Rational Basis for Accounting for the Impact of Concentration on ToxicologicalAssessment and Estimation of Injury Resulting From the Release of Chemical and Biological Warfare Agents

摘要

A rational, consistent, and simple methodology for the estimation of the degreeof injury or damage to exposed military personnel around a chemical or biological warfare (CBW) agent release is developed. The proposed hazard analysis methodology places particular emphasis on the following important factors: (1) recognition that the toxicity of rapidly acting inhaled toxic materials is usually highly nonlinear, and use of a nonlinear toxic load to quantify this effect; (2) recognition that realistic estimates for toxicological assessment must explicitly account for the fluctuating concentration in a dispersing plume, and development of a simple model for incorporation of these effects into the ensemble-averaged (mean) nonlinear toxic load; (3) recognition of the importance of identifying the relevant time scale for the application (i.e., the time scale appropriate for the response of the human lungs); and, (4) recognition of the variability in the exposed population to a specific toxic load of material, and use of probit relationships to model this varying susceptibility. Example calculations performed using the proposed methodology demonstrated the importance of accounting for concentration fluctuations in the hazard assessment. It is shown that failure to do so under realistic situations could lead to a serious underestimation of the severity of the toxic effects and of the crosswind and downwind extents of the hazard zones generated by the CBW agent release.