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."
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.
UNIVERSITY OF MARYLAND CENTER FOR ENVIRONMENTAL SCIENCE
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. http://www.
Amy Pelsinsky | EurekAlert!
Ice cave in Transylvania yields window into region's past
28.04.2017 | National Science Foundation
Citizen science campaign to aid disaster response
28.04.2017 | International Institute for Applied Systems Analysis (IIASA)
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences