Thaindian News

London, Jan 30 (IANS) Medical equipment used for diagnosis of patients with heart disease and cancer could be a key weapon in stopping nuclear waste seeping into the environment, according to new research.
A team of scientists from the universities of Manchester and Leeds have joined forces with experts in nuclear medicine at Manchester Royal Infirmary, using medical gamma-ray cameras to track radioactive isotopes in US soil samples from a nuclear site.

This is the first time the technique, which is used in hospitals for heart, bone and kidney scanning, has been used to study the environmental behaviour of nuclear waste - and its success could help scientists find new ways of using bacteria to control the spread of radioactivity.

Radioactive isotopes of the element technetium (Tc) are produced in bulk by nuclear facilities, while a specific isotope of Tc with a very short life is routinely used as a medical tracer in human bodies.

Nuclear fission of Uranium has released tonnes of Tc from nuclear facilities over the past decades, with the element remaining radioactive for thousands of years.

But although the short lived medical isotope is chemically indistinguishable from that in long lived waste, it can be used safely in tests.

Researchers from the University of Manchester, led by Jon Lloyd, professor, took soil samples from the Oak Ridge nuclear facility in the US and successfully tracked the movement of medical Tc through the soil.

Scientists at the University of Leeds were then asked to verify the observations using a special microscope technique called Transmission Electron Microscopy (TEM).

With the help of DNA analysis the Manchester team confirmed that certain microbes, particularly some that use ferric iron for energy, can fix Tc in place in soils.

Researchers found that nearly all the Tc remained fixed when ferric iron was present with these ‘iron-reducing’ bacteria, said a Manchester release.

This finding itself is not new - Lloyd and his colleagues had previously reported that microbes in lab cultures could perform this role in fixing Tc.

But the researchers’ success in using the gamma camera could see the technique being used to probe how Tc and ferric iron move together in far more complex soil systems more representative of the ‘real world’ - helping develop future remediation techniques.