Pulmonary toxic inhalants have been a military concern since the Age of Fire. Thucydides, in 423 BC, recorded the earliest belligerent use of a toxic inhalant. The Spartans used a burning mixture of pitch, naphtha, and sulfur to produce sulfur dioxide that was used in sieges of Athenian cities. There is scant reference in the literature to further military use of toxic inhalants until World War I. In early 1914, both the French and Germans investigated various tear gases, which were later employed. By early 1915, the German war effort expanded its gas research to include inhaled toxicants. As a result, on 22 April 1915, at Ypres, Belgium, the Germans released about 150 tons of chlorine gas along a 7,000-m battlefront within a 10-minute period. Although the exact number of injuries and deaths are unknown, this "new form" of warfare produced a degree of demoralization theretofore unseen. Although phosgene and chlorine have not been used militarily since 1918, vast amounts are produced annually for use in the industrial sector. The potential for accidental or deliberate exposure to a toxic inhalant exists, and military personnel should be prepared. During World War I, the number and types of pulmonary toxicants available to the military increased substantially. At least 14 different respiratory agents were used, as well as obscurants (smokes), harassing agents (chloracetone), and vesicants (mustard) that could cause pulmonary injury. Today, only a handful of these toxicants still exist in stockpiles around the world, but several, such as chlorine and phosgene, are currently produced in large quantities for industrial purposes. Whether produced for military or industrial uses, these chemical agents pose a very real threat to military personnel. Toxic inhalational injury poses a 2-fold problem for military personnel: 1. No specific therapy exists for impeding or reversing toxic inhalant exposures. 2. Toxic inhalational injury can cause large numbers of casualties that can significantly burden medical facilities. The importance of chronic health problems that occur postexposure to toxic inhalants is a contentious subject because of the nebulous signs and symptoms that mimic degenerative diseases, such as emphysema, common to the general population.
United States. Department of the Army. Office of the Surgeon General