The use of and problems associated with biological weapons have been of concern to NATO and non-NATO military organizations for many years. Until recently most of the readily available literature addressed the military issues associated with the possible use of biological weapons on the battlefield, the medical effects of the various agents, and what was known about medical prophylaxis and treatments. Information on other needed countermeasures, such as decontamination or public health issues associated with exposure of civilian populations were largely overlooked. This perspective changed dramatically after the events in the United States in the fall of 2001 in response to the contamination of the U.S. Mail system with powdered anthrax spores. Surprisingly, this use of a biological warfare agent, which gained widespread international attention, was not in the context of a military operation, but a terrorist action that involved civilians. The contaminated facilities were both private and government owned, including important mail-sorting and government offices within the Washington DC area. The exposed populations, including those killed by the attack, were exclusively civilians, and not those whose responsibilities would previously have been expected to put them at risk. Most likely, the intensity of the situation, sense of vulnerability of national security, and urgency to provide solutions were magnified by the context of the other unprecedented terrorist attacks that had occurred a few weeks earlier in the United States on 11 September.

Among the significant problems and defensive weaknesses that the anthrax attack revealed was the lack of established industrial-scale decontamination methods for large volumes of heterogeneous objects (e.g., the mail) or for complex physical environments, (e.g., the U.S. Postal Service sorting facilities). Ultimately, these two microbial decontamination problems were solved in very different ways. The contaminated mail was treated with ionizing radiation while the contaminated government buildings were treated with vapor/gasphase chemicals. The most urgent problems at the time, decontaminating the mail and establishing a process for prophylactic treatment of the mail, were solved relatively quickly. This was largely due to the robust radiation biology and technical base derived from the industrial use of ionizing radiation. For many years this industry has successfully used radiation to sterilize complex objects, and indeed most modern hospitals are wholly dependent on the wide variety of medical devices and supplies sterilized by such methods. Contributing to the speed of response was the fact that the attack occurred within the United States and in the "home town" of many of the technical experts and decision makers, allowing official response to be coordinated rapidly.

This volume presents the papers delivered at the NATO Advanced Research Workshop on Radiation Inactivation of Bioterrorism Agents, 7–9 March 2004 in Budapest, Hungary. The conference was graciously hosted by the Frédéric Joliot-Curie National Research Institute for Radiobiology and Radiohygiene, Budapest, Hungary and organized by Dr. L.G. Gazsó and Dr. C.C. Ponta. The conference was in part the outcome of the co-organizers' forward thinking in this area and previous recommendations on the use of ionizing radiation for biological weapon agent inactivation (VI. Int. Symposium on Protection Against Chemical and Biological Warfare Agents, Stockholm, 1998 and Symposium on Nuclear, Biological and Chemical Threats in the 21st Century, Helsinki, 2000). Wisely, the conference brought together experts from across a number of professional disciplines and geographic boundaries from the private sector, government, scientific research, and international regulatory agencies.

The conference papers within this volume cover many of the factors essential to the successful application of ionizing radiation to biological agent inactivation. Consideration of international law and treaty issues and defining what constitutes various kinds of attacks are reviewed, which are likely to be important if there is need for a multinational response. Because the most efficient application of radiation requires the total dose be well matched to the sensitivity of the microorganism(s) concerned, there were several valuable reports detailing progress on precise, accurate, rapid, and field-ready diagnostics to assay the type of microbial contamination. A strength of this conference was the inclusion of facility operators and experts on process control, safety, and dosimetry. Their operational knowledge, detailed information on the current state of the art, descriptions of facility capabilities, explanation of dosimetry standards, and presentation of available technology and emerging techniques provide a strong technical base. Only from such a technical base is it possible to consider what resources are available, determine those that could be used most effectively in any particular situation where there has been the illicit use of biological agents, and provide a high degree of assurance of the effectiveness of the decontamination effort. Also addressed was the radiation sensitivity of several types of agents of concern, including bacteria, bacterial spores, and viruses. Furthermore, factors that could alter an agent’s radiation sensitivity were discussed. Several conference participants presented information on the U.S. response to the mail contamination, the approach that was taken, and some of the lessons learned. This conference also provided a forum for radiation experts on a broad regional basis to meet one another or become reacquainted. Potentially, this may be one of the most important facets of the conference. An important aspect of the U.S. response was rapidly making the needed connections and coordination among the appropriate scientists, private sector facility operators, and regulatory officials.

The conference recommendations were encapsulated in a formal memo to the International Atomic Energy Agency. In brief, the memo made following recommendations: (a) there is a need for a comprehensive assessment of the potential use of ionizing radiation for the destruction of biologically hazardous materials, (b) a need to assemble a committee of experts to develop and maintain a database on the use of radiation technology for biological agent defeat and to identify critical areas that still need to be addressed, (c) consider organizing an experts’ meeting to advise the Coordinated Research Project on possible future Member States’ actions, and (d) compile a list of radiation sources and locations capable of contributing to biological agent inactivation.

This workshop is a valuable basic reference for the use of radiation decontamination technologies against bioterrorism agents. The conference and its proceedings also provide a template for future highly cooperative and productive meetings to facilitate international interactions among those concerned with preparing responses to biological agent attacks. Hopefully these proceedings will stimulate support and foster collegial efforts in research on these technologies, which will not only improve their use in biological agent defeat but also broaden their applicability for medical and industrial processing.

R. Joel LOWY, Thomas B. ELLIOTT, Michael O. SHOEMAKER, Gregory B. KNUDSON and Marc F. DESROSIERS