Chemical Agents of TerrorismHistory and Basic Awareness

Overview• Introduce various types of chemical warfare

agents and chemical weapons of opportunity• Introduce basic characteristics and history of

agents • Discuss issues related to toxicity and

exposure• Discuss past and potential use as a weapon

What makes a good chemical weapon?

• Cheap and easy to make (or obtain)

• Easily delivered/distributed

• Persistence in the environment (including clothing!)• high b.p., low v.p. increase persistency

• Little to no odor, taste

• Resistance to decontamination

What makes a good weapon better?

• “Thickeners” have been used in the past that increase persistency and skin uptake

• Combining different agents and/or chemicals into one weapon• Solvents can enhance skin uptake (i.e. DMSO)

• Environmental conditions upon release• Wind, temperature, rain

(… not to mention things that we haven’t thought of yet!)

Methods of Delivery

•Artillery and binary weapons, including IEDs•Point-sources: canisters, spray tanks•Manned/unmanned aircraft•Packages/mail

•PA man found with spray device mounted in car•MI man added nicotine solution to ground beef

(again, not to mention things that we haven’t thought of yet!)

Sometimes the THREAT of release is enough to achieve the terrorist purpose!

Choking/Lung-Damaging Agents

•Chlorine (CL)•Phosgene (CG), Diphosgene (DP)

•Some gases, some liquid•Some are common industrial materials

Choking Agents•Germany deployed CL, CG, and DP in 1915-1916•CL/CG caused ~80% of deaths from chemical agent exposure in WW I•Perfect for trench warfare as they are heavier than air and tend to sink

•CL is commonly manufactured chemical, used in bleach, paper production, swimming pools, drinking and wastewater treatment•CG commonly used to make plastics and pesticides•CL has large potential as industrial weapon of opportunity

Toxicity/Exposure – Choking Agents

•Severe irritants to skin, eyes, nose, throat, and lungs•Can cause corrosive effects in moist tissue•Can lead to severe pulmonary edema (and death if not treated)

•Routes of exposure: breathing, eye and skin contact•Will tend to be found in low-lying areas•CL is not very persistent in environment, CG/DP degrade more slowly in air

Weaponization – Choking Agents

“Blood” Agents•Hydrogen cyanide (AC)

•Cyanogen chloride (CK)

•Arsenic-based: arsine (SA)

•Gases or liquids

•CN compounds are ubiquitous in food and industry (CN salts very commonly used)

“Blood” Agents

•Napoleon considered use on bayonets•Used in combat in WW I by French; by Nazis in WW II•Intel from 2003 led DHS to issue fact sheet on “cyanide devices”

•CN used in chemical and plastics production, metallurgy, electroplating•CN found naturally in some foods; cigarette smoke•CN salts soluble in water, potential threat to water supplies

Toxicity/Exposure – “Blood” Agents

•All capable of preventing proper oxygen flow from blood •CK more effective at lower concentrations, also respiratory irritant•SA mainly confined space threat

•Routes of exposure: breathing, skin and eye contact, in food/water•Gaseous forms tend to dissipate quickly, liquid forms can persist longer•AC rises, CK sinks in air

Weaponization – “Blood” Agents

DHS Information Bulletin - September 2003

► Large amounts of CN salts and acids found in

Tyler, Texas in Nov 2003; presumed to be for large

“cyanide bomb”

Blister Agents

•Mustard agents: sulfur- (H or HD, “mustard gas”) or nitrogen-based (HNx)

•Arsenic-based agents: Lewsite (L)

•Phosgene oxime (CX)

•Liquids

•“vesicants”: blister-causing

Dep’t of Defense

Blister Agents•Sulfur mustards first used by Germans in 1917•Iraq made extensive use of mustard during Iran-Iraq war of 80s•Stockpiles of various vesicants still kept in US today

•HNs were once used as chemotherapy agents•L/H used strictly as warfare agents

Exposure/Toxicity – Blister Agents

•Produces blisters and corrosion of skin, eyes, respiratory tract•Lethality from exposure low; but treatment of casualties is labor- and resource-intensive•L/HNs have more systemic effects

•Routes of exposure: breathing, contact•Tend to be more persistent, depends on ambient temperature•Tends to sink as liquid or gas•L/CX are much faster acting

Weaponization – Blister Agents

• Mortars, artillery shells, rockets, land mines can be filled with liquid agent that aerosolizes upon detonation

• Aerial bombs used during Iraq-Iran war

• During WW I, night-time bombings would cause casualties after the sun rose due to mustard’s persistence, low volatility in colder temperatures

Nerve Agents•“G-Agents”: Tabun (GA), Sarin (GB), Soman (GD), Cyclosarin (GF)

•“V-Agents”: VX

•Colorless, odorless liquids when pure

•Related compounds commonly used as insecticides

Nerve Agents

•Germans produced many nerve agents in WW II, but never used•Iraq believed to have produced GB/GF•Japanese cult uses GB in 1994 and 1995•Exist today in US stockpile

•“Parent compounds” of organophosphorus pesticides•Toxicity well studied, extremely toxic via all routes of exposure•Developed in 40s as pesticides, shared with Army; no commercial use now

Exposure/Toxicity – Nerve Agents

•Extremely toxic: GA/GB less toxic, VX/GD more toxic•Disrupt nervous system function (via inhibition of acetylcholinesterase)•Death can occur within minutes of exposure

•Routes of exposure: breathing, ingestion, skin and eye contact, taken up through skin•VX tends to be more persistent than G-agents•All but GB tend to rise in air

Exposure/Toxicity – Nerve Agents

•G-Agents•Little to no odor when pure•“Thickened” agents more persistent, effective•Tend to be more viscous and “sticky”•Sink in air; lower tendency to volatilize

•V-Agents•Little to no odor when pure•“Thickened” agents more persistent, effective•Absorbed into porous material•Also sink in air but are extreme danger in confined spaces

Weaponization – Nerve Agents

Weaponization – Nerve Agents

Kyodo News International, Inc.

