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Dr Mark Hodson of the University of Reading has presented
new research on how earthworms can help scientists understand
more about contaminated soil and its potential impact on house-building
on brownfield sites.
The research, which was unveiled at the BA Festival of Science
in Liverpool, examines why some populations of earthworms
can inhabit contaminated soil and what impact earthworms have
on potentially toxic elements in soils.
Across the UK, thousands of brownfield sites have contaminated
soil due to previous industrial use such as mining, engineering
works or lead smelting operations. While the UK needs more
homes to cater for its growing population, many suitable sites
are polluted and, if developed before the contamination is
brought to light, can bring problems. In the last 5 years,
contaminated land has become a very real issue for homeowners
in Ashford (Kent), Cambridge, Stratford (London), Shrewsbury,
Hartlepool and Ross-shire.
A combination of laboratory, field and synchrotron X-ray
experiments have led to the finding that metal tolerant populations
of super earthworms are evolving. Modern X-ray absorption
spectroscopy techniques available at Diamond - such as EXAFS
(Extended X-ray Absorption Fine Structure) and XANES (X-ray
Absorption Near Edge Structure) - are allowing researchers
to examine the earthworms, the soil and the burrows as never
before.
Dr Mark Hodson said - "As a surgeon can examine your
vital organs to gain an understanding of how your body is
functioning, we can now look inside an earthworm and see what
is happening to the metals that have been ingested along with
the soil. The size of the metal samples we are tracking is
around one thousand times smaller than a grain of salt - so,
invisible to the human eye and impossible to detect in this
level of detail with our standard laboratory microscopes.
"Earthworms are the biggest beasts in the soil and the
best way to establish if the soil is healthy is to ask the
animals that live there. If, with the help of modern synchrotron
science, we can learn enough about what the earthworms are
capable of doing to the soil, they could also become 21st
century eco-warriors by helping to tackle soil pollution more
efficiently than man has been able to up until this point
in history."
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