a preliminary analysis of the nerve agent attack of august

A Preliminary Analysis of the Nerve Agent Attack of August 21, 2013 Against

Unprotected Civilians in the Suburbs of Damascus, Syria

17.477 The Politics and Technology of Weapons of Weapons Systems

Massachusetts Institute of Technology Theodore A. Postol

Professor of Science, Technology, and National Security Policy 1

The Nerve Agent Attack of August 21, 2013 in Damascis, Syria

Political Reasons Why Assailants in Syrian Civil War Might Want to Execute Chemical Attacks

Political Reasons Why Assad Government Might Want to Execute Chemical Attacks

Terrifying Causes people to leave

Does not require massive artillery attacks or ground operations to clear an area

Political Reasons Why Rebel Groups Might Want to Execute Chemical Attacks

Increases the likelihood of international intervention on behalf of the rebels Reduces the strength of rebel factions that could complete for power after

the collapse of the Assad regime Settles old scores between ethnically different groups

2The Nerve Agent Attack of August 21, 2013 in Damascis, Syria

A Man and Baby in Iraq in 1988. Investigators Found Evidence of a Nerve Agent in Soil in 1992


Dead Pigeons Photographed After the Nerve Agent Attack in Damascus Suburb on August 21, 2013


The Attack Was Much Larger than Has Been Reported in the Press

1. Analysis of the Munitions Debris Left from the Attack Suggests that the Attack Was Roughly Ten Times Larger in Terms of the Weight of Delivered Sarin Than Has So Far Been Reported by the Press.

2. This Error Appears to be Due to a Misidentification of How the Munitions Worked

3. It Appears that Each Launched Munition Contained About 100 lbs of Sarin (50 Liters) Rather than the 10 lbs (5 Liters) Widely Reported by the Press


How Explosives Can Be Used to Dispense a Chemical Agent


Explosive Dispersion of Sarin Liquid (Below is Water) Creates Small Droplets That Quickly Evaporate in Air of Fall to the Ground Creating a

Thin Layer of Liquid that Then Quicly Evaporates

3m

10,000 f/s


Efficiency of Dispersion

Depends on: 1. Ratio of the Weight of Explosives to Dispersant 2. Temperature of Explosive Gasses 3. Geometrical Method of Dispersion 4. Fragility of Dispersant Molecules to Heat and Shock 5. Thickness of Casing or Strength of Enclosing Plug


Efficiency of Dispersion Mechanisms Can Vary Strongly with Method


The Munition Used for Dispersing the Chemical Agent in the Attacks in Damascus on August 21 Delivered

a Far Larger Dose of Sarin than Reported by the Press


Estimated Dimensions and Payloads of Munitions Used in Sarin Gas Attack on Suburb of Damascus (August 21, 2013)

Attack Takes Place at About 2:30 AM, Atmospheric Conditions Strongly Stable

31 cm

125 cm

12.5 cm

Canister VolumeMisreported by Press

5.7 to 6.7 Liters

Rocket MotorExit Nozzle

StabilizingRing

RocketMotor

Rocket MotorFins

CanisterFront Wall

Canister forHolding Chemicals(About 50 Liters,

10 Times Larger ThanReported in the Press)

65 cm

35 cm

Contact orAcceleration Fuse

Explosive forDispensing Chemicals

11 cm

BlastContainment

Plate


Mechanism for Tearing Open Payload Container Used in Sarin Gas Attack on Suburb of Damascus (August 21, 2013)


31 cm

125 cm

12.5 cm

Canister VolumeMisreported by Press

5.7 to 6.7 Liters


StabilizingRing

RocketMotor

Rocket MotorFins

CanisterFront Wall

Canister forHolding Chemicals(About 50 Liters,

10 Times Larger ThanReported in the Press)

35 cm

Contact orAcceleration Fuse

Explosive forDispensing Chemicals

11 cm

BlastContainment

Plate

Explosion Partially Contained by Blast Plate Tears the Front End of

the Chemical Canister Open Materials Are Then Thrown Upward into the Air Around the Impact Point


Canister Assembly of Munition Used in Sarin Gas Attack on Suburb of Damascus (August 21, 2013)


Front Plate of Canister Section

Filling or Venting Stations for Chemicals and Explosive Gases?

