Lena Qiying Ma

"How can ferns live like that?" puzzled soil chemist Lena Qiying Ma. Visiting an abandoned arsenic-contaminated lumberyard in Florida, she noticed some remarkably green and healthy ferns. Ma and her team found that the ferns (Pteris vittata or brake ferns) have an appetite for arsenic, collecting it in their fronds. Indeed, the ferns grow better in arsenic-contaminated soil than in clean soil! Ma hopes these common ferns will help clean up arsenic pollution around the globe cheaply, quickly, and gently.

The brake fern is just one of many plants that can remove toxic heavy metals, like arsenic, from contaminated soil or water. Sunflowers were very effective at removing large amounts of radioactive materials from the water near the site of the 1986 nuclear-power-plant disaster at Chernobyl, Ukraine. Poplar trees are also very good at removing a wide range of pollutants from soil and have been used widely for this purpose. No one really knows why plants do this, but some speculate that plants store toxic heavy metals in their leaves to protect them from being eaten by bugs. Cleaning up the environment using plants' abilities to remove contaminants from soil is called phytoremediation. Ma is particularly interested in finding other plants that can remove toxins from soil.

In humans, compounds containing arsenic can cause cancer and other diseases. These compounds are used in pesticides and herbicides, and residues from these sources can contaminate both soil and groundwater, making them both unsafe. Today, thanks to Ma’s discovery, the brake fern is being studied for large scale cleanups of arsenic from both soil and drinking water.

About Her Life

Lena Qiying Ma was born in China in 1964 and earned her undergraduate degree in soil science at Shenyang Agricultural University. She came to the United States for graduate school, earning a Ph.D. in environmental soil chemistry from Colorado State University in 1991. Now a professor at the University of Florida, she heads the Biogeochemistry of Trace Metals Program at the school's Soil and Water Science Department.

Ma continues to investigate the many questions posed by her discovery. Her main goal these days is to figure out the chemistry that goes on in the brake fern that enables it to accumulate arsenic so effectively.

For Further Reading on the Web

Biogeochemistry of Trace Metals Program. The program’s official Web site at the University of Florida has links to the 1 February 2001 article in Nature, where Ma and colleagues first published their findings on the brake fern; to an interview with Ma on the BBC Radio 4 program Woman's Hour, 22 November 2001; and to “New Pollution Tool: Toxic Avengers With Leaves,” New York Times, 6 March 2001.