Mosquito-borne diseases affect millions of people worldwide each year. In the US alone there are over 150 species of mosquitoes. These mosquitos transmit diseases such as encephalitis, dengue fever and malaria. To combat mosquitoes and the potential public health hazards they present, many countries have established mosquito control programs. These programs can include ground and aerial application of pesticides along with non-chemical forms of control and prevention.
It is the priority of the Environmental Protection Agency (EPA) to protect human
health and the environment and provide support to states dealing with serious outbreaks of
infectious diseases from mosquitoes. EPA helps to ensure that states and localities apply
pesticides according to proper application methods to reduce human exposure.
questions and answers provide additional information on safety precautions, and
information on insecticides used for mosquito control programs.
How does EPA ensure the safest possible use of pesticides?
It is a priority of EPA to protect human health and the environment from the adverse
effects of pesticides. EPA must evaluate and register pesticides before they may be used,
sold or distributed in the United States. To evaluate a pesticide registration
application, EPA assesses a wide variety of potential human health and environmental
effects associated with use of the product. The producer of the pesticide must provide
data from tests done according to EPA guidelines. These tests must determine whether a
pesticide has the potential to cause adverse effects on humans, wildlife, fish and plants,
including endangered species and non-target organisms, as well as possible contamination
of surface water or groundwater from leaching, runoff and spray drift. If a pesticide
meets EPA requirements that ensure no harm to human health and the environment, the
pesticide is approved for use in strict accordance with label directions.
The EPA is working to ensure that the Food Quality Protection Act of
1996 (FQPA) is properly implemented to achieve high standards of protection, especially
for children, while preserving the strength of agricultural communities and
maintaining viable pest control products.
It must be noted however, that no pesticide is 100 percent safe and care must be exercised in the use of any pesticide.
What EPA-approved insecticides are used by countries most
Malathion is an insecticide used for mosquito control. EPA requires that
Malathion be applied at very low rates by sprayers operated by state or local applicators
from trucks or aircraft to ensure protection of public health and the environment.
Malathion kills mosquitoes when they contact spray particles in the air. mosquitoes,
unlike humans, lack the enzymes that quickly break down Malathion. Thus, Malathion can be
applied at low concentrations with little risk to humans.
Naled is an insecticide that is registered primarily for use on land to
kill adult mosquitoes and blackflies. Naled is also used on some food and feed crops to
control pests, and in pet flea collars. Most use of Naled for mosquito control occurs in
the southern states, particularly Florida and other Gulf states. When applied at low
concentrations as required by the label, Naled should pose little risk to humans from
mosquito control use. There is potential for acute and some potential for chronic risks to
freshwater invertebrates from the use of Naled. Naled breaks down rapidly in soil and
Malathion and Naled are part of a group of pesticides
known as organophosphates. All organophosphate pesticides are currently under new
review by EPA to ensure greater safety. The EPA made public a comprehensive risk
assessment of Malathion and Naled on 12 May 2000. This review is available for public comment until the end of July 2000.
Sumithrin is an insecticide registered for use
against mosquitoes in swamps, marshes and recreational areas. It imitates natural
pesticides found in chrysanthemums, and is the active ingredient in the product Anvil 10 +
10. Sumithrin can also be used to kill pests in transport vehicles such as aircraft,
ships, railroad cars and truck trailers, and for institutional non-food use, use in homes
and gardens, greenhouses and on pets. Sumithrin breaks down rapidly in the environment and
is expected to pose little risk to humans when used at low concentrations for mosquito
Resmethrin is an insecticide used to control flying and crawling insects in
the home, lawn, garden and at industrial sites. Resmethrin is the active ingredient in the
product Scourge, which is used to control adult mosquitoes. It also
imitates natural pesticides found in chrysanthemums. It is only registered for
outdoor use and is generally applied in very small amounts.
Resmethrin decomposes quickly in sunlight or when exposed to air. Resmethrin products have
low toxicity to humans, but are very toxic to fish. Resmethrin products for mosquito
control at or near aquatic sites are classified as Restricted Use Pesticides and may only
be used by specially trained and licensed applicators.
Bacillus sphaericus and Bacillus thuringiensis israelensis are
biological pesticides used for mosquito larvae control in water. When the larvae eat them,
the pesticides release a protein that disrupts the feeding process of the mosquito larvae
causing them to starve and die.Bacillus sphaericus and Bacillus
thuringiensis israelensis are a naturally occurring bacteria found throughout the
world and are of limited toxicity to humans.
What should be done to reduce exposure to pesticides during mosquito control spraying?
There are a number of common sense steps recommended by EPA to help reduce possible exposure to pesticides during spraying: