A chance find behind a chemical treatment works in Florida is offering the chance to literally suck one the world鈥檚 most notorious and widespread poisons from soils.
Lena Ma of the University of Florida noticed that the brake fern grew profusely on the land, despite heavy contamination with chromated copper arsenate from past exposure to wood preservative.
Back in the lab, she found that the fern didn鈥檛 just tolerate arsenic, it positively thrived on it, absorbing huge amounts of the normally-toxic metal into its stem and fronds.
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She told 快猫短视频: 鈥淚t鈥檚 early days yet and we can鈥檛 say yet that it will solve all arsenic contamination problems. But it has great potential.鈥�
High concentration
The brake fern (Pteris vittata) is the first plant known to detoxify soils poisoned by arsenic. In one experiment, Ma planted a clean fern in toxic soil. It absorbed so much arsenic that, in just two weeks, arsenic comprised two per cent of its entire weight.
Far from showing signs of stress, the plant grows up to 40 per cent faster than normal in poisoned soils, Ma found. She is now investigating why it happily accumulates so much arsenic 鈥� currently this 鈥渋s a mystery鈥�.
Arsenic is one of the most widespread naturally occurring poisons. Studies from Chile to Bangladesh and California to Taiwan have found the metal seeping from soils and rocks into underground water supplies in concentrations that may cause skin cancers.
According to a recent study by the World Health Organisation, up to 70 million Bangladeshis alone may currently be drinking water laced with arsenic.
Don鈥檛 touch
John McArthur, a geochemist from University College London, said: 鈥淧lant like this could make a real difference around waste dumps and mine workings that are poisoning water supplies.鈥�
There is only one drawback. The brake fern is itself toxic to humans and animals. Vets advise pet owners to keep dogs and cats away from the fern.
The discovery that the plant can also absorb large amounts of toxic metals can only reinforce that advice.
More at: Nature (vol 409, p 579)