Adapter for Connection to Rocket Motor

Second Welded Plate –Possibly Designed to Take Pressure from Expanding Explosive Gasses


Front End of Canister Assembly of Munition Used in Sarin Gas Attack on Suburb of Damascus (August 21, 2013)


Front Plate of Inner Canister Section Where Explosive

is Contained

Adapter for Connection to Rocket Motor

Note That the Front of the Canister is Bent and Aligned

with the Direction of the Camera

Edge of Metal Attached to

Front Flange


Rear Flange of Chemical Container

Chemical Filling Holes

Front Flange of Chemical Container

Hole for Explosive Detonator Associated

with the Fuse


Estimated Dimensions and Payloads of Munitions Used in Sarin Gas Attack on Suburb of Damascus (August 21, 2013)


31 cm

5700 to 6000 cubic cm

125 cm

11 cm


StabilizingRing

Rocket MotorFins

RocketMotor

Internal CanisterIdentified by Press

CanisterFront Wall

60 cm

12.5 cm

Canister Volume About

Chemical Canister SectionAdaptor Plate for

(Possible Holes for Filling and/or Dispensing Cemicals)

f H ldi Ch i l


Type of Chemical Munitions Canister Likely Used in Sarin Gas Attack on Suburb of Damascus (August 21, 2013)



Munition Used in Sarin Gas Attack on Suburb of Damascus (August 21, 2013)


RocketMotor

Chemical CanisterBroken Off

Tail Section

Reinforcing Tail-Fin Ring 18


Munition Used in Sarin Gas Attack on Suburb of Damascus (August 21, 2013)


Expended and Impact-Damaged

Rocket Motor

Partially Bent and Crushed Explosive

Canister

Tail SectionReinforcing Tail-Fin Ring

Rocket Motor Nozzle

Adapter Section for Connecting Rocket Motor and Canister and for

Filling and/or Dispensing Chemicals


Rocket Nozzle and Rear Fin Assembly of Munition Used in Sarin Gas Attack on Suburb of Damascus (August 21, 2013)


Rocket Motor Nozzle


Back End of Canister Assembly of Munition Used in Sarin Gas Attack on Suburb of Damascus (August 21, 2013)


Attachment RingFor Rocket Motor


Location of Main Gas Attack on Suburb of Damascus (August 21, 2013)


��

��


�

��

�

Blown Off Skin of 50 Liter Chemical

Container

Carcass of Explosive Gas

Dispenser Rocket Motor

Casing



Container


Dispenser

Rocket Motor Casing



Dispenser


Container

Rocket Motor Casing


Toxicity of Sarin


Sarin – Organophosphate Molecule

[(CH3)2CHO] CH3P(O)F



[(CH3)2CHO]

(CH3)

POF



[(CH3)2CHO]

(CH3)

POF

The POF piece of the Sarin molecule is extremely stable, and tends to persist (potentially for years) in the environment.


Characteristics of Nerve Agents Nerve agents –

examples are Sarin (GB), Tabun (GA), Soman (GD), and VX. These agents work by interfering with cholinesterase, the enzyme that breaks down acetylcholine after its release by the nervous system. Symptoms of nerve-agent poisoning include difficulty in breathing, sweating, nausea, vomiting, staggering, coma, and convulsion, followed by cessation of breathing and death. When inhaled, nerve agents are lethal in concentrations ten times smaller than choking, blood, or blister agents; like mustard, they are readily absorbed through the skin. They vary in consistency from sarin, which is watery and volatile, to VX, which has the viscosity and volatility of motor oil. Nerve agents were first discovered by the Germans shortly before World War II. Production costs are low--as little as $10 to $20 per kilogram of agent.


Nerve Agents Inhibit the Destruction of Acetylcholine (Ach), Leaving the Sodium (Na) Gates Open

Nerve Agents Interfere with Cholinesterase. Cholinesterase is an Enzyme that Breaks Down Acetylcholine After it is Release by the Nervous System.

