Early (Acute) Effects 

of Radiation

10/25/2010 
General

Categorizing Radiation Effects

Early EffectsUse of Absorbed Dose vs. Dose Equivalent

Radiation Syndromes

General

Contents

Three Radiation SyndromesThree Stages of the Acute Radiation Syndromes

Prodromal StageLatent StageIllness and/or Death Stage
Hematopoietic Syndrome

GeneralSymptoms as a Function of DoseComposition of BloodLymphocytes and the Effect of RadiationGranulocytes and the Effect of RadiationPlatelets and the Effect of RadiationEr

ythroc

ytes and the Effect of Radiation

Contents

y y

Blood Cells and the Effect of RadiationProgress of the Hematopoietic Syndrome

Gastrointestinal Syndrome

GeneralDescription of the Gastrointestinal LiningEffects of Radiation on Gastrointestinal LiningProgress of the Gastrointestinal Syndrome
Cerebrovascular (Central Nervous System) Syn

GeneralInitial Effects and Consequence to Organism

Partial Body Exposures

Skin - Cutaneous Radiation Syndrome/InjuryChronic Cutaneous SyndromeEpilation – loss of hair

Contents

Sterility in MalesSterility in FemalesFibroatrophy

Health Physicist’s Role Following Acute Exposu

Immediate ResponseDose EstimatesAssess Possible Intake
Dose Assessment

Initial Dose EstimateLymphocyte CountsCytogenetic DosimetryElectron Paramagnetic (Spin) ResonanceAccident Reconstruction – MathematicalAccident Reconstruction – PhysicalNeutron Exposure - Screening Method

Contents

p

Neutron Exposure – Na-24 Concentration in Blood

Medical Treatment: General

Hospitalization GuidanceGeneralIssues Regarding InfectionBlood Cell MonitoringPalliative TreatmentREACTS Guidance for Doses Exceeding 2 Gy
Hematopoietic Cell Transplantation and colony 

Stimulating Factors

Hematopoietic Cell TransplantationsBone Marrow TransplantsPeripheral Blood Progenitor (stem) Cell TransplantsPlacental/umbilical-cord Blood TransplantsHematopoietic Growth Factors (cytokines)

Contents

Rescuing Victims of Acute Whole Body Exposu

GeneralNCRP Report 39 GuidanceNCRP Report 116 GuidanceDepartment of Energy Regulations 10 CFR 835 

References
General
Categorizing Radiation Effects

Radiation effects are categorized in several differe

Perhaps the most fundamental way is to divide thtwo categories according to the length of time bet

exposure to radiation and the manifestation of the 

General

exposure to radiation and the manifestation of the 

(the latent period)

Latent Period

Exposure Effect

Time
Categorizing Radiation Effects

Early Effects (Acute Effects)

Occur within two months or so of the exposu

General

Late Effects (Delayed Effects)

Occur more than two months after the expos
Early Effects (Acute Effects)

Early effects occur within 2 months of the exposudefinition is somewhat arbitrary in view of the vafactors that can affect the length of time between exposure and the effect. As such, various authoracute effects in slightly different ways. For exam

General

define acute effects as those effects occurring w6 months of the exposure.Normally, acute effects are only observed if the dgreater than 1 Gy (100 rads) and delivered over time (acutely).
Late Effects (Delayed Effects)

Delayed effects are usually considered to be thosthat appear more than 2 months (in many cases, after the exposure.Depending upon the effect, they can be produced 

General

acute or chronic exposures.One type of delayed effect is considered possible with the smallest of exposures. The other types ooccurs if the dose exceeded a threshold value.
Radiation da

cell goes unmost importasuch damagto be chrom

Cell Death

Mainly due to DNA double strand breaks and 

lti h l b ti C ll

Cell 

Damage insuffi

b t ll t b 

resulting chromosomal aberrations. Cells 

might survive but are nonfunctional (fibrotic).

but cell metabo

Cell divides and many malfuncti

Early Effect Stochastic 

Death of cells with short cell cycle. The more rapidly the cells divide, the shorter the latent period.

Deterministic Late Effect 

(Non-Stochastic)

Death of slowly dividing cells. Cells survive longer since a longer time passes before cell divides. This creates a long latent period.
Absorbed Dose vs. Dose Equivalent

The quantity Dose Equivalent (or equivalent doserelated to the stochastic late effects that might occ

the relatively low doses commonly encountered in of radiation protection.

General

The dose equivalent, as measured in rems or siev(Sv), does not pertain to the early effects of radiatresult from relatively high doses.Discussions of the early effects of radiation involvquantity absorbed dose as measured in units of ragray (Gy). 
Radiation Syndromes
General

A syndrome is a combination of symptoms resulti

single cause (e.g., radiation exposure). These symoccur together so as to constitute a single clinical 

Collectively, the symptoms that result from an acu

Radiation Syndromes

Collectively, the symptoms that result from an acu

exposure to radiation are referred to as an acute syndrome (ARS). Another term, acute radiation si(ARS), is sometimes employed instead.It is common to recognize three or four acute radisyndromes (ARS) in humans. Which syndrome ocdepends on the magnitude of the dose. 
General

The designation of these discrete syndromes is h

arbitrary. In reality, a continuum of effects occur with increa

dose.

Radiation Syndromes

Some authors choose to assign overlapping dose to these syndromes. 
Three Radiation Syndromes

We usually identify the following Acute Radiation S

1. Hematopoietic/Bone Marrow Syndrome 

ca. 200 – 800 rads (2 – 8 Gy)

2 G t i t ti l S d

Radiation Syndromes

2. 

