Despite its foreign-sounding name, the West Nile virus is becoming an undeniably American concern. Eighty-eight new cases were reported in three states last week, and the Centers for Disease Control and Prevention announced yesterday that the mosquito-borne virus is here to stay. About one in five people who get the virus develop flu-like symptoms; less than 1 percent face the most serious complication, encephalitis, or inflammation of the brain. The virus is bad, of course — but what if the cure is worse than the disease? In Louisiana and other places experiencing West Nile outbreaks, mosquito populations are being sprayed with chemical and biological pesticides from trucks and planes, as well as by hand. The pesticides include malathion and naled, both of which can cause health problems ranging from nausea, dizziness, and confusion at low exposures to paralysis, respiratory failure, and death at high exposures. Although the amounts being used are said to pose minimal risks, pregnant women, children, and others sensitive to chemicals are being warned to take shelter when spraying occurs.

Grist thanks its sponsors. Become one.