October 11, 2002—In the five-month period following the discovery that letters containing Bacillus anthracis had been mailed to targeted locations in the US, a team of engineers and scientists from the National Institute for Occupational Safety and Health (NIOSH) assessed an array of public- and private-sector buildings. The primary goal of these assessments was to determine the vulnerability of building air environments, including heating, ventilation, and air-conditioning (HVAC) systems, to a terrorist attack with chemical, biological, and radiological (CBR) agents, and to develop cost-effective prevention and control strategies. A total of 59 buildings were evaluated from November 2001 to April 2002.
Collectively, the field observations and prevention recommendations from the building assessments were combined with input from government and industry experts to identify general guidance that encourages building owners, facilities managers, and engineers to review design, operational, and security procedures at their own facilities.
The recommendations include measures that can transform buildings into less attractive targets by increasing the difficulty of introducing a CBR agent, increasing the ability to detect terrorists before they carry out an intended release, and incorporating plans and procedures to mitigate the effects of a CBR release.
The guidelines recommend that building owners and managers first understand their buildings’ systems by conducting walk-through inspections of the HVAC, fire protection, life-safety, and other systems. Security measures should be adopted for air intakes and return-air grills, and access to building operation systems and building design information should be restricted. The guidelines also recommend that the emergency capabilities of the systems’ operational controls should be assessed, filter efficiency should be evaluated closely, buildings’ emergency plans should be updated, and preventive maintenance procedures should be adopted. The guidelines also caution against detrimental actions, such as permanently sealing outdoor air intakes.
Copies of Guidance for protecting building environments from airborne chemical, biological, or radiological attacks, DHHS publication no. NIOSH2002-139, are available from the NIOSH Web site or by calling 800/356-4674.