Gas

troin

testinal Syn

drome

ca. 800 – 3000 rads (8 – 30 Gy)

3. Cerebrovascular/Central Nervous System Sy

>3000 rads (>30 Gy)
Three Stages of the Acute Radiation Syndrome

The Hematopoietic Syndrome and the GastrointeSyndrome can be considered to progress through following stages:

1. prodromal (initial) stage

Radiation Syndromes

1. prodromal (initial) stage2. latent stage3. a period of illness and recovery or death

At higher doses associated with the central nervosystem syndrome, the onset of sickness and deatalmost immediate, i.e., there is no stepwise progrthrough the above stages.
1. Prodromal Stage of the Acute Radiation Synd

This is the initial set of symptoms that occurs follsufficiently large acute dose. The primary prodromal symptoms include: 

Radiation Syndromes

nausea vomiting (emesis)anorexia (loss of appetite) fatigue
1. Prodromal Stage of the Acute Radiation Synd

Other symptoms, especially at the higher doses 

fever (up to 41 degrees C) headache

diarrhea

Radiation Syndromes

dryness of the mouth (xerostomia)swelling of the parotid gland (parotiditis)

To some degree, the time of onset of these sympindicates the magnitude of the dose. This is partitrue regarding the time of onset of vomiting. Nevthese symptoms can also be induced psychologi
2. Latent Stage of the Acute Radiation Syndrom

This is an asymptomatic period between the prodstage and the onset of symptoms of later stagesThe higher the dose the shorter the latent phase

sufficiently high doses (e.g., > 3000 rads or 30 G

Radiation Syndromes

sufficiently high doses (e.g., 3000 rads or 30 G

latent phase effectively disappears.
3. Illness and/or Death Stage of the Acute Radia

Syndrome

Many of the characteristics of the prodromal pha

reoccur, e.g., nausea, vomiting, anorexia, fatigueAdditional symptoms might include fever, hemorr

Radiation Syndromes
3. Illness and/or Death Stage of the Acute Radia

SyndromeIt is generally believed that without medical atten

death is certain above 600 rads (6 Gy) 

50% of exposed would die from 400 rads (4 G

Radiation Syndromes

50% of exposed would die from 400 rads (4 G

5% of exposed would die from 200 rads (2 Gy

If the patient survives six weeks, recovery is very but not guaranteed.If the dose exceeds 1000 rads (10 Gy) death is cmost likely within 60 days.
Hematopoietic Syndrome
Hematopoietic Syndrome

General

The hematopoietic syndrome, sometimes referred 

bone marrow syndrome, is produced by acute whdoses of approximately 200 to 800 rads (2 – 8 Gyauthors place the range at 100 to 1000 rads and os

pecify the upper end of the ran

ge low as 600 rad

p y pp g

Death, if it occurs, is primarily a result of damage hematopoietic (blood forming) organs: red bone mlymph nodes and spleen. Damage to other systems, notably the gastrointesalso plays a role.
Dose Symptom Percentage of exposed experiencing symptom O

po

50 100 rads

Anorexia 15 – 50% 

5 30%

Symptoms as a Function of Dose

Hematopoietic Syndrome

50 – 100 rads

(0.5 – 1 Gy) Nausea 5 – 30% 

Vomiting 15- 20% 
Dose Symptom Percentage of exposed experiencing symptom O

po

Anorexia 50 - 90% 

Nausea 30 - 70% 

Hematopoietic Syndrome

Symptoms as a Function of Dose

100 – 200 rads

(1 – 2 Gy)

Vomiting 10 - 50% 

Fatigue and 

weakness 25 – 60% 

Bleeding 

(mild) 10% 

Fever and 

infection 10 – 50% 
Dose Symptom Percentage of exposed experiencing symptom O

po

Anorexia 90 - 100% 

Nausea 70 - 90% 

V ii 0 90% 

Hematopoietic Syndrome

Symptoms as a Function of Dose

200 – 350 rads

(2 – 3.5 Gy)

Vomiting 70 - 90% 

Diarrhea < 10% 

Fatigue and 

weakness 50 – 90% 2 h

Bleeding 10 - 50% 

Fever 10 - 80% 

Infection 10 – 80% 2 

Ulceration 30 3 
Dose Symptom Percentage of exposed experiencing symptom On

pos

Anorexia 100% 

Nausea 90 - 100% 

V ii 80 100% 

Hematopoietic Syndrome

Symptoms as a Function of Dose

350 - 550 rads

(3.5 – 5.5 Gy)

Vomiting 80 - 100% 

Diarrhea < 10% 

Fatigue and 

weakness 90 – 100% 1 h

Headache 50% 4 

Bleeding 50 - 100% 6 da

Fever and 

Infection 80 - 100% 6 da
Dose Symptom Percentage of exposed experiencing symptom On

pos

Anorexia and 

nausea

100% 

Vomiting 100% 

Hematopoietic Syndrome

Symptoms as a Function of Dose

550 - 750 rads

(5.5 – 7.5 Gy)

Diarrhea > 10% 

Fatigue and 

weakness 100% 1 h

Headache 80% 4 

Bleeding,fever and 

Infection

100% 10 

Dizziness 

and 

disorientation

100% 4 
Composition of Blood

Fluid (plasma)Blood Cells: a. lymphocytes (white blood ce

b. neutrophils (white blood cel

Hematopoietic Syndrome

p( 

c. platelets (cytoplasmic fragmd. erythrocytes (red blood cells
Lymphocytes and the Effect of Radiation

Lymphocytes are a type of leukocyte (white blood 

responsible for antibody production.They are produced in the lymph nodes, the thymu

parts of the s

pleen. 

Hematopoietic Syndrome

p pAlthough mature lymphocytes are long lived and they are very radiosensitive and can be killed direradiation. 
Lymphocytes and the Effect of Radiation

Within 15 minutes of a dose as low as 10 rads, th

lymphocyte population can be seen to decrease. The decrease in the white blood cell population is to as neutro

penia.

Hematopoietic Syndrome

The rate of decrease in the number of lymphocyteused to estimate the dose. Recovery of the lymphocyte population is slow.
Neutrophils and the Effect of Radiation

Neutrophils are the most common type of granulotype of leukocyte produced in the myelopoietic cesystem of the red bone marrow. They fight infectioengulfing foreign particles in the body. 

