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Chapter 16

Chapter 16. Detecting Weapons of Mass Destruction. Objectives. Students should gain an understanding of: Different types of chemical warfare agents Point detection technologies Standoff detectors Nuclear weapons Biological weapons. Introduction.

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Chapter 16

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  1. Chapter 16 Detecting Weapons of Mass Destruction

  2. Objectives • Students should gain an understanding of: • Different types of chemical warfare agents • Point detection technologies • Standoff detectors • Nuclear weapons • Biological weapons

  3. Introduction • Weapons of mass destruction inflict massive casualties by means of chemical, biological, and radiological or nuclear devices. • Such an attack would overwhelm local and state emergency responses. • Emergency personnel need to determine which weapon of mass destruction was used to bring appropriate emergency aid to victims.

  4. Chemical Warfare Agents (1 of 8) • Have the greatest potential for terrorist use • Are easy to obtain and make • Might be used in only small amounts to immobilize an entire city

  5. Chemical Warfare Agents (2 of 8) • Six types of CWA • Choking • Blister • Blood • Irritating • Incapacitating • Nerve

  6. Chemical Warfare Agents (3 of 8) • Choking agents • Stress the respiratory tract • Lead to a buildup of fluid in the lungs • May lead to asphyxiation (essentially drowning from your own bodily fluids) • Include chlorine gas, the first chemical agent used in modern warfare

  7. Chemical Warfare Agents (4 of 8) • Blister agents • Burn and blister the skin or any other part of the body • Lead to cell damage that begins immediately and becomes manifest 2–24 hours after exposure • Two major groups: • Sulfur mustard and nitrogen mustard • Arsenical vesicants

  8. Chemical Warfare Agents (5 of 8) • Blood agents • Interfere with the ability of the blood to transfer oxygen, resulting in asphyxiation • Can be fatal even in small doses • Must be treated with antidotes (if available) immediately after the poison is ingested

  9. Chemical Warfare Agents (6 of 8) • Irritating agents • Include tear gas, Mace, pepper spray • Riot-control agents

  10. Chemical Warfare Agents (7 of 8) • Incapacitating agents • Include LSD, 3-quinucildinyl benzilate, Agent 15 • Designed to cause hallucinations, confusion, and motor coordination problems

  11. Chemical Warfare Agents (8 of 8) • Nerve agents • Include tabun, sarin, Soman, and Soviet nerve agent • Disrupt nerve-impulse transmission or cause peripheral nervous system effects • Victims lose muscle control and die within minutes from suffocation • Nerve impulses are transmitted in quick succession, and nerves, muscles, and other organs become overstimulated

  12. Toxic Industrial Chemicals and Materials (1 of 2) • Include gases, liquids, and solids • Are used throughout the world for legitimate purposes • May also be used by terrorists

  13. Toxic Industrial Chemicals and Materials (2 of 2) • The more toxic a chemical, the smaller the amount required to cause harm. • Some TIMs are only slightly less toxic than CWA and pose a serious threat to human health and surroundings.

  14. Detection of Chemical Warfare Agents and Toxic Industrial Materials (1 of 7) • Point detection technologies • Rely on a sensor that samples the environment around it • Used to warn individuals about the presence of a chemical agent or to map the boundaries of a contaminated area • Might potentially be used to indicate who has been contaminated and who has not • Currently being used in subways of major cities

  15. Detection of Chemical Warfare Agents and Toxic Industrial Materials (2 of 7) • Photo-ionization detector • Uses an UV light as a source of energy to dislodge electrons from any molecules entering the detector • Does not result in permanent change in the sample • Offers high sensitivity (low ppm or even ppb levels) • Cannot differentiate between chemicals

  16. Detection of Chemical Warfare Agents and Toxic Industrial Materials (3 of 7) • Surface acoustic wave detectors • Have superior selectivity for detecting specific chemical vapors • Detect only certain kinds of molecules and hence identify the class to which a chemical agent belongs • May include a chemical concentrator, which can more readily detect any chemical agents present in the sample

  17. Detection of Chemical Warfare Agents and Toxic Industrial Materials (4 of 7) • Colorimetric tubes • End of tube is broken off and air is sucked through the tube • Material in tube changes color as the reaction proceeds • More than 100 tubes are available

  18. Detection of Chemical Warfare Agents and Toxic Industrial Materials (5 of 7) • Disadvantages of colorimetric tubes • Responders must guess which agent was used so they can pick which tube to use for the test • First responders have to be in the hot zone to sample the air

  19. Detection of Chemical Warfare Agents and Toxic Industrial Materials (6 of 7) • Analytical instruments • Instruments can confirm the presence of specific CWA or TIC at the ppm or ppb level • Interpretation of data requires training in chemistry

  20. Detection of Chemical Warfare Agents and Toxic Industrial Materials (7 of 7) • Standoff detectors • React to distant events or hazards • Can warn of approaching clouds of CWA or TIM • Measure infrared radiation emitted or absorbed from the atmosphere • Are less dependable and more difficult to operate than point detectors

  21. Nuclear Weapons (1 of 5) • Threat is that nuclear weapons may fall into the hands of terrorists through theft or purchase • “Dirty bombs” use conventional explosives to spread nuclear contamination • Nuclear material and warheads from Russia were poorly protected following the Cold War

  22. Nuclear Weapons (2 of 5) • Types of nuclear radiation • Alpha particle: mass of 4 mass units, 2+ charge, identical to helium nucleus • Beta particle: identical to electron, negligible mass, 1- charge • Gamma ray: not made up of particles, no mass • All have sufficient energy to break chemical bonds and disrupt living and nonliving materials upon contact

  23. Nuclear Weapons (3 of 5) • Alpha, beta, and gamma rays are emitted from radioactive nuclei at different speeds and have different penetrating powers • Alpha particles: slowest, travel at 1/10 the speed of light • Beta particles: travel at almost the speed of light • Gamma rays: travel at the speed of light, are more penetrating than X-rays

  24. Nuclear Weapons (4 of 5) • Nuclear reactions • Nuclear reactions occur when a radioactive isotope of an element emits an alpha or beta particle. • Uranium has several radioactive isotopes that spontaneously emit alpha particles. • Spontaneous emission of an alpha particle from a uranium atom results in a different element (transmutation).

