Chemical weapons detectionMustard plants help detect use of chemical weapons
Making nations comply with the Chemical Weapons Convention requires that scientists can accurately detect the use of chemical warfare agents. Currently they carry out tests on soil from areas where use is suspected. Many nerve agents composed of organo-phosophorous compounds, however, leach from soil over time, removing the evidence of use and making verifying the deployment of chemical weapons like sarin, soman, and VX difficult. Researchers report that white mustard plants can help by allowing detection for up to forty-five days after the chemical weapons were used.
The Chemical Weapons Convention prohibits the use of chemical weapons by its 190 member states. Making sure members comply with the convention requires that scientists can accurately detect the use of chemical warfare agents. Currently they carry out tests on soil from areas where use is suspected. Many nerve agents composed of organo-phosophorous compounds, however, leach from soil over time, removing the evidence of use and making verifying the deployment of chemical weapons like sarin, soman, and VX difficult.
A Royal Society release reports that today a collaborative team of scientists from the University of Central Lancashire and the U.K. Defense Science and Technology Laboratory present a method to detect chemical weapon use by analyzing the compounds present in white mustard plants. The plants, which grow wildly across the world, are pollutant tolerant and can absorb nerve agent chemicals through their roots.
The plants retain compounds from the agents for longer than soil can and act as a sort of ‘time capsule’ protecting the evidence of chemical weapon use for at least forty-five days.
The team of researchers grew white mustard plants in three different types of soil spiked with VX to see if the type of soil affected how long the plants retained traces of compounds from chemical weapon use. After eight days, plants grown in sandy soil had absorbed more VX than those grown in loam or clay soils, however, by 16, 33, and 45 days after the seeds were sown, the amount of VX in the plants from the different soils had converged. The team say this shows that regardless of soil type “evidence for the prior presence of VX in soil can be downloaded from the plant at least 45 days after application.”
As well as being useful for detecting chemical weapons use the team say their results show that the plants could also be used in the further as a sort of “green manure” absorbing chemicals from soil in polluted sites. The team even found some evidence that the plants may be able metabolize nerve agents, breaking them down into their less harmful degradation products and helping to reduce the “toxic environmental legacy” of chemical weapons from areas where they have been deployed.
— Read more in Matthew R. Gravett et al., “Evidence of VX nerve agent use from contaminated white mustard plants,” Proceedings of the Royal Society A 470, no. 2168 (21 May 2014) (doi: 10.1098/rspa.2014.0076)
