The agents in this group with the third highest priority include emerging pathogens that could be engineered for mass dissemination. The characteristics that render them amenable to bioterrorism are - Availability Ease of production and dissemination Potential for high morbidity and mortality and major health impact.
The agents included in this category are: Nipah virus Hantavirus - discussed in the presentation on viral hemorrhagic fevers Tick borne hemorrhagic fever viruses Tick borne encephalitis viruses Yellow fever - discussed in the presentation on viral hemorrhagic fevers Multidrug resistant tuberculosis. The - outbreak in Malaysia caused 1 million deaths in swine and encephalitis in humans. The disease was eradicated from swine but is still likely to be present in fruit bats.
Humans contracted Nipah virus by coming into direct contact with swine. Human-to-human transmission has not been documented. No cases have been documented in the United States. Tick borne hemorrhagic fevers include Crimean-Congo hemorrhagic fever, Omsk hemorrhage fever and Kyasanur Forest disease To enhance the preparedness at local and state levels, the CDC funded co-operative agreements with states and several large cities Five areas were emphasized for the first 3 years of this program -.
The United States Food and Drug Administrations is participating in an interagency group preparing for response in a civilian emergency 55 The USAMRIID maintains an aeromedical isolation team to minimize the risk of transmission from the troops to air crews, caregivers and civilians Traditional first responders like firefighters and law enforcement officers are the most likely to respond to an announced attack, whereas physicians and other health care providers would be most likely to uncover an unannounced attack. In either case, the medical community at large will be responsible for diagnosis and management of diseases caused by biological and chemical weapons.
The Association for Professionals in Infection Control and Epidemiology APIC in cooperation with the CDC has prepared a Bioterrorism Readiness Plan to serve as a reference document and a template to facilitate preparation of bioterrorism readiness plans for individual institutions National Association of Counties conducted a survey of county Public Health directors A significant number of responding counties counties in 36 states reported less than optimal levels of preparedness for biological and chemical warfare and for policies and procedures to enforce a quarantine.
Among the reasons cited for unpreparedness were insufficient funding, insufficient work force and insufficient communications networks. In most cities, large health care institutions have disaster plans and various types of task forces with "experts" in different areas in place. However, they need to be updated and modified to include new information on biological and chemical weapons. In addition to being able to recognize and manage diseases associated with bioterrorism events, health care providers will need to stay abreast of new developments.
The same issue of Emerging Infectious Diseases August, has a review on the activity of humoral immunity against several biological agents and discusses the use of passive antibody administration Immediate Immunity as a specific defense against biological weapons Various models and estimates of the economic impact of bioterrorism attacks have been published. Rapid implementation of a post-attack prophylaxis program is the single most important means of reducing the huge economic impact The model proposed by Kaufamnn et al.
In the field of Infectious Diseases, reality is stranger than anything a writer could dream up. The most menacing bioterroist is Mother Nature herself. Their assistance in collecting the most recent literature and helping convert thoughts and rough drafts into a presentable review was invaluable.
Skip to main content. Overview of Potential Agents of Biological Terrorism. Bioterrorism , National Security and Law Bioterrorism has now been defined as the intentional use of a pathogen or biological product to cause harm to a human, animal, plant or other living organisms to influence the conduct of government or to intimidate or coerce a civilian population 4. Historical Perspective and Trends Related to Bioterrorism The intentional use of living organisms or infected materials derived from them has occurred over centuries during war and "peace" time by armies, states, groups and individuals 14,15, Some of the more recent events of biological warfare are chronicled below - The Tartars catapulted bodies infected with plague into Caffa now Ukraine in at the end of a 3 day siege.
The inhabitants of Central and South America were decimated by small pox and measles that accompanied the Spanish conquistadors. British forces used blankets contaminated with small pox to infect North American Indians in the 18th century. The modern era of biological weapons development began immediately before and during World War II.
The Japanese released fleas infected with plague in Chinese cities in the 's and 's. Between and Japanese unit dropped bombs containing up to 15 million plague infected fleas on two Chinese cities - Quxian and Ning-hsien, resulting in at least deaths. Water supplies and food items were contaminated with B. Weather Underground , a United States revolutionary group intended to obtain agents at Ft. Detrick by blackmail and to temporarily incapacitate United States cities to demonstrate the impotence of the federal government.
