Going to Extremes - The Ripple Effect: The Fate of Freshwater in the Twenty-First Century - page 23

Because they weigh 35 percent more than water does, PCBs don't float in an obvious
slick on the surface, like the oil in Newtown Creek. They drop to the bottom of a wa-
terway, cling to sediments, and enter the food chain through aquatic plants and inver-
tebrates. PCBs are classic legacy pollutants: they do not break down readily in H 2 O and
can persist for years. After contaminated cooking oil poisoned thousands of residents
in Japan and Taiwan, many countries banned PCB use in 1977. It took another two
years before Congress banned PCB production and distribution in the United States.
The compounds are now outlawed in most nations. But it is estimated that over 1.5 bil-
lion pounds of PCBs still linger in the environment. They have been detected in a broad
variety of animal species and even in rain-forest tribes and Eskimos, who have never
used them.
As they work their way up the food chain, PCBs bioaccumulate in the tissue of
fish, amphibians, mammals, and birds. Predators at the top of the food chain—such as
eagles, orca whales, or humans—carry the highest levels of toxins. Doctors call the load
of pollutants that accumulates in animal tissues the body burden.
Prolonged exposure to PCBs can cause severe acne and rashes and has been linked
to childhood obesity and diabetes. PCBs may damage the liver, cause hormonal disrup-
tions, and impact fertility. In high doses, PCBs cause cancer in animals, and they are
regarded as probable carcinogens in people; they are especially linked to cancers of the
liver and biliary tract.
The maximum allowable exposure level of PCBs in humans is two parts per million
(ppm). The Housatonic's fish contain PCB concentrations of up to 206 ppm , which are
among the highest levels ever recorded. Housatonic ducks showed average PCB levels
of 100 ppm, levels rarely seen anywhere else in the world. One of the first ducks trapped
near Pittsfield registered a PCB count of an astonishing 3,700 ppm, and its carcass was
treated as “flying hazardous waste.” Even small amounts of PCBs are dangerous. In one
study, half the mink puppies fed Housatonic fish with PCB levels of only 4 ppm died
quickly, and the surviving pups eventually developed jaw lesions, tooth loss, anorexia,
and then died.
A 2009 EPA study of the Housatonic concluded, “Fish, other aquatic animals, and
wildlife in the river and floodplain contain concentrations of PCBs that are among the
highest ever measured…. Natural recovery from this contamination … will take dec-
ades if not hundreds of years.”
About forty miles south of Pittsfield, the Housatonic passes through the small town
in northwest Connecticut where my parents have a house. Here, the river sweeps be-
neath a red covered bridge, past boulder-strewn banks and verdant hills. Despite warn-
ing signs posted on trees, my friends and I spent countless hours canoeing and fishing
a ten-mile stretch of “the Housie” and occasionally swam in it and ingested its water.