Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Jordan's fossil water source has high radiation levels

26.02.2009
Ancient groundwater being tapped by Jordan, one of the 10 most water-deprived nations in the world, has been found to contain twenty times the radiation considered safe for drinking water in a new study by an international team of researchers.

"The combined activities of 228 radium and 226 radium – the two long-lived isotopes of radium – in the groundwater we tested are up to 2000 percent higher than international drinking standards," said Avner Vengosh, associate professor of earth and ocean sciences in the Nicholas School of the Environment at Duke University.

Making the water safe for long-term human consumption is possible, he said, but it will require extra steps to reduce its radioactivity.

Vengosh and his research team, made up of scientists from Jordan, Palestine, Israel and the United States, published their findings Feb. 19 in a paper in the peer-reviewed journal Environmental Science & Technology. The paper is online at http://pubs.acs.org/doi/abs/10.1021/es802969r.

Jordan's annual water use exceeds the natural replenishment of its major river, the Yarmouk, and its local aquifers that are becoming salinized as a result of over-pumping.

In 2007, the Jordanian government announced plans for a $600-million project to pump low-saline fossil groundwater from the Disi aquifer, located along the nation's remote southern border with Saudi Arabia, and pipe it 250 kilometers north to the capital, Amman, a city of 3.1 million people, and other population centers.

Fossil groundwater is a nonrenewable supply of water trapped underground in aquifers. In recent years, policymakers in countries facing chronic water shortages have increasingly viewed low-saline supplies of fossil groundwater as an important potential source of water for human and agricultural use. Libya and Saudi Arabia, for example, have relied extensively on fossil groundwater from Nubian sandstone aquifers similar to the Disi to meet their water needs in recent decades.

Most fossil groundwater resources in North Africa and the Middle East are characterized by high-quality water with low salinity. "The assumption has been that unsafe radioactive levels occur primarily in high-saline groundwater, so low-saline sources, such as water from a Nubian sandstone aquifer, are relatively safe resources just waiting to be tapped," Vengosh said.

To test that hypothesis, Vengosh and his colleagues investigated water from 37 pumping wells in the Disi aquifer's Rum Group, where low-saline groundwater is extracted from Cambro-Ordovician sandstone, and from wells in the Khreim Group, where saltier water is extracted from an aquifer containing larger amounts of clay minerals and oxides. All samples were analyzed for major and trace elements and for four radium isotopes. For comparative purposes, sandstone rocks from the Disi aquifer, along with Nubian sandstone rocks from the nearby Negev Desert in Israel, were also measured for radium.

"We found a lack of correlation between salinity and radioactivity," Vengosh said. "Instead, our findings suggest that an aquifer's geological properties may be a much more significant factor."

Vengosh and his group hypothesize that an aquifer with a higher content of clay minerals and oxides provides more adsorption sites for radium, and this results in lower radionuclide levels in the water itself. Sandstone aquifers, on the other hand, offer fewer adsorption sites, and, as a result, generate radium-rich groundwater.

"Given that most of the aquifers in the region that contain fossil water are composed of Nubian sandstone and are characterized by low-saline groundwater, similar to that in the Disi aquifer, we suggest that high-radioactive groundwater may also exist in these basins. This could pose health risks for a large population," Vengosh said. Groundwater from the Disi aquifer is already used for drinking water in parts of Jordan and, more extensively, in Saudi Arabia, where it is known as the Saq aquifer.

"Making groundwater from the Disi aquifer and similar sandstone basins in the region safe for long-term human use will require a significant reduction of radionuclide levels," Vengosh said.

Health officials could reduce radioactivity to safe levels by diluting radium-rich water with low-radium water from other sources, he said, or by treating it with ion exchange, reverse osmosis desalination or lime softening. Each of these three treatment technologies does a good job of removing radium, Vengosh noted, but each produces solid and liquid residues that would have to be handled and disposed of as low-level radioactive waste.

The U.S. Environmental Protection Agency (EPA) classifies radium as a Group-A carcinogenic material, which means exposure to it could cause cancer.

Tim Lucas | EurekAlert!
Further information:
http://www.duke.edu

More articles from Ecology, The Environment and Conservation:

nachricht Scientists team up on study to save endangered African penguins
16.11.2017 | Florida Atlantic University

nachricht Climate change: Urban trees are growing faster worldwide
13.11.2017 | Technische Universität München

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: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Previous evidence of water on mars now identified as grainflows

21.11.2017 | Physics and Astronomy

NASA's James Webb Space Telescope completes final cryogenic testing

21.11.2017 | Physics and Astronomy

New catalyst controls activation of a carbon-hydrogen bond

21.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>