health consequences of and lessons learned from medical response to selected radiation accidents...

HEALTH CONSEQUENCES OF AND HEALTH CONSEQUENCES OF AND LESSONS LEARNED FROM LESSONS LEARNED FROM MEDICAL RESPONSE TO MEDICAL RESPONSE TO

SELECTED RADIATION ACCIDENTSSELECTED RADIATION ACCIDENTS

Module XIX

ChernobylChernobyl

Module Medical XIX-(15)

2

Accident at Chernobyl NPP Accident at Chernobyl NPP (26 April 1986)(26 April 1986)

UKRAINE

BELARUS

RUSSIANFEDERATION

Moscow

Kaluga

Bryansk

Chernobyl

Gomel

Kiev

Map of area studied


3

Chernobyl Chernobyl rreactor eactor aaccidentccident

Total contaminated surface (> 1 Ci/km2): 1 000 000 km2

Near zone (<100 km): deposition of heavy particles ( Sr, Pu...Far zone (up to 2000 km) : deposition of volatile elements (I, Cs)


4

Chernobyl disaster: Chernobyl disaster: radionuclides radionuclides releasedreleased

Radionuclide Half life Estimated activity

PBq MCi

Sr-89 50 d 20–80 0.6–2.2

Sr-90 28 y 1–8 0.03–0.22

I-131 8 d 630–1660 17–45

I-132/Te-132 3 d 400–1800 10–50

I-133 20 h 2500 68

Cs-134

Cs-137

2 y

30 y

18–48

30–90

0.5–1.3

0.8–2.4


5

Main radionuclides contributingMain radionuclides contributing to health effectsto health effects

iodine - 131iodine - 131 volatilevolatile TT1/21/2: 8 day: 8 day

disappears from disappears from environment in 2 environment in 2 monthsmonths

inhalation and inhalation and ingestion ingestion

concentrates in concentrates in thyroidthyroid

caesium-137caesium-137 volatilevolatile TT1/21/2: 30 years: 30 years

stays long in stays long in environmentenvironment

body elimination in body elimination in about 100 daysabout 100 days

homogenous homogenous distribution in all distribution in all organs and soft organs and soft tissuestissues


6

Biological effects of exposure toBiological effects of exposure toionizing radiationionizing radiation

Deterministic effectsDeterministic effects occur when the dose is above given threshold

(characteristic for the given effect) severity increases with the dose many cells die or have function altered

examples: erythema, fibrosis, marrow depletion, cataractexamples: erythema, fibrosis, marrow depletion, cataract StochasticStochastic (probabilistic) (probabilistic)

have no known threshold probability of occurrence increases with dose may result from alteration in only one or few cells

examples: examples: carcinogeniccarcinogenic - various neoplasms - various neoplasms geneticgenetic - various hereditary disorders - various hereditary disorders


7

Erythema on a Chernobyl fireman on Day 17 (primarily from beta radiation)


8

Severe multiple necrotic-ulcerative radiation burns in Chernobyl fireman on

Day 40 after the accident


9 Lloyd, D.C.: Chromosome analysis to assess radiation dose, Stem Cells, 15: 195-201, 1997


10

DISTRIBUTION OF 237 CHERNOBYL PATIENTS TREATEDFOR ACUTE RADIATION SYNDROME BY THE SEVERITYOF SICKNESS AND RANGE OF WHOLE BODY EXPOSURE

Degreeof ARS

Numberof patients

Deaths in3 months

Whole bodydose, Gy

IV 21 20 6-16

III 22 7 4-6

II 50 1 2-4

I 41 0 1-2

I-IV 134 28 1-16Not confirmed 103 0 <2

Ref.: Ilyin L.A.: Chernobyl - Myth and reality, Megapolis, Moscow, 1995 Wagemaker G. et al., IAEA/WHO/CEC Chernobyl Conf. Vienna, 1996


11

14 death in 106 14 death in 106 confirmed confirmed ARS patientsARS patients, , 1987-20001987-2000

In 1987-2000 14 confirmed ARS patients died for different reasons

Cause of death only in three cases (Myelodysplastic syndrome) may be associated with II-III degree of ARS

[Ref.: UNSCEAR Report 2000, Part II, Table 55, p.542, United Nations, New York, 2000]


