Using Fungi to Transform Lead into a Safer Mineral
Researchers found fungi that break lead down to a more stable mineral near the Scottish town of Wanlockhead, formerly home to lead mines.
CREDIT: tigerweet on Flickr
It's always impressive to see fungi and lichen growing on barren-seeming rocks. Now scientists have found fungi that break down lead. Two species of fungi that biologists gathered from a former lead-mining area can transform metallic lead into a stable, less toxic form called chloropyromorphite. Lead-pollution cleanups now use chemicals to turn lead into chloropyromorphite and related minerals. This is the first time anybody has seen fungi do the same, researchers wrote in their paper, which was published January 12 in the journal Current Biology.
The researchers, from the University of Dundee and the James Hutton Institute in Scotland, incubated each of the two fungi species with some lead shot. After three months, lead without any fungus formed the expected byproducts of lead corrosion. Lead incubated with the fungi formed those same byproducts, but also began forming some chloropyromorphite. By three months, both species had formed much more of the stable mineral.
Perhaps the fungi had evolved their lead-alchemy abilities to help them survive in contaminated environments, said lead researcher Geoffrey Gadd. In the future, these fungi might be a part of a "bioremedial treatments" for lead-contaminated land, according to Gadd's paper.
Lead-polluted places all around the world would benefit from another lead cleanup tool. In a list of the world's top 10 worst-polluting operations, published by the nonprofit Blacksmith Institute, lead pollution shows up four times: in industrial estates, lead smelting, mining and ore processing, and lead-acid battery recycling. Metallic lead also ends up in parks where people hunt for sport, and near rivers where anglers use lead fishing weights. There may be tens of thousands of kilograms of lead in a hectare in a shooting range, one study found.