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.<\/p>\n
<\/p>\n
… The recent spate of widespread die-offs began in amphibians. Scientists discovered the culprit—an aquatic fungus called Batrachochytrium dendrobatidis,
of a class of fungi called “chytrids”—in 1998. Its devastation, says
amphibian expert Kevin Zippel, is “unlike anything we’ve seen since the
extinction of the dinosaurs.” Over 1,800 species of amphibians
currently face extinction.<\/p>\n
<\/p>\n
It may be, as many experts believe, that the chytrid fungus is a novel
pathogen, decimating species that have no armor against it, much as
Europe’s smallpox and measles decimated Native Americans in the
sixteenth and seventeenth centuries. But “there is a really good
plausible story of chemicals affecting the immune system and making
animals more susceptible,” as well, says San Francisco State University
conservation biologist Carlos Davidson.<\/p>\n
Shah goes on to explain a mechanism whereby pesticides applied to fields in California’s Central Valley drift into the Sierra Nevada mountains “where they settle in the air, snow, and surface waters, and inside the tissues of amphibians.” A scientist who studied the matter “found a strong correlation between upwind pesticide use … and declining amphibian populations.”<\/p>\n
<\/p>\n
Meanwhile, bees and bats have suffered a similar fate—killed off by powerful pathogens that in theory could be novel but in practice seem to have taken advantage of animal populations immuno-compromised by pesticides.<\/p>\n
<\/p>\n
One of the most interesting aspects of the piece was the description of an Italian scientist’s unpublished research that suggests the “missing link” between neonicotinoids, a powerful pesticide already banned in Europe but still in use in the U.S., and bee colony collapse. It relates to the practices of using neonicotinoids-coated seeds planted by machines that kick up clouds of pesticide as they work:<\/p>\n
… In as-yet-unpublished
research, [University of Padua entomologist Vincenzo] Girolami has found concentrations of insecticide in clouds
above seeding machines 1,000 times the dose lethal to bees. In the
spring, when the seed machines are working, says Girolami, “I think
that 90 percent or more of deaths of bees is due to direct pesticide
poisoning.”<\/p>\n
<\/p>\n
Girolami has also found lethal levels of neonicotinoids in other,
unexpected—and usually untested—places, such as the drops of liquid
that treated crops secrete along their leaf margins, which bees and
other insects drink.<\/p>\n
But Shah concludes by observing that this accumulating evidence comes with challenges and caveats that, I would point out, industry ruthlessly exploits:<\/p>\n
Proving, with statistical certainty, that low-level pesticide exposure
makes living things more vulnerable to disease is notoriously
difficult. There are too many different pesticides, lurking in too many
complex, poorly understood habitats to build definitively damning
indictments. The evidence is subtle, suggestive.<\/p>\n
Subtle and suggestive though it may be, it’s extremely unlikely that these chemicals aren’t also acting on us. This news plus the data surrounding the consequences to human health of low-dose exposure to chemicals like atrazine<\/a>, BPA and phthalates should have us in a panic and our government in a regulatory frenzy. Instead we get paralysis<\/a> and promises of “further study.” As we wait for a chemical “smoking gun,” I wonder what animal population will die off next. Anyone care to wager?<\/p>\n Related Links:<\/strong><\/p>\n Scientists confirm link between BPA and heart disease in humans<\/a><\/p>\n A scientist chases penguins chased by climate change<\/a><\/p>\n Food giants pile on salt to tart up flavorless dreck<\/a><\/p>\n
![\"\"](\"http:\/\/a.rfihub.com\/eus.gif?eui=2223\"\/)
<\/p>\n","protected":false},"excerpt":{"rendered":"