Report originated with a US Customs informant. College students influenced by ecoterrorist idealogy and 's drug culture planned on using agents of typhoid fever, diphtheria, dysentery and meningitis to target the entire world population initially and later narrowed the plan to five cities near Chicago. The attack was aborted when cultures were discarded.
- El hombre de arena (Spanish Edition)!
- Tower of the Blue Horses.
- Business Bullseye?
- You are here.
Bulgarian defector Georgi Markov was assassinated in Lauda using ricin-filled pellet infected with a spring-loaded device disguised in an umbrella. Similar device used against a second defector in the same area was unsuccessful. Accidental release of anthrax from Soviet bioweapons facility caused an epidemic of inhalational anthrax with at least 77 cases and 60 deaths.
Red Army Faction Members of a Marxist revolutionary ideology group allegedly cultivated botulinum toxin in a Paris safe-house and planned attacks against at least 9 German officials and civilian leaders. This probably was an erroneous report, later repudiated by the German government. Indian religious cult headed by Rajneeshee plotted to contaminate restaurant salad bars with Salmonella typhimanice in Dallas, Oregon.
The motivation was to incapacitate voters to win local elections and seize political control of the county. The incident resulted in a large community outbreak of salmonellosis involving patients and at least 45 hospitalizations. The plot was revealed when the cult collapsed and members turned informants. Minnesota Patriots Council Right wing "Patriot" movement obtained Ricin extracted from castor beans by mail order. New Age Doomsday cult seeking to establish a theocratic state in Japan attempted at least 10 times to use anthrax, botulinum toxin, Q fever agent and Ebola virus in aerosol form.
All attempts with biological weapons failed. Multiple chemical weapon attacks with Sarin, Vx, hydrogen cyanide in Matsumato, Tokyo and an assassination campaign were conducted. Nerve gas Sarin killed 12 and injured in Tokyo subway. Intentional contamination of muffins and donuts with laboratory cultures of Shigella dysenteriae.
The event caused gastroenteritis in 45 laboratory workers and 4 were hospitalized. Larry Wayne Harris Allegedly threatened to release "military grade anthrax" in Las Vegas, Nevada. Obtained plague and anthrax vaccine strains , repeatedly isolated several other bacteria. Made vague threats against US federal officials on behalf of right wing "patriot" groups. Arrested when he talked openly about biological weapons terrorism. Intentional dissemination of anthrax spores through the US Postal System leading to the death of five people, infection of 22 others and contamination of several government buildings.
Investigation into the attacks so far has not led to any conclusions. Chronology of Anti-Bioterrorism Biosafety Actions The United States signs but fails to ratify the treaty. The treaty contained no provision for verifications and inspection. International pressures mount to draw up new treaties to curb such weapons. November 25, President Richard M. Nixon unilaterally renounces the use of biological weapons in war by the United States and restricts research to immunization and safety efforts.
Three months later, he extends the ban to include toxins. The Biological and Toxin weapons Convention entered into force March 26, There are now states parties to the convention and an additional 18 signatories Article VI of the Convention that provides for actions against noncompliance has proved to be an inadequate mechanism. May 13, Shortly after the Allied victory against Iraq, President George Bush announced that the United States will renounce the use of chemical weapons for any reason. April, Russian President Boris N.
Yeltsin declares that Russia's biological weapons program is being discontinued.. January, President George Bush signs the Chemical Weapons treaty at the convention banning the production and use of chemical weapons. January 7, The Presidential Advisory Committee on Gulf War Veterans' illnesses, finds no conclusive evidence linking Gulf War Syndrome to exposure to chemical or biological weapons. April 15, New regulations aimed at limiting access to chemicals and pathogens that could be made into weapons go into effect under the Antiterrorism and Effective Death Penalty Act.
