Testing Exposure to Dangerous Chemicals.

• Position: Brief Article

When workers believe they have been exposed to dangerous chemicals on the job, they often must provide a sample of blood or urine and wait three weeks or more to learn their fate. A breath-analyzing device developed at the Department of Energy's Pacific Northwest National Laboratory, Richland, Wash., eases the uncertainty by providing immediate results of chemical exposure using a non-invasive technique.

The Exposure-to-Risk Monitoring System determines within minutes the amount and type of chemical a worker has been exposed to and how much has found its way inside the person. The system makes its determination by tracking how much of the chemical in question is exhaled.

The system uses physiologically based pharmacokinetic, or PBPK, mathematical models to translate exposure levels into the amount of internal dose received and the resulting health risk. The model describes how a compound gets into the body, where it goes within the body, how it breaks down, and how it leaves the body. Its relatively small size--approximately 70 pounds--allows it to be used on-site or taken to an emergency situation, such as a chemical spill.

The PBPK modeling also considers a person's physiology--height, weight, and body fat--to determine better how chemicals distribute in individuals. If, for instance, workers believe they have been exposed to a chemical, they would breathe into the monitoring system's...