Sodium(Na) Gate

Sodium (Na) Gate Receptors Open when ACh binds with the receptors. The firing is achieved by from Sodium passing through the gate during the ACh binding process. If ACh is not broken down by Cholinesterase, it remains present in the synapse, and the Sodium Gates continue to fire.


Symptoms of Sarin Poisoning (In Order of Appearance)

1. Runny nose 2. Bronchial secretions 3. Tightness in the chest 4. Dimming of vision 5. Pin-Point Pupils 6. Drooling 7. Excessive perspiration 8. Nausea, Vomiting 9. Involuntary defecation, urination 10. Muscle tremors, convulsions 11. Coma 12. Death by Asphyxiation

33


Symptoms of Sarin Poisoning (As They Appear in Victims)

Pinpoint Pupils Excessive Sweating and Trouble Breathing

Foaming at Mouth and Nostrals – Death by Sophocation 34The Nerve Agent Attack of August 21, 2013 in Damascis, Syria

Symptoms of Sarin Poisoning (As They Appear in Victims)


Why Choose Sarin Over VX for a Gas Attack Against a Civilian Population?

1. Sarin Has the Density of Water.

2. Sarin Evaporates at the Same Rate as Does Water (Hours or Less).

3. Sarin Has Nearly the Same Viscosity as Water.

4. Sarin Thus Creates a Lethal Gas-Inhalation Threat Very Fast, Before Populations Can Recognize Its Presence and React.

5. VX Does Not Evaporate Quickly (Takes Many Days).

6. VX Has a Viscosity Similar to that of Motor Oil.

7. VX Will “Persist” Long After and Attack, Making Verification of Chemical Attack Much Easier.


Properties of Various Chemical Warfare Agents.

Respiratoryb Percutaneousc

Agent

Volatility (mg/m3)a

Lethal Dose LCt50

(mg·min/m3)

Incap. Dose ICt50

(mg·min/m3)

Lethal Dose LCt50

(mg·min/m3)

Tabun (GA) 610 400 300 40,000

Sarin (GB) 22,000 100 75 15,000

Soman (GD) 3,900 100 75 10,000d

VX 10 100 50 1,000d

Mustard (HD) 920 1500 200 10,000

Phosgene (CG) 4,000,000 3200 1600 n.a.

Hydrogen Cyanide 1,100,000 5000e 2000e n.a. a Mass of vapor per cubic meter of air at 25° C. For comparison, the volatility of water at 25° C is 23,000 mg/m3. b Median lethal and incapacitating dosage for unprotected men breathing at a rate of 10 liters/min. c Median lethal dosage for men in ordinary combat clothing. d SIPRI, CB Weapons Today, pp. 42-43. e Depends on concentration; values given here are for a concentration of 100 mg/m3 LCt50 = 2000 mg-min/m3 at a concentration of 200 mg/m3. Source: Military Chemistry and Chemical Compounds (Washington, DC: Department of the Army, FM 3-9, October 1975). 37The Nerve Agent Attack of August 21, 2013 in Damascis, Syria

Illustration for Classroom of the Toxicity Level of Sarin Nerve Agent.



Assume release in this room – Room Dimensions Room Volume ~ 3m high � 4m wide � 8m wide = 96 m3 1 gram of Nerve Agent Released in Room Volatility leads to density of 0.01 gram/m3 (10 mg/m3) Hence, Roughly ten to Twenty minutes of breathing while in the room will lead to death.



One cm3 of Sarin ~ One Gram ~ 1000 milligrams.


