Simulation of Anthrax Spore Transport and Inactivation in a Room: Scaling Analysis

Abstract

Decontamination of large indoor spaces and buildings following release of biological agents is challenging, as the response to the fall 2001 anthrax-release events indicate. The ability to efficiently and rapidly decontaminate rooms/buildings is limited by the lack of quantitative understanding of the behavior of agent transport, and decontaminants. In response to any new releases it would be necessary to rapidly determine the optimal way to decontaminate the enclosed spaces. In the present study, we numerically simulate a biological agent (anthrax spores) transport and its inactivation by a decontaminant (chlorine dioxide). Such simulations can help us in deciding on decontamination strategies and also in better designs of the buildings and the associated air circulation system to minimize the risks in case of potential agent release. Furthermore, the study also determines the impact of scaling on predicted behavior of the agent distribution and disinfection process. From numerical simulations, a relationship for the inactivation time is obtained as a function of room geometry, ventilation rate, initial number of anthrax spore release, disinfectant injection rate and reaction kinetics. Such a relationship would help in determining decontamination strategies and in optimization of the decontamination processes.