Radiological Terrorism: An Imminent Threat? Possible Forms of Attack and Medical Provision for the Population in Case of an Attack

Abstract

The chapter “Introduction” defines terrorism as a phenomenon in the modern world. Introduced are the concepts of terrorism, radiological terrorism, mass fear, radiophobia, radiation accidents, and the possibilities for successful diagnostics and treatment in radiation accidents. The chapter “Possible Scenarios” describes the possible scenarios for deliberately exposing large groups to ionizing radiation, namely the detonation of nuclear warheads, an explosion in a nuclear installation or nuclear waste depot, a dirty bomb, the contamination of foods or waters, a source of ionizing radiation with high activity for contaminating a relatively small group of people with high doses. The chapter “Analysis of preceding radiological incidents” provides a quick historical recap of relevant incidents. The chapter “Health Consequences” focuses on the historical experience of radiation accidents in the past in terms of health consequences for the population and the adequateness of the reaction of medical personnel. The chapter “Psychological Effects” focuses on the disproportionate burden imposed by the psychological effects of radiation accidents – technogenic or man-made. The chapter “Medical Provision” focuses entirely on the clinical practice and public health background of radiation accidents.

1. Introduction

“A violent act is called a terrorist act when the physical results are completely out of proportion to the psychological ones”.

Raymond Aron, Paix et guerre entre les nations, Paris, 1962 [1]

Of all forms of terrorism, radiological, chemical, and biological pose the greatest threat. Radiological terrorism deserves special attention. The main weapon of terrorists is violence, and the means is fear. Due to the existing in the population radiophobia, the use of sources of ionizing radiation (SIR) will cause a very strong psychological effect. The amplification of the effects – fear of terrorism and fear of radiation makes the possibility of realizing radiological terrorism very high. After such a terrorist act, the health, economic, political, and psychological consequences will be enormous.

In its nature and consequences, the radiological terrorist act is a de facto accident, which, however, was deliberately and knowingly caused. This means that the experience gained from previous emergency situations must be used in the medical provision of the population [2, 3]. In this way, the health effects on the population and medical provision activities can be clarified. A thorough analysis of the information from the radiation incidents that have occurred so far shows that the main reason why radiation injuries remain unrecognized is insufficient knowledge of the consequences of SIR irradiation and their clinical manifestations. This leads to inappropriate and, in some cases, incorrect treatment of the injured in the first hours after the accident, aggravating their condition and limiting the possibilities for effective treatment. This requires medical professionals to have up-to-date information on behavior in cases of radiological terrorism and radiation injuries.

2. Possible scenarios

The bombing of the Twin Towers in New York and the Pentagon building in Washington showed the world that Al-Qaeda and similar terrorist organizations are capable of using other, so far unconventional, means. In 2002, US security forces arrested Al-Qaeda-affiliated Jose Padilla, who was planning to use a Radiological Dispersion Device (RDD) in a US city [4]. Thus, the world started talking about radiological terrorism, as an element of the possible arsenal of terrorist organizations. Radiological terrorism is a typical example of an “asymmetrical threat”, which contains unconventional, nontraditional, unknown, and unexpected tactics, actions, or means that are difficult to counter successfully. The International Commission on Radiological Protection (ICRP) uses the term radiological terrorism as an umbrella term for nuclear and radiation terrorism [2]. Nuclear terrorism refers to the deliberate use of a nuclear weapon or causing an accident in a nuclear facility, and radiation terrorism is the deliberate use of radioactive substances (sources or materials). If nuclear munitions are excluded, all other possibilities of using SIR will not lead to the occurrence of a large number of seriously injured people but will cause a very strong psychological effect, which is actually one of the main goals of terrorism – creating panic among the population and mistrust of the official authorities, as well as their ability to guarantee the security and normal functioning of the state. The various possible options for radiological terrorism are:

2.1 Nuclear weapons

Although nuclear weapons have so far only been used in Hiroshima and Nagasaki, the sheer number of dead and injured, as well as the long-term consequences, serve as a very effective deterrent to their use again. The Nuclear/Radiological Incident Annex (NRIA) to the US National Response Framework (NRF) states that even a small nuclear detonation in an urban area could result in over 100,000 deaths (and many more injured), massive damage to infrastructure and thousands of square kilometers of contaminated land [5]. The use of a nuclear weapon is unlikely but cannot be ruled out. In general, nuclear weapons are subject to increased control by the relevant institutions, and the possibility of theft is unlikely. The creation of an improvised nuclear device (IND) requires a significant amount of U-235 and Pu-239 of very high purity (4–5 kg of plutonium or 16 kg of highly enriched uranium) and special equipment, working technology, and highly qualified specialists. There are about 100 civil objects in the world that work with highly enriched uranium that can be used for terrorist purposes. The biggest security concerns are to be found in Russia, India, and Pakistan. In relation to this, The International Atomic Energy Agency (IAEA) appeals to all nuclear states to introduce urgent measures aimed at improving the effectiveness of the protection of these sites. The other direction is the transition to work with low-enriched uranium [6, 7].

