Use of computer dynamic simulation for indoor exposure assessment based on chronogram incident as air pollution source characterization

Determination of the level of exposure due to a chemical incident is crucial for the assessment of public health risks and environmental impact. This kind of information is also useful for the subsequent legal responsibilities. If the air contaminant concentrations are not quantified during the incident, then its air concentration may fall below detectable levels shortly after the incident has passed. In case of smelly compounds, usually the incident chronogram indicates the time when the smell was detected and when the smell was gone. Unfortunately, an objective and analytical measure of odour is impossible. The present study shows that it is possible to computer simulate the concentration evolution in time for a defined indoor scenario. Comparing the odour detection in the chronogram with the computer simulations, it is feasible to determine the maximum gas contaminant exposure during the incident and its evolution in time. Once the pollution source indoor concentration is characterized, considering the overall air renewal time and a plume model, the effects on the environment around the building can be estimated.