The neutrophils are radioresistant but their life sp

Hematopoietic Syndrome

The neutrophils are radioresistant, but their life sp

(less than one day). Damage to their radiosensitivprecursors results in a measurable decrease in thof neutrophils within a few days of the exposure.Recovery of the neutrophil population is faster thalymphocytes.
Platelets and the Effect of Radiation

Platelets (aka thrombocytes) are cytoplasmic fragproduced by megakaryocytes in the bone marrow known as the thrombopoietic cell renewal systemnot true cells but nevertheless play an important r

promoting the coagulation.

Hematopoietic Syndrome

pg gPlatelets and mature megakaryocytes are radiorehowever the megakaryocyte precursor stem cells immature megakaryocytes are radiosensitive. 
Platelets and the Effect of Radiation

The lifespan of platelets (8-9 days) is longer than neutrophils which means they disappear more sloThe decrease in the platelet population is referred thrombocytopenia.

Hematopoietic Syndrome

y p
Erythrocytes and the Effect of Radiation

Erythrocytes (red blood cells) are responsible for 

oxygen from the lungs to the various tissues of th

body. Com

parativel

y lon

g-lived, the

y have an avera

ge l

Hematopoietic Syndrome

p yg y g

four months (120 days).
Erythrocytes and the Effect of Radiation

Approximately one week after the exposure (abov

rads, 0.1-0.2 Gy), a drop in the number of red blowill occur. This decrease in er

ythroc

ytes is a result of dama

g

Hematopoietic Syndrome

yy g

radiosensitive precursors, the stem cells of the remarrow, the erythropoietic cell renewal system. For the victim to have any chance of survival, somstem cells must survive the exposure.
Lympocytes 

Neutrophils x 

141210

16 8

hrocytes (grams)

Erythrocytes Platelets

12 6

8 44 2

Eryth

Days 0 10 20 30 40 50 

Lymphocytes

Neutrophils

Prodromal phase

Latent period Manifest Illness Recovery

Dose 3 Gy
Blood Cells and the Effect of Radiation

Lymphocyte and Granulocyte Populations ApproximatWeek After Exposure (x 10

9

)

Dose Lymphocytes Granulo

100-200 rads 

(1-2 Gy) 0.8 - 1.5/liter > 2.0/

Hematopoietic Syndrome

(

200-400 rads (2-4 Gy) 0.5 - 0.8/liter 1.5 – 2400-600 rads (4-6 Gy) 0.3 - 0.5/liter 1.0 – 1600-800 rads (6-8 Gy) 0.1 – 0.3/liter < 0.5/

> 800 rads (>8 Gy) 0 – 0.1/liter < 0.1/
Progress of the Hematopoietic Syndrome

Prodromal PhaseFollowing doses of 200 - 800 rads, the prodromal 

with its associated symptoms (e.g., anorexia, nauvomiting) typicall

y occurs within 1 to 5 da

ys of the 

Hematopoietic Syndrome

g) yp y y 

Latent PhaseThis asymptomatic period lasts 1 to 3 weeks after prodromal phase.
Progress of the Hematopoietic Syndrome

Illness and Death or RecoveryFollowing the latent phase a period of extreme illn

begins. Symptoms include nausea, fatigue, anem

(brou

ght about b

y the decrease in the red blood c

Hematopoietic Syndrome

(g ypopulation), fever, epilation (hair loss), anorexia (appetite), impaired wound healing and petechial (hemorrhaging on the skin caused by damage to tcapillaries.
Progress of the Hematopoietic Syndrome

Illness and Death or Recovery

Death, if it occurs, is typically within 2 to 6 weeks 

exposure. The most probable causes of death are hemorrhaging and infection. 

Hematopoietic Syndrome

The hemorrhaging is caused by damage to the radiosensitive cells lining the fine blood vessels acompounded by the reduced population of plateleInfection occurs because the intestinal bacteria pethe damaged lining of the gastrointestinal tract. At time, the body's ability to fight infection is reduced decrease in white blood cell population..
Gastrointestinal 

Syndrome
Gastrointestinal Syndrome

General

The gastrointestinal (GI) syndrome is associated 

whole body exposures from 800 rads (8 Gy) up to rads (30 Gy). Estimates for the onset of the 

gastrointestinal s

yn

range from as low as 600 up to 1000 rads (6-10 G

Death results from both the damage to the lining o

gastrointestinal tract and damage to the hematopsystem.
Description of Gastrointestinal Tract Lining

Much of the lining of the gastrointestinal tract is cowith small finger like projections called villi. The vthe effective surface area of the lining and thereby the capacity of the body to absorb nutrients. 

Gastrointestinal Syndrome

The cells on the surface of the villi are constantly towards the tip of the projections where they are soff. Mitotically active stem cells at the base of the crypt area) replace those cells that are lost. Each contains 30-40 stem cells. The turnover rate of the epithelial cells is high - than average life span from 7 to 8 days.
Gastrointestinal Syndrome

Gastrointestinal Syndrome
Gastrointestinal Syndrome

Gastrointestinal Syndrome
Effect of Radiation on Gastrointestinal Tract Lin

Sufficiently large acute exposures lead to the repr

death of the rapidly dividing crypt cells. The cells the villi continue to be sloughed off but are no lonreplaced.