2.2 Explosion in a nuclear facility

This act is difficult to implement due to the increased security and automated safety systems that automatically shut down the installation in an emergency. Nuclear power plants, the largest objects in this group, are constructed in such a way that even if an airplane hits them, they will not cause destruction, leading to serious radioactive contamination. But that does not mean they are completely safe. According to US Nuclear Regulatory Commission (U.S.NRC) reports, 47% of the country’s nuclear power plants have failed to repel fake terrorist attacks [8]. Of particular concern is the war in Ukraine and the security of nuclear facilities in the country. The Zaporozhye Nuclear Power Plant, the largest nuclear power plant in Europe, is on the front line. The collapse of the Nova Kakhovka dam wall increases the risk that the plant will run out of water needed to cool the reactors, which is supplied by the dam.

2.3 Explosion in storage facilities for radioactive waste and spent nuclear fuel

These sites are more difficult to consider as immediate sources of radioactive contamination as they are located in relatively unpopulated areas, so this type of terrorist act is very unlikely and will not cause serious problems. It is more likely that security breaches will be sought to be used as a source for obtaining radioactive materials to make a “dirty bomb”.

The stated options for nuclear terrorism are difficult to implement and highly unlikely. Furthermore, the overwhelming effect of a nuclear weapon is mainly due to the shock wave and high temperature, and only in 5–10% to ionizing radiation.

2.4 Dispersal of radioactive material (dirty bomb)

The idea of using a “dirty bomb” was born during the Korean War. In 1951, General Douglas MacArthur proposed using radioactive sources on the border to prevent further Chinese involvement [9]. A dirty bomb is a device that is a combination of a conventional explosive and radioactive material. Its purpose is to disperse the radioactive sources over a relatively large distance and cause large-scale radioactive contamination, in which a large group of the population will fall. The number of casualties resulting from the explosion would be relatively small, mainly traumatic injuries to people who were in the area of impact of the detonated device caused by the shock wave and particles of the dirty bomb material. The probability of serious early radiation damage is also very small [2, 3]. According to mathematical models, the expected maximum radiation dose rate at the explosion site is about 10 mSv/h. In this case, a stay of 100 hours at the epicenter of the blast is required for a 5% probability of severe acute radiation syndrome (ARS) [10]. The probability of occurrence of stochastic radiobiological effects (oncological and hereditary) is measured in fractions of a percent to a few percent of the level of consequences of spontaneous exposure. According to some studies, over a 40-year period, one additional cancer death per 10,000 people [11]. The main effect will be on the psyche of the population and the need for very large financial resources to restore normal activity and decontamination of the environment. The following radionuclides deserve special attention: 137Cs, 60Co, 238Pu, 90Sr, 238 U, 226Ra, 192Ir, 241Am, and 252Cf. Half of these are alpha-emitters and will pose a health hazard only through internal contamination. In 1995, the IAEA established the “Incident and Trafficking Database (ITDB)”, which records information on cases related to the illicit trafficking of nuclear and other radioactive materials from 143 countries. Every year, there are at least 150–200 reports of disappearance, theft, or loss of control over radioactive materials. In 2022, a total of 146 incidents were reported. For the entire period so far, information has been received on 4075 slats, of which 344 are related to trafficking or malicious use [12]. The most likely scenario is the detonation of a “dirty bomb” in the central part of a large city. In this regard, the accident in Goiania is very telling [13, 14].

2.5 Contamination of a water source or food products with radioactive substances

Unlike the “dirty bomb”, radioactive contamination of drinking water or food products can be detected with some delay when it has already been consumed. Panic among the population, which has no way of knowing whether they have consumed contaminated water or food, will again be the leading factor. In this case, the state will more easily deal with the radiation problem by stopping the water supply from the contaminated water source or, respectively, the contaminated food. In terms of food, it will most likely be agricultural products that are stored in bulk or in a food processing plant [2, 3, 15].

2.6 Using a powerful source of ionizing radiation

The use of such a source will lead to serious health consequences for the irradiated persons. The problem is related to the fact that irradiation can be very difficult to detect, even in the presence of certain pathological changes, due to their nonspecific nature and the lack of information about the causative agent. Many similar cases of accidents with lost radioactive sources remaining for a long time in the environment are described in the scientific literature. They are characterized by the fact that mostly a small number of people are irradiated, but with relatively large doses that lead to serious health damage [2, 3].

