U.S. Water News Online
BLOOMINGTON, Ind. -- Indiana University scientists are
leading a federal effort to track the fluctuation of PCBs, pesticides
and other toxins in the Great Lakes basin.
IU recently received a $3.5 million Environmental Protection
Agency grant to continue operating a network of instruments on the
five lakes -- Huron, Ontario, Michigan, Erie, and Superior -- which
are the world's largest source of fresh water.
The study is part of a cooperative effort with Canada to measure
pollutants coming from the air. IU has operated the network since
"We're trying to understand how (the toxins) behave; how compounds
move around, where they come from and how fast they go from place to
place," said Ronald A. Hites, an IU professor who is an
internationally known expert in environmental toxins.
Earlier this year, Hites co-authored a report showing that farmed
salmon had higher concentrations of PCBs &emdash; polychlorinated
biphenyls -- than wild salmon.
His work on the Great Lakes could help the EPA determine whether
new measures are needed to reduce toxins, said Melissa Hulting, an
EPA scientist who manages the data collection program.
"The Great Lakes are pretty sensitive to inputs of these
pollutants from the air," Hulting said. "It may take awhile to get
the chemicals out of the lakes."
PCBs, an organic compound suspected of causing cancer and other
ailments, were once used to cool and lubricate transformers and
electrical equipment. PCBs persist for years in the environment and
build up in the fatty tissue of fish and mammals, becoming more toxic
as they move up the food chain.
The EPA banned the manufacture of PCBs nearly 30 years ago, but it
and other chemicals continue to accumulate in the Great Lakes at
levels that pose health risks to people.
PCBs move easily between a liquid and a gas, evaporating into the
atmosphere from soil and water before falling back to earth and
starting the cycle again.
Although the chemicals' levels in the lakes have been declining,
they're still high enough to prompt the EPA to advise people to limit
consumption of fish caught in all five Great Lakes and many regional
As part of the study, IU researchers measure PCBs and other toxins
in the atmosphere every 12 days at five U.S. locations, including
Chicago and Cleveland. Canadian researchers measure sites on lakes
Ontario and Huron.
Researchers then analyze the data to determine how much of the
compounds ends up in the lakes -- and how much is coming from the
lakes, Hites said.
Hites hopes the research explains the unsolved mystery of why
levels of PCBs, after dropping steadily for years, suddenly spiked in
1997 and 1998, then dropped again.
"We still don't know why this happened, but we hope the next few
years of data will provide us with some answers," he said.
Return to the
U.S. Water News Archives page
Return to the U.S. Water
Use a comma to separate e-mail addresses:
Hi, I thought you might like to read this article.