Power plants are major influence in regional mercury emissions

Jul 24, 2006
Power plant stack. Credit: FES/Yale
Power plant stack. Credit: FES/Yale

The amount of mercury emitted into the atmosphere in the Northeast fluctuates annually depending on activity in the electric power industry, according to researchers at the Yale School of Forestry & Environmental Studies.

Xuhui Lee, professor of meteorology, and Jeffrey Sigler, a recent Yale Ph.D. and now a postdoctoral researcher at the University of New Hampshire, co-authored the Yale study "Recent Trends in Anthropogenic Mercury Emission in the Northeast United States." They found that between 2000 and 2002 the emission rate of mercury decreased by 50 percent, but between 2002 and 2004 the rate increased between 50 and 75 percent. During that five-year period, overall emissions declined by 20 percent.

The dramatic annual changes in mercury emissions, the study's authors say, cannot be explained climatologically by air flow patterns that would bring either clean or polluted air into the region.

Mild winters and a correspondent decrease in the need for regional power plants to burn coal could partially explain the decline in mercury emissions, according to the authors. The study, published this summer in the Journal of Geophysical Research-Atmospheres, estimates that power plants account for up to 40 percent of total emissions in New Jersey, New York and Pennsylvania and in New England.

"The study highlights just how important power plants are in influencing regional mercury emission," said Sigler. "We should not forget other source categories when formulating abatement policies, since they also contribute significant amounts to the total emissions," Lee added.

Mercury, which converts to highly toxic methyl mercury in ground water, is found in fish and can cause neurological problems in developing fetuses and dementia and organ failure in adults who eat fish in large amounts and over long periods.

The Yale study was conducted at Great Mountain Forest in northwestern Connecticut. The measurements were restricted to wintertime so data on carbon dioxide that comes from the same combustion sources as mercury would not be distorted by photosynthesis. The researchers used carbon dioxide to trace mercury back to its sources with a unique method called "tracer analysis."

"To our knowledge, using the carbon dioxide to trace mercury over a long time period hasn't been done before," said the authors. "We started with actual mercury that's in the atmosphere, worked back to sources that emit it, then calculated the emission rate."

The U.S. Environmental Protection Agency, which does not regulate mercury emissions, determines the mercury emission rate by taking an inventory of existing sources. "Although the EPA's approach is highly useful, it requires accurate measurements of mercury emitted from the smokestack per ton of fuel burned," said Sigler. "These data are hard to come by. Our top-down technique circumvents those rather cumbersome problems and allows for much more timely estimates of mercury emission. It's difficult to get annual changes in the emission rate with the inventory approach."

Source: Yale University

Explore further: Switzerland 1st country to submit pledge for UN climate pact

add to favorites email to friend print save as pdf

Related Stories

Train car design reduced impact in Southern California crash

13 minutes ago

(AP)—After a horrific crash a decade ago that killed 11 people and injured 180 more, Southern California's commuter train network began investing heavily in passenger cars designed to protect passengers from the full force ...

Appeals court considering warrantless cellphone tracking

33 minutes ago

(AP)—Now that the cellphone in your pocket can be used to track your movements, federal appeals judges in Atlanta are considering whether investigators must get a search warrant from a judge to obtain cellphone tower tracking ...

Android dominant in two-horse smartphone race: IDC

33 minutes ago

Google Android dominated the global smartphone market in 2014, holding an 81.5 percent market share, with Apple's iOS second and no strong third player, market tracker IDC said Tuesday.

Recommended for you

Engineers are making strides in reducing air pollution

Feb 27, 2015

According to the Environmental Protection Agency (EPA), the average adult breathes 3,000 gallons of air per day—yet the same air that fuels our bodies also can harm them. In fact, inhaling certain air pollutants ...

Depth of plastic pollution in oceans revealed

Feb 27, 2015

Wind and waves can mix buoyant ocean plastics throughout the water column, but most of their mass remains at the sea surface, according to research led by The University of Western Australia.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.