Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Air pollutions control policies effective in improving downwind air quality


Emissions controls on coal-fired power plants are making a difference in reducing exposure of mercury to people, especially in the western Maryland community. A study of air quality from the University of Maryland Center for Environmental Science found that levels of mercury in the air from power plant emissions dropped more than half over a 10-year period, coinciding with stricter pollution controls.

"I was surprised when I first saw it," said the study's author Mark Castro, associate professor with the University of Maryland Center for Environmental Science's Appalachian Laboratory in Frostburg. "We've been measuring mercury for years. To see such a dramatic drop was exciting."

Emissions controls on coal-fired power plants are making a difference in reducing exposure of mercury to people.

Credit: University of Maryland Center for Environmental Science/Cheryl Nemazie

From 2006 to 2014, researchers monitored the atmospheric concentrations of mercury at a relatively pristine location in western Maryland that was also downwind from several power plants in Ohio, Pennsylvania, and West Virginia. The annual average concentrations of mercury declined by up to 75% and were strongly correlated with the power plant emissions from the upwind states.

Mercury is a serious threat to human health throughout the world. Many people, particularly pregnant women and their fetuses, and young children, are highly susceptible to the neurological effects. Important sources of mercury in the United States have been power plants and waste incinerators. Some regions in the U.S., particularly those downwind of large sources of mercury, receive 60-80% of their atmospheric mercury deposition from these man-made sources.

In 2005, the EPA issued the Clean Air Mercury Rule (CAMR) to reduce mercury emissions from power plants, and in 2011, the EPA issued the Mercury and Air Toxic Standards (MATS) to reduce mercury emissions by 90% upon full compliance in April 2016. (Note: Recently, the US Supreme Court ruled that MATS needs to be reexamined by the D.C. Circuit Court.)

Maryland, with one of the most aggressive power plant control programs in the nation, has in place regulations such as the Healthy Air Act that require significant reductions in mercury from coal burning power plants. The Healthy Air Act required an 80 percent reduction in mercury in 2010 and a 90 percent reduction by 2013.

The purpose of the study was to determine if power plant emission reductions have affected the atmospheric concentrations of mercury entering western Maryland before being transported to population centers further east by prevailing westerly winds. Measurements were made that the Piney Reservoir Air Monitoring Station in Garrett County, Maryland, a spot surrounded by forest and farm land, where winds arrive commonly from the west and northwest.

"Our site is located downwind from three states that are top mercury emitters," said Castro. "We are in a hot spot to be impacted by regional emissions. If those emissions change, we are in a good spot to see it."

Models predicted that power plant emissions from the state of Ohio, Pennsylvania, and West Virginia contributed up to 50% of the mercury that was deposited in Maryland from these states. The reductions in emissions could be seen in the frequency and maximum concentrations of the short-term episodic events of emissions, and the annual average concentrations.

There was a statistically significant decrease in the annual average concentrations from 2006 to 2013 and a strong correlation with annual power plant mercury emissions from the upwind states of Ohio, Pennsylvania and West Virginia. This was a relatively large reduction and strongly suggested the emissions reduction strategies of CAIR and MATS were very effective at reducing the concentration of mercury in western Maryland. Full compliance with MATS, which includes a 90% reduction in power plant mercury emissions, is expected to lower concentrations even further.

The paper, "Effectiveness of Emission Controls to Reduce the Atmospheric Concentration of Mercury," was published by Mark Castro of the University of Maryland Center for Environmental Science's Appalachian Laboratory and John Sherwell of the Maryland Department of Natural Resources' Power Plant Research Program. It was published in Environmental Science & Technology.


This project was funded by the Maryland Department of Natural Resources and the U.S. EPA's Clear Air Markets Program.


For 90 years, the University of Maryland Center for Environmental Science has led the way toward better management of Maryland's natural resources and the protection and restoration of the Chesapeake Bay. From a network laboratories located across the state, UMCES scientists provide sound advice to help state and national leaders manage the environment, and prepare future scientists to meet the global challenges of the 21st century.

Media Contact

Amy Pelsinsky


Amy Pelsinsky | EurekAlert!

More articles from Earth Sciences:

nachricht Wandering greenhouse gas
16.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht Unique Insights into the Antarctic Ice Shelf System
14.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>