What happens to chemical vapors that are released to the air? Fate and transport analysis, a holistic way of looking at chemicals in the environment, involves a modeling system that shows how a chemical changes in the presence of other chemicals and how a chemical moves through the air, water and soil.
"In the same way forensic chemistry and fingerprints are used in the courtroom to link crime evidence to the circumstances of who, what, why and how, scientists are using fate and transport analysis to investigate chemical residuals or 'signatures,'" said Kathy Probasco, a senior research scientist at Pacific Northwest National Laboratory involved in fate and transport studies. "Environmental signatures tell which chemical is present and provide clues about the source." Fate and transport analysis is currently used to analyze pesticide and herbicide residues, industrial process vapors and vehicle exhaust emissions.
To improve analyses, Pacific Northwest scientists are developing a chemical kinetics chamber that tracks various chemical reactions in a controlled environment and provides information on the chemical signatures present. The chamber can react chemicals with light, moisture, dust, soil, vegetation or other chemicals. "We are performing cutting-edge research to understand gas-phase kinetics and how chemicals change in specific environments. This research will ultimately lead to new sensor technology," said David Maughan, who developed the chamber.
Today, Probasco's work on fate and transport analysis is applied to national security efforts. "If you're building a sensor to detect a chemical in the environment, you need to know what's going to happen with the chemical," Probasco said. "How that chemical will change depends on the climate, soils and vegetation, and distance from the sensor. A chemical released in a wet climate may have a very different signature than the same chemical released in a dry climate."
By combining fragments of information from diverse sources in the process of data fusion, fate and transport analysis offers researchers a big picture view of chemicals in the environment. This understanding can help researchers develop more accurate and effective sensors and hazard assessment technologies.
The Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time.