Frequency

United States

There are no reported instances of the use of vomiting agents within the United States against civilians. In 1932, adamsite was suspected to have been laced into riot control gas deployed in Washington D.C. against the Bonus Army, which was composed of World War I veterans, civilian members of their families, and affiliated groups, who were demanding financial compensation for their service certificates.

Currently, the US government is funding numerous programs to prepare the nation for potential chemical terrorist attacks against its citizens and military.

International

The use of vomiting agents has been reported during international conflicts. Da first was used by German troops in 1917. Since Da was not well filtered by the standard-issue gas masks at that time, troops inhaled Da and experienced nausea and vomiting. As a result of emesis, soldiers removed their gas masks, which made them vulnerable to subsequent attacks by other highly toxic chemical warfare agents, including phosgene and chlorine gas. The Germans also produced Dc and Dm, but limited documentation exists for use of these agents during World War I. Questionable reports exist of vomiting agents used in other countries as riot control agents.

In June 2003, letters containing Dm (adamsite) were sent to the United States, British, and Saudi Arabian Embassies, Belgium’s Prime Minister Guy Verhofstadt, the Court of Brussels, a Belgian ministry, the Oostende airport, and the Antwerp port authority. At least two postal workers and five police officers were hospitalized with symptoms of skin irritation, eye irritation, and breathing difficultly after exposure to the substance. Three people who were exposed in Oostende were also hospitalized. Belgium police suspected a 45-year-old Iraqi political refugee opposed to the US Iraq War. Upon searching his residence, antiterrorism investigators found a plastic bag containing powder. The investigators suffered symptoms similar to those who were exposed to the letters, and the Iraqi was charged with premeditated assault. No other instances of vomiting agent use have been reported, although buried adamsite has been found in one of many chemical weapons dumping sites in Shikhany, Russia. North Korea has been suspected of synthesizing and stockpiling adamsite (DM) at its Aoji-ri chemical complex.

Mortality/Morbidity

Dm is the most toxic agent of this group, with an estimated LCt50 of 11,000 mg·min/m3 (ie, an estimated 50% lethality for a group of patients breathing air with a concentration of 11,000 mg/m3 for 1 min). Other factors also are important, such as the exposed patient's preexisting health status and the time from exposure to medical care. The dose at which vomiting reportedly begins for Dm is estimated as 370 mg·min/m3.

Race-, Sex-, and Age-related Demographics

No published studies demonstrate a significant difference in the effects of vomiting agents on various races or either sex. Intuitively, persons at the extremes of age would be less tolerant of exposure to these three chemical agents. However, no published studies prove this.

In a case series from Japan describing cerebellar symptoms associated with drinking well water contaminated with diphenylarsinic acid (DPA), a degradation product of diphenylchloroarsine or diphenylcyanoarsine, an infant presented with cognitive impairment and developmental delay with mild cerebral atrophy documented by magnetic resonance imaging. [10] These signs and symptoms improved when the patient was no longer exposed to the contaminated water.