Biological Agent

NARAC predicts the near-term health effects caused by the inhalation of a biological agent in terms of percentages of the exposed population that may experience death, incapacitation, or infection. A plot showing surface contamination (deposition levels) may also be provided.


Lethal doses are the concentration which can cause fatal effects:

  • LD85, 50, 15, 2: Lethal doses predicted to be experienced by 85%, 50%, 15% and 2% of the exposed population

Exposure calculations assume that individuals remain outdoors in the same location throughout the plume passage.


CFU: Colony Forming Unit.

LDs: Drawn from multiple references most of which are restricted access.