Current Information About Areas that Were Hit


Ethnic and Political Map of Areas of Damascus Attacked with Sarin Attack of August 21, 2013


Location of Main Gas Attack on Suburb of Damascus (August 21, 2013)


Presidential Palace

Area Hit with Munitions

1 Mile


Size of Damascus Gas-Attack Area Projected onto the City of Boston, MA (August 21, 2013)



1 Mile


Size of Damascus Gas-Attack Area Projected onto the City of Washington, DC (August 21, 2013)



1 Mile


Area of Main Gas Attack on Suburb of Damascus (August 21, 2013) Attack Takes Place at About 2:30 AM, Atmospheric Conditions Strongly Stable

1 Mile


Buildings in Area of Main Gas Attack in Damascus (August 21, 2013) Attack Takes Place at About 2:30 AM, Atmospheric Conditions Strongly Stable

100 Yards



100 Feet



Building in Area Attacked with Sarin


Estimate of Possible Population Densities in Built Up Areas Where Munitions May Have Fallen (August 21, 2013) Attack Takes Place at About 2:30 AM, Atmospheric Conditions Strongly Stable

Assumptions for Guestimate: Building ~ 100ft × 100ft = 10,000 ft2 ? Roughly 10 Apartments of 1000 ft2 each per floor? 4 Occupants per Apartment = 40 Occupants per floor? 4 to 5 Stories = 160 – 200 Occupants? One Munition ~ 50 kg (100 lbs) Sarin (About 50 Quarts) Cloud ~ 10 m × 10 m× 10 m = 1000 m3, 50 kg = 50 × 106 milligrams Density in Initial Cloud ~ 50,000 mg/m3 30 minute Cloud Grows to About 100 m on a Side and 20 meters in the vertical direction Volume of Cloud ~ 100 m × 100 m× 20 m = 1,000,000 m3 5 × 107 / 1× 106 ~ 50 mg/m3 Lethal Dose ~ 100 mg × m3 / min


Effects of Weather, Air-Motion, Particle Size,

and Other Factors on the Effectiveness of Chemical and Biological Agents


Factors Affecting Aerosol and Solid-Particle Deposition Regions

ys

Cloud of Solid-Particles or Liquid-Droplets

z

y

x


Small Scale Air Motion Carries the Gas and Small Droplets

Air Can Vertically Rise Due to Hot Surfaces that are Illuminated by the Sun Air Can Also Settle if there is Efficient Radiation Cooling at Night

�


Unstable Meteorological Conditions

Bright and Sunny Days


Particle and Gas Dispersal Paths in Unstable Meteorological Conditions

Bright and Sunny Days


Formation of Mixed Layer Near the Ground

Cool Dry Nights with Little or No Wind and Cloud Cover



ys


z

y

x


Estimating Inhalation Doses from Chemical/Biological Attacks

� � � �MaterialMassDose=Concentration Time TimeVolume

Q x Q xt

xx y z y zt

��

� � ��

g g

3mg minDose=Concentration Time

m�

gg

For example:

3mg5 minutes in 20 leads to 50% Fatalitiesm



×

× ×


The Gaussian Plume Model for Predicting Aerosol Dispersion

� � � �2 2

2 22 2, y z

y h

y z

Q xC x y e e

U

�

� �

�

Where C(x,y) is the time-integrated ground-level concentration of agent in mg s/m3 Q(x) is the weight of material released (mg) �y and �z are the cross-wind and vertical standard deviations of the concentration distribution at the downwind distance x from the release point. U is the effective wind speed (m/s) h is the height of the cloud-center (m)


The GaussianPlume Model for Predicting Aerosol Dispersion

� �1 y

y y yf I x x�

��

� �1 zz z zf I x x � ��

Where I, �, and � are constants that vary with the atmospheric stability and surface roughness f depends on the length of time of the release f � 1 for evaporation of a puddle and f � 0.3 for explosively generated aerosol clouds

60


The Gaussian Plume Model for Predicting Aerosol Dispersion

Parameters of Gaussian plume Aerosol Dispersal Model for

Unstable, Neutral, and Stable Meteorological Conditions

Atmospheric Stability Condition

Rural Iy �y �y Iz �z �z

Unstable 0.30 0.0001 -0.5 0.20 0.00 0 Neutral 0.15 0.0001 -0.5 0.10 0.0015 -0.5 Stable 0.10 0.0001 -0.5 0.05 0.0003 -1

Atmospheric Stability Condition

Urban Iy �y �y Iz �z �z

Unstable 0.33 0.0004 -0.5 0.22 0.001 0.5 Neutral 0.19 0.0004 -0.5 0.13 0.0003 -0.5 Stable 0.14 0.0004 -0.5 0.07 0.0015 -0.5


