Assessing every breath you take

What are your chances if a terrorist dumps a big batch of chlorine bleach into the ventilation system of the government building where you work?

Researchers at Pacific Northwest National Laboratory have developed a sophisticated modeling system that assesses health and safety impacts of contaminated indoor air.

Health Modeling and Assessment System (HMAS) uses several different software programs and analytic capabilities to predict what will happen and how people will be affected in a building with contaminated airflow.

The system involves several steps. First it runs a vulnerability analysis on the building. "We create scenarios based on where the facility is open to attack," said Bob Stenner, the Laboratory scientist who heads the project.

Based on an analysis of the building, the system uses models to estimate contaminant dispersion for various attack scenarios and determines how long different chemicals will persist. The human element is next. How long will people stay in the building, how long will they be in rooms with specific concentrations and what effect will it have on human lives? "If you get this kind of dose, you'll get these kinds of symptoms, and this is what you could do in terms of emergency health care," Stenner said.

Users then consider exposure management or "how can we do it differently?" Flipping off the HVAC to restrict contaminants to a smaller area, evacuating people to a different floor and even determining safe areas within the building are all possible safeguards against this type of attack.

Finally, the system provides necessary information for building managers considering remodels to make buildings less vulnerable, or even designing new buildings.

HMAS is an integration of several stand-alone models and databases operating under the FRAMES architecture. Pacific Northwest developed Framework for Risk Analysis in Multimedia Environmental Systems (FRAMES) so users can integrate one stand-alone program with another program or set of programs and link them to disparate databases simply and easily.