Radiologic Terrorism Thomas P. Foley, Jr. M.D. May 1, 2004.

Radiologic Terrorism

Thomas P. Foley, Jr. M.D.May 1, 2004

Radiologic Terrorism• Radiation Exposure• Dirty Bombs• Atomic Bombs

Five decades after the first atomic bomb

Terrorist atomic bomb

• Nuclear Power Plants

Three Mile Island accident 1978 in PA

Chernobyl accident, April 26, 1986, in the Ukrainian SSR

• Management of pregnant women and children

Exposure to Ionizing Radiation

Definitions• Unstable atoms emit energy in the form of

ionizing radiation to achieve stability.• High frequency particles and electromagnetic

energy causes adverse biologic effects– Damage to DNA– Production of free radicles– Disruption of chemical bonds– Production of new macromolecules

• Radionuclides are elements that emit ionizing radiation. They occur naturally [uranium] or are created by man [plutonium].

Types of Ionizing Radiation• Alpha ( α ) particles = Helium atom nucleus

(2 protons + 2 neutrons); source: nuclear weapon detonation.• Beta ( β ) particles = electrons (high speed particles)

Source: nuclear reactors and radioisotopes of iodine• Gamma ( γ ) rays = photons (visible light)

High energy & penetrance, external radiation hazardSources: nuclear reactors and weapon detonation.

• X-Rays = energy emitted from electronsUnlikely source of ionizing radiation from disasters

• Neutrons = powerful and very damaging to tissuesEmitted only from a nuclear weapon detonation.

Characteristics• Extremely heavy with limited penetrability.• Cellular injury when ingested or inhaled.

Sources of Ionizing Radiation• Nuclear weapon

detonations– α particles– γ rays– Neutrons

• Nuclear reactors– β particles– γ rays

• Medical therapy– X rays– β particles– γ rays

Radiation Exposure Units of Measure

Energy Absorbed from γ-rays and X-raysOld SI Units Conversion

Radiation absorbed dose Rad Gray (Gy) 1 Gy = 100 rad 1 cGy = 1 rad

Roentgen equivalent mass Rem Sievert (Sv) 1 Sv = 100 rem

Average Annual Exposure = 360 mRem or 0.0036 SvChest X-Ray = 5-10 mrem CT Scan = 5,000 mRem (0.05 Sv)

Activity for Radiation Emission of RadionuclidesUnit of Decay Old SI Unit Disintergrations/sec

• Curie Ci - 1 Ci = 3.7 X 1010 dps1 Ci = 37 MBq

• Becquerel - Bq 1 Bq = 1 dps1 MBq = 109 dps

Environmental (Natural) Radiation Exposure

Average Annual Exposure• 360 mRem or 0.0036 Sv

• Sources:– Cosmic radiation and radon– Cigarette smoke– Medical devices– Home appliances– Pharmaceutical agent

Specific Exposures• 5-10 mRem: Flight from New York to Los Angeles• 5-10 mRem: Chest radiograph• 5,000 mRem (0.05 Sv): CT Scan

Dirty Bombs• Radiological dispersion device

– Conventional explosives (dynamite) with radioactive chemicals in powder or pellet form

• Purposes– Expose buildings and people to radioactivity.– Instill fear in people and contaminate buildings.

• Sources of radioactivity– Nuclear facilities: high-level radioactive material

(unlikely)– Hospitals, construction sites, and food irradiation

plants: low-level radioactive materials.• Dangers

– The effect of the explosive blast– Low-level radiation exposure: not enough radiation to

cause severe illness from exposure

Dirty Bombs• Previous use of dirty bombs in a UN report:

– Iraq tested a device in 1987: abandoned its use because radiation levels were too low to cause significant damage.

• Clinical management– Humans cannot see, smell, feel, or taste radiation– They likely will not know if radioactive materials are present.– If they are not severely injured, they should:

• Leave the area to the nearest building & remain inside.• Remove clothes and place into sealed bags for testing.• Shower or wash themselves as best they can.• Maintain contact with emergency information.

– These procedures reduce injury from chemicals & radiation.

Atomic Bomb Detonation in NagasakiAugust 9, 1945 at 11:02 AM

Distance from Hypocenter500 m 1000 m

RadiationGamma rays 70-80 Gy 9-10 GyNeutrons 7-8 Gy 0.9-1 Gy

Heat Energy 111.5 Cal/cm2 42.2 Cal/cm2 Wind Pressure 19.0 ton/m2 8.7 ton/m2

Wind Velocity 280 m/sec 160 m/sec

Deaths before December 1945 73,884Atomic Bomb Survivors 110,716 in 1978

88,249 in 1995Total Population in Nagasaki City 210,000 in 1945

Late Effects from Atomic Bomb Exposure

Diseases Increase IncreaseSuspected

Confirmed

Thyroid adenoma 3 years 5 yearsLeukemia 3 years 10 yearsThyroid cancer 7 years 10 yearsBreast cancer 10 years 20 yearsLung cancer 10 years 20 yearsGastric cancer 15 years 30 yearsColon cancer 15 years 30 yearsMultiple myeloma 23 years 30 yearsParathyroid adenoma 30 years

Thyroid Disease and Atomic Bomb Radiation

Age at Radiation Exposure and Breast Cancer

Land CE. JAMA 1995;274:402-407, Figure 4

Atomic Bomb Survivors: Breast Cancer 1950-1990

Land CE, et al. Radiat Res 2003;160:707-717. Figure 6

Hypothetical Atomic Bomb Detonation in New York City

A 150 kiloton bomb constructed by terrorists is detonated in the heart of Manhattan, at the foot of the Empire State Building. The bomb goes off without warning at noon time. It's a clear spring day with a breeze to the east.


1 second after detonation: Blast wave 0.4 mile, Fireball thermal effects 0.2 mi


4 seconds after detonation: Blast wave for 1 mile, buildings destroyed


6 seconds after detonation: Blast wave for 1.5 miles, thermal effects and fires


10 seconds after detonation: Blast wave extends 4 miles, damage to buildings


Long-Term fallout pattern from a 150 kiloton surface burst, with a uniform 2 mph wind from the east.

Hypothetical Atomic Bomb Detonation in New York City Fallout Effects

Rem Effects 5-20 Possible late effect; Possible chromosomal damage. 20-100 Temporary reduction in white blood cells.100-200 Mild radiation sickness within a few hours: vomiting, diarrhea, fatigue; reduction in resistance to infection.200-300 Serious radiation sickness effects (as above) and hemorrhage; Lethal dose to 10-35% of population after 30 days (LD 1-35/30).300-400 Serious radiation sickness; also bone marrow and intestinal destruction; LD 50-70/30).400-1000 Acute illness, early death; LD 60-95/30.1000-5000 Acute illness, early death in days; LD 100/10.

Radiologic Terrorism Thomas P. Foley, Jr. M.D. May 1, 2004.

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