recover from a bioterrorist attack in a manner that effectively reduces the risk posed by exposure to the biological agent to an acceptable degree of assurance and without incurring unnecessary expense. Factors to consider for effective response and recovery include the geographic extent of contamination, the timing and duration, and the method of decontamination, all of which are influenced by characteristics of the agent released. Underlying all of this is a question: “How clean is clean enough?” The original question placed before the Committee on Standards and Policies for Decontaminating Public Facilities Affected by Exposure to Harmful Biological Agents was “How clean is safe?” Is there a standard that we should anticipate, beyond which additional decontamination efforts would yield insubstantial benefit?
In response to the attacks of 2001 and their subsequent cleanup, the Department of Homeland Security funded a project called the Restoration and Domestic Demonstration and Application Program, which was run by the Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories. As part of the study, the LLNL subcontracted to the National Research Council (NRC) to convene a committee of experts to consider the criteria that must be met for a cleanup to be declared successful, allowing the reoccupation of a facility. The committee specifically was asked to consider a scenario in which decontamination of a facility approaches completion, but it was not asked to review all issues that should be considered in the aftermath of a biological attack. Therefore, this report does not address in any detail the risk that such an attack would occur, the emergency response to an attack, the identification of the appropriate allocation of resources for research or response, or broader public health issues related to transmissible diseases. It does not recommend specific decontamination technologies, although such technologies are discussed to provide information for those who need to understand them to make informed decisions about reoccupation. Rather, the report reviews the key factors that influence decision making and lays the foundation for establishing standards and policies for relevant aspects of biological decontamination. Because the sponsors are seeking additional information for their demonstration project, this committee focused its effort on indoor facilities, and it uses an airport as a model.
The committee considered the issues outlined above and concluded that remediation must meet appropriate technical considerations from several perspectives, and it must be convincing to the stakeholders, especially the users of a facility. There is no single standard to apply to all situations. Thus, based on its scientific analysis of the available information, the committee outlined steps that would help achieve a socially acceptable standard for cleanup.
This report has 12 chapters, each containing information relevant to the decision about what constitutes “acceptable cleanup.” It considers the history of biological weapons, the biology of 3 microorganisms that are considered threats for use in biological warfare, the nature of the response to infection, the issues associated with the determination of infectious dose and quantitative microbio-