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 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: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

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....

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

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>