April 29, The Chemical Weapons Convention went into effect. It has more than signatories and 65 ratifications. July 25, The United States rejected a protocol to strengthen the Biological Weapons Convention as well as the whole approach to it Like the Chemical Weapons Conventions CWC , a strong bioweapons protocol could add to the deterrence of bioweapons which are a much greater threat.
The Threat of Biological Weapons The Biological weapons system is comprised of four components; a payload, munition, delivery system and dispersion system. Types of Bioterrorism Attacks A bioterrorist attack may occur in 2 scenarios - overt and covert. Agents of Bioterrorism Attacks Based on the ease of transmission, severity of morbidity, mortality, and likelihood of use, biological agents can be classified into 3 categories Table 1 Table 1 Table 2 Category A Agents Category A includes the highest priority agents that pose a risk to national security because of the following features - i.
Plague Microbiology and Epidemiology Plague is caused by Yersinia pestis , previously called Pasturella pestis. Laboratory Diagnosis A high index of clinical suspicion and a careful clinical and epidemiologic history and physical examination are required to allow timely diagnosis of plague. Post Exposure Prophylaxis Close contact for purposes of initiating antimicrobial prophylaxis is defined as contact with a patient at less than 2 meters. Vaccination A licensed killed whole cell vaccine was available in the United States from to late Infection Control Procedures Standard precautions should be used for bubonic plague patients.
Category B Agents This category 47 contains the second highest priority agents because they a. H7 Vibrio cholerae Cryptosporidum parvuus Q fever First described in Australia and called Q fever because the causative agent was unknown. Diagnosis - The incubation period is 2 - 14 days, varies according to number of organisms inhaled. Management - All suspected cases of Q fever should be treated to reduce the risk of complications. Brucellosis Also called undulant fever, Mediterranean Fever, Malta Fever Epidemiology and Microbiology Brucellosis is a zoonotic disease caused by infection with one of the six species of Brucellae, a group of facultative intracellular gram negative coccobacilli 36,44, Diagnosis The usual incubation period is 8 - 14 days but may be longer.
Management The United States military recommends doxycycline mg Q12 hr plus rifampin mg a day for six weeks. Glanders and Melioidosis Epidemiology and Microbiology Caused by Burkholderia mallei and Burkholderia pseudomallei respectively Diagnosis The incubation period is 10 - 14 days. Epsilon Alpha Toxin Clostridium perfringens produces 12 toxins Enterotoxin B These toxins are proteins with a molecular weight of 23, - 29, daltons 44, T-2 Mycotoxins Trichothecene mycotoxins are a group of more than 40 toxins produced by common molds like Fusarium, Myrotecium, Trichoderma, Stachybotrys and other filamentous fungi.
The characteristics that render them amenable to bioterrorism are - Availability Ease of production and dissemination Potential for high morbidity and mortality and major health impact The agents included in this category are: Nipah virus Hantavirus - discussed in the presentation on viral hemorrhagic fevers Tick borne hemorrhagic fever viruses Tick borne encephalitis viruses Yellow fever - discussed in the presentation on viral hemorrhagic fevers Multidrug resistant tuberculosis Nipah virus The - outbreak in Malaysia caused 1 million deaths in swine and encephalitis in humans.
Five areas were emphasized for the first 3 years of this program - Preparedness, planning and readiness assessment Surveillance and epidemiology capacity Biological laboratory capacity Chemical laboratory capacity Health alert network and training The United States Food and Drug Administrations is participating in an interagency group preparing for response in a civilian emergency 55 The USAMRIID maintains an aeromedical isolation team to minimize the risk of transmission from the troops to air crews, caregivers and civilians We would like to conclude this discussion with a quote "Modern adventurers like to up the ante, but even the most extreme sports wouldn't produce the adrenaline of a race against pandemic influenza or a cloud of anthrax at the Super Bowl.
Guns, Germs and Steel. Natonal Intelligence Council; Hearing on the Threat of bioterrorism and the Spread of Infectious Diseases. American Security in the 21st Century, supporting research and analysis. Shining light on dark winter. A plague on your city: Lessons learned from a full-scale bioterrorism exercise. Large scale quarantine following biological terrorism in the United States. Testimony Before the Foreign Relations Committee: Public Health Law and Ethics: Berkeley and New York, NY: Bioterrorism, Public health and civil liberties. New England Journal Of Medicine.
