PALISADES – A new study
conducted by scientists at Columbia University’s Lamont-Doherty
Earth Observatory in Palisades has found that fecal bacteria from sewage
are living in far greater quantities in near-shore sediments of the Hudson
River than in the water itself.
The river’s pollution levels are generally monitored from samples
of clear water, not sediments, so the findings suggest that people stirring
up the bottom while wading, swimming or kayaking may face previously unrecognized
health risks, researchers said.
The scientists sampled 11 sites along the river banks in Rockland and
Westchester counties as well as in eastern Queens. In some they found
as much as 10 times more fecal bacteria in sediments as in overlying water.
Sites with sandier bottoms tended to have fewer germs, while levels were
higher in fine, mucky organic-rich areas.
“These organisms originate in the human gut, where it’s organic
rick and dark,” said Lamont-Doherty biologist Andrew Juhl. “The
water in the river is neither organic rich nor dark, but the sediments
on the bottom typically are, and that makes them a better environment
for potentially harmful microorganisms.” Juhl said this is one of
the first studies to test that idea in a river estuary, and the first
one in this area.