12

BMT/CHERNOBYL

CRITERION FOR TRANSPLANTATION IN CHERNOBIL: IRREVERSIBLE MYELOSUPPRESSION (OVER 5,6 Gy)

BMT CONTROL

DOSE (Gy)

PATIENT DIED SURVIVED PATIENT DIED SURVIVED

< 6,5 4 3 1 (5,6 Gy) 5 0 5 6,5-9 3 2 1 (8,7 Gy) 4 3 1 > 9 6 6 0 5 5 0 TOTAL 13 11 2 14 8 6


13

Human data on Human data on radiation cancerogenesisradiation cancerogenesis

Populationgroups

Leukemia Thyroid Lung Breast Bone Skin

A-bombsurvivors

+ + + +

Ra-dialpainters

+

Earlyradiologist

+

U-miners +

Exposed ina nuclearaccident

+


14

Thyroid cancer and Thyroid cancer and ionizing radiationionizing radiation

Chernobyl accident shows that exposure to iodine isotopes may cause increase in prevalence of thyroid carcinoma

In 1990-2000 about 1800 thyroid cancers observed in 18 million children and adolescents, i.e. under 18 years old, living in the most contaminated areas of Belarus, Ukraine and Russia


15

Post-Chernobyl Post-Chernobyl thyroid cancerthyroid cancer

• increase observed mainly in children under 15

• incidence rates increased by 100 in the most affected areas (Gomel, Belarus and North of the Ukraine) in 1990-94

• incidence rate multiplied by 3 in adults (Belarus)


16

0102030405060708090

10019

86

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

An

nu

al n

um

ber

of

case

s in

ch

ildre

n

(<15

yrs

old

at

dia

gn

osi

s)

Belarus

Ukraine

Russia

Childhood thyroid cancerChildhood thyroid cancer around Chernobyl in 1986-1998 (children

<15 years old at diagnosis<15 years old at diagnosis)

[UNSCEAR: Exposures and Effects of the Chernobyl Accident, Annex J, New York, 2000]


17

0123456

Russia

Belarus

Ukraine

IncidenceIncidence of childhood thyroid cancerof childhood thyroid cancer (<15 years old at diagnosis(<15 years old at diagnosis)

around Chernobyl in 1986-1998


Incidence, number of new cases in 100 000 children per year


18

Thyroid cancerThyroid cancer around Chernobyl in 1986-1998 (Annual number of cases

among ~18M citizens <18 years old in 198618 years old in 1986)


Total No. of thyroid cc. in 13 years =1791

0

20

40

60

80

100

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998A

nn

ual

nu

mb

er

of

cas

es

in

child

ren

(<1

5 yr

s o

ld a

t d

iag

no

sis

)

020406080

100120140160180

1990 1991 1992 1993 1994 1995 1996 1997 1998

An

nu

al n

um

be

r o

f ca

se

s

(am

on

g c

itiz

en

s b

ein

g <

18 y

rs

old

in 1

986)

Belarus

Ukraine

Russia

-


19

Clinical and epidemiological features of Clinical and epidemiological features of childhood thyroid carcinomas diagnosed in childhood thyroid carcinomas diagnosed in

Belarus Chernobyl accidentBelarus Chernobyl accident

less influenced by gender female/male ratio was 1.4:1.0 (spontaneous: 2.5/1)

mean agemean age At time of first diagnosis: 9.4±2.8 yearsAt time of first diagnosis: 9.4±2.8 years At time of the accident: 3.8 ± 2.4 yearsAt time of the accident: 3.8 ± 2.4 years More than 90% of the patients were less than 6

years old and 3% were still in utero at time of accident.


20

Morphological analysis of post-Chernobyl Morphological analysis of post-Chernobyl

childhood thyroid carcinomaschildhood thyroid carcinomas

Large majority are papillary carcinomas, very few follicular histotype. Among papillary type, many (33%) solid and follicular variants

Focal micropapillary hyperplasia frequently found in post-Chernobyl thyroid glands

J Clin endocrinol Metab 1997;82:3563Cancer 1994;74:748J Clin Endocrinol metab 1996;81:9-14


21

Distribution of thyroid doses in children and Distribution of thyroid doses in children and adolescents in Belarus and the Ukraineadolescents in Belarus and the Ukraine