Gastrointestinal Syndrome

This deterioration of the lining of the gastrointestin

then leads to a loss of body fluid, inadequate absnutrients and infection from the intestinal flora (ba

Above 1,000 - 1,200 rads (10-12 Gy) the crypt ce

completely destroyed. At this point, death is certa
Effect of Radiation on Gastrointestinal Tract Lin

Gastrointestinal Syndrome

Irradiated GI – loss of epithelial cells
Effect of Radiation on Gastrointestinal Tract Lin

Gastrointestinal Syndrome

Irradiated GI 
Progress of the Gastrointestinal Syndrome

Prodromal PhaseWithin a couple of hours of the exposure the indivdemonstrate a sharp loss of appetite, upset stomapathy. Several hours later nausea, severe vomit

Gastrointestinal Syndrome

py 

diarrhea (possibly bloody) will occurLatent PhaseBy the third day after the exposure the previous swill have disappeared and the victim will appear hThis asymptomatic phase might last for 1-7 days
Progress of the Gastrointestinal Syndrome

IllnessThis can include nausea, vomiting, ileus (failure intestinal tract to move contents), diarrhea, fever

(whole body inflammation due to infection) hemo

Gastrointestinal Syndrome

( y ) apathy, anorexia and loss of weight.Death usually occurs within 3 to 12 days of the eSince the cell renewal mechanism of the gastroin

tract has been completely destroyed and cannot replaced, death is inevitable. 
Progress of the Gastrointestinal Syndrome

IllnessCauses of death include fluid and electrolyte losthe destruction of the lining of the GI tract. These losses also account for the loss of weight, diarrh

f G

Gastrointestinal Syndrome

thickening of the blood associated with the GI sy

There is an inability to absorb nutrients. A contributing cause of death is infection which cwithin 24 hours of the exposure as the endogenobacteria that inhabit the GI tract invade the body the damaged lining. Damage to the hematopoietsimultaneously reduces the body's ability to copinfection.
Cerebrovascular

(Central Nervous System(Central Nervous System

Syndrome
Cerebrovascular Syndrome

General

Associated with doses over 3000 rads (>30 Gy) to 

body. Always fatal.

Immediate nausea, vomiting, anorexia, disorientaprostration, and irreversible hypotension; blood pbe markedly unstable. Within hours of exposure, the victim will be listlestremulous, convulsive, and ataxic. Will likely fall inDeath most likely will occur within 24 to 48 hours.
General

Direct damage to the brain might occur due to electrochemical inactivation of the nerve cells tha

from damage to the cell membranes. Most likely, death results from several causes, e.g

Cerebrovascular Syndrome

y g

meningitis (inflammation of the membranes coverbrain), myelitis (inflammation of the spinal cord), encephalitis (inflammation of the brain), and vascdamage.
General

The blood vessels of the brain are known to be da

large doses of radiation. Because this damage incthe permeability of the vessel walls, fluid from the leaks into the skull cavity (edema) and causes a b

pressure inside the skull. Perhaps death is partly 

Cerebrovascular Syndrome

p p pyincreased pressure on certain areas of the brain (respiratory center). Death might also involve the change in the blood the brain.
Initial Effects Consequence to Orga

DIGESTIVE SYSTEMDecreased food intakeDecreased absorptionDiarrheaUlcerationHEMATOPOIETIC SYSTEM

Poor NutritFluid LossElectrolyte Infection

Decreased lymphocytesDecreased granulocytesDecreased plateletsDecreased erythrocytesVASCULAR SYSTEMVascular fragility Increased capillary permeabilityObstruction of blood vessels

HemorrhagAnemiaAnoxiaDamage to Resistant T
Partial Body Exposures
Partial Body Exposures

Skin - Cutaneous Radiation Syndrome/Injury

Exposure limited to skin and adjacent underlying 

Exposure might be from low energy x-rays, contaon skin, external source adjacent to body.Immediate dama

ge from acute ex

posures onl

y oc

g py

exposed region of skin. This might lead to indirect adjacent tissues at a later time.The magnitude of the effect is primarily dependendose, but the characteristics of the exposed skin arole. Fair skin is more radiosensitive than darker sskin of the hands, feet, scalp, and eyelids is more radiosensitive than that of the face, trunk, arms an
Skin - Cutaneous Radiation Syndrome/Injury

The larger the area exposed (up to 400 cm

2 or so

greater the effect.The term “cutaneous radiation syndrome” or “cutaradiation in

jur

y” re

places the older term “radiation 

Partial Body Exposures

jy p

describing these injuries. There are two components to the cutaneous syndearly phase during the initial few months following exposure and the long term chronic phase.
Skin - Cutaneous Radiation Syndrome/Injury

Initial symptoms: itching, tingling, erythema. 

Transient erythema (associated with itching) can within a few hours of exposure. This is followed bs

y

m

ptom-free 

phase lastin

g from a few da

ys to se

Partial Body Exposures

y p pg y

weeks. After the latent phase, intense reddening, blisterinulceration of the irradiated site are visible. It is possible that a third or fourth wave of erythemoccur over the ensuing months or possibly years. 
Skin - Cutaneous Radiation Syndrome/Injury

As long as the basal layer of the skin is not destro

skin will heal itself. Large doses can cause permanent hair loss, damsweat 

glands, atro

p

h

y, fibrosis, decreased or incre

Partial Body Exposures

g py

pigmentation, and ulceration or necrosis of the extissue. 
Skin - Cutaneous Radiation Syndrome/Injury

Doses of 300-800 rads (3 - 8 Gy)

The minimum threshold for erythema (reddening skin). The effects can be compared to a first degr

i.e., sunburn. There is a reddenin

g of the skin with 

Partial Body Exposures

scaling (dry desquamation) possible. This redness is caused by a dilation of capillaries beneath the surface of the epidermis - probably drelease of histamine. No medical treatment is reqthe skin will completely recover. 
Skin - Cutaneous Radiation Syndrome/Injury

Doses of 300-800 rads (3 - 8 Gy)

In the first wave of erythema (if it occurs) the skin 

1 to 3 days after the exposure. The redness beginb

y the end of the first week.

Partial Body Exposures

The second phase begins 2 to 3 weeks after the eand may last as long as one month. The second wseems to be due to damage to the blood vessels. the capillaries dilate to compensate for a decreasoxygen reaching the tissue, a consequence of raddamage to the small arterioles.
Skin - Cutaneous Radiation Syndrome/Injury

Doses of 1000 - 5000 rads (10 - 50 Gy)

The effects from doses in this range can be consi

similar to those from second degree burns. 

