EHS Core Course PowerPoint Tempate

1
Ionizing Radiation, Public Health, and
Radiological Terrorism
David J. Brenner, PhD Professor of Radiation
Oncology and Public Health
Week 9 November 9, 2004
Email djb3_at_columbia.edu
2
Ionizing Radiation,Public Health, and
Radiological Terrorism

• What is ionizing radiation?
• How is it harmful?
• How harmful is it?
• Radiological terrorism

You can view or download this lecture at
www.columbia.edu/djb3
3
November 1895 Roentgen discovers x rays
4
February 1896 Becquerel discovers radioactivity
5
Radioactivity

• The spontaneous emission of ionizing radiations
  alpha rays, beta rays, gamma rays from
  radioactive materials

6
Alpha, beta and gamma rays
7
Radioactivity Alpha Rays
8
Radioactivity Beta Rays
9
Radioactivity Beta Rays
10
Radioactivity Gamma Rays The Electromagnetic
Spectrum
11
Interaction of x or ? rays (photons) with
matter Ionization
12
Interaction of electrons with matter Ionization
13
Radiation Dose

• Energy Deposited per Unit Mass
• Dose measured in milli-Gray (mGy) (1/1000 joule
  / kg)
• Equivalent dose is measured in milli-Sievert
  (mSv)
• For our purposes, 1 mGy 1 mSv
• Old units are the rad and the rem
• 10 mGy 1 rad 10 mSv 1 rem
• Average background radiation dose is 3 mSv /
  yearA mammogram produces about 0.01 mSv.A CT
  scan produces about 10 mSv.

14
Radioactivity

• The activity (strength) of a radioactive
  source, measured inCuries (Ci) or Becquerels
  (Bq)
• 1 Bq 1 radioactive disintegrations / sec
• 1 Ci 37 GBq
• 37 thousand million disintegrations /
  sec

15
How does ionizing radiation damage DNA?
16
The Principal Hazards ofIonizing Radiation

• Genetic effects
• Carcinogenic effects
• Effects on the developing embryo/fetus

17
The Carcinogenic Effects of Ionizing Radiation
18
Radiation and Cancer
Most of our information comes from studies of
A-bomb survivors
19
Radiation and Cancer

• A-bomb survivors
• 87,000 survivors followed
• 7,800 cancer deaths observed
• 7,400 expected
• Therefore 400 excess cancers

20
Extrapolating radiation risks from high to low
doses
21
A BIG caveat
Radiation cancer risk estimates at low doses are
based on plausible assumptions, but are estimates
nevertheless. They are not, and can never be,
direct measurements!
22
Lifetime cancer mortality risk as a function of
age at exposure
23
Individual Susceptibility to Radiation
Carcinogenesis

• There are likely to be subpopulations of
  individuals who are significantly more sensitive
  to ionizing radiation than the average
• Children
• ATM heterozygotes (Ataxia Telangiectasia, 1-2
  of the population)
• BRCA1
• BRCA2

24
Radiation Risks
Teratogenic risks Order of magnitude larger than
Carcinogenic risks Order of magnitude larger
than Hereditary risks
25
Radiation-Induced Mutations

• Radiation does not produce new, unique mutations,
  but simply increases the incidence of the same
  mutations that occur spontaneously

26
Inherited radiation damage does not work this
way...
27
Heritable Effects

• Children of the survivors of the A-bomb attacks
  have been studied for
• Untoward pregnancy outcomes
• Death of live-born children
• Sex chromosome abnormalities
• Electrophoretic variants of blood proteins
• But no statistically significant effects have
  been observed

28
We are heavily reliant on animal data for
hereditary risk estimates
29
Effects of exposure to ionizing radiation of the
developing embryo and fetus
30
Teratogenic Risks(i.e., to the embryo/fetus, if
relevant)

• Moderate doses of radiation can produce
  catastrophic effects on the developing embryo and
  fetus.

31
The principle effects of radiation on the
developing embryo and fetus are

• Growth retardation
• Embryonic, neonatal, or fetal death
• Congenital malformations and functional
  impairment,such as mental retardation.

32
Radiation Risks
Teratogenic risks Order of magnitude larger than
Carcinogenic risks Order of magnitude larger
than Hereditary risks
33
Radiological Terrorism

• Mohamed ElBaradei,
• Head, International Atomic Energy Agency (IAEA)
• Nov 8, 2004
• "The threat of nuclear terrorism is real and
  current.
• We need to do all we can to work on the new
  phenomena called nuclear terrorism, which was
  sprang on us after 9/11 when we realized
  terrorists had become more sophisticated, and had
  shown an interest in nuclear and radioactive
  material.
• We have a race against time because this was
  something we were not prepared for."

