Chemicals from ammunition have penetrated into the soil of an estimated 10 million hectares of land used for shooting ranges across the United States. One such chemical, an explosive called RDX, can seep into groundwater and cause seizures and possibly cancer.Study now exist Natural biotechnology It shows that genetically modified switchgrass (a plant common in North American grasslands) can absorb and decompose RDX.
York University biologists Neil Bruce and Liz Rylott and colleagues changed the switchgrass species to carry two genes from a bacterium that produces enzymes that can reduce RDX to harmless components. After conducting laboratory tests, the researchers planted improved switchgrass at the Fort Drum military base contaminated by RDX in New York State.
For three years, the team tested soil and water extracted from modified plants, wild plants, or plastic-lined plots without plant growth, and painstakingly removed seeds from modified switchgrass to prevent cross-pollination with local varieties. They found that the modified plants absorb RDX, which significantly reduces the level in the surrounding water and decomposes it-RDX does not appear in the tissues of the modified plants, but does appear in wild plants.
“There is convincing evidence that genetically modified [switchgrass] It works well and grows under conditions where RDX is not toxic to plants,” said Jerald Schnoor, an environmental engineer at the University of Iowa, who was not involved in the study.
Facts have proved that the removal of this pollutant is particularly challenging, partly because many large shooting ranges in the country have unexploded ordnance. There are bacteria that decompose RDX in the soil, but they do not consume toxins fast enough to prevent them from infiltrating into the aquifer.
“Nature has the power to clean [RDX] Up; sometimes it needs a little help,” Rylott said. “This is a combination of Batman and Robin-the bacterial Batman, the plant is Robin. “Other researchers use plants to remove PCB, DDT, nickel and arsenic.*
The researchers also genetically modified another plant, western wheatgrass, to absorb RDX. “If we modify a few more species,” Rylott said, “we can get a toolbox that can remove RDX, but we can also maintain biodiversity throughout the training range.”
*Editor’s note (8/10/21): This sentence was edited after publication to correct the reference to PCBs.