Looks like the lakes are off gassing a bit....

TORONTO (Reuters) - Canadian and U.S. scientists say they have
proof the world's biggest fresh water system, the Great Lakes on the
U.S.-Canada border, are cleansing themselves of pollutants, and they
are planning tests to see if the same is true in the Arctic.
The unusual phenomenon was discovered by the bi-national Integrated
Atmospheric Deposition Network (IADN), which says tests since
1992 show that significant quantities of polychlorinated biphenyls, or
PCBs, and pesticides were being released into the atmosphere by the
five Great Lakes -- Erie, Superior, Ontario, Michigan and Huron.
The combined surface area of the lakes, which hold about 20 percent
of the world's fresh surface water, is about 94,250 square miles.
Dr. Keith Puckett, Environment Canada's manager of the IADN,
likened the process to giant lungs that have been sucking in polluted
air for the past 50 years. Now that the atmospheric levels of many of
these pollutants have dropped, the lakes have started breathing out the
pollutants again.
He said that since Canada and the United States began regulating the
use of certain chemicals, levels in the atmosphere started dropping
and the lakes then began their own process of cleansing -- at twice the
rate they took in.
"As air pollutants over the air drop, this then allows the lakes the
opportunity to cleanse themselves and they do this through a process
of volatilization or out-gassing of these compounds into the air,"
Puckett told Reuters.
Now, Puckett and his team want to do the same tests around an
archipelago of islands in the Arctic Ocean.
"Our greatest interest will be a group of small islands where we know
that the wildlife there, the seals, walrus, polar bears, have high levels
of these pesticides we can try to make same measurements there," he
said.
The studies of the IADN on the Great Lakes show that Lake Ontario,
the smallest of the five lakes, released almost two tons of PCBs into
the air from 1992 and 1996 as well as significant amounts of dieldrin,
a widely banned insecticide.
Puckett said data between 1992 and 1996 show there was a decrease
of roughly 10 tons of PCBs in the lake and a net decrease of more than
4 tons of dieldrin.
From remote IADN stations at each of the lakes, which are linked to a
series of satellites, the scientists track some 20 atmospheric
pollutants, he said. This year they will expand their monitoring to
include mercury.
Puckett said it was time to pay closer attention to air pollution from
power plant smokestacks, factory boilers, household furnaces,
fireplaces and smoking tailpipes on millions of vehicles. Each
contributes its share of fine particles and ash, acid gases and smog-
forming compounds to the atmosphere, some of which ends up in the
Great Lakes.
This was part of a new challenge, he said, adding that the IADN was
still trying to determine the quantity of pollutants coming from local
sources within the Great Lakes Basin, and how much was coming from
continental or global sources outside.
He estimated that about 30 percent to 40 percent of dioxins dropping
into the lakes comes from local sources, but toxaphene, a now banned
pesticide, was blowing in from the southern United States where it is
used on cotton fields.
"There is still material going into the lakes but there is more coming
out," Puckett said.
"In order to stop the material going in we have to ensure that material
still being used in Canada and elsewhere is sort of limited and
international agreements are put in place. With that, pollution levels
will go down faster."

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Mike Wallace
Wilson Lumber Company, Inc.
256.852.7411 x225
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