Because of the widespread fear, bordering on panic, that has accompanied the continued appearance of the West Nile Virus, massive pesticide spraying campaigns are underway in many areas on the Northeastern US, including New York City and Boston.

The insecticides being used in New York are sumithrin (Anvil) and resmethrin (Scourge), both synthetic pyrethroids. In Boston, only resmethrin is being used. The use of both pesticides are coming under considerable criticism, as potentially toxic chemicals that pose a danger to humans, wildlife and the environment.

• The Pyrethroids may interfere with the immune and endocrine systems.

• Other adverse chronic effects, including effects on the liver and thyroid, have been reported in toxicology testing.

• According to toxicologists, animal tests showed that chronic exposure to resmethrin could increase thyroid weight and cause thyroid cysts.

• In animal studies, it was found that in addition to a variety of other health effects, exposure to pyrethroids can suppress both the thyroid's T4 and T3 levels, and raise Thyroid Stimulating Hormone (TSH) levels.

• According to researchers writing in the Journal of Applied Toxicology, "immense care is warranted in the use of insecticides, because they not only affect the liver, kidney and other organs but also may alter the activity of the endocrine glands." (J Appl Toxicol 1996 Sep-Oct;16(5):397-400)

• Other researchers have found that pyrethroids are environmental estrogens, and may contribute to reproductive dysfunction, developmental impairment, and cancer" (Abstract).

• Another study found that some pyrethroids have the potential to promote breast cell proliferation, an action that can increase cancer risk (Abstract).

Jay Feldman, is executive director of the National Coalition Against the Misuse of Pesticides, a Washington, D.C.-based environmental organization.

• According to him, "The city has overstepped the boundaries of safety and law in the handling of its mosquito prevention and management program, exposing the public to hazardous pesticides."

• The group has filed a lawsuit against the City of New York over the spraying, citing violations of federal and state environmental statutes.

William Cooke, a spokesman for the National Audubon Society in New York, commenting on the spraying to the New York Times, saying: "There's a grossly inadequate effort to track the collateral impact on the environment and on humans."

Potentially toxic spraying such what is taking place in New York City and Boston may become a concern in other areas of the country soon, as experts believe that the West Nile virus is on the move.

"The virus is probably in every corner of North America by now," as well as parts of South America, says John Rappole from the Smithsonian Institution's zoo, in the July issue of Emerging Infectious Diseases magazine.

For More Information Contact:

New York Public Interest Research Group / New York Coalition for Alternatives to Pesticides -- Statement Regarding Emergency Pesticide Spraying for Mosquito Control

National Coalition Against the Misuse of Pesticides

This information taken from an article by Mary Shomon on About.com's Thyroid page.