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Neurosurg Focus 12 (3):Article 4, 2002, Click here to return to Table of Contents

Weapons of mass destruction:

CHRIS J. NEAL, M.D., AND LEON E. MOORES, M.D. Pediatric Neurosurgery, National Capital Consortium, Walter Reed Army Medical Center, Washington, D.C.

The purpose of this review is to present a concise overview of the types of radiation, methods of dispersal, injury patterns, and treatment considerations in a scenario involving radiation-based weapons of mass destruction. Radiation- related casualties, although uncommon, are a potential threat because more nations and organizations are developing the technology for producing radioactive substances capable of being used as weapons.

KEY WORDS • radiation • • casualties • war

The perception about radioactive substances has The terminology used to describe any dose of radiation changed over the last century. Prior to the detonations of conforms to the International System of Units for radia- nuclear bombs in and Nagasaki, radioactive tion , the . This energy equals 1 joule substances were used in a variety of public sources, such per kilogram, or 100 . Alpha particles, beta particles, as luminous paints, with minimal concern for their patho- gamma rays, and neutrons are four types of clinically rel- logical effects. Public sensitivity continued to change dur- evant radiation. Alpha particles are large, charged parti- ing the Cold War, as fear of nuclear warfare mounted. cles that can travel short distances. Although stopped by Current availability of radioactive substances and technol- clothing, when alpha particles are internalized, they can ogy, as well as the threat of terrorist use, have raised threat cause significant localized damage. Beta particles are credibility to levels not seen since the end of the Cold War. , charged particles found in fallout radiation, which travel a short distance in tissue. They produce dose-de- WEAPONS OF MASS DESTRUCTION: pendent damage to the basal stratum of the skin similar RADIATION to thermal injury (a “beta burn”). Gamma rays are un- charged, highly energetic radiation that thoroughly pene- Radiation-induced casualties can be caused by a variety trate all body tissue. Neutrons are uncharged particles only of devices. Nuclear weapons, although a great public con- emitted during a nuclear detonation. Because of their size, cern, are not the most likely source of radiation injury. they interrupt atomic structures and cause 20-fold greater Limited availability of weapons-grade fuel, tremendous damage than gamma radiation.1 technical obstacles, complexity of delivery, and expense Radiation-induced illness can be acute or chronic, de- of maintenance limit proliferation. A more probable threat pending on the dose and duration of exposure. Other dam- is a “,” a device constructed to disseminate ra- age includes carcinogenesis, infertility, and fetal effects. dioactive material without a nuclear detonation.1 Radio- The LD50/60, the of radiation that will active material for such a bomb can be obtained from kill 50% of the exposed persons within 60 days, is 3.5 Gy innocuous sources including university research facilities, when medical care is not instituted.1 Recovery of an organ medical radiotherapy clinics, industrial complexes, nu- system exposed to such an insult will depend on the dam- clear power plants, and nuclear waste processors. A simi- age to the stem population, with delayed somatic ef- lar effect can be achieved by destroying a target that con- fects being common. tains radioactive elements. A hijacked truck carrying has variable symptoms de- , for example, can be used for dispersal of radioactive elements without an explosion to contami- pending on the radiation dose, type, and individual sensi- nate a public water system or space. tivity. The prodromal phase is marked by rapid onset of , , and malaise. The latent phase follows and is relatively symptom free. Abbreviations used in this paper: GI = gastrointestinal; US = Individuals exposed to 0.7 to 4 Gy will suffer bone mar- . row effects, with changes in the peripheral blood smear

