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Many Gaps Exist In Plans for Environmental Decontamination Following a Large-Scale Bioterrorism Attack

By Eric Toner, MD, April 16, 2010

If another anthrax attack occurred today, how would the contaminated environment be cleaned up? Who is in charge of the clean up? What is the most effective technology? And how clean is clean? These are some of the issues raised in a new analysis of environmental decontamination recently published by Franco and Bouri1 in the journal Biosecurity and Bioterrorism. Their article identifies gaps in federal decontamination policy and technical practice, including safety standards, that must be addressed to facilitate a successful recovery from a biological attack.

Large scale decontamination could take years and cost billions.

Decontamination following the relatively small-scale 2001 anthrax attacks cost hundreds of millions of dollars, and some facilities could not be reopened for more than 2 years. Following a large scale bio-attack, the area of contamination is likely to be much larger and to include streets, parks, vehicles, and buildings (including hospitals). Before being inhabited again, it is likely that all of these areas would have to be decontaminated. Given our previous experience, it is possible that a city might be uninhabitable for an extended period of time, perhaps years, following a large scale biological attack.

Not all biological agents pose the same decontamination challenge.

Agents that are environmentally stable are of greatest concern, and topping the list is the hardy, spore-forming bacterium, Bacillus anthracis, which causes anthrax. Other agents of particular concern are ricin and Francisella tularensis, the causative agent of tularemia. Most of the viral agents, such as Ebola, are relatively fragile and less of a decontamination concern.

Many policy gaps and unanswered questions remain.

The authors identify the following key challenges:

  • Federal roles and responsibilities are not clear. Many federal agencies have responsibility (sometimes overlapping) for decontamination, and federal plans do not spell out leadership roles and responsibilities in decontamination efforts.

  • Research is underfunded and is not coordinated among federal agencies.

  • There are insufficient resources and methods for sampling, testing, and analysis. There is no experience with sampling and laboratory testing of contaminated areas following a large bio-attack in an urban area. Consequently, the resources and technologies necessary to support these activities have not yet been developed.

  • Unresolved scientific, technical, and social science issues critical to decision making remain. For instance, the magnitude of risk posed by secondary aerosolization is not known.

  • There are not enough personnel trained to perform decontamination, and there are no standards for determining how clean is safe or acceptable for human habitation.

  • There is inadequate guidance for building owners.


The authors make the following recommendations:

  • The Department of Homeland Security should further define federal agency decontamination roles and responsibilities for large-scale biological events.

  • Congress should increase funding for biological decontamination research.

  • Future biological decontamination research should focus on the scientific, technical, and social science questions that must be answered in order to respond to a large bioterrorism event.

  • Beyond science and technology, the Obama administration must invest in human resources for a decontamination response.

  • Federal agencies must develop specific guidance and provide a list of reliable decontamination vendors and other resources for owners of commercial and residential buildings.

Environmental decontamination is essential to recovery from a large-scale bio-attack. Of particular concern to the clinical community is the potential for contamination of hospitals, either by an aerosol or by secondary contamination from patients. If contaminated hospitals must close for a prolonged period of time, a contingency not accounted for in many disaster plans, the burden on hospitals that do remain open will be even greater than has been anticipated, and will impede medical response.


  1. Franco C and Bouri N. Environmental decontamination following a large-scale bioterrorism attack: Federal progress and remaining gaps. Biosecurity and Bioterrorism 2010;8(2). Accessed April 14, 2010