Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

It's only natural: Lawrence Livermore helps find link to arsenic-contaminated groundwater

05.03.2013
Human activities are not the primary cause of arsenic found in groundwater in Bangladesh.

Instead, a team of researchers from Lawrence Livermore National Laboratory, Barnard College, Columbia University, University of Dhaka, Desert Research Institute and University of Tennessee found that the arsenic in groundwater in the region is part of a natural process that predates any recent human activity, such as intensive pumping.

The results appear in the March 4 edition of the Proceedings of the National Academy of Sciences.

Millions of people in Bangladesh and neighboring countries are chronically exposed to arsenic-contaminated groundwater, which causes skin lesions and increases the risk of certain cancers. Bacterial respiration of organic carbon releases naturally-occurring arsenic from sediment into groundwater, but the source of this organic carbon remains unclear.

Brian Mailloux of Barnard College and his team isolated microbial DNA from several depth intervals in arsenic-contaminated aquifers in Bangladesh and analyzed the DNA's radiocarbon signature, which reflects whether the organic carbon used by the microbes derives primarily from younger, surface-derived sources that are transported by groundwater into the aquifers, or older, sediment-derived sources.

Using "bomb pulse" radiocarbon analysis, Lawrence Livermore scientist Bruce Buchholz dated the DNA of groundwater bacteria. He found that the DNA samples were consistently younger than the sediment, suggesting that the microbes favor using surface-derived carbon.

The surface-derived carbon has flowed into the aquifer over hundreds to thousands of years -- a rate that is approximately 100 times slower than groundwater flow. The results suggest that recent human activities, such as intensive groundwater pumping, have not yet significantly affected the release of arsenic into the groundwater at this site.

Above-ground testing of nuclear weapons during the Cold War (1955-1963) caused a surge in global levels of carbon-14 (14C), and remains in all living things. Carbon-14 or radiocarbon is naturally produced by cosmic ray interactions with air and is present at low levels in the atmosphere and food. Although nuclear weapon testing was conducted at only a few locations, excess levels of 14C in the atmosphere rapidly dispersed and equalized around the globe.

According to Buchholz, "The bomb curve forms a chronometer of the past 60 years."

The radiocarbon signature of DNA is a direct measure of the carbon used during microbial respiration and growth. In this study, the team developed a method to filter, extract and purify DNA from groundwater aquifers for radiocarbon analysis to determine the organic carbon pools fueling microbial reduction.

"We were able to separate the recent bomb pulse radiocarbon from the natural carbon signature and found the arsenic levels are now directly tied to a natural process as opposed to being driven by human activities," Buchholz said.

The results may help scientists understand the causes of arsenic contamination in the region, and the development of potential mitigation strategies.

More Information

"Cold cases heat up through Lawrence Livermore approach to identifying remains," LLNL news release, Oct. 10, 2012

"Putting teeth into forensic science," LLNL news release, May 19, 2010

"Date for a heart cell," Science & Technology Review, April/May 2010

"New technique determines that the number of fat cells remains constant in all body types," LLNL news release, May 5, 2008

Founded in 1952, Lawrence Livermore National Laboratory provides solutions to our nation's most important national security challenges through innovative science, engineering and technology. Lawrence Livermore National Laboratory is managed by Lawrence Livermore National Security, LLC for the U.S. Department of Energy's National Nuclear Security Administration.

Anne Stark | EurekAlert!
Further information:
http://www.llnl.gov

More articles from Ecology, The Environment and Conservation:

nachricht Analytical lamps monitor air pollution in cities
26.05.2015 | Heraeus Noblelight GmbH

nachricht Nordic forests under pressure
26.05.2015 | International Institute for Applied Systems Analysis (IIASA)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Solid-state photonics goes extreme ultraviolet

Using ultrashort laser pulses, scientists in Max Planck Institute of Quantum Optics have demonstrated the emission of extreme ultraviolet radiation from thin dielectric films and have investigated the underlying mechanisms.

In 1961, only shortly after the invention of the first laser, scientists exposed silicon dioxide crystals (also known as quartz) to an intense ruby laser to...

Im Focus: Advance in regenerative medicine

The only professorship in Germany to date, one master's programme, one laboratory with worldwide unique equipment and the corresponding research results: The University of Würzburg is leading in the field of biofabrication.

Paul Dalton is presently the only professor of biofabrication in Germany. About a year ago, the Australian researcher relocated to the Würzburg department for...

Im Focus: Basel Physicists Develop Efficient Method of Signal Transmission from Nanocomponents

Physicists have developed an innovative method that could enable the efficient use of nanocomponents in electronic circuits. To achieve this, they have developed a layout in which a nanocomponent is connected to two electrical conductors, which uncouple the electrical signal in a highly efficient manner. The scientists at the Department of Physics and the Swiss Nanoscience Institute at the University of Basel have published their results in the scientific journal “Nature Communications” together with their colleagues from ETH Zurich.

Electronic components are becoming smaller and smaller. Components measuring just a few nanometers – the size of around ten atoms – are already being produced...

Im Focus: IoT-based Advanced Automobile Parking Navigation System

Development and implementation of an advanced automobile parking navigation platform for parking services

To fulfill the requirements of the industry, PolyU researchers developed the Advanced Automobile Parking Navigation Platform, which includes smart devices,...

Im Focus: First electrical car ferry in the world in operation in Norway now

  • Siemens delivers electric propulsion system and charging stations with lithium-ion batteries charged from hydro power
  • Ferry only uses 150 kilowatt hours (kWh) per route and reduces cost of fuel by 60 percent
  • Milestone on the road to operating emission-free ferries

The world's first electrical car and passenger ferry powered by batteries has entered service in Norway. The ferry only uses 150 kWh per route, which...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International symposium: trends in spatial analysis and modelling for a more sustainable land use

20.05.2015 | Event News

15th conference of the International Association of Colloid and Interface Scientists

18.05.2015 | Event News

EHFG 2015: Securing health in Europe. Balancing priorities, sharing responsibilities

12.05.2015 | Event News

 
Latest News

Siemens will provide the first H-class power plant technology in Mexico

28.05.2015 | Press release

Merging galaxies break radio silence

28.05.2015 | Physics and Astronomy

A New Kind of Wood Chip: Collaboration Could Yield Biodegradable Computer Chips

28.05.2015 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>