The first a e of er thema occ rs er shortl aft

Partial Body Exposures

The first w

a

v

e of er

ythema occ

urs very shortly aft

exposure while the second phase may begin withto second week.The second phase involves dry desquamation anhigher doses (> 2000 – 3000 rads ), wet desquamThis loss of epidermis is due to the death of the glayer. With wet desquamation the loss of epidermassociated with ulceration and the exudation of flu
Skin - Cutaneous Radiation Syndrome/Injury

Doses of 1000 - 5000 rads (10 - 50 Gy)

In many cases the affected area is sharply demar

forming a clear contrast with the surrounding hea

Treatment is aimed at keeping the tiss e clean p

Partial Body Exposures

Treatment is aimed at keeping the tiss

u

e clean, p

infection and reducing any pain or irritation that is Healing will take weeks to months. After recoveryskin might be pigmented and more susceptible to Treatment might include the oral administration of antihistamines (e.g., Loratadine) which can reducsensation and shorten the duration of the erythem

steroids can also be used to alleviate the erythem
Skin - Cutaneous Radiation Syndrome/Injury

Doses of 1000 - 5000 rads (10 - 50 Gy)

Partial Body Exposures

Twenty-four days after the exposure. Blisters are breakin

g

and dead skin is sloughing off.
Skin - Cutaneous Radiation Syndrome/Injury

Doses above 5000 rads (> 50 Gy)

The results can be compared to a third degree bu

The associated 

pain ma

y be intense.

Partial Body Exposures

p y

The germinal cells is destroyed and sufficient dambe done for necrosis of the skin to result. Infection and gangrene are among the short term Carcinogenesis is the long term worry. 
Skin - Cutaneous Radiation Syndrome/Injury

Doses above 5000 rads (> 50 Gy)

Treatment may require skin grafts and/or amputat

Dela

yed tissue death ma

y occur as dee

p fibrosis 

Partial Body Exposures

y yp

collagen deposition gradually reduce the blood suto the tissue. Rather than healing with time, the condition may gprogressively worse.
Skin - Cutaneous Radiation Syndrome/Injury

Doses above 5000 rads (> 50 Gy)

Partial Body Exposures

This arteriogram shows the circulatory system in the hand of an individual who 

picked u

p an 

p p

industrial radiography source three weeks earlier. The dose was large enough to destroy many blood vessels.
Skin - Cutaneous Radiation Syndrome/Injury

Doses above 5000 rads (> 50 Gy)

Partial Body Exposures

Day 6. Beginning of erythema

Day 12. Dark erythema with beginning of dry desquamation

Day 15. Tissue necr
Skin - Cutaneous Radiation Syndrome/Injury

Partial Body Exposures

Day 9 following criticality accident. Blood vessels become permeable to fluid so that exposed areas swell (edema). Hempelmann et al., Ann. Int. Med. 36:289-510, 1952
Skin - Cutaneous Radiation Syndrome/Injury

Partial Body Exposures

Day 9 following criticality accident. Blood vessels become permeable to fluid so that exposed areas swell (edema). 

Day 11 Da

Hempelmann et al., Ann. Int. M36:289-510, 1952
Chronic Cutaneous Syndrome

The chronic phase of the cutaneous radiation syn

involve a gradual fibrosis brought about by the forcollagenous tissue from the dermal and subcutanfibroblasts. There is a disappearance of fatty tissupossibly blockage of blood vessels. Treatment mi

ff 

Partial Body Exposures

the administration o

f interferon, Vitamin E and pe

Small localized spider-like veins, possibly associaan itching and feeling of warmth, might appear on (Telangiectasis). In most cases, these veins can bremoved with a laser treatment.Keratoses might develop in the exposed area - smgrowths such as a wart. Since these might be precancerous, they might be excised or at least m
Epilation – loss of hair

Acute doses from 300 to 600 rads (3 – 6 Gy) to th

may lead to a temporary hair loss approximately tweeks after the exposure. The hair can be expectregrow within one to two months after the exposunew hair may be of a different color (white or gray

ff

Partial Body Exposures

di erent texture.Acute doses above 700 rads (7 Gy) or so will lead 

permanent hair loss within three weeks.These results are typical for exposures to the beascalp area. Hair on other parts of the body is less affected.
Sterility In Males

10 rads (0.1 Gy) to the gonads can result in a slig

decrease in the sperm count.25 rads (0.25 Gy) can reduce the sperm count by weeks after exposure.

Partial Body Exposures

50 rads (0.5 Gy) can cause brief temporary sterilitmen. Recovery of the spermatogonia and the subincrease in the sperm count to normal levels may weeks. 250 rads (2.5 Gy) will lead to sterility for 1 to 2 ye500 - 600 rads (5 – 6 Gy) results in permanent ste
Sterility in Females

100 – 200 rads (1 – 2 Gy) temporary sterility for 1 

350 - 400 rads (3.5 – 4 Gy) destroys the primary asecondary oocytes and leads to permanent sterili

Partial Body Exposures
Fibroatrophy

Months or years after exposures of several hundr

the exposed tissues can deteriorate and be replacfibrotic tissue. The result is a gradual loss of tissu

Partial Body Exposures
Health Physicist’s Role 

Following Acute ExposuresFollowing Acute Exposures
Immediate Response

First aid treatment for physical injuries should havpriority.If external contamination is possible, it should be 

and dealt with.