Biological warfare and bioterrorism. What practitioners need to know. Historical trends related to bioterrorism: Historical overview of biological warfare. Medical aspects of chemical and biological warfare. Chemical and Biological weapons. Investigating disease outbreaks under a protocol to the biological and toxin weapons convention. US rejects stronger bioweapons treaty. An overview of the biological weapons programs of the former Soviet Union and Iraq.
New Challenges and new policy priorities for the ;s. Biologic Weapons; weapons of the future. Center for Strategic and International Studies; Annals of Internal Medicine. Bioterrorism as a public health threat. Daplan E, Marchell A. The Cult at the End of the World. Crown Publishing Group; Potential biological weapons threats. The past or future? Emergency physicians and biological terrorism. Biological weapons - a primer for microbiologists. Danzig R, Berkowsky PB. Why should we be concerned about biological weapons.
The economic impact of a bioterrorist attack: Are prevention and past attack intervention programs justifiable? Biological and Chemical Terrorism: Strategic Plan for Preparedness and Response: Agents of bioterrorism; preparing for bioterrorism at the community health care level. Infect Dis Clinc North Am.
Plague as a biological weapon: Medical and public health management. Pneumonic plague - Arizona, Yersinia pestis - etiologic agent of plague. Fatal human plague - Arizona and Colorado, Multidrug resistance in Yersinia pestis mediated by a transferable plasmid. New England Journal of Medicine. Glanders in a military research microbiologist. N England J Medicine. American Public health Association. Control of Communicable Diseases Manual. American Pubic Health Association; Public Health assessment of potential biological terrorism agents. The American Journal of Medicine. Preparing for the Unthinkable Emergency.
Viral encephalitis; familiar infections and emerging pathogens. Hemorrhagic fever viruses as biological weapons. Clinical recognition and management of patients exposed to biological warfare agents. Bioterrorism preparedness for the public health and medical communities. Public health preparedness for biological terrorism in the USA.
Vaccines, Pharmaceutical products, and bioterrorism: Air evacuation under high-level biosafety containment: The Aeromedical Isolation Team. English JF et al. A template for Healthcare Facilities.
RADIOLOGIC TERRORISM SCENARIOS
National Association of Counties. County Public Health preparedness hHp: Use of automated ambulatory care encounter records for detection of acute illness clusters, including potential bioterrorism events. The Economic Impact of a bioterrorist attack: Are prevention and post attack intervention programs justifiable. The Geneva Protocol prohibits the use of biological and chemical weapons in war. The Soviet Union and United States build arsenals of biological and chemical weapons.
Convention on the prohibition of the development, production, and stockpiling of bacteriological biological and toxin weapons and their destruction opened for signature at Washington, London, and Moscow on April 10, The Reagan administration presented a draft treaty to ban the production and storage of chemical weapons to the Conference on Disarmament in Geneva. Concerns over exposure to chemical and biological weapons during the Persian Gulf War increased support for international treaties.
Shortly after the Allied victory against Iraq, President George Bush announced that the United States will renounce the use of chemical weapons for any reason.
Russian President Boris N. President George Bush signs the Chemical Weapons treaty at the convention banning the production and use of chemical weapons. The Presidential Advisory Committee on Gulf War Veterans' illnesses, finds no conclusive evidence linking Gulf War Syndrome to exposure to chemical or biological weapons. New regulations aimed at limiting access to chemicals and pathogens that could be made into weapons go into effect under the Antiterrorism and Effective Death Penalty Act. The Chemical Weapons Convention went into effect. National Terrorism Advisory System.
Contact Information Email questions to: What are the potential adverse health consequences from a terrorist nuclear attack? The adverse health consequences of a terrorist nuclear attack vary according to the type of attack and the distance a person is from the attack.
Overview of Potential Agents of Biological Terrorism | SIU School of Medicine
Potential terrorist attacks may include a small radioactive source with a limited range of impact or a nuclear detonation involving a wide area of impact. In the event of a terrorist nuclear attack, people may experience two types of exposure from radioactive materials: Understanding terrorism begins with defining it—a complex task in itself.
