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CHAPTER 13 TERRORISM, TOXICITY, AND VULNERABILITY: CHEMISTRY IN DEFENSE OF HUMAN WELFARE

This chapter explores the vulnerability of our environment and infrastructure to terrorist attacks and accidents involving harmful chemicals. It discusses the importance of green chemistry in mitigating terrorist threats, protecting the anthrosphere, and minimizing the risks associated with explosive, flammable, and toxic substances. The chapter also examines the metabolism of toxic substances and the use of xenobiotic substances in detoxication.

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CHAPTER 13 TERRORISM, TOXICITY, AND VULNERABILITY: CHEMISTRY IN DEFENSE OF HUMAN WELFARE

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  1. CHAPTER 13 TERRORISM, TOXICITY, AND VULNERABILITY: CHEMISTRY IN DEFENSE OF HUMAN WELFARE From Green Chemistry and the Ten Commandments of Sustainability, Stanley E. Manahan, ChemChar Research, Inc., 2006 manahans@missouri.edu

  2. 13.1. VULNERABILITY TO TERRORIST ATTACK Chemicals harming people in terrorist attacks and accidents • Explosive mixture of ammonium nitrate (a common agricultural fertilizer) and diesel in the attack on the Alfred P. Murrah Oklahoma City Federal Building in 1995 • Explosives used by suicide bombers in the Middle East • Methyl isocyanate in the industrial chemical accident in Bhopal, India, in 1984 • Almost 200 killed by hydrogen sulfide in natural gas released Chuandongbei natural gas field of southwestern China in December, 2003 Environment susceptible to terrorist attack

  3. Protection With Green Chemistry Green chemistry to mitigate terrorist threats • Uses the safest possible chemicals as safely as possible • Minimizes the accumulation of hazardous chemicals and eliminates hazardous chemical wastes • Better detection of hazardous materials • Effective substitute materials to reduce potential for “resource blackmail” • Sustainable energy sources to reduce “energy blackmail” such as supplies of petroleum and natural gas • Biochemistry and recombinant DNA science to enable the development of better vaccines against pathogenic biological warfare agents and antidotes to chemical and biological toxins

  4. 13.2. PROTECTING THE ANTHROSPHERE Infrastructure • Water purification and delivery • Electricity generation and distribution • Transportation infrastructure Vulnerability due to interconnectivity • Failure of electrical grids Cascading failures on complex networks that operate “close to the edge” so that a relatively small failure can rapidly cascade into a major failure • Electrical grids •Internet systems •“Just in time” manufacturing Chemistry can be applied to infrastructure protection • Example: Production of materials that resist heat and flame

  5. 13.3. SUBSTANCES THAT EXPLODE, BURN, OR REACT VIOLENTLY Explosives

  6. Hazardous Substances (Cont.) Flammable fuels and solvents Corrosive substances • Sulfuric acid Hazardous substances widely used in industry Practice of industrial ecology and green chemistry minimizes threats, producing and using hazardous substances • In minimal quantities • Where needed • As needed, “just-in-time”

  7. 13.4. TOXIC SUBSTANCES AND TOXICOLOGY Table 13.1. Major Target Systems of Toxic Substances Target system Typical toxic responses Respiratory system Emphysema from cigarette smoke, lung cancer from asbestos Skin responses Allergic contact dermatitis, such as from exposure to dichromate; chloracne from exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (“dioxin”); skin cancer from exposure to coal tar constituents Hepatotoxicity (toxic effects) Steatosis (fatty liver), such as from exposure to carbon tetrachloride cirrhosis; (deposition and buildup of fibrous collagen tissue) from excessive ingestion of ethanol; haemangiosarcoma, a type of liver cancer observed in workers heavily exposed to vinyl chloride in PVC plastic manufacture Reproductive system Interference with sperm development by some industrial chemicals, interference with cells involved with egg formation by chemicals such as cyclophosphamide

  8. Table 13.1. Major Target Systems of Toxic Substances (Cont.) Blood Carboxyhemoglobin formation from binding of carbon monoxide to blood hemoglobin, methemoglobinemia consisting of conversion of iron(II) to iron(III) in hemoglobin from exposure to substances such as aniline or nitrobenzene, aplastic anemia from exposure to benzene Immune system effects Immunosuppression from exposure to radiation, hypersensitivity from exposure to beryllium Endocrine system effects Disruption of endocrine function by endocrine disruptors such as bisphenol-A Nervous system Encephelopathy (brain disorder), such as from exposure to lead; peripheral neuropathy from exposure to organic solvents; inhibition of acetylcholinesterase enzyme in nerve function by exposure to organophosphate military poisons Kidney and urinary tract system Nephrotoxicity to the kidney by heavy metal cadmium

  9. Relative Toxicities * LD50 values are in units of mg of toxicant per kg of body mass. # Puffer fish toxin

  10. Relative Toxicities of Insecticidal Parathion and Nerve Gas Sarin

  11. Metabolism of Toxic Substances Xenobiotic substances are those that are normally foreign to living systems Xenobiotic substances, are subject to metabolic processes • Activate to more toxic substance • Convert to less toxic substance (detoxication) Two phases of metabolism of toxic substances Phase I reactions normally consist of attachment of a functional group, usually accompanied by oxidation Phase II reactions consist of binding to an endogenous conjugating agent, typically glucuronide

