Effectiveness of Widespread Mosquito Spraying for West Nile Virus in Question

Aug 24, 2006, 01:00 ET from Beyond Pesticides

    WASHINGTON, Aug. 24 /PRNewswire/ -- As mosquito vector control
 officials rev up their truck-based and aerial pesticide spray programs for
 West Nile virus (WNv) and Eastern equine encephalitis (EEE), important new
 evidence on the ineffectiveness of their methods is making headlines in
 scientific circles.
     A critical new study by a group of scientists and practitioners,
 concludes, "We find that ULV applications of resmethrin had little or no
 impact on the Culex vectors of WNv, even at maximum permitted rates of
 application, [and] such insecticidal aerosols, delivered from the road, may
 not effectively reduce the force of transmission of WNv."
     Recognizing the lack of research on the effectiveness of pesticide
 spraying, the researchers measured mosquito populations in eastern
 Massachusetts after a typical resmethrin, a synthetic pyrethroid, spraying.
 About as many eggs were deposited before the pesticide application as after
 in both treated and untreated areas. This study, "Efficacy of Resmethrin
 Aerosols Applied from the Road for Supressing Culex Vectors of West Nile
 Virus," funded in part by the Centers for Disease Control (CDC) and the
 National Institutes of Health and led by the Harvard School of Public
 Health, appears in the June 2006 issue of Vector-Borne and Zoonotic
     An earlier study on truck-spraying, which appeared in the Journal of
 the American Mosquito Control Association (1998), concludes that the
 average upwind and downwind mosquito kill from truck-mounted spraying to be
 between 21% and 45%.
     "Source reduction, the elimination of mosquito larval habitat, remains
 the most effective and economical method of providing long-term mosquito
 control, yet communities are reverting to spraying adult mosquitoes with
 little or no monitoring of effectiveness," says Eileen Gunn, Project
 Director for Beyond Pesticides, a national environmental organization.
     Public health officials and environmental groups are equally disturbed
 by the lack of information officials are providing to the public on the
 impacts of the chemicals they are spraying. Officials claim the pesticides
 are safe because they are registered by the Environmental Protection Agency
 (EPA) -- a claim that is illegal to make. Many mosquito control and
 household insecticides are synthetic pyrethroids, with impacts typical of
 neurotoxins, such as headaches, dizziness, nausea, and irritation.
     EPA classifies some pyrethroids as possible human carcinogens and many
 are endocrine disruptors, meaning, even at low levels, they can adversely
 affect reproduction, sexual development, interfere with the immune system,
 and increase chances of breast cancer. Last summer, CDC's Third National
 Report on Human Exposure to Environmental Chemicals, showed pyrethroids in
 the urine of more than 50% of the subjects tested.
     With the threat of WNv and EEE, public health advocates say mosquito
 control must be conducted in a way that truly reduces the risks of getting
 the disease and the hazards from harmful pesticides, so that the public is
 not given a false sense of security.
     Beyond Pesticides has several publications and activists tools online
 at http://www.beyondpesticides.org/mosquito.

SOURCE Beyond Pesticides