b'Removing arsenic from soilsEnvironmental remediation of arsenic-contaminated sites takes some bold steps forward.Treena Hein treenahein@outlook.comHAVE YOU EVERheard of arse-nic? Its a naturally occurring element found in the Earths crust, but arsenic contamination of soil and groundwa-ter is a very serious health concern for Americans and hundreds of millions of people worldwide. In terms of how many arsenic-con-taminated sites exist in the United States, the vast majority of the most serious current and former hazardous waste sites (Superfund sites) on the Environmental Protection Agencys (EPA) National Priorities Listat least 1,149 of 1,684contain arsenic. In the future, that number may increase as more sites are evaluated.Cleaning up this metal in soil is both labor-intensive and costly. Just how costly, notes EPA spokesperson Maggie Sauerhage, depends on many factors. Costs for soil removal and disposal, the traditional clean-up method, are sig-nificant, and if the site has buried utility lines and limited space to operate equip-ment due to trees and other objects, it becomes even more expensive.Phytoremediation Jody Banks and her former graduate student, Chao Cai, show off their Chinese brake fern. According to the EPA, phytoremediationusing plants to remove contaminantsBanks is currently taking the first stepspublished results on how three different from soilmay be an application thattowards inserting genes from the Chinesegenes in the brake fern allow it to toler-suits some soil remediation situations.brake fern into fast-growing plants, genesate arsenic in the cytoplasm (the watery Sauerhage says some concerns related tothat give the brake fern an extraordi- contents) of a cell. Banks and her former this strategy include the amount of con- nary ability to absorb, tolerate and storegraduate student Chao Cai found that taminants plants are able to remove andarsenic. In other plants and animals, oncesilencing each one of these genes leads how long it therefore takes to reduce thearsenic enters a cell, it causes cell deathto death of the plant in the presence concentration of contaminants at a giveneither through a process called oxidativeof arsenic, demonstrating their critical site to an acceptable level.stress or by interfering with the cells abil- importance in arsenic tolerance. Jody Banks, a professor of botany andity to produce cellular energy. One gene codes for a protein which plant pathology at Purdue University, isBefore they got to this point, Bankscontrols the transfer of compounds working on just such issues. and her colleagues discovered andthrough the cell membrane, and a second 18/ SEEDWORLD.COMDECEMBER 2019'