A brief overview of relevant historical events can aid in our understanding of radiologic and nuclear terrorism threats. In , a nonterrorism—related radiologic emergency in Brazil involved health effects and radioactive material mirroring what might be expected in a radiation terrorism scenario. In this incident, a group of men seeking scrap metal dismantled an abandoned teletherapy unit at the Goiana Institute of Radiotherapy, exposing the unit's platinum core containing Cs 5.
The purchaser of this scrap metal then unknowingly distributed the radioactive material among relatives, friends, and children, resulting in contamination of people and 4 deaths 5. The well-documented physical, economic, and psychosocial impacts on the area were significant 5. More recently, threats of radiologic terrorism from al Qaeda were raised in when y-old Jose Padilla was detained on suspicion that he intended to deploy a radiologic dispersal device RDD in the United States 5 ; detailed plans for RDDs were uncovered after the destruction of an al Qaeda training camp in Afghanistan.
Development of nuclear weapons began in the s 6. In , the British began a nuclear weapons' research program 6. When this failed to persuade the Japanese to surrender, the United States dropped a second bomb on Nagasaki, Japan, 3 d later, resulting in another 40, deaths. The Japanese surrendered within 5 h of the second bomb. Within 5 y, an estimated , Japanese, mostly civilians, had died as a result of the 2 bombs 7.
In , the Cold War began with the Soviet Union's first nuclear test 6. Since , approximately 2, nuclear test explosions have taken place around the world 6. The Treaty on the Non-Proliferation of Nuclear Weapons sought to promote nuclear disarmament and prevent the development of additional nuclear weapons and the spread of nuclear weapons' technology 6. At present, countries have signed the treaty 6. However, several countries continue to have active nuclear weapons' programs, and the concern exists that terrorist organizations have or may obtain nuclear weapons 6.
Terrorist acts or threats involving radioactive materials are broadly categorized into radiologic events, which involve the nonnuclear release of radioactive materials, and nuclear events involving nuclear weapons. Other RDD dispersal methods may include techniques such as an aerosol or spray 6 , 8 , 9. Nuclear events involve the use of nuclear weapons, devices that use fission or fusion reactions to produce destructive energy in pulses or waves of heat, electromagnetic energy, air pressure, and radiation 6. Nuclear weapons are described by their potential yield or the energy released in their detonation, measured in kilotons kT.
A 1-kT nuclear device, for example, refers to the approximate equivalent explosive yield from 1 metric ton of the chemical explosive trinitrotoluene. Weapons that are capable of producing 0. For several reasons, including the high-level security of intact high-yield weapons and extreme sophistication needed to construct high-yield weapons, low-yield weapons are considered much more likely to be used by terrorist organizations 8 , Although these weapons are called low yield, even the lowest-yield weapon, 0.
The nuclear weapons detonated at Hiroshima and Nagasaki had a yield of 15 and 21 kT, respectively 7. RDDs are said to be the most likely radiation weapons because of their relatively simple technology and the widespread use of RDD-adaptable radioactive materials in medicine, scientific research, and industries, such as civil engineering, petroleum engineering, aeronautics, and radiothermal energy generation 9 , Such sources of radioactive material often have little security and may be small and portable Some important radionuclides that may be used in RDDs, their sources, and maximum radioactivity for the source are listed in Table 1 11 — Although virtually any radionuclide could be used in an RDD, most experts consider those listed in Table 1 as the most likely candidates for RDDs because of their relative ease of access compared with other radionuclides.
The type of radionuclide used in RDDs is critical because this influences dispersion due to the physical and chemical characteristics of the source containing a specific radionuclide , risks based on type of emissions and available activity , and later mitigation. Discussions are currently under way about changing the chemical form of larger sources such as used in irradiators so that these will pose less of a hazard if used for RDDs. RDD events may result in physical injuries, variable radiation contamination, and psychologic trauma to a population.
The severity of physical injuries depends on the nature of the explosives used, and the extent of contamination depends on the degree to which the radioactive material is dispersed.
