Chemical Agent Releases
On the basis of estimates of release amounts, computer modeling, and distance from US troops, we assess that only the Khamisiyah Pit release probably exposed US troops to low levels of chemical agents. This minimal exposure can be attributed to several factors:
Most chemical munitions were missed by Coalition aerial bombing. Iraq made a significant effort to avoid the destruction of its chemical agents to preserve its military options and to avoid contaminating its own troops and civilians. Iraq’s efforts included storage of chemical weapons in the open and in standard bunkers, dispersal from the main CW facility at Al Muthanna, and open burial of bulk agent storage containers. As a result, only about 8 percent of the over 700 tons of chemical agent and chemicals UNSCOM found in chemical weapons or bulk containers was released as a result of Coalition bombing.
Low nerve agent purity. Although Iraqi mustard agent was relatively pure, Iraq’s more toxic nerve agents were only about 60 percent pure when produced and rapidly degraded such that, by the time of release, the purity varied from 50 percent to less than 15 percent.
Less toxic binary munitions. Most of Iraq’s Gulf war–era nerve agent was kept in binary form. Iraqi binary munitions contained only relatively nontoxic alcohols into which a second chemical would have to be manually added before forming toxic nerve agents within the munition.
Chemical agent neutralization and burning. Only a small proportion of the chemical agent released from Iraqi munitions damaged by Coalition action actually entered the atmosphere. Laboratory testing indicates roughly half of the agent released from damaged munitions is retained by, or neutralized in, crates and soil. Chemical agents subjected to fire will burn or otherwise break down—causing anywhere from 95 to more than 99 percent of the agent to degrade, according to field tests and computer modeling.
Dispersion and environmental degradation. The great distance of most storage locations from US troops allowed significant time for the chemical agent to disperse and degrade in the environment.
Winds were not always blowing toward US troops. Chemical agents are carried by winds, and during the Gulf war, the prevailing wind blew from the south, east, or west—generally away from US troops—as often as it did toward troops. For example, the Khamisiyah Bunker 73 release did not expose US troops—some only several kilometers away at the time—because winds were blowing from the southwest away from troop locations.