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The emergency
response to a large-scale incident of chemical terrorism would involve
the following elements:
Seal Off the Contaminated Area
The first step in responding to an
incident of chemical terrorism is for police and fire fighters to
establish a perimeter around the danger zone to prevent more people from
becoming exposed to the toxic agent. A complicating factor, however, is
that the danger zone can move. Although volatile gases such as
chlorine or
phosgene dissipate
rapidly, more persistent agents such as
sarin can form clouds that
last for hours, forming an elongated plume downwind from the point of
release. In an urban environment, air turbulence generated by tall
buildings can redistribute the agent plume into zones of high and low
concentrations, creating "hot spots" in unexpected locations. Moreover,
ventilation systems can spread a toxic gas throughout a building, and
subway cars can force an agent cloud down tunnels, spreading it from one
station to the next.
Identify the Toxic Agent
Rapid detection and identification of the
toxic agent are crucial to ensure prompt medical treatment of those who
have been exposed, and to reassure those who have not. Most fire
departments lack specialized equipment needed to detect and analyze CW
agents rapidly. To address this problem, scientists at the U.S. National
Laboratories are developing handheld detectors that first responders
could use to identify about a dozen different CW agents.
Decontaminate the Victims
A key challenge for emergency workers is
to decontaminate the victims of a chemical attack before they are
evacuated for treatment. If people have come in contact with liquid
agent or concentrated vapor, they will carry traces of the toxic
substance on their clothes and skin. Accordingly, decontamination is
needed not only to prevent further absorption of the toxic agent through
the skin or by inhalation of vapor, but also to prevent the victims from
contaminating other people and the interior of cars and ambulances. In
general, water is the best decontamination solution, with soap
recommended for oily or otherwise sticky chemicals.
Decontaminating
large crowds presents complex logistical problems. The usual approach is
to direct victims to "decontamination corridors" where they strip off
their clothes and shower. But persuading a frightened and mixed-gender
group of strangers to undress and leave their valuables behind could
easily result in panic and chaos, and showering outdoors in winter could
cause hypothermia. Although special decontamination trucks or trailers
containing showers are commercially available, this equipment is
expensive and time-consuming to set up. Alternative approaches include
the use of protective tarpaulins, inflatable heated tents, and plans to
use nearby buildings equipped with showers, such as a high school or
college.
Decontamination training session in 2002
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