Homeland Security for Radiological and Nuclear Threats

Where we are and where we need to go

By Mary Sproull, Biologist, National Institute of Health/ National Cancer Institute/ROB, USA

Since the events of 9/11, comprehensive emergency planning and preparedness guidelines for management of a radiological or nuclear event in the United States have been developed at the federal level. These efforts include protective action recommendations, proposed systems for mass casualty management and triage, development and licensure of new medical countermeasures and comprehensive playbooks to guide emergency response. Though enormous strides have been taken to improve our readiness as a nation to face the unique challenges of a radiological or nuclear event, there also remains much work to be done.

Civil defense for radiological and nuclear threats has greatly advanced at both the federal, state and local level over the last two decades. Federal guidelines for emergency response have been developed by the White House and national labs and include “Planning Guidance for Response to a Nuclear Detonation,” “Key Response Planning Factors for the Aftermath of Nuclear Terrorism” and the Department of Homeland Security’s “Nuclear/Radiological Incident Annex to the Response and Recovery Federal Interagency Operational Plans” and “Radiological Dispersal Device (RDD) Response Guidance: Planning for the First 100 Minutes. Organizations such as the National Alliance for Radiation Readiness (NARR), the Radiation Injury Treatment Network (RITN) and the National Association of County and City Health Officials (NACCHO) have also been leveraged to provide guidance on emergency management specific to disasters involving radiation exposure and support medical management of mass casualty radiation injury. There are also web-based resources now available from the Centers for Disease Control and Prevention (CDC) and the REMM portal managed by the Department of Health and Human Services, which provide “just in time” information for management of radiation injury.

Perhaps the greatest operational challenge of a radiological or nuclear event is diagnosing radiation injury.

Perhaps the greatest operational challenge of a radiological or nuclear event is diagnosing radiation injury. As radiation exposure comes in many forms, including external and internal exposure to radioactive isotope (either deposited on the skin externally or internally through inhalation or ingestion), or from external exposure to ionizing radiation energy alone, one of the most essential elements of mass casualty management is diagnosing and triage of radiation injury. As radiation is essentially invisible to the naked eye, a large population of “worried well” are expected to overwhelm existing medical resources. These “worried well” are those persons in the affected population who do not have other physical injuries but are concerned about whether they have received a radiation exposure. To meet this operational challenge, development of new radiation biodosimetry diagnostics has been supported over the last decade by the Radiation and Nuclear Countermeasures Program of the National Institute of Allergy and Infectious Disease (NIAID) and by the Biomedical Advanced Research and Development Authority (BARDA). These blood diagnostics estimate the dose of radiation a person has received without the need for physical dosimetry and are designed to be used both for population screening to assure the worried well and to support existing triage algorithms. Several biodosimetry diagnostics are currently in late-stage validation phase and expected to be added to the Strategic National Stockpile (SNS). Through support of these programs, several radiation specific medical countermeasures have also received Food and Drug Administration (FDA) licensure for treatment of radiation injury and been added to the SNS. Though much has been done to prepare the nation for large scale emergencies involving radiation exposure, key areas remain to be addressed. These areas are not limited to, but include current capacity to manage burn victims and the overall willingness of first responders and other medical personnel to work with patients who have been either exposed and/or contaminated with radiation or radioactive materials.

Though scarce resource allocation is expected for any large scale radiological or nuclear event, particularly with regard to radiation specific medical countermeasures, the current national capacity for medical management of patients with burn injuries has not been widely addressed. Currently, there are relatively few hospitals which have the resources to care for patients with severe burn injuries. Care of such patients requires surgeons and nursing staff with specific training, and dedicated hospital space to care for these immunocompromised patients. Though radiation exposure is the predominant concern in a radiological or nuclear event, it is not the most important form of injury. The biological effects of radiation exposure take time to manifest and are not immediately relevant to basic triage. Conventional blast and thermal injuries should always take precedence over radiation injury, and though these forms of injury might be handled locally for a radiological event, for a nuclear event the numbers of injured with either thermal or radiation specific burns would require a national level of response. This topic was the focus of the 2019 meeting of the RITN where the lack of national surge capacity to handle burn victims was discussed, as well as the need to educate burn specialists on the differences between thermal and radiation specific burns.

Several recent survey studies of first responders have reported that amongst different types of conventional and CBRN type disasters, radiological and nuclear events held the highest level of anxiety or fear.

The other key element to emergency planning for radiological and nuclear events which remains to be addressed, is the willingness of first responders, medical professionals and even hospital support staff to show up for work during a scenario where radioactive materials or patients exposed to radiation may be present. Radiation, like other CBRN agents, falls into the category of “dreaded risks.” Dreaded risks are a class of risks which are associated with exceptionally strong emotions of anxiety, fear and other avoidance behaviors. Several recent survey studies of first responders have reported that amongst different types of conventional and CBRN type disasters, radiological and nuclear events held the highest level of anxiety or fear. Survey studies of first responders, medical personnel and hospital support staff have also reported levels of willingness to work during a radiological or nuclear event ranging from 57% to 85%, with the higher level of willingness to work amongst the first responder participants as compared to the general hospital staff. The ability of the general public to understand basic radiation science, including the units for radiation dose, how that dose translates to added lifetime cancer risk and the difference between radiation exposure and contamination, all contribute to increase radiation as a dreaded risk. Many first responders and medical personnel have not received training on radiation specific hazards or have the knowledge that the low levels of radiation exposure which may be incurred by medical personnel treating contaminated victims, doesn’t represent a significant health risk. Leveraging existing experts in radiation exposure for mass casualty planning is needed. This may be done by integrating medical dosimetrists, health physicists and other medical professionals, such as radiologists or radiation oncologists in local hospital response planning. Further, having experts on radiation risk onsite to provide support for emergency response personnel would be beneficial. The Radiological Operations Support Specialist (ROSS) program was recently created to help integrate these experts into emergency response for radiological and nuclear events, and there are other efforts within the radiation health science community to improve communication to first responders and to the public on radiation specific hazards.

As a nation, we have many of the tools in place to successfully respond to a radiological or nuclear disaster. We have response playbooks, official guidance for public safety measures, medical countermeasures and will soon have screening diagnostics. What remains, is to address the unique operational challenges specific to a mass casualty response with radiation hazards. Education and training for first responders and other medical response personnel on the relative risks of radiation exposure and the unique nature of radiation injury is critical for the successful implementation of the resources and planning guidelines which have been so painstakingly prepared.

Mary Sproull is a biologist in the Radiation Oncology Branch of the National Cancer Institute at the National Institutes of Health, and a doctoral candidate in the Biodefense Graduate Program at the Schar School of Policy and Government at George Mason University. Her current work at the National Institutes of Health, in the laboratory of Kevin Camphausen, is funded by the Radiation and Nuclear Countermeasures Program/National Institute of Allergy and Infectious Diseases, as part of an initiative to develop new radiation biodosimetry models for dose prediction for use during mass casualty management during a radiological or nuclear event.