Tear gas--harassing agent or toxic chemical weapon?
H. Hu, J. Fine, P. Epstein, K. Kelsey, P. Reynolds and B. Walker
Channing Laboratory, Brigham and Women's Hospital, Boston, Mass.
Tear gas has gained widespread acceptance as a means of controlling
civilian crowds and subduing barricaded criminals. The most widely used
forms of tear gas have been o-chlorobenzylidenemalononitrile and
omega-chloroacetophenone. Proponents of their use claim that, if used
correctly, the noxious effects of exposure are transient and of no
long-term consequences. The use of tear gas in recent situations of civil
unrest, however, demonstrates that exposure to the weapon is difficult to
control and indiscriminate, and the weapon is often not used correctly.
Severe traumatic injury from exploding tear gas bombs as well as lethal
toxic injury have been documented. Moreover, available toxicological data
are deficient as to the potential of tear gas agents to cause long-term
pulmonary, carcinogenic, and reproductive effects. Published and recent
unpublished in vitro tests have shown o-chlorobenzylidenemalononitrile to
be both clastogenic and mutagenic. Sadly, the nature of its use renders
analytic epidemiologic investigation of exposed persons difficult. In 1969,
eighty countries voted to include tear gas agents among chemical weapons
banned under the Geneva Protocol. There is an ongoing need for
investigation into the full toxicological potential of tear gas chemicals
and renewed debate on whether their use can be condoned under any
circumstances.
