Regional Shelter Analysis - Inhalation Exposure Methodology

During normal operations, buildings can protect their occupants from outdoor hazards, including airborne pollutants. Purposeful sheltering increases this protection. A long-term international research effort has advanced our knowledge of building protection physics. However, an operationally efficient, regional-scale methodology to account for US building protection effects is not available. Such a method is necessary because (a) the overwhelming majority of the US population is indoors at any given time and (b) a regional-level building protection methodology could better estimate populations truly at risk in emergencies, support improved decision-making (shelter vs. evacuation decisions), help guide resources towards those most at risk, and improve population level dose-response relationships, which are often derived by estimating ambient (outdoor) exposures and then tuning dose-response relationship parameters to best match the distribution of illness reports.

The Regional Shelter Analysis (RSA) methodology provides a comprehensive, yet operationally efficient method for population-based risk analyses. Specifically, it accounts for (a) building protection distributions (within and among different buildings) and (b) population postures (how people are distributed within and outside of buildings). It can generate predictions to support decision makers simultaneously on multiple operational levels, ranging from individual buildings and neighborhoods to larger regions. The method employs existing building and population databases and is compatible with many modern exposure and injury assessment tools.

This report develops the RSA methodology and discusses general operational considerations, with a focus on inhalation exposures. To place this work in the context of prior efforts and current initiatives, a focused literature review is provided that identifies the relevant literature, theory, scientific findings, and datasets from a variety of scientific fields. Planned follow-on reports will discuss (a) the external radiation exposure pathway and (b) specific RSA implementations.