OT:Fungi could reduce uranium risk

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Fungi could reduce uranium risk

The Press Association*

http://ukpress.google.com/article/ALeqM5hL-LPpTTGoeMbUjBWxgvl87RnfEA

Fungi could help reduce the threat of potentially dangerous depleted

uranium left behind in war zones, according to new research.

Scientists have found evidence that fungi can " lock " depleted

uranium into a mineral form that may be less likely to find its way

into plants, animals or the water supply.

The testing of depleted uranium ammunition and its recent use in

Iraq and the Balkans has led to contamination of the environment

with the unstable metal.

Previous studies have raised questions over the potential genetic

and neurological effects of depleted uranium on humans.

Now scientists at Dundee University have found that free-living and

plant fungi can colonise depleted uranium surfaces and transform the

metal into uranyl phosphate minerals.

While they would still be likely to pose some threat, the fungal-

produced minerals are capable of long-term uranium retention, so may

help prevent uptake of uranium by plants, animals and microbes.

Professor Geoffrey Gadd, from the university's College of Life

Sciences, said: " This work provides yet another example of the

incredible properties of micro-organisms in effecting

transformations of metals and minerals in the natural environment.

" Because fungi are perfectly suited as biogeochemical agents, often

dominate the biota in polluted soils, and play a major role in the

establishment and survival of plants through their association with

roots, fungal-based approaches should not be neglected in our

attempts to deal with metal-polluted soils. "

Depleted uranium differs from natural uranium in the balance of

isotopes it contains. It is the by-product of uranium enrichment for

use in nuclear reactors or nuclear weapons and is valued for its

very high density.

Although less radioactive than natural uranium, depleted uranium is

just as toxic and poses a threat to people. The research, published

in the journal Current Biology, concludes that the discovery could

lead to uranium-polluted soils eventually being brought back into

use.