Health Physicist’s Role following Acute E

Consideration might be given to administering a msedative.
Dose Estimates

The health physicist does not prescribe medical t

That is the physician's responsibility.Once the exposed individual is in the care of a phthe health physicist's role is to help obtain an initia

Health Physicist’s Role following Acute E

py p

estimate and to provide any assistance that is reqThe dose estimate can help determine the appropcourse to follow during the initial handling of the eindividual. A more detailed determination of the dose may be later to help guide the medical treatment.
Assess Possible Intake

If there was a potential for radioactive material to 

the body, the health physicist might be involved in quantifying the potential intake. This assessment involve some or all of the following:

In vitro bioassay:

Health Physicist’s Role following Acute E

• Analysis of nasal swabs• Analysis of urine• Analysis of feces• Analysis of blood (possible but not standard p

In vivo bioassay:

• Whole body count 
Assess Possible Intake

“Nasal swabs should always be promptly collecteanalyzed, because a rule of thumb is that the ante

contain approximately 5% of the total inhaled actian hour or two after inhalation.” (Ricks et al 2002

Health Physicist’s Role following Acute E

Potentially contaminated clothing, wound dressingshould be bagged, labelled and analyzed.
Dose Assessment
General

Volume 98 (No. 2), February 2010 of the Health PhJournal contains the papers presented at the 8th Int

Symposium on EPR Dating and Dosimetry and 3rd International Conference on Biodosimetry. 

Dose Assessment

It is an excellent source of information concerning dassessment following radiological incidents.
Initial Dose Estimate

• Observe and record all clinical responses. Altho

of these (e.g., nausea, vomiting, etc.) may have psychological causes independent of the magn

the dose, it should first be assumed that they aconsequence of the exposure. 

Dose Assessment

• If erythema occurs, obtain color photographs. T

help determine how localized the exposure was

• Collect and process all personnel dosimeters b

remember that this information may be misleadexposure was highly localized and/or the dosimshielded by some part of the body. Obtain avaiinformation from area monitors.
Initial Dose Estimate

Dose Assessment

Time to emesis (vomiting) after exposure 
Initial Dose Estimate

• Obtain available information from area monitor• Carefully interview all witnesses as soon as po

Obtain their names, addresses and phone numEarly interviews are important because memor

Dose Assessment

short and witnesses may become unavailable 

weekend or holiday is near. When conducting interview obtain information about the duration exposure, the position of the individual's body respect to the source and the location of any omight have served as shields.
Lymphocyte Counts

Following an initial dose estimate of 20 to 100 radGy), a blood sample might be taken the first day.If the dose is estimated to be greater than 100 rad

Gy), blood samples might be taken every 6 to 12 

Dose Assessment

y) p g y

during the first two days after the exposure.The absolute lymphocyte count is considered the single indicator of the severity of the exposure. As lymphocyte counts will be performed on each blooThe hematocrit, platelet count, and total white blo(WBC) count might also be determined.
Dose Assessment

Classical Andrewlymphocyte deplcurves and accoclinical severity r

Lymphocyte Counts

Curves 1-4 correroughly to the fowhole-body dose

Curve 1 - 3.1 Curve 2 - 4.4 Curve 3 - 5.6 Curve 4 - 7.1 
Lymphocyte Counts

Goans et al (2001) described the following metho

estimating the dose – it assumes an exponential din the lymphocyte population during the first 48 hoMultiple lymphocyte counts are obtained in the fir

hours following the exposure and the following eq

Dose Assessment

hours following the exposure and the following eq

solved for K.

Lt = L0 e-Kt

Lt is the lymphocyte count at day t

L0 is the lymphocyte count at the time of the exp

t is the time after the exposure (days)K is the depletion rate constant (days-1)
Lymphocyte Counts

The depletion rate constant (K) is determined from 

collected data. This constant is then used to estimate the dose (Dvia the following equation:

Dose Assessment

g q

D = 8.6 K
Cytogenetic Dosimetry “the gold standard”

Experts in cytogenetic dosimetry include the REA

cytogenetics group at the Oak Ridge Institute for and Education, and the Department of Defense’s group. The technique can be useful in situations wex

posure exceeds 10-20 rads 

(0.1-0.2 Gy).

Dose Assessment

p

( y)

Peripheral blood lymphocytes are obtained and ca couple of days. The cells are arrested in mitosis analyzed under a microscope. The average numbdicentric chromosomes per cell is determined.The number of dicentrics per cell is related to the dose with a graph such as the following:
Dicentrics/cell 

1.5

1.0

High LET

Radiation

Low 

Dose Assessment

Dose (Gy) 

0

0.5

01234

Radi
Electron Paramagnetic (Spin) Resonance

In this technique an electron paramagnetic resona(EPR) spectrometer is used to estimate the numb

radicals produced in certain materials. The greateradiation dose, the greater the number of free rad

In most materials the free radicals disappear almo

Dose Assessment

In most materials the free radicals disappear almo

immediately after the exposure to radiation. Howeorganic materials that contain little to no water (e.bones, hair, fingernails, sugar, etc.), free radicals for weeks to years. As little as 10 mg of material irequired in the analysis. EPR is only applicable if the exposures exceed 10 Gy) or so, but it can do so long after the exposure
Accident Reconstruction - Mathematical

It might be possible to assess the dose to the vict

mathematically. Given a sufficiently straightforward situation (e.g., ex

posure to a 

gamma source

), the calculations m

Dose Assessment

pg ) 

done by hand.A more sophisticated approach would be to estimdose via computer modeling. A “standard” mathehuman model might be used, or a voxel phantom constructed from a CT or MRI scan of the victim. case, the dose to the different “tissues” would be determined using a Monte Carlo analysis.
Accident Reconstruction - Physical

In some situations (e.g., sealed source exposure)

be possible to physically duplicate the accident coA tissue equivalent phantom would be positioned same distance

(

s

) from the source and for the sam

Dose Assessment

( )

period(s) of time as the victim. This phantom wounumerous dosimeters (e.g., TLDs) distributed throvolume. Analysis of the dosimeters would indicatto different body tissues. One of the most widely used phantoms for this puthe Alderson Rando phantom.
Neutron Exposure - Screening Method 

If the exposure involved neutrons, the following m

be used as a screening technique to separate thowere seriously exposed from those who weren’t: A GM reading out in mR/hr is placed across the s

the potentially exposed individual. The latter bend

Dose Assessment

the potentially exposed individual. The latter bend

that the probe is surrounded by the body. The neis roughly estimated by using the following relatio

(

)

(

/

)

(

)

3.6

(

)

(

/

)

(

) 8000

Body weight kg

Exposure rate Sv hr Dose Gy

Body weight pounds

Exposure rate mR hr Dose rads

μ

=

=
Neutron Exposure - Screening Method

Ricks et al (2002) provided another quick and dirt

estimate the neutron dose: “In terms of count ratecounts per minute above background equals one neutron dose.” 