From all that has been said so far, it is clear that the fight against radiological terrorism is a difficult and complex task, which is often beyond the power of a single country alone. In this regard, the IAEA is developing special plans to improve the protection of nuclear materials and the facilities where they are used or received. In them, the emphasis is focused on three main directions: prevention, control, and action plan [16].

3. Analysis of preceding radiological incidents

No case of radiological terrorism has been registered so far. Only a few unrealized threats are described. The expected consequences are based on the analysis of some previous radiation incidents. In this way, the reasons for their occurrence, the health effects for the population, and medical insurance activities can be clarified, and a program for prevention and behavior in case of radiation terrorism can be developed. Emergency situations with sources most likely to be used for terrorist purposes containing long-lived radionuclides with relatively high radioactivity (¹³⁷Cs, ⁶⁰Co, ²²⁶Ra, ¹⁹²Ir) have been analyzed, which will ensure a longer effect of impact on people and the environment – Goiania, Brazil [13, 14, 17], Jilin, China [18], Tammiku, Estonia [19], Lilo, Georgia [20], Istanbul Turkey [21], Yanango Peru [22], Samut Prakarn, Thailand [23] and others.

It is noteworthy that they all have common features – violation of preventive radiological protection measures, lack of elementary awareness of citizens about SIR, as well as, unfortunately, insufficient knowledge of the consequences of radiation and the clinical manifestations of radiation damage of a large part of the medical staff. The medical aspects are directed in four main directions: dealing with ARS, local radiation injury (LRI) therapy, decontamination and decorporation, and last but not least, overcoming the psychological effects.

4. Health consequences

The likely damages that can be caused by radiological terrorism are – mechanical and thermal trauma, deterministic and stochastic radiobiological effects, combined damages, and psychological effects.

Mechanical trauma can be subdivided into primary – injuries from the contact of the shock wave with the surface of the body (tympanic membrane rupture, lung damage, eye damage, damage to hollow abdominal organs), secondary – projectile injuries (penetrating and nonpenetrating injuries), tertiary injuries from the rejection of the body by the blast wave and its impact with surrounding partitions (penetrating and nonpenetrating injuries, and fractures), quaternary – other injuries caused by the blast (asphyxia, burns, toxic exposures, exacerbation of chronic diseases).

The severity of thermal trauma is determined by the area of the burned surface, the depth of impact, the anatomical area, the age, and the general condition of the organism. Dermal burns are divided into two degrees – superficial and deep. In the course of deep burns, four phases are distinguished – thermal shock, toxic infection, recovery, and late consequences. Deep dermal burns usually require surgical intervention and skin grafting.

Irradiation of biological structures causes two types of effects: deterministic and stochastic [24]. In Publication 103, the ICRP recommends using the descriptive term – damaging tissue or organ reactions for these effects, taking into account the fact that they are not determined solely by the radiation dose but can be modified under the influence of many biological modifiers (antioxidants, prostaglandins, cytokines, growth factors, stem cells, etc.) [25]. Deterministic effects are characterized by the presence of a threshold dose. The severity of the observed biological effect is proportional to the magnitude of the dose received above the threshold. Usually, irradiation of the human body with doses below 0.5 Gy does not lead to the appearance of deterministic effects. Irradiation at lower doses can mutate somatic or germ cells and initiate stochastic effects – cancer or hereditary effects. They usually appear after a long latent period. Their severity does not depend on the size of the received dose, which affects only the probability of their manifestation. Unlike deterministic ones, they are considered thresholdless, and the clinical picture is not tied to the received dose. The linear nonthreshold model for the dose-effect relationship is a highly debatable and long-established dogma in radiobiology and radiation protection. According to him, each dose of absorbed ionizing radiation corresponds to a proportional biological effect. Despite its many uncertainties in the area of low radiation levels – doses below 0.2 Gy and dose rates below 0.1 Gy.h-1 – the ICRP officially makes it the basis of normalization of radiation effects on man and the human population yet in Publication 26 [26].

