne
disease. An integrated mosquito management program should include
several components: (1) surveillance (monitoring levels of mosquito
activity, and where virus transmission is occurring), (2) reduction
of mosquito breeding sites, (3) community outreach and public
education, and (4) the ability to use chemical and biological
methods to control both mosquito larvae and adult mosquitoes.
Control
measures, including the decision to use chemical adulticides
(pesticides
to kill adult mosquitoes) should be based on surveillance data
and the risk of human disease. CDC's Revised
Guidelines for Surveillance, Prevention, and Control of West
Nile
Virus in the US, 2003
[PDF - 77 pages ].)provides detailed guidance about the
use of control measures, including a suggestions for a phased
response and the actions that are possible at different levels
of virus activity.
Q.How are mosquitoes controlled during outbreaks?
A. Adult mosquito control may be undertaken to combat an outbreak of mosquito-borne disease or a very heavy nuisance infestation of mosquitoes in a community. Pesticides registered for this use are known as adulticides and are applied either by aircraft or on the ground employing truck-mounted sprayers. State and local agencies commonly use the organophosphate insecticides malathion and naled and the synthetic pyrethroid insecticides permethrin, resmethrin, and sumithrin for adult mosquito control.
Mosquito adulticides are applied as ultra-low volume (ULV) sprays. ULV sprayers dispense very fine aerosol droplets that stay aloft and kill flying mosquitoes on contact. ULV applications involve small quantities of pesticide active ingredient in relation to the size of the area treated, typically less than 3 ounces per acre, which minimizes exposure and risks to people and the environment.
Adulticides can be used for public health mosquito control programs without posing unreasonable risks to the general population or to the environment when applied according to the pesticide label. More information on pesticides commonly-used in public health mosquito control programs is available at http://www.epa.gov/pesticides/health/mosquitoes/mosquito.htm.
Q.
Are pesticides harmful to people?
A. Effect on human health is one of the primary factors considered
in regulation of pesticides. Pesticides that can be used for mosquito
control have been judged by the EPA not to pose an unreasonable
risk to human health. People who are concerned about exposure
to a pesticide, such as those with chemical sensitivity or breathing
conditions such as asthma can reduce their potential for exposure
by staying indoors during the application period (typically nighttime).
A published study, (MMWR,
July 11, 2003) examined illnesses in nine states associated
with exposure to pesticides used to control mosquito populations
from 1999-2002. This study found that "application of certain
insecticides poses a low risk for acute, temporary health effects
among person in areas that were sprayed and among workers handling
and applying insecticides." This article can be viewed online.
For
more information on pesticides and health, consult the US
Environmental Protection Agency, which oversees the registration
of these chemicals. The National
Pesticide Information Center (NPIC) can also provide information
through a toll-free number, 1-800-858-7378 or online.
Q.
What should I do if I think that I am having health problems because
of pesticides used in my area?
A. If you are experiencing health problems for any reason
it is important to see your health care provider promptly. If
you are experiencing severe health problems go immediately to
an Emergency Room.
Q.
How does pesticide spraying affect the environment?
A.
A great deal of research must be done before pesticides can be
used in the environment. The best source for finding out about
the pesticides used in your area, and their effect on specific
types of wildlife, is with the US
Environmental Protection Agency, which oversees the registration
of these products. The National
Pesticide Information Center (NPIC) can also provide information
through a toll-free number, 1-800-858-7378 or online.
Q.
What training is required for workers who apply pesticides?
A.
Each state has mandated training and experience requirements that
must be met before an individual can commercially apply pesticides.
In New York state, for example, certified pesticide apprentices
must be at least 16 years of age, have completed an 8-hour core
training course on safety issues and the use of pesticides, and
have at least 40 hours of pesticide use experience in the field
under the direct supervision of a certified pesticide applicator.
In addition, these applicators must follow the instructions and
precautions that are printed on the pesticide label. All pesticide
products are required to have a label which provides information,
including instructions on how to apply the pesticide and precautions
to be taken to prevent health and environmental effects. All labels
are required to be approved by U.S. EPA.
Q.
Where can I get information regarding the safety of specific pesticides?
A.
Questions concerning specific pesticides can be directed to the
U.S. Environmental Protection Agency, as this agency has responsibility
for registration of pesticides. Many issues are addressed on the
EPA's
Mosquito Control Web site.
The
National
Pesticide Information Center (NPIC) provides pesticide information
and questions about the impact of pesticide use on human health.
NPIC is cooperatively sponsored by Oregon State University and
the U.S. Environmental Protection Agency. NPIC can be reached
online
or toll-free: 1-800-858-7378.
Q.
How can I find out what type of pesticides are being used in my
area?
A.
Your local mosquito control program or health department can give
information about the type of products being used in an area.
Mosquito control activities are most often handled at the local
level, such as through county or city government. Check with your
health department or in the "blue" (government) pages
of the phone book for the contacts in your area.
Another
resource to learn more about mosquito control is the American
Mosquito Control Association.
