Module 2
Health and Medical
Effects
1
Health and Medical Effects
Terminal Objective:
DESCRIBE the indicators, signs, and
symptoms of exposure to radiation.
2
Health and Medical Effects
Enabling Objectives:
1. LIST the major sources of natural
background and man-made
radiation.
2. STATE the average annual dose to
the general population from natural
background and man-made sources
of radiation.
3. DESCRIBE the purposes of
radiation dose limits and the
guidance for emergency doses.
3
Health and Medical Effects
Enabling Objectives (continued):
4. DESCRIBE acute radiation dose
and chronic radiation dose and
the possible effects of each.
5. STATE the routes of entry by
which radioactive material can
enter the body.
4
Sources of Natural
Background Radiation
• Cosmic
Radiation
• Sources in
the Human
Body
• Sources in
the Earth’s
Crust
• Radon
5
Cosmic Radiation
• Cosmic radiation comes from the sun
and outer space.
• At sea level, the average annual
cosmic radiation dose is about 26
mrem per year.
• The higher the elevation, the higher
the dose of cosmic radiation.
• The exposure increases about 1
mrem per year for every 100 feet up
in altitude.
6
Terrestrial Radiation
Sources in the Earth’s Crust
• Ground, rocks, soil, and sand
• Sources – natural radioactive
elements of radium, uranium,
thorium, and potassium
7
Terrestrial Radiation average in
continental U.S.: 28 mrem per year
Terrestrial Radiation average in continental US: 28 mrem per year
75
55
40
15
mrem per year
8
Internal Sources of Natural
Background Radiation
• Sources in the human body
• Food and water in trace amounts
• Naturally occurring radioactive
materials deposited in our bodies
• Combined exposure from internal
sources – radioactive dose of
about 40 mrem per year
9
Radon
• (Gas) formed from the radioactive
decay of uranium in the soil
• Can collect in basements
• Emits alpha radiation
10
Man-Made Sources of
Radiation
• Tobacco products
• Medical radiation
• Building materials
• Domestic water supply
11
Sources of Radiation
NATURAL BACKGROUND
Cosmic Radiation
Terrestrial (Earth’s crust)
Internal Sources (body)
Radon
mrem/year
26
28
40
200
MAN-MADE SOURCES
mrem/year
Smoking (Tobacco Products)
1300
Medical X-rays
40
Medical Diagnosis and Therapy
14
Building Materials
7
Domestic Water Supply
5
12
Sources of Radiation
Total of natural background and man-made
sources for the average American (non-smoker):
360 mrem per year
(about 1 mrem per day)
Average due to smoking cigarettes
(1 pack a day):
1300 mrem per year
(about 3 mrem per pack)
Round-trip airline flight across the U.S.:
about 5 mrem
13
Biological Effects
QuickTime™ and a
Cinepak decompressor
are needed to see this picture.
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Effects of Radiation on Cells
•
•
•
•
•
Atoms
Molecules
Cells
Tissues and Organs
Body
16
Effects of Radiation on Cells
(cont.)
Some cells are more sensitive:
• Blood
• Cells that form sperm
• Intestinal tract
• Hair follicles
17
Effects on Cells Exposed to
Ionizing Radiation
• No damage
• Repair and operate
normally
• Damaged and operate
abnormally
• Cells die
18
Biological Pathways
Inhalation
Absorption
Ingestion
Puncture or Injection
19
Acute vs. Chronic
Radiation Doses
Acute
• Large
dose
• Short time
Chronic
• Small
doses
• Long time
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Acute Radiation Dose
Exposure to high doses of radiation
over a short period of time
(minutes,
hours,
days)
21
Biological Effects of
Radiation Exposure
• Damage in exposed individual
• No proven cases of genetic damage
to humans passed on to future
children
• Survivors of Hiroshima and Nagasaki:
genetic mutations in their children no
higher than the general population
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Factors Affecting Cell Damage
•
•
•
•
•
•
•
Total dose
Dose rate
Type of radiation
Area of the body
Cell sensitivity
Individual sensitivity
General state of health
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Acute Radiation Effects
Dose
Less than 50,000 mrem
• No symptoms
Between 50,000 and 100,000 mrem
• Temporary lowering of white cell count
Between 100,000 and 200,000 mrem
• Hours Later: Nausea, vomiting, diarrhea
• No permanent disability
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Acute Radiation Effects
Dose (continued)
Between 200,000 and 450,000 mrem
• Vomiting, diarrhea, hair loss
• 200,000 mrem lethal for 5% people in 60 days
450,000 mrem
• Lethal Dose 50% in 60 days LD50/60
600,000 mrem
• Death for most people
25
Radiation Burns
Bronze-coloring,
“tanning” of the skin
Cloth
Red-coloring,
Swelling, Blistering
Chernobyl Firefighter
Victim from the country of Georgia
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Radiation Burns –
Gamma and Beta Radiation
27
Beta Burns from Contamination
28
Beta Burns on Foot
29
Beta Burns from
Radioactive Fallout
Healing Skin, 30 Days after Burn
30
Hair Loss
32
Casualties from a
Nuclear Detonation
33
Effects of Nuclear Detonation
• Thermal (flash) injuries from
thermal pulse
• Shock wave injuries, collapsed
buildings
• Radiation burns and sickness
• Injuries from fires
• External/internal contamination
• Long-term effects
34
Thermal Pulse Injury from
Nuclear Blast
Flash Burns
36
Acute Exposure and Fatal Cancer
Dose (mrem)
Percent
1,000
0.08
5,000
0.4
10,000
0.8
25,000
2.0
50,000
4.0
38
Fatal Cancer
Risk Estimates (Example)
• 10,000 mrem dose – extra 0.8%
• 1,000 survivors receive 10,000 mrem
– estimated 8 extra cancer deaths
• 200 cancer deaths from other causes
• 208 total cancer deaths
39
Chronic Radiation Dose Risks
• A small amount of ionizing
radiation received over a long
period of time (months, years)
• Small increase in cancer risk
40
Estimated Loss of Life
Expectancy from Health Risks
Estimated Days Lost
•
Smoking one pack a day
•
Being 25% overweight
777
•
Agricultural accidents
320
•
Construction accidents
227
•
Automobile accidents
207
•
Chronic Radiation
2250
(1000 mrem per year from 18 to 65)
51
•
All industry
50
•
Chronic Radiation
(100 mrem per year for 70 years)
•
Medical radiation
10
6
43
EPA Guidelines
for Emergency Procedures
Dose Limit:
Maximum radiation dose that a
responder is allowed to receive.
Purpose of Dose Limit:
Allow responders to perform
emergency actions, yet keep risk as
low as possible
44
EPA Guidelines
for Emergency Procedures*
(expected only once in a lifetime)
Dose limit
Emergency
Activity Performed
Condition
All activities during
5,000 mrem
All activities
10,000 mrem
Protecting major
property
Where lower dose not
practicable
25,000 mrem
Lifesaving or protection
of large populations
Where lower dose not
practicable
Lifesaving or protection
of large populations
Only on a volunteer
basis to persons fully
aware of the risks
involved.
More than
25,000 mrem
emergency
* Minors and pregnant females have much lower limits
45
Health and Medical Effects
1. If there are low-level radiation readings,
what are the possible sources of
radiation?
2. How much radiation do you receive
daily?
3. If there is radiation from the explosion,
could it get onto or into your body?
4. What happens if radiation gets into the
body?
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