At least four different models have been proposed to describe the human dose-response relationship for inhalation anthrax. This research examined the 1979 outbreak of inhalation anthrax in the city of Sverdlovsk, Russia, in which approximately 70 people died, to gain a better understanding of the low-dose infectivity of inhalation anthrax in humans, since this was a low-dose exposure event. The results suggest that primate data originally published by Harold Glassman in 1966 probably represent the best human dose-response model currently available for inhalation anthrax.