Daily News Archive

Ft. Worth, TX and Washington, DC Maintain No-Spray Policy for WNv

(Beyond Pesticides, August 8, 2002) The first 2002 human case of West Nile virus (WNv) in the Washington DC area was confirmed yesterday. A 55-year-old man has been diagnosed as having WNv and remains hospitalized. Although mosquito pools have tested positive for the disease, District health officials continue their no spray policy stating that pesticide spraying is inappropriate in a heavily populated area with many asthma patients according to the Washington Post. Instead, officials are focusing on prevention through larviciding and pubic education.

Other communities agree with such a mosquito management approach. According to the Ft. Worth Department of Public Health, city officials there have not sprayed for mosquitoes since 1991. Health officials say there are many reasons including the questionable effectiveness of insecticides and the negative impacts they pose to the environment. Brian Boerner, director of Environmental Management, states that, "the spraying of chemicals also has the potential of contaminating our waterways, killing the beneficial fish and organisms that feed on mosquito larva, adding harmful volatile organic chemicals to the atmosphere-a precursor chemical to ozone formation-and providing a potential inhalation or ingestion hazard to residents who are in affected areas shortly after spraying occurs."

Dr. Brian Rogers, health authority for the city of Ft. Worth said, "The risk of becoming seriously ill and dying from West Nile is extremely minimal. Fewer than 1 percent of mosquitoes in areas where the virus has been found actually carry the virus. And if bitten by an infected mosquito, there's only a 1 percent chance of becoming seriously ill."

In the U.S. from 1999 through 2 August 2002, WN virus has been documented in 32 states and the District of Columbia.

Louisiana has had five deaths related to WNv this year. Individual parishes (counties) are undertaking intensive spray programs including aerial and ground spraying of malathion and resmethrin, both of which are neurotoxins.

Beyond Pesticides agrees that community education, prevention and monitoring are essential in effectively managing insect-borne illnesses. While some communities have good intentions, some policies and programs may be dangerous and inadequate by relying too heavily on spraying hazardous pesticides to kill adult mosquitoes. Thousands of people become sick from pesticide exposure each year. While spraying pesticides is not recommended, if a community decides to do this, it is important that it sprays responsibly, using the least toxic pesticide. First, the public should be notified in advance so that exposure to dangerous chemicals can be avoided. Second, pesticide operators should be properly protected and trained on when, where, and how to spray.

There are several steps individuals can take to protect you and your family.

Eliminate Breeding Sites

Mosquitoes need only a bottle cap of water to breed. Getting rid of mosquito breeding sites gets rid of mosquitoes. Because many types of mosquitoes do not travel far from where they hatch, individuals can have a dramatic impact on local mosquito populations by following the prevention measures below.

  • Clean up standing water on your property.
  • Get rid of unnecessary debris on residential and commercial property, such as old tires.
  • Empty water from toys, buckets, birdbaths, swimming pool covers, and any other areas where water may be collecting twice per week.
  • Drill holes in the bottom of recycling bins and other outside containers.
  • Clean out rain gutters and make sure they drain properly.
  • Turn garbage can covers right side up.

Avoid the Bite

  • Ensure that window and door screening is properly maintained.
  • Wear protective clothing if going outside when mosquitoes are most active, which is often in the early morning and evening. Put on a hat, wear long sleeves, and tuck pants into socks-especially in highly infested areas. Wear light colors, as they are less attractive to mosquitoes.
  • Consider using mosquito repellants, according to directions, when outdoors. Choose products containing geraniol (MosquitoSafe), citronella (Natrapel), a combination of soybean, and coconut oils (Bite Blocker), or other all essential oils (All Terrain). These are effective mosquito repellants that are safer than DEET, but may need to be reapplied. Always wash off repellants with soap and water once indoors. These products can be purchased at many pharmacies and camping stores. If they are not available, be sure to ask for them!

Warning: Avoid products that contain DEET (N,N-diethyl-meta-toluamide), especially when choosing a product for children or when using it in combination with other chemicals or medications. Several cases of DEET poisonings have been reported by EPA, including three fatalities. Doctors recommend using products that contain no more than 30 percent DEET for adults. DEET should not be used on infants or children. In 1998, EPA made it illegal for any product containing DEET to make child safety claims. The Canadian Government recently banned products containing more then 30% DEET. A new study by Duke University researchers found that combined exposure to DEET and permethrin, which is a mosquito spray, can lead to motor deficits and learning and memory dysfunction. We strongly recommend that only DEET-free products be used.

  • Set up large fans for home barbeques or other outdoor gatherings.
  • Use citronella candles or yellow outdoor light bulbs to repel mosquitoes.
  • Fill holes or depressions in trees with sand or mortar, or drain after each rain.
  • Stock ornamental pond with mosquito-eating gambusia fish.
  • Set up carbon dioxide traps, which attract mosquitoes.

For more information, see the West Nile Virus program page on this website. For more information on the Ft. Worth no spray policy, see http://www.fortworthgov.org/health/HP/Mosquito_Spray2002.asp