Factors Affecting Aerosol and Solid-Particle Deposition Regions Source: 1000 m3 (10×10×10 m); 100 kilograms, 100% Ingestion Efficiency

0 1000 2000 3000 4000 5000 60000

50

100

150

200

250

300

350

400

450

500Unstable Rural Cloud Dispersal Dimensions

Cloud Downwind Range (m)

Cros

s Wind

Widt

h an

d Ve

rtica

l Heig

ht (m

)

0 1000 2000 3000 4000 5000 60000

100

200

300

400

500

600

700

800

900

1000Dispersal in Unstable Rural Conditions


Tota

l Dos

e as

Clou

d Pa

sses

Vict

im (m

g)

0 1000 2000 3000 4000 5000 60000

50

100

150

200

250

300

350

400

450

500Neutral Rural Cloud Dispersal Dimensions


Cros

s Wind

Widt

h an

d Ve

rtica

l Heig

ht (m

)

0 1000 2000 3000 4000 5000 60000

100

200

300

400

500

600

700

800

900

1000Dispersal in Neutral Rural Conditions


Tota

l Dos

e as

Clou

d Pa

sses

Vict

im (m

g)

0 1000 2000 3000 4000 5000 60000

50

100

150

200

250

300

350

400

450

500Stable Rural Cloud Dispersal Dimensions


Cros

s Wind

Widt

h an

d Ve

rtica

l Heig

ht (m

)

0 1000 2000 3000 4000 5000 60000

100

200

300

400

500

600

700

800

900

1000Dispersal in Stable Rural Conditions


Tota

l Dos

e as

Clou

d Pa

sses

Vict

im (m

g)

0 1000 2000 3000 4000 5000 60000

50

100

150

200

250

300

350

400

450

500Unstable Urban Cloud Dispersal Dimensions


Cros

s Wind

Widt

h an

d Ve

rtica

l Heig

ht (m

)

0 1000 2000 3000 4000 5000 60000

100

200

300

400

500

600

700

800

900

1000Dispersal in Unstable Urban Conditions


Tota

l Dos

e as

Clou

d Pa

sses

Vict

im (m

g)

0 1000 2000 3000 4000 5000 60000

50

100

150

200

250

300

350

400

450

500Neutral Urban Cloud Dispersal Dimensions


Cros

s Wind

Widt

h an

d Ve

rtica

l Heig

ht (m

)

0 1000 2000 3000 4000 5000 60000

100

200

300

400

500

600

700

800

900

1000Dispersal in Neutral Urban Conditions


Tota

l Dos

e as

Clou

d Pa

sses

Vict

im (m

g)

0 1000 2000 3000 4000 5000 60000

50

100

150

200

250

300

350

400

450

500Stable Urban Cloud Dispersal Dimensions


Cros

s Wind

Widt

h an

d Ve

rtica

l Heig

ht (m

)

0 1000 2000 3000 4000 5000 60000

100

200

300

400

500

600

700

800

900

1000Dispersal in Stable Urban Conditions


Tota

l Dos

e as

Clou

d Pa

sses

Vict

im (m

g)

U=1 m/s U=1 m/s U=5 m/s U=5 m/s

U=2 m/s U=2 m/s U=1 m/s U=1 m/s

U=5 m/s U=5 m/s U=2 m/s U=2 m/s

Cross-Range Disperson Distance

Vertical Dispersion Distance












Bright and Sunny Day Wind Speed About 2 m/s

~100 mg Kills Resting Adult Male,

0 1000 2000 3000 4000 5000 60000

50

100

150

200

250

300

350

400

450

500Unstable Urban Cloud Dispersal Dimensions


Cros

s Wind

Widt

h an

d Ve

rtica

l Heig

ht (m

)

0 1000 2000 3000 4000 5000 60000

100

200

300

400

500

600

700

800

900

1000Dispersal in Unstable Urban Conditions

Cloud Downwind Range (m)To

tal D

ose

as C

loud

Pass

es V

ictim

(mg)