After external irradiation, two deterministic effects with different latent periods can appear – LRI and ARS. LRIs are significantly more common than whole-body ones. Involvement of a large area of the skin is part of a complex pathology, life-threatening at high doses, often called cutaneous radiation syndrome (CRS), which must be distinguished from LRI [27]. The pathophysiology is complex and not fully understood. Ionizing radiation damages multiple skin structures, including epidermal keratinocytes, dermal fibroblasts, skin vasculature, and hair follicles. Maturation, reproduction, and repopulation of cells are disturbed. Free radicals, DNA lesions, and an inflammatory response are generated. Immediately after irradiation, cytokine synthesis is initiated by skin cells (epidermal keratinocytes, dermal fibroblasts, and immunocompetent cells, including dermal dendritic cells, neutrophils, eosinophils, and lymphocytes) and continues as a cascade during all stages of development [28, 29]. There is no gold standard for clinical assessment of the severity of radiation-induced skin damage. The degrees of severity are: mild 8 – 12 Gy, medium severe 12 – 20 Gy, severe 20 – 25 Gy, and extremely severe degree above 25 Gy, the course of which shows pronounced phasicity (Table 1) [25, 27, 30, 31, 32].

Degree	Dose (Gу)	Objective symptoms	Subjective symptoms
Mild	8–12	Minimal, transient erythema	Pruritus
Medium	12–20	Moderate erythema, edema, blisters	Slight pain
Severe	20–25	Marked erythema, edema, blisters, ulcers	Moderate persistent pain
Extremely severe	над 25	Severe erythema, edema, hemorrhagic blisters, deep ulcers, necrosis	Severe persistent pain

Table 1.

Cutaneous symptoms depending on the dose.

Various diagnostic methods are used to assess the severity – serial color photography to analyze the evolution of clinical symptoms, echography, computed tomography and magnetic resonance imaging (MRT), assessment of blood flow (scintigraphy, Doppler echography), thermography, cytogenetic dosimetry [27, 31]. Therapy includes – analgesics, corticosteroids, and nonsteroidal anti-inflammatory drugs, local or systemic antibiotics, antihistamines, pentoxifylline, methylxanthines, hyperbaric oxygen, and photobiomodulation [27, 30, 31, 32, 33, 34]. Studies with superoxide dismutase, down-regulating the expression of transforming growth factor-β by myofibroblasts, acting as an anti-inflammatory agent and antioxidant [35, 36] are promising. Mesenchymal stem cell therapy combined with surgical excision has shown significant success in severe radiation burns [37, 38, 39].

ARS is caused after whole-body irradiation or after irradiation of a significant volume of the body with highly penetrating ionizing radiation, as well as in case of massive contamination – external and/or internal. Dose threshold is around 1 Gy. ARS comprises a combination of clinical symptoms occurring phasically hours to weeks after radiation. They are a manifestation of damage not only to important organs and in particular to those in which continuous and rapid cell replacement takes place but also to changes in the vascular system (in particular induced endothelial dysfunction) and the immune system, which leads to the development of uncontrolled systemic inflammatory response [40, 41]. ARS should be considered as a multi-organ dysfunction that can lead to multi-organ failure [42]. It is usually divided into three types depending on the absorbed dose and the organs mainly affected – hematopoietic (HT-ARS) at doses of 1 to 6 Gy, gastrointestinal (GIT-ARS) at doses of 6 to 20 Gy, and neurovascular (NVT-ARS), also called cerebrovascular at doses above 20 Gy [27, 43]. The hematopoietic, gastrointestinal, neurovascular, and skin systems are the four main critical systems to be analyzed in the European Association for Bone Marrow Transplantation (EBMT) approved single standardized procedure for the diagnosis and treatment of radiation accident victims, which is the basis of the METREPOL program (Medical Treatment Protocols for Radiation Accident Victims) proposed by Fliedner et al. [44]. The typical picture of HT-ARS includes several phases: prodromal with nonspecific symptoms starting a few hours after irradiation – mental agitation, headache, and dizziness, rigidity of the neck muscles, impaired consciousness, tachycardia, hypotension, anorexia, guessing, vomiting, sometimes diarrhea with an increase in body temperature; a latent phase of varying duration follows, inversely proportional to the dose; the height of the disease (critical phase) including – infections, bleeding, and gastrointestinal symptoms, expression of cellular deficiency in the hematopoietic system, and at higher doses also in the gastrointestinal tract; recovery phase. At extremely high doses, such phasing is not observed. GIT-ARS occurs as a result of the death of the stem cells of the small intestinal mucosa and disturbances in the intestinal microcirculation. Fluid and electrolyte loss, dehydration, acute renal failure, shock, hemorrhage, malabsorption, malnutrition, and infectious complications have been observed. Mortality is extremely high and usually occurs within two weeks [45]. NVT-ARS occurs due to a change in the permeability of the vessels based on the accumulation of toxic decay products and the release of cytokines into the circulation. The cell membranes of the neurons are also damaged, leading to electrochemical inactivation. Vomiting is observed in the first minutes after irradiation, respiratory distress, short-term loss of consciousness, fever, and prostration. Histologically, microvascular and cerebral edema was observed as a result of intracranial hypertension. Death occurs by the fifth day [46].