0

10

20

30

40

50

60

0-0

,3 G

y

0,3

-1 G

y

1-2

Gy

2-5

Gy

5-1

0 G

y

>1

0 G

y

Ukraine: 67475subjects

Belarus: 15000subjects

%


22

-500 Gy

-250 Gy

-100 Gy

-70 Gy

-0.15-5.7 Gy

I-131 therapy of hyperthyroidism

I-131 therapy of differentiated thyroidcarcinoma

radiation induced thyroid carcinoma

Thyroid doses inThyroid doses in I-131 therapy vs radiation induced I-131 therapy vs radiation induced

thyroid carcinomathyroid carcinoma


23

Other factors contributing to the Other factors contributing to the increased rate of childhood thyroid increased rate of childhood thyroid

cancer around Chernobylcancer around Chernobyl

moderate to severe iodine deficiency late iodine prophylaxis (or thyroid

blocking in many villages and towns not evacuated)

active screening (ultrasound, fine needle biopsy) manifesting also the occult cases

awareness (parents request more thyroid examinations of their children than before)


24

Leukemia and Leukemia and other cancerother cancer

No significant increase in leukemia or cancer other than thyroid; solid tumor observed in Chernobyl cleanup workers*

Tendency for elevated leukemia rates, however, among those who received significant doses while working on site in 1986 and 1987. So far statistically significant leukemia excess reported for Russian cleanup workers only**


25

Psychological disordersPsychological disorders

Significant psychological disorders caused by mental distress, among most frequent consequences of accident

Psychological effects of Chernobyl accident mainly due to lack of reliable public information

Distress caused by misperception of radiation risk extremely harmful


26

Lifetime mortality in population of all Lifetime mortality in population of all

ages from fatal cancer after ages from fatal cancer after

exposure to low dosesexposure to low dosesOrgan or tissue Fatal Cancer

ProbabilityCoefficient(10-4 Sv-1)

BladderBone MarrowBone SurfaceBreastColonLiverEsophagusOvarySkinStomachThyroid Remainder1

Total

30 50 5 20 85 15 30 10 2 110 8 50

500*

* general public (all age groups) only

Summary factor of cancer risk for working population taken to be 400x10-4 Sv-1

Reference ICRP, Publ. 60, 1991


27

Att

rib

uta

ble

life

tim

eri

sk,

% p

er

sie

vert

Age at time of exposure

Attributable lifetime risk of fatal cancerAttributable lifetime risk of fatal cancerdepending on age at exposuredepending on age at exposure


28

PREDICTIONS OF BACKGROUND AND EXCESS DEATHSFROM CANCER DUE TO CHERNOBYL

Populationgroup

Number ofpersons

Excess dose,mSv/70 yrs

Clean-up workers 200,000 100

Evacuees (30 km z.) 135,000 10

Residents at 137Cs:(>555 kBq/m2)

270,000 50

Residents at 137Cs:(<555 kBq/m2)

6,800,000 7

Total 7.4 M ps --- background cancer death = 932,500 --- excess from Chernobil = 8,900

Ref.: Cardis et al: Estimated Long Term Health Effects of the Chernobyl Accident, in: (< 1 %)“One Decade after Chernobyl”, EC/IAEA/WHO, Vienna, 8-12 April, 1996 , 241-279


29

PREDICTIONS OF BACKGROUND AND EXCESSCANCER DEATHS AND HEREDITARY DISORDERS

DUE TO CHERNOBYL

In 7 .4 M person s exp osed and liv ing in contam in ated areas --- back grou nd cancer d eath = 932 ,500 --- excess from C hernoby l = 8 ,900

(< 1 % )U p per lim it o f the

--- back grou nd hered itary d isorders = 284 ,000 --- excess r isk from C hernoby l = 275

(< 0 .1 % )

R ef.: C ard is e t a l: E stim ated L ong Term H ealth E ffec ts o f the C hernoby l A cciden t, in :“O ne D ecade afte r C hernoby l” , E C /IA EA /W H O , V ienna, 8 -12 A pril, 1996 , 241-279


30

Chernobyl conclusionsChernobyl conclusions

Radiation burns frequent Burns over 50% of body surface led to death in

19 of 28 cases Internal contamination present in most patients

but was significant in few Sepsis was uniform cause of death BMT –very limited indication Some radiation burns did not re-epithelialize,

required surgery

health consequences of and lessons learned from medical response to selected radiation accidents...

Documents

module medical

medical response

chernobyl npp

health consequences