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Unauthenticated | Downloaded 09/25/21 05:19 AM UTC C. J. Neal and L. E. Moores seen as early as 24 hours postexposure. sup- Death occurs if sufficient irradiation occurs prior to im- pression causes an increased risk of and plantation. Teratogenesis occurs during organogenesis, from 10 to 60 days postirradiation. In acute radiation syn- and the is often affected. Analysis drome, prevention and management of infection is criti- of data obtained from survivors of Hiroshima and Na- cal. The extent of is the greatest risk factor for gasaki showed that congenital microcephaly could result infection. The management of a patient in whom neutro- from free-in-air radiation doses of 100 to 190 mGy.1 De- penia occurs secondary to is no differ- velopmental abnormalities and growth retardation have ent from cases of neutropenia from other causes.1 In a been noted following exposure in the fetal period. conventional nuclear detonation, the majority of victims The detonation of a results in two types who reach medical care will fall into this category— of blast forces and two types of thermal injury. The first patients exposed to higher doses die instantly or immi- blast force results from direct overpressurization. This nently of thermal- or blast-related injuries. In nonconven- does not extend far from the point of detonation, and the tional radiation dispersal scenarios, however, higher-dose extent of the damage depends on the rate of pressure exposures may occur in survivors. In either situation, low- change at the blast wave front, the magnitude of the peak dose exposure produces injury that can be treated. overpressurization, and the duration of the blast wave.2 Exposure to 6 to 8 Gy of radiation results in a GI syn- The more clinically significant indirect wind drag force is drome. Hemorrhage, fluid loss, and are common proportional to the velocity and duration of blast winds. manifestations of the GI syndrome as the mucosa is These tremendous energies vary from the point of detona- denuded of functional cells after villi . tion, yield of the weapon, and altitude of the burst, and With concomitant injury to the microvasculature, are of short duration. Injuries occur as mobile objects can occur within 1 to 2 weeks.1 become missiles and as individuals are blown into stable A neurovascular syndrome occurs in victims exposed to structures.2 acute high-dose radiation of 20 to 40 Gy. In these cases the Thermal injuries result from the direct absorption of latent phase lasts only hours before the onset of symp- thermal energy (flash burns) and/or indirect environment toms. Clinically, these patients deteriorate into a coma re- fires (flame burns). The pattern of flash burns depends on sulting in death. Convulsions may or may not occur with the patient’s type of clothing and coverage. Exposed skin few signs or symptoms to suggest an increased intracra- facing the blast will be burned, sparing the contralateral nial pressure. Exposure to this amount of radiation in side. The amount of energy absorbed by the clothing- a nuclear explosion would cause 100% lethality due to covered skin depends on the properties of the clothes. blast and thermal effects. With this level of exposure, sur- Dark-color clothing absorbs energy, resulting in vival is not likely.1 In the event of a mass-casualty situa- pattern burns, whereas light colors reflect this energy. Sec- tion for which limited resources are available, patients ondary fires result in common flame burns that may be should be sorted in triage to the category of “expectant” if complicated by inhalation injury.2 they exhibit mental status changes attributable to radia- When treating an injured contaminated patient in an tion exposure. acute setting, the provider should realize that it is highly Chronic radiation syndrome occurs as a result of long- unlikely that a survivor is so contaminated that he poses term radiation exposure. Patients present with neuroregu- a radiation hazard to the provider.1 Initial decontamina- latory disorders, , and thrombocytopenia. In tion steps should be performed outside the medical fa- severe cases anemia, of the GI membranes, and cility. Confirmation of radiation contamination is per- encephalomyelitis can be observed. Exposure to at least 1 formed by use of a radiation detector (a radiac). Prior to Gy/year for 3 years may result in symptoms.1 Patients decontamination, cover open wounds and remove conta- present with localized tenderness, , tachycar- minated clothing, placing clothing in labeled plastic bags dia, intention , , asthenia, or hyperreflexia. that will be discarded. Removing clothing and washing Removal of the patient from the source of radiation may exposed skin and hair rids the victim of approximately resolve the symptoms. 95% of the contaminant.1 Hypochlorite solution (0.5%) Radiation exposure may result in carcinogenesis. The can be used to wash the body. The skin must not be irri- annual lifetime risk in the US of a fatal is 20%. An tated because this increases the absorption of some ra- exposure to 100 mGy causes a 0.8% increase in the life- dioactive particles. Wash solution should be collected and time risk of cancer-related death. This exposure is double disposed of appropriately. If this is not feasible, flush the US occupational annual limit. The period between ex- water to standard drains and notify the local water treat- posure and carcinogenesis is unpredictable but may be as ment facility. long as decades.1 Remove all bandages and flush wounds liberally. Re- Radiation adversely affects fertility. Sublethal doses of move particulate matter in the wound and debride. A radi- radiation result in a transient period of azoospermia with ac is used to determine adequate wound decontamination. sterility lasting months to years. Germ cells, when affect- All fluids must be evacuated from the wound because they ed, do not produce mature sperm or ova and therefore do may mask the detection of alpha and beta particles. not transmit genetic abnormalities that could occur from Suction, rather than sponging should be used to remove the radiation. Theoretically, radiation exposure increases fluids to decrease environmental contamination. After the rate of point mutations and thus could result in an the wound is decontaminated, it should be flushed again. increase in genetic abnormalities in subsequent genera- Do not perform aggressive surgical procedures to remove tions. This has not been seen in humans.1 trace contamination, because the lifetime risk from radia- Fetal exposure to radiation has three main effects: tion exposure is less than the risk of immediate wound death, teratogenesis, and developmental abnormalities. complications and infection.

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Treatment of acute or life-threatening injury must pre- sures, because the threat has increased substantially in the cede treatment for radiation injury. Immune system com- past several months. promise and delayed wound healing, however, may com- promise any treatment provided. Surgical procedures should be performed within 48 hours of the radiation References injury, and sooner is better. Wound sites should be closed 1. Jarrett DG: Medical Management of Radiological Casualties primarily because wound healing is markedly compro- Handbook. Bethesda, MD: Armed Forces Re- mised within hours of radiation injury.1 Anticontami- search Institute, 1999 nation coveralls should be worn by the provider prior to 2. United States Armed Forces: Joint Publication 3-11. Joint the patient’s initial decontamination, but standard univer- Doctrine for Operations in Nuclear, Biological, and Chemi- sal precautions are adequate for those treating limited cal (NBC) Environments. 2000 numbers of radiologically contaminated patients. After treating and decontaminating the patient, providers them- Manuscript received January 18, 2002. selves should undergo decontamination. Accepted in final form February 20, 2002. The opinions and views expressed in this article are those of the Although it is difficult to predict the method of delivery authors and do not reflect the official policy or position of the US of a radiation threat, common diagnostic and treatment Army, US Navy, Department of Defense, or US Government. algorithms apply based on the acuity, radiation dose, and Address reprint requests to: Chris J. Neal, M.D., Walter Reed duration of exposure. Physicians, particularly in metro- Army Medical Center, 6900 Georgia Avenue, Building 2, 6446, politan areas, should be prepared to treat radiation expo- Washington, D.C. 20307-5001 email: [email protected].

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