07 Jan 2010: Report
Behind Mass Die-Offs,
Pesticides Lurk as Culprit
In the past dozen years, three new diseases have decimated populations of amphibians, honeybees, and — most recently — bats. Increasingly, scientists suspect that low-level exposure to pesticides could be contributing to this rash of epidemics.
by sonia shah
Ever since Olga Owen Huckins shared the spectacle of a yard full of dead, DDT-poisoned birds with her friend Rachel Carson in 1958, scientists have been tracking the dramatic toll on wildlife of a planet awash in pesticides. Today, drips and puffs of pesticides surround us everywhere, contaminating 90 percent of the nation’s major rivers and streams, more than 80 percent of sampled fish, and one-third of the nation’s aquifers. According to the U.S. Fish and Wildlife Service, fish and birds that unsuspectingly expose themselves to this chemical soup die by the millions every year.
But as regulators grapple with the lethal dangers of pesticides, scientists are discovering that even seemingly benign, low-level exposures to pesticides can affect wild creatures in subtle, unexpected ways — and could even be contributing to a rash of new epidemics pushing species to the brink of extinction.
In the past dozen years, no fewer than three never-before-seen diseases have decimated populations of amphibians, bees, and — most recently — bats. A growing body of evidence indicates that pesticide exposure may be playing an important role in the decline of the first two species, and scientists are investigating whether such exposures may be involved in the deaths of more than 1 million bats in the northeastern United States over the past several years.