Spraying for mosquitoes has increasingly become a summer routine
in many areas, thanks to the West Nile virus. Residents who want
to find out what's being sprayed could turn to the product label
on the container. But even a thorough reading of the label won't
tell the whole story. Most "inert" ingredients, which often
constitute up to 99 percent of the product contents, are not
listed. Yet they can be biochemically active--for example, an
unlisted ingredient in the mosquito pesticide Dibrom is
naphthalene, which might cause cancer and developmental problems
in exposed children. Now some activists are trying to get the
Environmental Protection Agency to force chemical makers into
revealing their hidden compounds. According to the Federal
Insecticide, Fungicide and Rodenticide Act, pesticide
ingredients qualify as inert when their function in a product is
something other than killing the target pest. For instance, an
inert may make a product sticky, or sprayable, or attractive to
a particular kind of bug or rod