Dose Assessment

Metal objects such as coins, rings, watches and bbuckles should be collected. Activation products quantified by gamma spectroscopy. An estimate neutron fluence (n/cm

2) can then be made if the e

composition of the target material is known. The ethe fluence is used to estimate the dose.
Neutron Exposure - Na-24 Concentration in Bloo

To determine the neutron dose more precisely, th

concentration in the victim’s blood might be meagamma spectrometry. This concentration is decacorrected to the time of the exposure.

Dose Assessment

Given the Na-24 concentration in the blood, a gras the following might be used (from IAEA TechnReport Series #152) to estimate the dose due to neutrons.

Medical Treatment:

General
Hospitalization Guidance (from Ricks et al, 2002)

Dose less than 100 rads (< 1 Gy): 

Treat victims as outpatients.

Dose of 100 - 200 rads (1-2 Gy): 

While the victim could be treated as an outpatie

most cases they will be hospitalized

Medical Treatment: General

most cases they will be hospitalized.

Dose of 200 – 400 rads (2-4 Gy): 

Hospitalization required, preferably in a hospitaintensive care unit and hematology department

Dose above 400 rads (>4 Gy): 

Victim should be placed in the intensive care uhematology department.
General

The treatment depends on the symptoms. Neverthemain effort is devoted to avoiding and fighting infecassisting in the recovery of the blood forming tissueThis might involve the use of antibiotics, erythrocyte 

Medical Treatment: General

g ,y y

platelet transfusions, administration of cytokines (costimulating factors), and possibly bone marrow tranDuring the prodromal phase, any nausea and diarrhbe treated with Ondansetron.
Issues Regarding Infection

Since infections can appear soon after a large expowithin 24 hours), nasal, mouth, throat, vaginal, skincultures are made as soon as possible after the expIdentified infections are treated immediately, e.

g., o

Medical Treatment: General

y, g ,

mystatin to reduce Candida. Cultures will continue made twice a week. The patient may be isolated in a laminar flow (bacteroom. If such a facility is unavailable, consideration given to sending the individual home; the chances odeveloping an infection at home are less than in a nhospital setting.
Blood Cell Monitoring

Close watch is kept on the granulocyte and platelet If the granulocyte count drops below 1,500/mm3 the 

steps may be taken: administration of oral antibiotic

daily antiseptic baths 

Medical Treatment: General

trim and scrub finger and toe n

If the granulocyte count drops below 750/mm3 and 

infection is not responding, a transfusion of white bmay be performed. If the platelet count falls below 40,000/mm3 and/or b

occurs injections of platelets may be warranted
Palliative Treatment

If the exposure exceeded 1000 rads (10 Gy), the panot expected to survive and treatment will be palliatAttempts will be made to provide relief from the symrather than provide a “cure.” For example, the patie

Medical Treatment: General

p p, p 

be administered pain killers, anti-depressant medicbe fed intravenously. 
REACTS Guidance for Doses Exceeding 2 Gy ( 

• Vomiting - use selective blocking of serotonin 5-

T3 receptors or use 5-HT3 receptor antagonists.

• Consider initiating viral prophylaxis.• Consider tissue, blood typing.• Treat trauma.

Medical Treatment: General

• Consider prompt consultation with hematologist 

radiation experts, re: dosimetry and prognosis, ucolony stimulating factors, stem cell transfusion, treatment options.

• Draw blood for chromosome analysis; use hepar

tube.

• Note areas of erythema and record on body char

possible, take photographs.
REACTS Guidance for Doses Exceeding 2 Gy ( 

• SUPPORTIVE CARE in a CLEAN environment.• Prevention and treatment of infections.• Stimulation of hematopoiesis (use of growth fact

GCSF, GMCSF, interleukin 11).

• Stem cell transfusions: cord blood, peripheral blo

Medical Treatment: General

bone marrow. Platelet transfusions if bleeding ocplatelet count too low.

• Psychological support.• Observe carefully for erythema (document locati

loss, skin injury, mucositis, parotitis, weight loss, 

• Consultation with experts in radiation accident 

management is encouraged.
Hematopoietic Cell Transplant

and

Colony Stimulating Factor
Hematopoietic Cell Transplantation

Hematopoietic cell transplantation consists of har

blood progenitor or stem cells from one individual administration to the exposed victim. The donor arecipient should be matched as closely as possib

Hematopoietic Cell Transplantation and 

Colony Stimulating Factors

The three most important sources of these cells:

bone marrowperipheral blood progenitor cellsplacental/umbilical-cord blood
Bone Marrow Transplants

With doses between 800 - 1200 rads (8-12 Gy), consideration might be given to a bone marrow tr

a closely matched donor is available. Much above rads (10 Gy), the crypt cells of the gastrointestinacom

pletel

y destro

yed and attem

pts at salva

gin

g t

Hematopoietic Cell Transplantation and 

Colony Stimulating Factors

p y y p gg

hematopoietic system are pointless.The bone marrow is collected from the posterior pbones under anesthesia. Significant pain that lastdays is common with this procedure.Since it takes 2 to 3 weeks for the transplanted mdevelop sufficiently to do some good, the transplabe performed within a week of the exposure.
Bone Marrow Transplants

The body may attempt to reject the transplanted t

in the process so weaken itself. However, if the bomarrow transplant is accepted for several weeks, provide enough granulocytes for the victim to surv

their own bone marrow recovers and the transpla

Hematopoietic Cell Transplantation and 

Colony Stimulating Factors

their own bone marrow recovers and the transpla

rejected.Of the 13 accident victims at Chernobyl who were bone marrow transplants, two became long-term It has been speculated that the transplants may, ihave been a contributing cause of death in a few 
Peripheral Blood Progenitor (stem) Cell Transpl

