Cleaner war zones: Fungal hyphae with crystals of uranyl phosphate attached.
Credit: University of Dundee
SYDNEY: Humble soil fungi are being tested for their ability to clean up toxic depleted uranium left in the wake of modern warfare.
Currently, the task of removing potentially dangerous DU from soil involves chemical treatments that are time-consuming, expensive and hazardous in themselves.
However, British scientists have now cultivated a variety of fungi that can mop up depleted uranium (DU) dust from the soil and turn it into a form less likely to get taken up be people and other organisms.
Weakly radioactive
Artillery containing DU has been developed relatively recently and has been used in conflicts in Iraq and the Balkans. DU is a by-product of the process that produce enriched uranium for nuclear power stations and atomic weapons. It has a level of radiation roughly 40 per cent lower than the natural uranium ore it is extracted from.
However, since uranium is around twice as dense as lead, the military uses DU in the form of superdense anti-tank rounds able to punch holes in armoured vehicles.
There has been considerable debate about the risk associated with DU in the environment. Many studies have found no link between the metal and ill health, while others have reported small rises in birth defects in areas contaminated with it. Even though DU is only weakly radioactive, it has a half-life of thousands of years and also has a chemical toxicity similar to lead.
When a DU round hits a tank, 10 to 35 per cent of the shell turns into a widely dispersed fine dust. If these particles are inhaled or ingested, they can cause tissue damage and long-term exposure may lead to cancer, argues Marina Fomina an environmental microbiologist at the University of Dundee in Scotland. Furthermore, crops in the soil may take it up, and deliver it along the food chain to animals and people, she said.
Fomina is part of a team of researchers in the U.K. who have identified a range of fungi that can take up DU; both free-living soil fungi and symbiotic species that live in a partnership with plants.
These fungi can "chemically lock up" the DU, said Fomina, preventing it from entering the food chain for several years. Her team's experiments have shown that the fungi colonise the surface of the uranium dust and biochemically transform it into more inert uranyl phosphates. This prevents the uptake of the metal by plants and microbes, and stops it from leaching out of the soil, the researchers report in a study published last week in the journal Current Biology.
"Very useful process"
"This phenomenon could be relevant to the future development of various remediation and revegetation techniques for uranium-polluted soils," write the authors.
"This is a process that no-one really knew about before," commented Victor Galea of the University of Queensland's School of Land, Crop and Food Sciences, in Brisbane, Australia. While the research is still in its very early stages "it could translate down the track to being a very useful process," he said.
The next step to a viable decontamination agent is finding a way to harvest these fungi from the soil, and that will be no easy task. The fungi tested by Fomina's team is very delicate, so it would be difficult to remove it from the soil. "It is made up of hyphae, which are microscopic threads – it's a little like having fairy floss grow through sand," said Galea.
While the researchers have made an important first step in this direction, more work will be needed before the fungus can be used to extract the DU from the soil for good, he said.
Eventually, Fomina's team hope that the fungi could be used in former war zones by simply sprinkling it on the ground or cultivating symbiotic fungi alongside the plants it lives off.
Morphology a wild idea.
I was listening to a radio program about a year ago.
Some Woman who has been chasing depleted Uranium for about twenty five years said that the contamination by depleted Uranium has been around since they first started testing the bomb in the forty's.
She mentioned that if you were to lite off a bunker buster in Iraq it was nine days later, it would be in the LA drinking water.
That Depleted Uranium has a "LOVE AFFAIR" with phosphate. That Phosphate is a major binder in our DNA. In fact with any DNA. Plant, animal, human, fish.
Depleted Uranium has been contaminating everything for decades.
It makes me wonder about the state of disease. I wonder if the entire pharmalogical discipline is going to be turned upside down because of the morphology of mutation. That it is not the bugs that are getting stronger, rather we are getting weaker or we are turning into something else that is a tastier treat.
I wish I could better direct you to who this Woman was that I listened to. She was on KBOO radio here in Portland Oregon. She is on some kind of Lecture curcuit.
The hit I got from what she was talking about was we need to stop using this crap. But then again if it has a half life of 3.5 billion years and we have been taking the hit for over 60 years, what the hell, let's see where the mutation takes us.
john