Understanding Bioterrorism Threats Can Protect Facilities
Protecting building occupants from the threat of bioterrorism continues to be a challenge for engineering and maintenance managers, particularly since nearly all of today’s commercial and institutional buildings were constructed well before bioterrorism was an issue.
As a result, buildings were not designed to reduce exposure risks for biological threats. Similarly, operating and maintenance procedures in these buildings rarely consider biological threats and how to best respond to them. As is the case with other potential emergencies managers face, preparation and advance planning are the keys to reducing both the risk of an event and the severity of the impact should it actually take place.
Without preparation and advance planning, managers cannot quickly respond appropriately during a crisis. Even worse, actions taken without careful consideration could actually increase the severity of the incident, resulting in additional exposures, injuries, and even deaths.
The first step in protecting a facility against a bioterrorism incident is learning what the most likely threats are. Unfortunately, many of the biological agents that could be used in a bioterrorism attack on a facility occur naturally, are readily accessible, can spread rapidly, and can be contagious.
The U.S. Department of Health and Human Services Centers for Disease Control lists the most likely biological agents terrorists could use in an attack, including anthrax, smallpox, plague, tularemia, botulism, and viral hemorrhagic fevers. These are the biological agents that managers must take into consideration to protect their facilities.
Besides understanding the most common biological agents, managers also must understand the most likely mechanisms terrorists could use in an attack. Four methods are the most likely. Each will require a different response to protect building occupants. Additionally, the response will vary with the type of building and the type of HVAC systems serving that building.
The first type of incident involves an indirect attack. In this scenario, a large-scale release of a biological agent occurs outside a facility. If the facility is downwind from the release, a portion of the biological agent could enter the building through outdoor-air intakes for the HVAC system.
A second type of incident is the release of the biological agent directly into the HVAC system outdoor-air intakes. The biological agent enters the system and is distributed to areas of the building that system serves. How widely the agent is spread will depend on the system’s design and how much of the building the system serves.
A third possible scenario is similar to the second, only the agent is released within the building itself, directly into the return-air portion of the HVAC system. Again, the distribution of the agent depends on the design of the HVAC system.
The fourth scenario involves the release of a biological agent within a specific area, such as a conference room, lobby, or classroom. While much of the release would be confined to that space, the biological agent can spread readily through the building’s HVAC system or even as people move from one area in the building to another.