The Daily Star:  February 02, 2001 


      Fabulous fern to fight arsenic



      AFP, Paris


      Scientists have come across a fern that sucks up arsenic, holding out the 
      prospect of a fast, cheap and safe way of cleaning up contaminated mines 
      and industrial sites. The plant could also be a potential boon for helping 
      Bangladesh, which is facing a health crisis caused by arsenic in its 
      drinking water, they hope. 
      The remarkable plant, called brake fern, is native to Africa, Asia and 
      Australia, and is now widely naturalised in warm parts of the Americas.
      A team led by University of Florida soil expert Lena Ma analysed fern 
      found at an abandoned wood-preservation site in central Florida where 
      there were high concentrations of arsenic compounds.
      Brake ferns growing in uncontaminated soil at the site were found to have 
      arsenic levels ranging from 11.8 to 64.0 parts per million.
      But those growing in contaminated soil were found to have an astonishing 
      fondness for the poison, flourishing as they extracted it from the soil. 
      They had arsenic levels of between 1,442 and 7,526 parts per million, most 
      of which was found in the plant's long-fingered green leaves. 
      In addition, the arsenic-absorbing trick is done quickly. Lab tests showed 
      that within two weeks, the levels of arsenic in ferns rose by a factor of 
      126 when they were transplanted to contaminated soil. 
      "Brake fern has great potential to remediate arsenic-contaminated soils 
      cheaply," the researchers report in Thursday's issue of Nature, the 
      British science weekly.
      "It has considerable bio-mass and is fast-growing, easy to propagate and 
      perennial."
      Arsenic is used in several industrial processes, notably to remove 
      impurities in glassmaking, and in the manufacture of semiconductor wafers.
      Research is now underway for devising a way of disposing of 
      arsenic-enriched fern by burning it in ovens, which would provide a source 
      of energy, and enable the element to be recovered in the form of a gas. 
      Ma, a native of north-eastern China, said that brake fern held out promise 
      for helping Bangladesh, where between 35 and 77 million people out of a 
      population of 125 million are at risk of being exposed to arsenic in their 
      drinking water.
      The peril stems from the creation over the past two decades of water pipes 
      that have been drilled into shallow rock containing naturally occurring 
      arsenic. 
      "Conceptually, the water in Bangladesh could flow through reservoirs 
      planted with brake fern to filter out the arsenic," Ma told AFP, stressing 
      however that further tests would be needed to check out this suggestion.