Diagnosis is mainly based on clinical (nausea, vomiting, diarrhea, fever, hypotension, tachycardia, tachypnea, neurological manifestations, hydration, skin lesions, etc.) and paraclinical signs (complete blood count with differential count; increased serum amylase); decreased concentration of serum citrulline as a biomarker of radiation-induced intestinal mucosal damage; elevated C-reactive protein (CRP) levels; elevated FMS-like tyrosine kinase 3 (FLT-3) ligand concentration. Particularly telling are changes in lymphocyte counts that can to be used as an effective prognostic criterion (Table 2) [27, 31, 47, 48, 49, 50, 51].

Absolute lymphocyte count per μL	Degree of severity of ARS	Survival prediction
700–1000	Mild	Good
400–700	Moderate	Likely
100–400	Severe	Possible with highly specialized treatment
<100	Extremely severe	Poor

Table 2.

Absolute lymphocyte count 48 h after total body irradiation.

The most widely used methods for biological assessment of dose are based on radiation-induced chromosomal aberrations – cytogenetic analysis of dicentrics, translocations, micronuclei, and premature chromosome condensation. Dicentric analysis is considered the “gold standard” of biological dosimetry [52]. Treatment is generally aimed at supporting hematopoiesis, maintaining electrolyte balance, preventing or treating infectious and hemorrhagic complications, and applying symptomatic agents. It includes cytokines – granulocyte colony-stimulating factor (G-CSF) – filgrastim or granulocyte-macrophage colony-stimulating factor (GM-CSF) – sargramostim; antibiotic, antiviral, and antifungal agents; transfusion of blood components; antiemetic therapy - dopamine receptor (D2) antagonists and serotonin receptor (5-HT¬3) antagonists, diarrhea control - loperamide, vasotonics, anxiolytics, analgesics [53, 54]. The results of the application of erythropoiesis-stimulating agents (ESAs) and hematopoietic stem cell transplantation (HSCT) did not justify the initial optimistic expectations, mainly due to accompanying severe comorbidity [54, 55, 56]. HSCT may be considered in individuals with an absorbed dose of 7–10 Gy, no evidence of hematopoietic recovery, no severe trauma or burns, and a suitable donor [57]. With whole-body irradiation above 10 Gy, treatment is palliative, and survival is up to 6 months.

In the case of radiological terrorism, a special place is occupied by combined radiation injury (CRI) from a radiation factor and mechanical, thermal, and/or chemical trauma. This requires not only their in-depth scientific study but also familiarization of the medical staff with the main features of their course. In them, the lesions occur against the background of altered reactivity of the body. The lethality increases from 1.5 to 3 times compared to pure radiation exposure [58]. Early development of ARS and significant shortening of the latent phase was observed. This is important from a surgical point of view because it shortens the time for operative intervention [32]. A characteristic feature is that conventional trauma also causes lymphopenia, which makes it difficult to use this parameter for “biological dosimetry”. Results may also be affected by cytogenetic techniques for dose estimation. A cascade of inflammatory and neurohormonal events is often activated that has systemic consequences leading to more severe disturbances of hemodynamic function. Hypoxia, which regularly accompanies ARS, predisposes to rapidly occurring and severe shock [59]. In this regard, severe mental trauma should not be neglected. Infection is a very common companion of CRI. An important feature in the course of combined injuries is the presence of frequent hemorrhages, which complicate the course of the disease. The reduced regenerative capacity of tissues damaged by mechanical or thermal trauma should not be ignored. As a result, wound healing is usually slow and accompanied by various complications [59, 60]. Treatment of CRI combines treatment measures required by all factors. The need for more rapid use of myeloid growth factors should be considered. An individualized approach is required according to the nature and severity of the CRI. Priority is given to life-saving actions and medical treatment of conventional injuries, which must be carried out as quickly as possible.

Contamination – external and internal, presents a radically different picture. Radioactive dust, liquids, or gases can enter the environment and from there contaminate the skin or enter the human body. In this case, the irradiated individual is in direct contact with the radiation sources and it continues until they are removed from him. On the other hand, radioactive dust falling on the body can lead to the contamination of the medical personnel in contact with it or to their significant irradiation. Radionuclides that have entered the body can be excreted through the urine and fecal mass and thus lead to the contamination of the area and personnel. Contamination with radioactive materials is not much different from a bacterial infection, which is why the behavior of personnel in both cases is similar [27, 47].

