Microscopic section of lung tissue damaged by phosgene gas poisoning during World War I

Color halftone printed in two colors after Scottish artist A. Kirkpatrick Maxwell (1884-1975), ca. 1917. The victim died 19 hours after exposure. Most of the pulmonary alveoli are filled with edema fluid, and the walls of the air sacs are ruptured in many places. The rounded edges of these torn walls can be recognized both in the areas of emphysema and in the parts that are flooded with edema fluid. The bronchus also is filled with edema fluid, but its lining is intact, and pus cells have not accumulated in the secretion. The blood vessels of the alveolar network are congested; although intravascular thrombosis is frequently found in these small vessels with phosgene poisoning, it is not present in this section. The main changes in the lung are: (1) congestion, and occasional thrombosis, of the network of pulmonary vessels; (2) abundant outpouring of inflammatory edema fluid both into the tissues and into the airspaces of the alveoli and bronchi; and (3) disruptive emphysema of the weakened lung tissue. The result of these changes is that the blood circulation through the lungs is impeded, and the respiratory exchange of gasses between the blood and the air in the lung is seriously diminished. In this era, before the development of respirators, a gassed man would be in danger of death by asphyxia so long as his lung was drowned in edema fluid. (Source: Wellcome Collection, London, UK. Wellcome Library no. 571919i. Creative Commons Attribution 4.0 International [CC BY 4.0] license, creativecommons.org/licenses/by/4.0.)