● Sarin (GB) placed in lunch boxes and soft-drink containers, punctured with umbrellas by terrorists before leaving train

● Attack scheduled to coincide with rush hour

● 12 killed, thousands impacted

Incapacitating/Riot-Control Agents

•Riot-Control Agents: tear agents (CS,CN), pepper spray, vomiting agents (DA, DC, DM), chloropicrin (PS)•Psychedelics (BZ, LSD, psilocybin, MDMA, PCP, Ibogaine)•CNS Stimulant (amphetamines, strychnine)•CNS Depressants (barbiturates, opioids, benzodiazepines)•Common therapeutics, law enforcement tools, and drugs of abuse

Incapacitating/Riot-Control Agents

•30 R-C agents used during during WW I•Used in civil disturbances in late 1960s•CS used extensively in Vietnam•Used in Waco in 1993

•Long history of use of incapicitants•Studied in 1950-60s by military/gov’t•BZ only weapon that was standardized and stockpiled by Army•Used in Moscow in 2002

Exposure/Toxicity – Riot-Control Agents

•R-C agents have quick onset, brief duration, and high “safety ratio”•R-C agents are irritants of eyes and respiratory tract, can also cause sneezing and vomiting

•Incapacitating agents have CNS effects after easily passing blood-brain barrier•Interfere with higher mental functions•Longer-lasting effects

Weaponization – Riot-Control Agents

•Incapacitating agents could be used as aerosol sprays, in food/water, gases

•Riot-control agents generally used as gases/aerosols

•personal use consists of Mace (CN) or pepper spray (capsaicin)

Comparison of Selected Chemical Agent Vapor Toxicity

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CL CG AC H GB VX BZ CS

Ct50(mg-min/m3)

Biologically-Derived Toxins

•Plant (ricin, abrin)•Marine (saxitoxin, tetrodotoxin)•Animal venom•Bacterial (botulinum, tetanus, staphylococcal enterotoxins)

•Fungal (T-2 mycotoxins)

Exposure/Toxicity - Toxins

•Often accompanied by latency period•Neurotoxins affect CNS or PNS•Membrane-damaging toxins can harm tissues and/or organs•Biomediator toxins induce body to produce excessive chemicals

•Routes of exposure: breathing, ingestion•Most toxins not dermally active (except T-2 mycotoxins)•Effects range widely from incapacitating to lethal effects and vary upon route of exposure

Bio-Toxins as Weapons

•Use of T-2 mycotoxins reported in Laos (“yellow rain”), Kampuchea, and Afghanistan in 70s•US maintained bio-toxin program with interest in ricin (“Compound W”)•Bulgarian defector killed by ricin “umbrella weapon” in 1978

•Plot in MN in 1991to use ricin and DMSO solvent as assassination tool

•Ricin found in London apartment in January 2003, SC post office in October 2003, and Dirksen Senate Office Building in February 2004

Weaponization - Toxins

• Likely route via inhalation of aerosols or powders

• Contamination of water supplies possible for some toxins

• Most severe effects to be seen via contaminated food, or bites and stings

Chemical Weapons of Opportunity

•Ammonia•Acids (nitric, sulfuric, HCL, HF)•Isocyanate compounds•Pesticides•Other “extremely hazardous substances”•Delayed effect toxins

Ammonia and Acids•Ammonia commonly used as fertilizer (“anhydrous ammonia”)•Used to make textiles, plastics, explosives, cleaning products, paper•High potential for opportunistic use

•Acids used for a wide variety of manufacturing processes•Acids can be combined with CN salts to make cyanide gas•Ammonia and acids can be severe irritants to lungs, eyes, skin, throat

Methyl Isocyanate

•Used to produce carbamate pesticides•Accidental exposure at Union Carbide plant in Bhopal, India in 1984•Killed over 3,000; left over 150,000 with adverse health effects

Delayed-Effect Chemical Toxins

•No real immediate health effects•Greater psychological effect right away•Long-term health problems could be an issue•Unlikely opportunistic weapons

•Dioxins•PCBs/PBBs•Organic mercury compounds•Compounds that have minor effects on behavior and/or cognition

Opportunistic Weapons

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Useful References and Resources

• US Army, Medical Aspects of Chemical & Biological Warfarehttp://www.nbc-med.org/SiteContent/HOmePage/WhatsNew/MedAspects/contents.html

• eMedicine Emergency Medicine for Warfare Agentshttp://www.emedicine.com/emerg/WARFARE__CHEMICAL_BIOLOGICAL_RADIOLOGICAL_NUCLEAR_AND_EXPLOSIVES.htm

• Centers for Disease Control and Prevention Bioterrorism Resourceshttp://www.bt.cdc.gov

• National Library of Medicine Chemical Warfare Agents Resourceshttp://sis.nlm.nih.gov/Tox/ChemWar.html