'Dose as small as a grain of sand can kill you': alarm after Canada carfentanil bust
Dispersal is dependent on the physical and chemical form of the radioactive material, the explosives, and the atmospheric conditions Smaller particles are more easily dispersed but more difficult to make More explosive will disperse the material further Higher winds would distribute the material more widely, and wind direction would determine where contamination occurred Rain or snow would more quickly remove the material from the air, but concentrate it in water sources Greater dispersal results in a larger area of contamination, whereas less dispersion might result in higher levels of radiation exposure for those exposed In spite of the common concern about radiation contamination, the blast- and radiation-related physical health consequences from an RDD would likely be limited to a maximum area of a few city blocks, and the most significant contributor to injury and mortality will be the blast rather than the radiation itself 15 ; any victim close enough to receive an acute lethal radiation dose would likely have been killed by the explosion itself 8.
In an RDD event scenario, it has been estimated that, for most people directly involved, the exposure would have an estimated lifetime health risk comparable to that from smoking 5 packages of cigarettes or the accident risk of taking a hike For example, we modeled a dirty bomb explosion in Baltimore, based on National Planning Scenario 11, which involves In our modeling, the 0.
It is possible, but unlikely, for some victims to survive the blast and receive high doses; imbedded radioactive source fragment from the RDD may have high specific activity and associated high dose rates. Therefore, from a public health perspective, the RDD is much more of a psychologic weapon than a physical weapon for an affected community. After an event, public fear and panic could disrupt social order and overwhelm emergency response and medical systems.
Depending on the location of an event, extended clean-up and site restoration could disrupt commerce and transportation. On the basis of the responses by the public and relevant officials, the degree of social disruption will influence whether RDD might continue to be used as a terrorism modality. We consider the psychosocial effects of terrorism, especially radiologic terrorism, to be so important from a public health perspective that we consider such effects separately.
Nuclear facilities, including nuclear reactors and fuel storage depots, are potential terrorist targets 8. Modern commercial nuclear reactors are well secured and protected, contained by walls of steel and concrete that are several meters thick. The barrier secondarily protects the reactor from air or other outside explosive attack, and even high-level explosives would be unlikely to significantly penetrate the protective barrier. In , an unmanned airplane was flown at miles per hour into a 3. The plane penetrated only a few centimeters Only a reactor that is being refueled, with its containment structure open, would be at risk for releasing radioactive material into the surrounding environment 8.
However, in this scenario the reactor would be shut down, and much less radioactive material would be present compared with active operation since fission products quickly decay to low levels during shutdown. The Nuclear Regulatory Commission has stated that the likelihood of a direct attack on a reactor, resulting in both direct damage to the reactor and the release of radioactive materials, is low If a terrorist attack on a nuclear facility were able to penetrate a reactor and breach containment, release of radioactive material and subsequent health effects would likely be on a smaller scale than Chernobyl, because efficient and effective dispersal of source materials requires an explosion with significant energy 8.
Depending on the nature of the explosives used and material attacked, the area at risk for health effects would range from a few city blocks to several miles 8. Nuclear facility fuel storage depots are less well protected than nuclear reactors, but spent fuel contains much less radioactive material 8. A terrorist attack on spent fuel would be unlikely to expose a population to significant amounts of radiation However, as with an RDD, though the mortality and level of radiation exposure resulting from a terrorist attack on a nuclear facility would be relatively low, the psychologic impact, even of an unsuccessful attack, might be severe.
An analysis of the Three Mile Island incident has demonstrated that mental health issues were one of the main public health consequences of the event 6. A low-yield, crude nuclear bomb, or improvised nuclear device constructed by a terrorist organization, might contain weapons-grade plutonium, reactor-grade plutonium, or highly-enriched uranium HEU and might be either a gun-type or an implosion-type device 8 , Because of presumed easier access to HEU and the relative simplicity of a gun-type device, a HEU gun-type device is considered the nuclear weapon most likely to be developed by a terrorist group The successful use of a nuclear weapon by terrorists would require significant technical and financial resources for planning; access to fissile material; expertise to construct a weapon; the ability to covertly transport and place the weapon; and the motive, will, and ability to detonate the weapon without detection 8 , A weapon constructed de novo by a terrorist group would likely be much larger than a stolen weapon and would, therefore, be easier to detect.