Range at Which Munition delivers

a Lethal Dose (400m, 800 seconds or About 12 to 13 minutes)



Cool Dry Nights with Little or No Wind and Cloud Cover Wind Speed About 2 m/s

~100 mg Kills Resting Adult Male,

0 1000 2000 3000 4000 5000 60000

50

100

150

200

250

300

350

400

450

500Stable Urban Cloud Dispersal Dimensions


Cros

s Wind

Widt

h an

d Ve

rtica

l Heig

ht (m

)

0 1000 2000 3000 4000 5000 60000

100

200

300

400

500

600

700

800

900

1000Dispersal in Stable Urban Conditions


Tota

l Dos

e as

Clou

d Pa

sses

Vict

im (m

g)

Range at Which Munition delivers a Lethal Dose

(2300m, 1150 seconds or About 19 to 20 minutes) 64The Nerve Agent Attack of August 21, 2013 in Damascis, Syria

Ground-Level Release of Sarin in Stable Dispersal Conditions

(2 m/s Wind Speed)


Ground-Level Release of 1000 Kilograms Sarin in Stable Dispersal Conditions

Ground-Level Release of 1000 Kilograms of Sarin

(2 m/s Wind Speed)




1000 Kilograms VX (Defense Intelligence Agency Scud Release)



(2 m/s Wind Speed)



ys


z

y

x


ams Sarin in Stable Dispersal Conditions

Distance Toxic Cloud Travels in 2.5 Minutes

(2 m/s Wind Speed)

Arrives at 20+ Minutes After Release





*Roughly the same as 1000 Kilogram Dispersal with 10% Absorption/Dispensing Efficiency


Ground-Level Release of 1000 Kilograms Sarin in Unstable Dispersal Conditions


Ground-Level Release of 100 Kilograms* Sarin in Unstable Dispersal Conditions

*Roughly the same as 1000 Kilogram Dispersal with 10% Absorption/Dispensing Efficiency


Concluding Remarks (1 of 3) � On August 21, 2013 a vicious and very carefully planned attack was executed on unprotected civilians

various suburbs of Damascus, Syria. � 1400 to 1500 people were killed from exposure to nerve agent. Between 400 and 500 of these people

were children. � This attack was designed to cause the maximum possible harm to civilians with the technology that

was available to the attacker. � The attack was executed at a time of day that would maximize the density of nerve agent near the

ground where the civilians reside. � The pancake geometry of spreading nerve agent at that time of day greatly increased the area on the

ground, causing the maximum number of people possible to be exposed to an organophosphorous nerve agent.

� If soldiers with proper equipment had been attacked in this manner, casualties would have almost certainly been very low.

� Detectors would have warned the soldiers that chemicals were present. � The chemical agent would take tens of minutes or more to reach soldiers that are outside the

immediately affected delivery areas. � Rapid communications would have made it possible for properly equipped soldiers to put on gas

masks. � Thus, the only effective target for this kind of attack are unprotected civilians.


Concluding Remarks (2 of 3) � Very large amounts of high explosive munitions would be required to drive people out of the areas that

were hit. � On the order of thousands of high explosive munitions would be required to effectively kill the

thousands of people living in these areas. � The chemical munitions that achieve the same goal were probably delivered by no more than several

tens of munitions. � The question currently under debate in the United States is whether military action against those who

use such weapons could produce useful results.


Concluding Remarks (3 of 3) � These results might include: � Deterring these kinds of attacks against civilians. � Weakening a brutal existing regime and moving it closer to collapse. � Send warnings to others who might contemplate such attacks in the future.

� Unexpected results could include: � The mass murder of innocent bystanders associated with the collapse of a terrible regime. � Mass reactions against the United States and its allies for interventions that are seen as aimed at

replacing unfriendly governments with friendly governments. � Reactions from extremist elements who would see Western intervention as further proof of western ill

intentions towards the people of the region. � A provoking of the Syrian regime to “take off the gloves” and use chemicals more widely. � And numerous totally unpredictable results that could influence the politics within and without the

region for decades.

� What would you do if you were in the position to take a military action in response to this atrocity?


a preliminary analysis of the nerve agent attack of august

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