  25. Nuclear Weapons (5 of 5) • Radioisotope half-life • The more unstable an isotope, the more rapidly it will emit alpha or beta particles. • The rate of decay is expressed in terms of half-life: the time required for one-half of any quantity of the isotope to decay. • Many radioisotopes of radioactive wastes have long half-lives.

  26. The Harmful Effects of Radiation on Humans (1 of 5) • Why is radiation harmful? • The energy can knock electrons from atoms, forming positively charged ions. • By disrupting the normal workings of cells in living tissues, these ions can produce abnormalities in the genetic material DNA and increase a person’s risk of cancer. • Cells that undergo rapid replication are readily damaged by radiation, which disrupts the mechanism by which they are reproduced.

  27. The Harmful Effects of Radiation on Humans (2 of 5) • Factors influencing radiation damage • Type and penetrating power of the radiation • Location of the radiation (inside or outside of the body) • Type of tissue exposed to the radiation • Amount and frequency of exposure

  28. The Harmful Effects of Radiation on Humans (3 of 5) • Ability to enter the body from the outside environment: alpha < beta < X-rays < gamma • Amount of damage produced internally by radiation: gamma < X-rays < beta < alpha

  29. The Harmful Effects of Radiation on Humans (4 of 5) • Damage caused by radiation depends on three characteristics of the radiation: • The number of disintegrations per second • The radiation’s energy • The radiation’s penetrating power

  30. The Harmful Effects of Radiation on Humans (5 of 5) • Units of radiation • Curie: measures nuclear disintegrations; represents a very high dose of radiation • Rad (radiation absorbed dose): measures the amount of energy released in tissue when it is struck by radiation • Rem: takes into account the potential damage to living tissues caused by ionizing radiation

  31. Detection of Radiation • Geiger counter • Modified cathode-ray tube • Gamma spectrometer • Detects radioisotopes that are gamma emitters • Quantifies the amount of gamma radiation present • Identifies which radioisotopes are present

  32. Biological Weapons (1 of 10) • Biological weapons were banned in 1975 • Biological terrorism: dispersal of disease-producing biological agents within the civilian population • Bioterrorism: “intentional or threatened use of viruses, bacteria, fungi, or toxins from living organisms to produce death or disease in humans, animals, or plants”

  33. Biological Weapons (2 of 10) • Challenges for law enforcement • BWs are odorless, colorless, and tasteless. • They are readily acquired. • They are easily transported. • Small amounts produce major damage. • BWs can be released in a variety of ways.

  34. Biological Weapons (3 of 10) • Challenges for terrorists • It is difficult to control the direction of dispersal. • BWs could infect the terrorists themselves. • Massive quantities may be needed depending on the target (e.g., a water supply). • It might be difficult to avoid detection. • Particles transmitted through the air must be small enough to be absorbed into the respiratory system.

  35. Biological Weapons (4 of 10) • Government efforts to thwart bioterrorism • CDC has fine-tuned its reporting system for suspicious events • DOD has placed a high priority on research and development to detect credible threats • Credible threat: the presence of a biowarfare agent in sufficient quantity to kill people who come in contact with it • Airborne pulsed laser system can scan lower altitudes upwind from a target area • Military is developing a detection unit to be mounted on a vehicle

  36. Biological Weapons (5 of 10) • Detection of biological agents • Finding the agent in the environment • Making a medical diagnosis of the agent’s effects on victims

  37. Biological Weapons (6 of 10) • Challenges in BW detection • Current BW-detection systems are not as reliable as CWA-detection systems • BW detectors are slow to recognize the presence of a pathogen • Detectors have difficulty discriminating between pathogenic and nonpathogenic organisms • Detectors lack adequate sensitivity

  38. Biological Weapons (7 of 10) • Immunoassays • Antibodies can be used to detect the organism of interest. • When a person comes in contact with an antigen or a certain biological agent, the body reacts by developing antibodies.

  39. Biological Weapons (8 of 10) • Anthrax Quick ELISA test • Was first point test approved for detecting antibodies to anthrax • Gives quick, easy-to-interpret results

  40. Biological Weapons (9 of 10) • DNA PCR-based technologies • Can be used to amplify a biological agent’s DNA • Includes the Ruggedized Advanced Pathogen Identification Device (RAPID

  41. Biological Weapons (10 of 10) • RAPID components • Thermal cycler to amplify DNA probes • Highly sensitive fluorescence detector to determine whether the sample contains a BW • RAPID capabilities • Uses hydrolysis with fluorescent dyes attached to test for the presence of specific organisms • Includes a carousel that can take 32 samples • Offers probe kits for 10 different BWs, though all 10 tests cannot be carried out simultaneously

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