FIU Researching Arsenic-Eating Ferns

Plants Could Play Major Role in Arsenic Mitigation

MIAMI, Fla. (May 21, 2001) -- A group of Florida International University scientists is collaborating with another research team to look at how the lowly brake fern might be used to intervene in a dangerous and growing environmental problem: arsenic in soil.

Yong Cai, FIU assistant professor of Chemistry and faculty member of the Southeast Environmental Research Center, is leading the team that is working with scientists at the University of Florida that recently discovered that the Pteris Vittata (brake fern) is extremely efficient in extracting arsenic from soils and relocating it to its fronds. Cai co-authored an article on the discovery in the February issue of Nature.

The possible future use of the brake fern for "phytoremediation" - an emerging, plant-based technology for the removal of toxic contaminants from soil and water - has project members energized. Arsenic-tainted soil is a major cause of arsenic-tainted drinking water and food worldwide. Concerns over arsenic-tainted soil found at playgrounds constructed of specially treated wood recently prompted Miami-Dade County officials to shut down or restrict access to portions of several county parks and playgrounds.

Cleanup is an even more difficult proposition: Current methods of soil remediation are expensive, according to Cai, and would be far less practical than use of the versatile, hardy, fast-growing brake fern. Although many plants have been identified as those that accumulate metals extremely quickly and efficiently -- "hyperaccumulators"-- no hyperaccumulator for arsenic had been previously reported.

"We're trying to figure out why the brake fern accumulates arsenic so efficiently," explained Cai, who's been at FIU for six years. "There is something happening in this plant and, right now, no one knows what it is."

The UF team sought out Cai because his area of expertise is biogeochemistry of trace metals and metalloids, including arsenic. His research group is now approaching the mechanisms of arsenic accumulation and detoxification by this plant with the help of Kelsey Downum, plant biochemist and associate dean of Arts and Sciences. Gautam Sen, professor and chairperson of the Earth Sciences Department, and Keith Condon, assistant professor of Biology, have provided technical assistance.

The UF team sought out Cai because his area of expertise is biogeochemistry of trace metals and metalloids, including arsenic. His research group is now approaching the mechanisms of arsenic accumulation and detoxification by this plant with the help of Kelsey Downum, plant biochemist and associate dean of Arts and Sciences. Gautam Sen, professor and chairperson of the Earth Sciences Department, and Keith Condon, assistant professor of Biology, have provided technical assistance. "I can't predict the exact outcome of our research, but I can say that what we're investigating is new and exciting," said Cai.

Founded in 1965, FIU is now one of America's largest and leading public universities. It is the only public university in Florida to hold both the Carnegie Foundation's top designation for research universities and a chapter of Phi Beta Kappa. Its Department of Biology is considered one of the best in the nation and has a special expertise in Tropical Biology.

Media contacts: : Mercedes Martha Ponce, FIU Institute for International Professional Services, (305) 348-2894, or Aileen Izquierdo, FIU Media Relations, (305) 348-6999.