4.1 External contamination

Life-saving actions are always a priority. Before undertaking decontamination procedures, it is desirable to carry out appropriate monitoring by a competent specialist, since the interpretation of the data obtained is not always elementary. In principle, when reading values more than twice the predetermined background level, the patient is considered contaminated. If the values are less than twice the background radiation level, it is assumed that the person is not contaminated to a medically significant degree [61, 62]. Patients’ clothing should be removed immediately. Changing clothing and footwear typically reduces contamination by up to 90% [31]. All contaminated materials should be collected in labeled plastic bags to be transported very carefully. If a violation in the integrity of the skin is detected, the priority is the decontamination of the wound by washing with saline solution or water. Decontamination of the ear canal, nose, and mouth is done before decontamination of the body. The oral cavity is washed with lukewarm water, the teeth with a brush and toothpaste, and rinsed with 3% hydrogen peroxide; it is also recommended to gargle. The eyes are flushed with saline or distilled water using a pipette from medial to lateral to avoid contamination of the nasolacrimal duct. Ears – with lukewarm water using a syringe. Decontamination of healthy skin is done using water, neutral pH soap, or other detergents. For persistent contamination, abrasive soaps or chelating agents such as ethylenediaminetetraacetic acid (EDTA) can be carefully used. The water should be lukewarm, cleaning from the outside in with a soft brush or pads without rubbing [27, 47, 63].

4.2 Internal contamination

Once inside the body, radioactive substances become a source of internal radiation. The consequences of this radiation have many features in common with the external, but also have a number of specific features. An important problem is measuring the magnitude of the absorbed tissue dose, which is significantly more complicated than the determination of doses during external irradiation. Internal doses are calculated, not measured. Certain mathematical models are used for this purpose. Initially, internal contamination is established by monitoring biological samples. Final dose estimation is performed by excreta bioassay, a whole-body counter, and for some radionuclides a gamma camera [31, 64]. The nature of the damage to the body from the incorporated radioisotopes is largely determined by the manner of their distribution and the critical organs in which they accumulate. Usually, no early symptoms are observed, except when large amounts of highly radiotoxic isotopes such as ²¹⁰Po are ingested [65, 66]. Risk is mainly related to stochastic effects. Life-saving actions are also a priority here. The radiological risk to healthcare personnel is similar to the biological risk arising from ordinary medical practice [64].

The main goal of therapy is to reduce the risk of radiation-induced cancer by preventing or reducing the absorption of radionuclides into the blood and their deposition in critical organs or tissues, and increasing their excretion from the body. The identification of the isotope is critical to the decorporation. Therapeutic and preventive measures are divided into nonspecific and specific [62, 64]. The nonspecific measures are applied to all radioisotopes and aim at their mechanical separation – washing the nasopharynx and stomach, emetics, laxatives, enemas, alkalizing the stomach, washing wounds, and expectorants. The effectiveness of these measures is significantly reduced if they are delayed. It is optimal to start within the first hour after admission. There are different opinions about the start of the specific events. Some authors believe that specific therapy should be carried out only in victims with incorporation of activity exceeding 10 times the limit of annual admission [67]. Others recommend that it be started as early as possible due to the low toxicity and high efficiency of the preparations [68]. Specific treatment methods can be divided into several groups – saturating the target organ with a corresponding stable isotope, therefore, its incorporation of radioisotopes will be reduced (potassium iodide when incorporating ¹³¹I); isotopic dilution to accelerate the elimination process of the radionuclide (hydration of the body with tritium); displacement of the radioisotope by administration of a nonradioactive element with a different atomic number (calcium gluconate with ⁹⁰Sr); reduction and/or inhibition of radioisotope absorption in the gastrointestinal tract – aluminum hydroxide with ⁹⁰Sr, ion exchange compounds (hexacyanoferrate, also called Prussian blue, with ¹³⁷Cs); chelation aiming at the formation with the incorporated radionuclides of soluble complexes that are easily separated from the kidneys – application of diethylenetriaminepentaacetic acid (DTPA) with ²³⁹Ru. Direct separation of radioisotopes from blood by means of hemodialysis is a successfully applied method when incorporating large amounts of radionuclides. It is desirable to apply it in the first 4 hours. In rare cases, for inhaled insoluble particles (Ru), bronchoalveolar lavage can be performed. The specific means of treatment depend on the type of isotope (Table 3) [27, 31, 61, 64, 69].