34
Goiânia, Brazil, 1987Population 1.3 million
35
Abandoned medical clinic in Goiânia contained
1,400 Curie radioactive cesium source
The radioactive sources were stolen, broken open,
and dispersed
36
Goiânia incident Equivalent to large-sized
dirty-bomb scenario in Manhattan

• 130,000 people (10) came to ER / temporary
  screening locations
• 250 (0.2) were contaminated
• 20 (0.01) required treatment

37
Radiation Threat Scenarios

• Nuclear device
• Damage to nuclear power plant
• Dirty bombs

38
Nuclear Device

• Risk
• Exposure to ? rays and neutrons
• Fallout of fission products (including
  short-lived iodine isotopes)
• Outcome
• Large number of acute deaths
• Long-term carcinogenesis
• Likelihood
• Remote

39
Attack on a nuclear power plant

• Risk
• Attack on the reactor itself
• Attack on stored used fuel elements
• Release of fission products I-131, Cs-137, etc
• Outcome
• Unlikely to involve acute deaths
• Long-term carcinogenesis
• Likelihood
• Extremely unlikely

40
Dirty Bombs (Radioactive dispersal devices, RDD)

• Risk
• Release of radioactive cesium, cobalt or
  americium
• Small number of contaminated people
• Large number of very slightly contaminated people
• Psychological chaos (many frightened people)
• Outcome
• Unlikely to result in acute deaths
• Risk of long-term carcinogenesis
• Likelihood
• Likely

41
Radioactive Dispersal Device (RDD)
42
Dirty Bombs

• How available are the radioactive materials?

43
August 1994

• Three people arrested at Munich airport having
  flown on a Lufthansa flight from Moscow carrying
  363 grams of plutonium

44
November 1995
Moscow, Russia -- A group of Chechen rebels
contacts a Russian TV station to claim that they
have buried a cache of radiological materials in
Moscow's Ismailovsky Park. There, the authorities
find a partially buried container of radioactive
cesium.
45
December 1998
Argun, Chechnya A container filled with
radioactive materials found attached to an
explosive mine hidden near a railway line. It is
safely defused. The location is Argun, near the
Chechen capital of Grozny, where a Chechen group,
led by Shamil Basayev, operated an explosives
workshop.
46
June 2002
Chicago, Illinois -- Jose Padilla, a US citizen
with links to Al Qaeda, is arrested in Chicago
airport on suspicion of planning to build and
detonate a dirty bomb. F.B.I agents suspect
Padilla had recently undergone training in
Pakistan, where he allegedly studied the
mechanics of dirty-bomb construction, including
how to wire explosive devices and how to optimize
bombs for radiological dispersion.
47
January 2003
Herat, Afghanistan -- Based on evidence uncovered
in Herat, including detailed diagrams and
computer files, British intelligence agents
conclude that Al Qaeda has succeeded in
constructing a small dirty bomb, though the
device has not been found.
A collage of dirty bomb plans journalists
recently discovered in Afghanistan
48
March 1998
Greensboro, North Carolina -- Nineteen small
tubes of cesium are taken from a locked safe in
Moses Cone Hospital. The total activity was 22
Gbq (0.6 Ci). Each tube was three-quarters of an
inch long by one-eighth of an inch wide and were
used in the treatment of cervical cancer. The
cesium is never recovered.
Cesium tubes similar to the ones missing from
Greensboro
49
March 2002Nucor Steel Mill, Hertford, NC

• 2 Ci cesium industrial gauge found on scrap metal
  conveyer belt
• Traced back to a batch of four belonging to a
  bankrupt Baltimore chemical company. Three have
  been located....

50
Moisture Density Gauges, contain small quantities
of americium-241 and cesium-237 About 22,000 in
use in the US. About 50 per year reported as
missing
51
August 2004

• London Islamic terrorist cell, led by Dhiren
  Barot, raided. Large cache of household smoke
  detectors found, each containing small quantities
  of americium-241

52
Small and large dirty bombs (RDD Radioactive
dispersal device)

• Small RDDHigh explosives dispersing 0.1 to 10
  Curies
• Intermediate RDDHigh explosives dispersing 10 to
  1,000 Ci
• Large RDDHigh explosive dispersing 1,000 to
  10,000 Ci

53
Small Dirty Bomb (RDD) 2 Ci cesium source 10
lb TNT

• Inner Ring One cancer death per 100 people due
  to remaining radiation(typical dose 25 cGy)
• Middle Ring One cancer death per 1,000 people
  due to remaining radiation(typical dose 2 cGy)
• Outer Ring One cancer death per 10,000 people
  due to remaining radiation(typical dose 0.2
  cGy)EPA suggests decontamination

54
Intermediate RDD 2,000 Ci of cesium chloride,
from a seed irradiator, and 10 lb of Semtex
55
Large RDD 10,000 Ci cobalt source (food
irradiator rod)

• Inner Ring One cancer death per 100 people due
  to residual contamination (typical dose 25 cGy)
• Middle Ring One cancer death per 1,000 people
  due to residual contamination (typical dose 2
  cGy)
• Outer Ring One cancer death per 10,000 people
  due to residual contamination (typical dose 0.2
  cGy)

