Air deposition is when air pollution settles out into lakes and streams and becomes water pollution. (Photo by Lester Graham)
We’re continuing our series, Ten Threats to the Great Lakes. Our guide through the series is Lester Graham. In this report he explains one of the threats that experts identified is air pollution that finds its way into the Great Lakes:
We’re continuing our series ‘Ten Threats to the Great Lakes’. Our guide through the
series is Lester Graham. In this report he explains one of the threats is air pollution that
finds its way into the Great Lakes:
It’s called ‘Air Deposition.” Melissa Hulting is a scientist at U.S. Environmental
Protection Agency. We asked her just what that means:
“Air deposition simply is just when materials, in this case pollutants, are transferred from
the air to the water. So, pollutants in particles can fall into the water. Pollutants in rain
can fall into the water, or pollutants in a gas form can be absorbed into the water.”
So, it’s things like pesticides that evaporate from farm fields and end up in the rain over
the Great Lakes. PCBs in soil do the same. Dioxins from backyard burning end up in the
air, and then are carried to the lakes
One of the pollutants that causes a significant problem in the Great Lakes is mercury. It
gets in the water. Then it contaminates the fish. We eat the fish and mercury gets in us.
It can cause babies to be born with smaller heads. It can cause nervous system damage
and lower IQ in small children if women of childbearing age or children eat too much
One of the notable sources of mercury is from power plants that burn coal.
(Sound of coal car)
Railroad cars like this one empty their tons of coal at power plants all across the nation.
More than half of the electricity in the nation is produced at coal-burning power plants,
and with a 250-year supply, coal is going to be the primary fuel for a while.
One coal producing state is acknowledging that mercury is a problem. Doug Scott is the
Director of the Illinois Environmental Protection Agency. He says coal is important to
the energy mix, but we need to reduce pollutants such as mercury as much as possible.
“The policy of the state has been to try to work with the power plants to try to burn
Illinois coal as cleanly as you can. Now, that means a lot more equipment and a lot more
things that they have to do to be able to make that work, but we’re committed to trying to
do both those things.”
And, Scott says the federal government’s mercury reduction program does not go far
enough soon enough, but the electric utility industry disagrees.
Dan Riedinger is spokesman for the Edison Electric Institute, a power industry trade
organization. Riedinger says, really reducing mercury emissions at power plants just
won’t make that much difference.
“Power plants contribute relatively little to the deposition of mercury in any one area of
the country, including the Great Lakes, and no matter how much we reduce mercury
emissions from power plants in the Great Lakes Region, it’s really not going to have a
discernable impact in terms of improving the levels of mercury in the fish people want to eat.”
“Relatively little? Now, that flies in the face of everything I’ve read so far. Everything
I’ve read, indicates coal-fired power plants are a significant contributor to the mercury
issue in the Great Lakes and other places.”
“It’s really not quite that simple. Power plants are a significant source of mercury
emissions here in the United States, but most of the mercury that lands in the Great
Lakes, particularly in the western Great Lakes is going to come from sources outside of
the United States.”
Well, it’s not quite that simple either. The U.S. EPA’s Melissa Hulting agrees some of
the mercury in the Great Lakes comes from foreign sources, but recent studies show
some mercury settles out fairly close to the smokestacks. She says you can blame both
for the mercury in your fish.
“You blame the sources that are close by and you blame the sources that are far away.
The bottom line with mercury is that we’re all in this together and it’s going to take
everybody reducing their sources to take care of the problem.”
Taking care of the problem is going to take some money, and that will mean we’ll all pay in
higher utility bills. The Illinois EPA’s Doug Scott says it’ll be worth it if we can reduce
mercury exposure to people.
“We know what the issue is. It’s not a matter of us not understanding the connection
between mercury and what happens in fish, and then what happens in humans as a result
of that. We understand that. We know it, and we also know to a great degree what we
can do to try to correct the problem, and so, it’s a matter of just going out and doing it,
and so I’d like to think it’s something that can be done sooner rather than later.”
And since Great Lakes fish have elevated levels of mercury, sooner would be good.
It’ll take a while for the mercury already there to work its way out of the ecosystem and
return to more normal levels.