Researcher Neil Bruce is pictured sampling switchgrass planted in contaminated soil, which researchers say could help remove toxins left behind from military weapons testing. Photo by Neil Bruce/University of York
May 3 (UPI) -- Toxins from explosives and fire-fighting foams are known to leach into the environment at military bases around the world. But a new type of grass could help clean up the mess.
To tackle the problem of water contamination at training ranges, munitions dumps and other military facilities, scientists genetically modified a special grass variety to capture and trap RDX, a toxic chemical common used in munitions.
Researchers detailed their engineering feat in a new paper, published Monday in the journal Nature Biotechnology.
For the project, scientists selected a switchgrass variety typically used to control soil erosion. In the lab, researchers inserted a pair of genes from a bacteria species known to breakdown RDX.
When planted in contaminated soil, the modified grass successfully absorbed and degraded the RDX to undetectable levels in their plant tissues.
Like many of the most problematic environmental contaminants, RDX is resistant to natural degradation. In other words, it remains in the environment and accumulates.
Scientists estimate their successful experiment marks one of the first times a genetically modified crop has been used to degrade environmental contaminants.
"The removal of the toxic RDX from training ranges is logistically challenging and there is currently a lack of cost-effective and sustainable solutions," study co-author Liz Rylott, plant biotechnologist and postdoctoral researcher at the University of York in Britain, said in a press release.
"Our research demonstrates how the expression, in switchgrass, of two bacterial genes that have evolved specifically to degrade RDX give the plants the ability to remove and metabolize RDX in the field at concentrations relevant to live fire military ranges," Rylott said.
Tests showed the new grass variety can remove and degrade RDX at a rate of 27 kilograms per hectare, or about 24 pounds per acre.
Environmental contamination from toxins like PDX and others are a major problem at military bases in the United States.
Millions of acres have been contaminated by PDX and the "forever chemicals" called PFAS, among other chemicals dangerous to human health. The Pentagon itself has catalogued more than 40,000 contaminated sites.
"The recalcitrance of RDX to degradation in the environment, combined with its high mobility through soil and groundwater, mean that plumes of toxic RDX continue to spread below these military sites, threatening drinking water supplies," said lead study author Neil Bruce, a York professor and director of the Center for Novel Agricultural Products.