  12. Phase I Reactions • Most Phase I reactions are microsomal mixed-function oxidase • Reactions • Catalyzed by the cytochrome P-450 enzyme system • Associated with cell endoplasmic reticulum • Occurring most abundantly in the liver of vertebrates

  13. Phase II Reactions

  14. Phase I and Phase II Reactions and Toxicity In some cases, Phase I and Phase II reactions make substances toxic or more toxic • Most human carcinogens are produced metabolically from non-carcinogenic precursors

  15. Dynamic Phase of Toxicity

  16. 13.5. TOXIC CHEMICAL ATTACK Bhopal Accidental release of methyl isocyanate from a chemical manufacturing operation in Bhopal, India, during the night of December 2/3, 1984 illustrates potential for terrorist attack • About 40 tons of methyl isocyanate was released exposing thousands • More than 3000 died, primarily from pulmonary edema (fluid accumulation in the lung) • Immunological, neurological, ophthalmic (eye), and hematological effects Methyl isocyanate is the most toxic of the isocyanates • High vapor pressure • Toxicity to multiple organs • Cross cell membranes • Reach organs far from exposure site

  17. Potential Chemical Agents Carbon monoxide • Has killed thousands accidentally and by suicide • Odorless, no warning Carbon monoxide binding with hemoglobin: O2Hb + CO  COHb + O2 (13.5.1) Effects • 10 ppm: Impaired visual perception and judgment • 100 ppm: Dizziness, headache, and fatigue • 250 ppm: Unconsciousness • 1000 ppm: Rapid death

  18. Potential Terrorist Agents (Cont.) Chlorine (Cl2) Widely used First military poison in World War I Strong oxidizer that forms acids and is especially damaging to respiratory tissue • 10-20 ppm: Acute respiratory tract discomfort • 1000 ppm: Rapidly fatal Hydrogen cyanide, HCN, is a highly toxic gaseous substance with potential for attack through the atmosphere • Also toxic as salts, such as KCN (potential attack through food and water) Cyanide binds with iron in the +3 oxidation state of ferricytochrome oxidase enzyme preventing utilization of O2 leading to rapid death • Antidote is to form iron in the +3 oxidation state from blood hemoglobin to produce methemoglobin that binds with cyanide

  19. Potential Terrorist Agents (Cont.) Hydrogen sulfide, H2S • Colorless gas with a foul, rotten-egg odor • As toxic as hydrogen cyanide and may kill even more rapidly • 1000 ppm: Rapid death from respiratory system paralysis • Nonfatal doses can cause excitement due to damage to the central nervous system; headache and dizziness may be symptoms of exposure

  20. Military Poisons Mustard oil, bis(2-chloroethyl)sulfide: • Vapors penetrate rapidly and deeply into tissue • Tissue damage and destruction well below the point of entry • Blistering gas producing severely inflamed lesions that are susceptible to infection • Likely to be fatal in lungs • Mutagen and possible carcinogen

  21. Nerve Gases Nerve gas organophosphates are the military poisons of most concern Sarin •Tokyo subway attack •Fatal at a dose of only about 0.01 milligrams of Sarin per kilogram of body mass • Single drop through the skin can kill a human

  22. Action of Organophosphate Poisons Organophosphate military poisons act on the nervous system by binding with and inhibiting acetylcholinesterase enzyme

  23. Toxins from Biological Sources Biotoxins • Some of the most toxic substances known Botulinum toxin • From Clostridium botulinum bacteria growing in the absence of oxygen • As little as 1 millionth of a gram can be fatal to a human • In principle, millions of people could be killed by the amount of botulinum toxin carried in a terrorist’s pocket • Binds with nerve terminals causing paralysis of the respiratory muscles and death

  24. Ricin Biotoxin Ricin • Very stable proteinaceous material extracted from castor beans (Ricinus communis) • Injection of an amount about the size of a pinhead can be fatal •Failure of kidneys, liver, and spleen along with massive blood loss from the digestive tract • Hazard lessened by need to inject

  25. 13.6. PROTECTING WATER, FOOD, AND AIR Chemical attack on food supply at a sufficient scale to cause many poisonings is not likely Attack on food supply by microorganisms • Anthrax bacteria through air or contact, such as through mail •Shigella dysenteriae bacteria on food can cause severe dysentery •Salmonella bacteria in contaminated food can cause debilitating digestive tract effects • Although usually not fatal, Salmonella on food have the potential to cause temporary disability

  26. Protection of Water Supplies Central distribution to large numbers of people Susceptible to both chemical and biological attack, though such an attack would be difficult Arsenic in Bangladesh well water shows potential of chemical attack A small amount of botulinus toxin in water could kill many Microorganism contamination of drinking water • Millions have been killed by waterborne cholera, typhoid, and dysentery • In 1993, more than 400,000 people in Milwaukee were sickened and over 50 died from waterborne protozoal Cryptosporidium parvum • In May, 2000, approximately 3000 people were made ill and seven died in Walkerton, Ontario, Canada, from drinking water contaminated with Escherichia coli bacteria that produced shiga toxin by transfer of DNA from Shigella dysenteriae bacteria • Bacteria that could be added deliberately to drinking water include Shigella dysenteriae, Vibrio cholerae, and Yersinia pestis.

