Putting science to work to ensure public safety
In the event of a nuclear disaster such as a plant meltdown or "dirty bomb," thousands of people could potentially be exposed and require immediate treatment. Currently, however, no technology exists to triage a population and determine who has been exposed to relatively minor or critical levels of radiation. A team of scientists at Arizona State University is working to provide a solution to this problem.
The test under development in Dr. LaBaer’s lab is based on PCR (polymerase chain reaction) technology, which is already widely used in clinical diagnostic laboratories throughout the United States, and can deliver results in a matter of hours. The test will be designed to run on PCR instruments manufactured by Thermo Fisher.
According to Dr. LaBaer, the test will eventually examine the status of approximately 30 genes, whose activity levels are affected by radiation exposure. "Some of these are genes you would expect," he said, "such as genes known to be involved in DNA repair." Radiation is known to directly impact DNA, causing it to break and, therefore, interrupting critical cell functions.
Of primary importance is that the test is quantitative. "In the circumstances of a nuclear accident, we need to know not just who has been exposed but how much radiation they have been exposed to," said Dr. LaBaer, explaining that it is not only distance from the initial incident but also whether or not a person may have had all or part of their body shielded by a wall.
The test will sort people into low, medium and high levels of exposure; exposure is measured in units called Grays (abbreviated Gy), with 4 to 7 grays indicating medium exposure and 7 to 10 or higher indicating high levels. People with medium level exposure typically receive drug treatment designed to stimulate white blood cell growth, while those with high exposure would require hospitalization.
"We hope that a dirty bomb is very unlikely to happen," said Dr. LaBaer. "But if it does, we’ll need to have a test kit in place in a lab close by, using well understood technology that can rapidly identify those people in need of immediate help. We believe our work has a good chance of leading to that result."