56
Large RDD 10,000 Ci cobalt source (food
irradiator rod)

• Inner Ring Same radiation level as permanently
  closed zone around Chernobyl
• Middle Ring Same radiation level as permanently
  controlled zone around Chernobyl
• Outer Ring Same radiation level as periodically
  controlled zone around Chernobyl

57
Getting Prepared for a Radiological Terrorist
Event
58
Dealing with a large-scale radiological incident
in a medical centerExposure vs. Contamination

• External Exposure irradiation of the body from
  external source
• Contamination radioactive material on patient
  (external) or within patient (internal)

59
Immediate Medical Management Issues

• Triage
• Decontamination
• Initial stabilization and treatment of
  life-threatening injury
• Health care provider health and safety
• Surge capacity availability of staff (quantity
  and specialists), supplies, space

60
Almost all the individual presenting at ER /
clinic will not have a measurable radiation
exposure

• Goiânia
• 99.8 of individuals at ER/clinic not
  contaminated
• 8 had psychosomatic reactions which mimicked
  radiation exposure
• Israel, attacked by Scud missiles during 1991
  Gulf war
• 51 of individuals at ER were stress casualties

61
Staff radiation protection

• Fundamental Principles
• - Time
• - Distance
• - Shielding
• Contamination Control
• Personnel Protective Equipment

62
Contamination Control
Separate Entrance
CONTAMINATED AREA
Trauma Room
HOT LINE
BUFFER ZONE
CLEAN AREA
Clean Gloves, Masks, Gowns, Booties
63
Protecting Staff from Contamination

• Use standard precautions (N95 mask if available)
• Survey hands and clothing frequently
• Replace contaminated gloves or clothing
• Keep the work area free of contamination

64
Pregnant Staff

• Pregnant staff should be reassigned

65
We need to be prepared for a radiological incident

• Facilities should plan in advance and include
  procedures in their Disaster Plan

2002 AHA Survey 46 of hospitals do not have
radiological terrorism in their disaster plan....
? Everyone needs training!
66
If there is a plan in place and staff are well
trained, radiation exposure to staff should be
very low
When workers at Chernobyl who were in the
reactor area at the time of the nuclear accident
were decontaminated, the medical personal at the
site received less than 10 mGy of radiation.
Mettler Voelz,New England Journal of Medicine,
346 1554 (2002)
67
Patient Management - Priorities

• Standard medical triage is the highest priority
  dont delay givingcritical care because a
  patient is contaminated
• Radiation exposure and contamination
  aresecondary considerations

68
External Contamination

• Radioactive material (usually in the form of dust
  particles) on the body surface and / or clothing
• Radiation dose rate from contamination is usually
  low, but while it remains on the patient it will
  continue to expose the patient and staff

69
Patient Decontamination

• Remove and bag patients clothing and personal
  belongings
• (typically removes 80 - 90 of contamination)
• Handle foreign objects with care until proven
  non-radioactive with survey meter
• Survey patient and collect samples

70
Removing internal contamination is more
problematic
71
Internal contamination countermeasures?

• Potassium iodide blocks radioactive iodine from
  being absorbed in the thyroid.
• Very limited utility

72
Internal contamination countermeasures?

• Potassium iodide blocks radioactive iodine from
  being absorbed in the thyroid.
• Totally useless

73
Internal contamination countermeasures?
Traps cesium in the intestine, so that it can be
passed out of the body in the stool rather than
bere-absorbed Recently approved by FDA Only
useful if the radioactive material is cesium
74
High-dose radiation syndromes
75
Self Renewing Tissuese.g. lining of the G.I.
tract
Stem-cell compartment Differentiating
compartment Mature functioning cells
76
Prodromal Effects

• Symptoms to be expected at about 50 lethal dose
• Neuromuscular Easy fatigability
• Gastrointestinal Anorexia, vomiting
• Additional symptoms to be expectedafter a
  supra-lethal dose
• Neuromuscular Fever hypotension
• Gastrointestinal Immediate diarrhea

77
Bottom Line

• Medical centers in major cities need to be able
  to quickly assemble a competent team to cope with
  a radiation incident
• Physicists / dosimetrists
• Emergency room specialists
• Radiation oncologists / radiologists
• Administrators / public health experts /
  psychologists

78
Further Information
CDC and OSHA have good starting
websites www.bt.cdc.gov/radiation/index.asp www.o
sha.gov/SLTC/emergencypreparedness/rdd_tech.html
Documents American College of RadiologyDisaste
r Preparedness for Radiology Professionals
Download at www.acr.org/departments/educ/disaster
_prep/dp_primer.html National Council on
Radiation Protection and Measurement Report No.
138, 2001Management of Terrorist Events
Involving Radioactive Material
79
The real bottom line

• The threat of radiological terror is real
• Most scenarios will present primarily
  organizational challenges

80
The real bottom line

• The threat of radiological terror is real
• Most scenarios will present primarily
  organizational challenges
• The answer