  27. Attack Through The Atmosphere Atmosphere as a medium for chemical attack • Means of delivery, such as a low-flying crop-spraying plane would give warning Atmosphere as a medium for biological attack • Anthrax spores from Bacillus anthracis are a particular concern •Variola major, which causes smallpox •Francisella tularensis, which causes tularemia • Viruses that cause viral hemorrhagic fevers, including Ebola, Marburg, Lassa, and Machupo • Bubonic plague caused by Yersinia pestis bacteria that killed tens of millions during the Middle Ages

  28. 13.7. DETECTING HAZARDS Explosives • Residues of TNT, RDX, and PETN explosives detected by sophisticated instruments including ion mobility spectrometers and chemiluminecence sensors • Nuclear quadrupole resonance (NQR) may be useful to detect explosives because it responds to nitrogen, which all major explosives contain • Canine olfactory detection (dog’s nose)

  29. 13.8. GREEN CHEMISTRY TO COMBAT TERRORISM Safe and sustainable green chemistry can help combat terrorism • Hazardous substances that might be stolen or diverted for use in attacks are not made or used in large quantities • Chemical products do what they are supposed to do and are used in minimum quantities • Materials and processes that are likely to result in violent reactions, fires, high pressures, and other extreme conditions are avoided • Potentially hazardous auxiliary substances and flammable materials are avoided • Minimizes energy consumption, thereby reducing energetic, high-temperature processes that might be susceptible to sabotage

  30. Green Chemistry to Combat Terrorism • Biological processes used in green chemistry are carried out under the mild, low temperature, toxic-substance-free, inherently less hazardous conditions conducive to biochemical reactions • Reduces demand on uncertain sources of energy and raw materials controlled by potentially hostile populations that are inherently subject to disruption and blackmail The practice of green chemistry requires exacting process control combined with real-time, in-process monitoring techniques • Conditions that resist sabotage • Passive safety systems that function by default in the event of failure of or deliberate damage to intricate control systems • Example: Making methyl isocyanate on site as needed

  31. 13.9. GREEN CHEMISTRY FOR SUSTAINABLE PROSPERITY AND A SAFER WORLD Reducing poverty, human misery, and hopelessness helps alleviate conditions that promote terrorism People with satisfied material needs able to lead comfortable and fulfilling lives are relatively less likely to commit violent acts •Green chemistry fulfills human needs and makes life more comfortable Prosperity, narrowly defined, has resulted in consumption of increasingly scarce resources and environmental degradation • Quote: “We are past the days when we can trade environmental contamination for economic prosperity; that is only a temporary bargain, and the cost of pollution both economically and on human health is too high.” Green chemistry and the practice of industrial ecology can provide high living standards sustainably

  32. Abundant, Inexpensive, Sustainable Energy is Key

  33. Energy (Cont.) Problems with energy • Energy sources tend to be contentious and competition for them has precipitated past wars • Some major regions of petroleum of petroleum production are breeding grounds for terrorists. The provision of adequate energy independent of such sources would substantially reduce terrorist threats. Abundant, sustainable energy can lead to less terror-prone societies • Production of food through synthesis of fertilizers (particularly by synthetic fixation of atmospheric nitrogen) and for irrigation, cultivation, and reclamation of farmland • Fabricate materials for housing and provide the heating, cooling, and lighting required to make dwellings comfortable • Pump water from abundant sources to more arid regions • Purify marginal sources of water and reclaim water after use • Desalinate water • Provide safe, comfortable, non-polluting transportation systems

  34. Energy (Cont.) Abundant, sustainable energy requires the best practice of green chemistry, green engineering, and industrial ecology • Increased efficiency of energy utilization is a key aspect of providing more usable energy • Solar, wind, and biomass energy are sustainable, renewable energy sources • Fossil fuels will play an interim role, especially if sequestration of greenhouse gas carbon dioxide byproduct can be achieved • Nuclear fission with uranium fuel can provide abundant energy safely with new-generation nuclear reactors and reprocessing of nuclear fuel.

  35. Energy (Cont.) Because wind and solar sources are by nature intermittent and dispersed and often produce electricity in locations far from where it is used, storage and transport of energy are very important • Superconductor or quantum conductor power cables are candidates for transport of electrical energy from source to use • Pumped water hydroelectric storage or high-speed flywheels coupled with electric motor/generators • Elemental hydrogen, H2, will be widely used for energy storage and transport as well as for fuel, moved by pipeline and used to produce electricity directly in fuel cells • Hydrogen from electrolysis of water • Direct photoconversion of water to hydrogen and oxygen may eventually become practical

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