Weapons with increasing nuclear yield potential would be larger and more detectable, not only because of size but also because of increasing radiation signature 8. Detonation of a nuclear weapon, resulting in an initial air blast and the release of radiation, produces pressure and heat waves causing the greatest amount of destruction. For the initial radiation exposure, conventional time, distance, and shielding principles apply, although the inverse-square relationship for distance does not always completely apply because of the complex atmospheric, mixed radiation field created initially after detonation 8.
In addition, unlike RDDs, where the amount of radioactive material released is directly proportional to the amount of radioactive material in the bomb, the amount of initial radiation produced from detonation of a nuclear weapon does not increase linearly with the yield of the weapon However, initial blast and thermal effects do increase proportionally, and as the weapon size increases they play a much greater role in initial health effects than initial radiation The fallout pattern from a ground-level nuclear explosion, the most likely scenario for a terrorist nuclear incident, would depend on the weapon yield, the height of the burst, and the meteorologic conditions 8.
The greater the nuclear yield and the height of the burst, the greater the distance the fallout will travel. Wind direction determines the area that will be affected, and wind speed can increase the fallout area Rain and snow can accelerate fallout locally We assume that readers of The Journal of Nuclear Medicine are well aware of the health effects of ionizing radiation; thus, we only briefly review these effects here.
There are 2 basic models for understanding the health effects of ionizing radiation. The deterministic model states that as the dose of radiation increases, the severity of a given health effect increases 22 , According to the deterministic model, there is a threshold of radiation dose below which a given health effect will not occur and above which a given health effect will occur All health effects of ionizing radiation, with the exception of cancer and genetic effects, follow the deterministic model Examples of deterministic effects include bone marrow suppression, cataract formation, and fertility impairment The stochastic model states that as the dose of ionizing radiation increases, the risk not the severity of cancer increases 22 , Radiation injury occurs through ionization of water molecules leading to the production of free radicals, which directly cause organelle and cellular damage 9.
- Overview of Potential Agents of Biological Terrorism.
- Finding Purpose Beyond Our Pain: Uncover the Hidden Potential in Lifes Most Common Struggles.
Ionization can also break covalent bonds in macromolecules such as proteins and DNA and lead to changes in the biologic or chemical function, particularly when cellular repair mechanisms are ineffective 9 , In acute injury, the risk of cellular damage is proportional to the total absorbed dose, becoming clinically apparent in organ malfunction or failure when significant numbers of cells have been damaged Rapidly dividing cells, such as intestinal mucosal cells and blood-producing cells, are the most susceptible Cutaneous radiation injuries CRI , occurring from direct contact with radioactive material in doses as low as 2 Gy rad , follow the deterministic model 24 , Unlike thermal burns, where tissue injury is quickly apparent, CRI findings are delayed 24 , Early signs and symptoms within hours include itching, tingling, and transient skin reddening or swelling.
This is followed by a symptom-free latent period of days to weeks, and then, depending on the dose, by intense skin reddening, blistering, peeling, and ulceration that may occur in several waves In cases of high-dose exposures, irreversible tissue damage may occur and result in permanent hair loss, damaged sebaceous and sweat glands, tissue atrophy and fibrosis, alterations in skin pigmentation, and tissue necrosis When acute whole-body exposure to high doses of penetrating radiation occurs, acute radiation syndrome ARS may result ARS is the manifestation of radiation-induced cellular death and deficiency in hematopoietic, gastrointestinal, and neurovascular tissue 22 , Damage to these tissues results in clinical presentations termed the hematopoietic, gastrointestinal, and neurovascular or cerebrovascular syndrome, respectively.
ARS also follows the deterministic model and occurs only above a threshold dose of about 0. With increasing doses, onset of the syndrome is more rapid, and the ARS is more severe and includes an increasing number of tissue types In practice, it is difficult to specify meaningful threshold doses and dose ranges for each syndrome because of individual variations in susceptibility , but we will make an attempt here. ARS is described in 4 stages: