baggage processing, mechanical rooms, offices, storage, and a host of other activities. Although the baggage-handling spaces are not usually partitioned, other support spaces tend to be subdivided into relatively small rooms.
Although it is not outside the realm of possibility that a biological attack could be launched against any element of an airport to disrupt the overall operation, the passenger terminal would seem to be the most likely target. That terminal usually would be a large single building or complex of buildings that can range in size from several hundred thousand square feet to several million square feet. When the terminal consists of several buildings, they often are connected to facilitate easy movement of passengers and employees. The result is that air also mixes and spreads easily within the facility, and biological contaminants could migrate easily as well. Airport terminals are tied into the full range of utilities needed to serve large modern buildings. Often the utilities are linked to airport-wide plants by tunnels that are large enough to accommodate foot traffic by maintenance workers and, occasionally, by small vehicles. Another key functional element of all major airports is ground transportation for passengers, including public transit systems, car rental agencies, and facilities for privately owned vehicles. Sometimes these services are tied to enclosed or semi-enclosed spaces that also connect to passenger terminals.
All of the terminal spaces described above are served by heating ventilation, and air-conditioning (HVAC) systems that are similar to those in other large commercial buildings. There are greatly varying levels of sophistication and automation in airport HVAC control systems, largely as a function of the system’s age. Although all move air into zones throughout the building to maintain appropriate temperature and humidity, the degree to which air flow can be rapidly modified or halted varies widely. HVAC systems are, of course, a major factor in any attack that would seek to release a biological agent into an airport terminal and therefore a major factor in the contamination that must later be remediated.
Few generalizations can be made about the interior materials in airport passenger terminals. Most have hard surfaces for floors and walls to facilitate maintenance and longevity, but some have softer materials (like carpeted floors) despite the need for frequent replacement. Such site-specific particulars as surface materials will have a major influence on decontamination after a biological attack.
Another consideration for decisions related to decontamination after a biological attack is that at any given time some aircraft generally are parked at a terminal. Those planes often are attached to the building by loading bridges, which in many respects render the aircraft an integrated element of the terminal building. Similarly, rail systems sometimes run through or are attached to airport buildings. Thus, contamination could extend to docked aircraft and rail systems, and possibly to other locations served by these aircraft or rail systems. The potential for contamination of docked aircraft and rail systems would be influenced by several factors, such as the method used at a particular gate for provid-