Featured Research

from universities, journals, and other organizations

New challenges for mercury cleanup

Date:
August 5, 2013
Source:
DOE/Oak Ridge National Laboratory
Summary:
More forms of mercury can be converted to deadly methylmercury than previously thought, according to a new study. The discovery provides scientists with another piece of the mercury puzzle, bringing them one step closer to understanding the challenges associated with mercury cleanup.

ORNL researchers are learning more about the microbial processes that convert elemental mercury into methylmercury.
Credit: Image courtesy of DOE/Oak Ridge National Laboratory

More forms of mercury can be converted to deadly methylmercury than previously thought, according to a study published Sunday in Nature Geoscience. The discovery provides scientists with another piece of the mercury puzzle, bringing them one step closer to understanding the challenges associated with mercury cleanup.

Earlier this year, a multidisciplinary team of researchers at Oak Ridge National Laboratory discovered two key genes that are essential for microbes to convert oxidized mercury to methylmercury, a neurotoxin that can penetrate skin and at high doses affect brain and muscle tissue, causing paralysis and brain damage.

The discovery of how methylmercury is formed answered a question that had stumped scientists for decades, and the findings published this week build on that breakthrough.

Most mercury researchers have believed that microbes could not convert elemental mercury -- which is volatile and relatively inert -- into methylmercury. Instead of becoming more toxic, they reasoned that elemental mercury would bubble out of water and dissipate. That offered a solution for oxidized mercury, which dissolves in water. By converting oxidized mercury into elemental mercury, they hoped to eliminate the threat of methylmercury contamination in water systems.

ORNL's study and a parallel study reported by Rutgers University, however, suggest that elemental mercury is also susceptible to bacterial manipulation, a finding that makes environmental cleanup more challenging.

"Communities of microorganisms can work together in environments that lack oxygen to convert elemental mercury to methylmercury," study leader Baohua Gu said. "Some bacteria remove electrons from elemental mercury to create oxidized mercury, while others add a methyl group to produce methylmercury."

Mercury is a toxin that spreads around the globe mainly through the burning of coal, other industrial uses, and natural processes such as volcanic eruptions, and various forms of mercury are widely found in sediments and water. Methylmercury bioaccumulates in aquatic food chains, especially in large fish.

The fight against mercury pollution involves scientists with expertise in chemistry, computational biology, microbiology, neutron science, biochemistry and bacterial genetics. Other ORNL efforts are focusing on when, where and why bacteria are producing methylmercury.

"Our research allows us to understand generally where and how bacteria might produce methylmercury so that we can target those areas in the future," said ORNL's Liyuan Liang, a co-author and director of the DOE-funded mercury research program. "We are trying to understand the process of microbial mercury methylation. Once we understand the process, we can begin to form solutions to combat mercury pollution."

This research was funded by the DOE Office of Science. ORNL co-authors of the paper, titled "Oxidation and Methylation of Dissolved Elemental Mercury by Anaerobic Bacteria," are Haiyan Hu, Hui Lin, Wang Zheng, Stephen Tomanicek, Alexander Johs, Dwayne Elias, Liyuan Liang and Baohua Gu. Another co-author, Xinbin Feng, is from the State Key Laboratory of Environmental Geochemistry of China.


Story Source:

The above story is based on materials provided by DOE/Oak Ridge National Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. Haiyan Hu, Hui Lin, Wang Zheng, Stephen J. Tomanicek, Alexander Johs, Xinbin Feng, Dwayne A. Elias, Liyuan Liang, Baohua Gu. Oxidation and methylation of dissolved elemental mercury by anaerobic bacteria. Nature Geoscience, 2013; DOI: 10.1038/ngeo1894

Cite This Page:

DOE/Oak Ridge National Laboratory. "New challenges for mercury cleanup." ScienceDaily. ScienceDaily, 5 August 2013. <www.sciencedaily.com/releases/2013/08/130805223440.htm>.
DOE/Oak Ridge National Laboratory. (2013, August 5). New challenges for mercury cleanup. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2013/08/130805223440.htm
DOE/Oak Ridge National Laboratory. "New challenges for mercury cleanup." ScienceDaily. www.sciencedaily.com/releases/2013/08/130805223440.htm (accessed September 22, 2014).

Share This



More Earth & Climate News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Will Climate Rallies Spur Change?

Will Climate Rallies Spur Change?

Newsy (Sep. 21, 2014) Organizers of the People's Climate March and other rallies taking place in 166 countries hope to move U.N. officials to action ahead of their summit. Video provided by Newsy
Powered by NewsLook.com
Thousands March in NYC Over Climate Change

Thousands March in NYC Over Climate Change

AP (Sep. 21, 2014) Accompanied by drumbeats, wearing costumes and carrying signs, thousands of demonstrators filled the streets of Manhattan and other cities around the world on Sunday to urge policy makers to take action on climate change. (Sept. 21) Video provided by AP
Powered by NewsLook.com
Climate Change Rally Held in India Ahead of UN Summit

Climate Change Rally Held in India Ahead of UN Summit

AFP (Sep. 20, 2014) Some 125 world leaders are expected to commit to action on climate change at a UN summit Tuesday called to inject momentum in struggling efforts to tackle global warming. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
New Music With Recycled Instruments at Colombia Fest

New Music With Recycled Instruments at Colombia Fest

AFP (Sep. 19, 2014) Jars, bottles, caps and even a pizza box, recovered from the trash, were the elements used by four musical groups at the "RSFEST2014 Sonorities Recycling Festival", in Colombian city of Cali. Duration: 00:49 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins