Daily Mail Publications Ltd
estuary mud could show us how to prevent the
spread of radioactive pollution. Microbes
within the mud trap radioactive
elements, Leeds researchers have discovered.
Theyre examining this natural process
to see if it can provide a new means of handling
Drs Kath Morris and Ian Burke from the school
of environment are looking at technetium
a by-product of fuel reprocessing. The Humber
estuary (pictured above) is free of
the pollutant, so the researchers take samples
of its normal, clean mud, to compare
with others where technetium has been added.
When microbes in estuary mud are cut off from
air, they survive by using other elements
to breathe in place of oxygen.
This happens naturally and is shown by the
black colour often seen in shoreline mud just
below the surface. The NERC-funded research
at Leeds has found that when microbes in the
mud are cut off from air, they trap technetium
within the sediment.
If technetium is trapped in sediment,
there is less in the water, and so the pollutant
doesnt spread as far, said Dr
Morris. This explains how technetium
may behave once its released in liquid
waste into the sea, but also opens up possible
ways to treat and trap the pollutant.
Since the 1950s, technitium has been released
into the sea at Sellafield in small concentrations
in liquid waste, but its behaviour once in
the environment is still not fully understood.
Other countries, particularly Norway, have
expressed concern about increasing levels
of technetium along their coastlines. The
British government is considering a moratorium
on discharges until appropriate technology
can be developed to deal with the pollutant.
the DEFRA press release on techetium discharge.