Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sediment sleuthing

23.03.2012
A University of Delaware oceanographer has stumbled upon an unusual aid for studying local waterways: radioactive iodine.

Trace amounts of the contaminant, which is used in medical treatments, are entering waterways via wastewater treatment systems and providing a new way to track where and how substances travel through rivers to the ocean.

"This is a really interesting convergence of medicine, public health and environmental science," said Christopher Sommerfield, associate professor of oceanography in UD's College of Earth, Ocean, and Environment.

Sommerfield found small quantities of radioactive iodine, also called radioiodine or I-131, by accident while sampling the Delaware River, the main source of freshwater to Delaware Bay. The amounts were at low concentrations that do not pose a threat to humans or the environment, according to the Environmental Protection Agency (EPA).

Sommerfield measures naturally occurring radionuclides, variants of elements emitting radiation, that attach to mud particles carried along by water. The work is part of his research on how river sediments move through estuaries to the coastal ocean and influence the sea floor and coast.

When I-131 showed up in his samples, he thought it was a mistake.

"I-131 is a man-made radionuclide produced in nuclear reactors, so when we first detected it my heart skipped a beat," Sommerfield said. "However, after further research and consultation with government experts, I realized that it was I-131 waste from thyroid cancer treatments."

Therapeutic I-131 administered at hospitals enters urban sewage after thyroid cancer patients return home and excrete the medicine. Last summer the Philadelphia Water Department discovered extremely low levels of I-131 in the Schuylkill River, which serves as a drinking water source for the city, in samples collected following the Fukushima nuclear disaster in Japan.

The department determined that the substance was coming from local medical treatments. Like the amounts Sommerfield found throughout the Delaware Estuary around the same time, the levels were well below the maximum accepted level set by the EPA, which periodically monitors I-131 at a limited number of sites.

Sommerfield shared his findings with Philadelphia and Delaware officials, who continue to examine the situation. He discovered that the highest I-131 concentrations were present in the highly urbanized section of the Delaware River, which receives a large amount of treated wastewater from municipalities, and that levels steadily decreased downstream to zero in Delaware Bay.

I-131 has a half-life of eight days, meaning its radioactivity decreases by half during that time period as it transforms to non-radioactive elements. Sommerfield was unable to find much information about the fate of I-131 in coastal waterways.

"There are only a few recent research papers documenting the behavior I-131 in rivers and estuaries worldwide, and nothing for Delaware," he said.

Sommerfield recently shared his experience at the international Ocean Sciences Meeting in Utah, where fellow researchers were interested in learning more about how I-131 could be used as a water and sediment tracer. Radionuclides help oceanographers study transport processes in estuaries and coastal waters, and I-131 has the potential to fill a void among natural and man-made radionuclides that are typically measured because it has a very short half-life and comes from a specific source.

"Wastewater-derived I-131 provides a tool to better understand how estuaries disperse water and suspended particles," Sommerfield said. "With further research, we expect to learn more about how sediment from the Delaware River is delivered to the estuary and fringing tidal marshlands, which require muddy sediments for nutrients and stability."

This research is funded by the National Science Foundation and Delaware Sea Grant.

Andrea Boyle Tippett | EurekAlert!
Further information:
http://www.udel.edu

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany
25.06.2018 | Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF

nachricht Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.

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: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>