BACKGROUND: The edenfern soil cleanser is a fern that extracts arsenic from soil, waste, or water and stores the arsenic in its fronds, where it can't damage the environment. It can store 200 times as much arsenic as other plants. The fronds are then harvested for disposal.
THE PROBLEM: Residues from old pesticides, gardening chemicals, and treated lumber can stay in the soil for years. These residues often contain arsenic, posing a significant health hazard. In the past, arsenic could only be removed by digging up the soil itself and depositing it in a landfill.
THE SOLUTION: Planting ferns is a much less expensive and more convenient approach than digging up vast pieces of land. In 2004, about 2,800 edenfern plants were installed at 14 test sites in Washington, D.C. The plants removed about 9 parts of arsenic per million parts of soil across all the sites in the first year. Before, the soil held between 16 and 127 parts of arsenic per million parts of soil. The project's scope is being expanded to plant 10,000 ferns at up to 35 sites.
WHAT IS ARSENIC: Arsenic is a semi-metallic chemical that is difficult to detect because it has no odor or flavor. It can kill humans quickly if consumed in large amounts -- it was once a popular poison -- and even long-term exposure to small doses can be unhealthy. Arsenic causes cancer, mutations and birth defects, and has also been associated with the development of diabetes. Once used as an embalming fluid in the 19th century, arsenic was also widely used in insecticides, and as a component in wood preservatives in lumber and furniture. Decades after arsenic is introduced into the environment, soil concentrations can be hundreds of times higher than the residential standard in many states.
ON THE WEB: The edenfern soil cleanser can be purchased from Edenspace.