Transcript Title

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
[email protected]
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
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
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
13.3. SUBSTANCES THAT EXPLODE, BURN, OR REACT
VIOLENTLY
Explosives
H
H C ONO2
H C ONO2
H C ONO2
H
CH3
O2N
NO2
Ni trogl yceri n
O2N
N
N
N
NO2
NO2
2,4,6-Tri n itrotolu e n e (TN T)
ONO2
HH C H H
NO2
O2NO C
C
C ONO2
HH C H H
ONO2
1,3,5-Tri n itro-1,3,5tri azacycl oh exan e (RDX)
Pe n taeryth ri tol
te tran itrate (PETN)
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”
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
Allergic contact dermatitis, such as from exposure
to dichromate; chloracne from exposure to 2,3,7,8tetrachlorodibenzo-p-dioxin (“dioxin”); skin cancer
from exposure to coal tar constituents
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
Interference with sperm development by some
industrial chemicals, interference with cells
involved with egg formation by chemicals such as
cyclophosphamide
Skin responses
Hepatotoxicity (toxic
effects)
Reproductive system
Table 13.1. Major Target Systems of Toxic Substances (Cont.)
Blood
Immune system effects
Endocrine system effects
Nervous system
Kidney and urinary tract
system
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
Immunosuppression from exposure to radiation,
hypersensitivity from exposure to beryllium
Disruption of endocrine function by endocrine
disruptors such as bisphenol-A
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
Nephrotoxicity to the kidney by heavy metal
cadmium
Relative Toxicities
Substance
DEHP
Ethanol
Sodium chloride
Malathion
Chlordane
Heptachlor
Parathion
TEPP
Tetr odotoxin#
Inland taipan venom
TCDD5
Botulinus toxin
Approximate LD 50*
– 105
– 4
– 10
– 3
– 10
– 2
– 10
–
– 10
–
– 1
–
– 10 -1
–
– 10 -2
– -3
– 10
–
– 10 -4
–
– 10 -5
* LD50 values are in units of mg of toxicant per kg of body mass.
# Puffer fish toxin
Toxicity rating
1. Practically nontoxic
> 1.5  10 4 mg/kg
2. Slightly toxic, 5  10 3
to 1.5  10 4 mg/kg
3. Moderately toxic,
500 to 5000 mg/kg
4. Very toxic, 50 to
500 mg/kg
5. Extremely toxic,
5 to 50 mg/kg
6. Supertoxic,
< 5 mg/kg
Relative Toxicities of Insecticidal Parathion and Nerve Gas Sarin
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
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
Phase II Reactions
Xenobiotic
compound,
often Phase
1 reaction
product
Carboxyl:
O
C O
Hydr oxyl:
OH
F,Cl,Br,I
C
Epox ide :
O
C
H
Amino:
N
H
+
Endogenous
conjugating
agent
Halogen:
Functional groups that react
with a conjugating agent
Glucuronide conjugate
O
C OH
O
OH
X R
HO
OH
Conjugation
product
• Higher polarity
• Greater water
solubility
• More easily
eliminated
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 noncarcinogenic precursors
Dynamic Phase of Toxicity
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
H
H C N C O
H
Me thyl i s ocyanate
• 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
Potential Chemical Agents
Carbon monoxide
• Has killed thousands accidentally and by suicide
• Odorless, no warning
N
N
N O2 N
Fe2 +
N
N
Fe2 +
N
N
He mogl obi n
mol e cu l e
Hb
+ O2
He mogl obi n
mol e cu l e
O2Hb
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
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
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
Military Poisons
Mustard oil, bis(2-chloroethyl)sulfide:
H
Cl C
H
H
H
C S C
H
H
H
C Cl
H Mu s tard oil
• 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
Nerve Gases
Nerve gas organophosphates are the military poisons of most concern
H O
H C P F
H
H C
O
HN P
H
O
H
H
H
O
H C C C H H CH C
H
H
H H H
S ari n
C N
H
C H
H
Tabu n
H
H3C C CH3
O
O P F
O
H3C C CH3
H
Dii sopropylph os ph oflu oridate
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
Action of Organophosphate Poisons
Organophosphate military poisons act on the nervous system by
binding with and inhibiting acetylcholinesterase enzyme
Inh i bite d e nz yme
S e ri n e s ide -ch ain on
e n z ym e active s ite
CH3
H C O
CH3
H3C
F
P O +
O
C CH3
H
H H O
N C C N
H C H
OH
Di is opropyl ph os ph oflu ori date
H H O
N C C N
H C H
CH 3
H C O P O
CH 3 O
H3C C CH3
H
(13.5.2)
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
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
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
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.
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
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)
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, hightemperature processes that might be susceptible to sabotage
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
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
Abundant, Inexpensive, Sustainable Energy is Key
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
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.
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