Radionuclide	Decorporating medicine
Cesium, Thallium	Prussian blue
Cobalt, Plutonium, Iridium, Americium, Californium	DTPA
Strontium, Radium	Aluminum hydroxide, Calcium chloride, Calcium gluconate
Uranium	Sodium bicarbonate, dialysis
Iodine	Potassium iodide
Polonius	Dimercaprol

Table 3.

Specific decorporation therapy for internal contamination.

5. Psychological effects

Psychological effects are much more challenging than radiological ones [2, 3, 70, 71]. The very important role of mass media should be emphasized here. Inaccurate, contradictory, or hyperbolized information heightens the psychological effects. After a radiological terrorist act, continuous information should be provided, providing the population with clear, concise, timely, and understandable instructions for behavior, which should be repeated many times and based on an internationally approved manual for action in such a situation. Timely warning is one of the most important psychological aspects of dealing with an incident. This maintains trust in national institutions and reduces confusion and anxiety. Society builds a sense of control over the situation [72, 73].

Psychological effects are manifested through: stress, psychological distress, and changes in the ability to adequately assess risk, changes in individual and social behavior. Psychological distress can range from feelings of psychological discomfort to the degree of manifestation with clinical signs and symptoms. Changes in the affected person’s attitude to their health can also occur. Even the smallest symptoms in such cases are perceived as manifestations of radiation damage. Many people are affected by Multiple Idiopathic Physical Symptoms (MIPS) and conduct unnecessarily extensive medical examinations accompanied by undue anxiety in the interpretation of the obtained results or in anticipation of the subsequent results [31, 74]. Psychological complications are characterized by a variety of psychopathological symptoms and syndromes. In the acute phase, effective shock reactions with polymorphic symptoms can be observed – stupor, substupor, fugiform reactions with disorders of sensory synthesis, depressive episodes, aphasia, abasia, pseudoparalysis, and delusional experiences. These symptoms fall under so-called severe stress reactions and adjustment disorders, which include acute stress reactions and posttraumatic stress disorder (PTSD). The list of reactions to acute stress disorder (ASD) that can be observed includes dynamic polymorphic symptomatology, confusion, narrowed field of clear consciousness, disruption of the receptive-representational sphere, disorientation, anxiety, hyperactivity, withdrawal, escape, depression, anger, despair, autonomic symptoms, but none of the symptoms predominated for long [75, 76]. True posttraumatic stress disorder (PTSD) can occur with a latency period of no longer than 6 months. They are characterized by a feeling of re-experience, repeated reproduction of the event in memories (flashbacks), in dreams or nightmares, alienation, indifference, insensitivity, indifference, avoidance of actions, and situations reminiscent of the psychotrauma. Adjustment disorders, substance abuse, generalized anxiety disorders, and depression can also be seen. A pathological axis is often formed: “physical disability, mental stress, psychosomatic disorder” [75, 76, 77, 78]. Besides these fundamental reactions, there are other important psychological problems that arise long after the accident – the so-called “radiation scar syndrome” or the “social stigma” phenomenon. After the incident in Goiania, a young woman whose brother died of ARS reported: “They started treating us like lepers.” Local cemeteries refuse to bury the dead, hotels do not accept residents of Goiania, Brazilian airlines refuse to book passengers from this region, etc. [13, 14, 17].

Many people from different professions are involved in the preparation and implementation of rescue and emergency recovery work in case of radiological terrorism. They are also psychologically affected by ionizing radiation. Particularly important are the problems that arise among medical personnel: fear, anxiety, isolation of the team, insufficient knowledge, insufficient experience in interacting with experts, public figures, reporters, etc., lack of independence in actions [47, 79, 80].

A terrorist act cannot be predicted, but the psychological reaction to it can be mitigated by using various methods before, during, and after it. Reducing psychological consequences is a basic functional requirement that must be met in accordance with the disaster preparedness and response program. This requirement is applicable to all categories and must be fulfilled at all levels of action: site, municipality, district, and national [81]. After the accident, one of the main measures is related to the provision of medical assistance to persons who show real somatic symptoms or symptoms of mental stress. In these cases, the role of not only mental health professionals but also general practitioners is extremely important. This requires general practitioners to have the necessary training in cases of radiological terrorism and radiation damage. In this way, they can determine the necessary approach to the injured – psychiatric or psychological treatment, medical consultation, specific treatment, etc. Periodic visits to the family doctor reassure the population. In addition, family doctors should monitor risk groups (children, pregnant women, the elderly, and the chronically ill) for a longer period of time. Long-term health care is needed for several reasons: to provide information about the severity of health problems, to identify radiation-induced health effects at an early stage, to predict the need for medical and psychological care, and to respond to unfounded fear or anxiety of people [27, 47, 82, 83].