These cells are collected directly from the donor’s 

bloodstream following their mobilization from the marrow cavity by the use of hematopoietic growth 

Their collection is usually four top five days after t

Hematopoietic Cell Transplantation and 

Colony Stimulating Factors

Their collection is usually four top five days after t

mobilization. The donor is likely to experience somduring the mobilization phase.
Placental/umbilical-cord Blood Transplant

This is the blood (60 to 180 mls) that remains in th

umbilical cord and placenta following birth. The red blood cells and plasma are often remove

cord blood is frozen Advantages include the fact 

Hematopoietic Cell Transplantation and 

Colony Stimulating Factors

cord blood is frozen. Advantages include the fact 

are no donor side effects (e.g., pain) and the fact cord blood - recipient HLA matching is less crucia
Hematopoietic Growth Factors (cytokines)

Cytokines are naturally occurring proteins secrete

human leukocytes that stimulate the production oprogenitor cells in the hematopoietic tissue. 

One important group of cytokines are referred to a

Hematopoietic Cell Transplantation and 

Colony Stimulating Factors

One important group of cytokines are referred to astimulating factors (CSFs). The most important of can be produced in useful quantities are the grancolony stimulating factor (G-CSF) and the granulomacrophage stimulating factor (GM-CSF). Both happroval are standard treatments for neutopenia. Daily administration should begin soon after the e
Hematopoietic Growth Factors (cytokines)

Another agent, recombinant human IL-11 ( interle-2), has been approved by the FDA for the treatm

thrombocytopenia as has TPO (thrombopoietin).

Other similar agents currently being evaluated inc

Hematopoietic Cell Transplantation and 

Colony Stimulating Factors

Other similar agents currently being evaluated inc

MGDF and SD/01 (sustained-duration G-CSF).These agents are not without side effects. For exaadministration of G-CSF can slow down the recovplatelets.
Rescuing Victims of 

Acute Whole BodyAcute Whole Body

Exposures
General

In the course of an accident involving acute whole 

overexposures, decisions regarding rescue operabe made quickly and on the basis of fragmentary information. 

Rescuing Victims

NCRP Report 39 Guidance

Where it is necessary to search for and rescue inj

persons as part of a life saving operation, the NCReport #39) at one time offered the following recommendations:
NCRP Report 39 Guidance

1. Rescuers should be volunteers or professional re

personnel.

2. Rescue personnel should be familiar with the pos

conse

quences of ex

posure.

Rescuing Victims

q p

3. Women capable of reproduction should not partic4. Where possible, volunteers should be over 45 ye

age. [This recommendation does not take into acrisks to an elderly individual from the physical strthat exhaustive rescue efforts might entail.]
NCRP Report 39 Guidance

5. The "planned" dose to the whole body should no

100 rems [rads].

6. Hands and forearms may receive a total dose of 

[rads].

Rescuing Victims

7. Such exposures should be limited to once in a lif8. Persons receiving such exposure should avoid p

for several months.

9. The best available respiratory protection and pro

clothing should be used if appropriate.
NCRP Report 116 Guidance

Only lifesaving activities justify doses much in exc

annual worker limits. If the actions do not involve lifesaving the recommlimit is 0.5 Sv (50 rems).

Rescuing Victims

For lifesaving purposes when 0.5 Sv might be excthe volunteers should understand the potential fo(early) effects and the lifetime increased risk of caThe use of volunteers is desirable.Older workers should be chosen whenever possib
Department of Energy Regulations 10 CFR 835 

Subpart N—Emergency Exposure Situations§ 835.1301 General provisions.(a) A general employee whose occupational dose has exceed

numerical value of any of the limits specified in § 835.202 

an authorized emergency exposure may be permitted to re

Rescuing Victims

in radiological areas during the current year providing that following conditions are met:

(1) Approval is first obtained from the contractor managemen

Head of the responsible DOE field organization;

(2) The individual receives counseling from radiological protec

medical personnel regarding the consequences of receivinoccupational exposure during the year; and

(3) The affected employee agrees to return to radiological wo
Department of Energy Regulations 10 CFR 835 

Subpart N—Emergency Exposure Situations§ 835.1302 Emergency exposure situations.(a) The risk of injury to those individuals involved in rescue an

operations shall be minimized.

(b) O ti t h ll i h t l d t ti l i 

Rescuing Victims

(b) Operating management shall weigh actual and potential ri

the benefits to be gained.

(c) No individual shall be required to perform a rescue action 

involve substantial personal risk.

(d) Each individual authorized to perform emergency actions 

result in occupational doses exceeding the values of the limat § 835.202(a) shall be trained in accordance with § 835.9briefed beforehand on the known or anticipated hazards to individual will be subjected. 
References
Goans, R.E., Holloway, E.C., Berger, M.E. and Ricks, R.C. Ea

Assessment in Criticality Accidents, Health Physics 81 (4): 2001.

Gusev, I.A., Guskova, A.K. and Mettler, F.A. Medical Managem

Radiation Accidents 

2nd edition, CRC Press Inc., Florida, 1

Mettler, F.A., Kelsey, C.A., and Ricks, R.C. Medical Managem

R di ti A id t CRC P I Fl id 1990

References

R

adiation 

Acciden

ts CRC

Press Inc., Florida, 1990.

Mettler, F.A. and Moseley, R.D. Medical Effects of Ionizing Ra

Grune & Stratton , Orland Florida, 1985.

Ricks, R.C., Berger, M.E., and O’Hara, M. The Medical Basis 

Radiation-Accident Preparedness- the Clinical Care of VicOf the Fourth International REAC/TS Conference. ParthenGroup, Florida, 2002.

Swindon, T.N. Manual on the Medical Management of Individu

in Radiation Accidents Technical Report 131, ARPANSA, A