Social support and training are a very important part of how to deal with the psychosocial consequences of a radiological terrorist act. Solving this problem requires the participation of a number of specialists, organizations, and institutions [47, 79, 80, 84]. Psychological support for rescuers and medical personnel should be based on continuous training. Many of the problems are related to the lack of knowledge about ionizing radiation and its effects on humans. Adequate training and practical training are the main elements for the psychological resilience of medical personnel involved in the elimination of the consequences of terrorism [27, 31, 47, 79, 80].

6. Medical provision

Medical provision of the population in case of radiological terrorism can be divided into three main directions: planning and preparation for action, providing first medical aid at the scene of the incident, and medical assistance outside the scene of the incident [2, 3, 32, 47, 80, 85]. Effective response requires making adequate decisions in a chaotic and emotionally charged environment. This can only be done through prior information on the execution of terrorist acts, planning of the events, and preparation of the teams, which are specific to the various departments, agencies, and other structures related to liquidation of the consequences. The development of an optimal emergency response system requires a preliminary analysis of available resources, forces, and means, and knowledge of the main health consequences that may occur in any particular situation [47, 81]. The basic requirements for medical preparedness to respond to radiological terrorism include assessment of possible terrorist acts according to local circumstances; training of medical professionals; creation of a base of instructions and algorithms for action in case of damage caused by ionizing radiation; provision of equipment for dosimetric control; provision of pharmaceutical products necessary for the treatment of persons with radiation injuries; provision of laboratories with the possibility of biodosimetric studies; determining the hospitals for the treatment of patients affected by the terrorist act; developing an effective crisis communication strategy [27, 47, 86, 87]. An important principle in building the organization of radiological assistance is that the created structure should be based on the existing health system as much as possible. Another essential principle is that the organization of radiological care should be primarily functional, especially as regards inpatient care facilities. Day-to-day peacetime needs practically do not require this kind of activity [2, 3, 27, 47, 80].

The main measures that must be included in the medical provision of the population are first aid to the victims at the scene of the accident, opening of a reception-sorting department with primary sorting of the injured according to predeveloped criteria and action algorithm, and staged evacuation to provide qualified medical assistance; providing emergency medical assistance to all those in need, providing treatment for both radiation injuries and other injuries; conducting decontamination procedures; registration of all affected persons with subsequent analysis of the lesions and provision of long-term medical monitoring; provision of psychological assistance to victims, their families and members of emergency response teams; implementation by the health authorities of appropriate protective measures for the population; public awareness, advice, and behavioral recommendations. Each one of these measures must find a mandatory place in the medical insurance plans drawn up by the state [2, 3, 27, 31, 32, 47, 80, 88, 89, 90].

In order for medical assistance to be effective, it is necessary that the medical teams work in close cooperation with the forces involved in the rescue operations be guided by the rule that resuscitation takes place before decontamination – life-saving actions take priority as required under normal circumstances; taking measures to limit radiation doses for all victims and support partial decontamination; in the primary sorting, the victims should be divided into only two categories – absolutely urgent (with immediate vital danger and a high chance of survival) and relatively urgent (victims with minor injuries, in which deterioration is not expected) [91]; providing continuous medical assistance to the victims along the entire chain, from the source of defeat to the relevant medical facilities. Responders at the scene of the accident must observe several basic principles: the area of the radiation emergency should not be entered without an individual dosimeter and protective clothing; maximally short time for treating the injured; maximum distance from the radiation source; use of protective barriers. The successful approach to action takes into account three borders – green, yellow, and red, determined by the most easily measurable indicator – the power of the ambient equivalent dose in the relevant area is successful: green limit – about 0.1 μSv/h, which is around the natural radiation background and there is no danger; yellow limit – about 0.1 mSv/h, the reaction time without danger is several days; red limit – about 0.1 Sv/h, reaction time is only a few hours, the danger is great, and only life-saving actions should be taken [80].

When organizing radiological care, personnel training is of utmost importance. Many of the problems are related to the lack of knowledge about ionizing radiation and its effects on humans. The development of a system of practical training and assessment of the capabilities of emergency teams and medical specialists for action can be considered the most important component of preparedness for a medical response to radiological terrorism. Training should include five main areas: quantities and units; prevention, diagnosis, and therapy of radiation damage; decontamination and decorporation; overcoming psychological effects; and crisis communication. One of the important elements of this preparation is the training of medical students. The inclusion of the discipline “Disaster Medicine” in the regular medical education program is a real opportunity at the moment to improve the quality and quantity of the training of medical students in this important area of public health.