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Acute Radiation Syndrome Survivors after Chernobyl Accident: History of Irradiation, Diagnostic Mistakes and Death Reasons in Long-term Period

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  • National Research Center for Radiation Medicine, Kiev, Ukraine
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Acute Radiation Syndrome Survivors after Chernobyl Accident: History of Irradiation, Diagnostic Mistakes and Death Reasons in Long-term Period

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In 1986 it was officially stated that 237 patients got acute radiation syndrome (ARS) of different severity as a result of the Chernobyl accident but till 1989 this diagnosis was confirmed for 134 persons, including those 28 persons, who died within 11 to 96 days. Amongst 103 patients with unconfirmed ARS the main criteria for retrospective decline of diagnosis in 27 patients with typical clinical symptoms were incompleteness of early haematological data, and in 76 – the atypical character of haematological parameters recovery after their initial decrease. Of those individuals, 190 were living in the territory of Ukraine, and 19 persons in other republics of the former Soviet Union. Amongst Ukrainian residents 42 (24 ARS survivors and 18 non-ARS patients) have died till the end of 2012. The causes of death included oncological (16 patients from 22 with cancer and leukaemia diagnosed) and cardiovascular (14 patients) diseases, somatic diseases and infections (7 patients), accidents (5 cases). The localisation of cancer was rather different: kidney, colon, stomach, lung, lower jaw, thyroid gland, throat, prostate. Sudden cardiac death was the main reason of cardiovascular mortality whereas acute cerebrovascular disease ranked second and was followed by acute myocardial infarction and chronic heart failure.
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In 1986 it was officially stated that 237 patients got acute radiation syndrome (ARS) of different
severity as a result of the Chernobyl accident but till 1989 this diagnosis was confirmed for 134
persons, including those 28 persons, who died within 11 to 96 days. Amongst 103 patients with
unconfirmed ARS the main criteria for retrospective decline of diagnosis in 27 patients with
typical clinical symptoms were incompleteness of early haematological data, and in 76 – the
atypical character of haematological parameters recovery after their initial decrease. Of those
individuals, 190 were living in the territory of Ukraine, and 19 persons in other republics of
the former Soviet Union. Amongst Ukrainian residents 42 (24 ARS survivors and 18 non-ARS
patients) have died till the end of 2012. The causes of death included oncological (16 patients
from 22 with cancer and leukaemia diagnosed) and cardiovascular (14 patients) diseases,
somatic diseases and infections (7 patients), accidents (5 cases). The localisation of cancer was
rather different: kidney, colon, stomach, lung, lower jaw, thyroid gland, throat, prostate. Sudden
cardiac death was the main reason of cardiovascular mortality whereas acute cerebrovascular
disease ranked second and was followed by acute myocardial infarction and chronic heart
failure.
Key words: Chernobyl accident; acute radiation syndrome; leukaemia; cancer
Radiation Emergency Medicine 2013 Vol. 2 No. 2 5-12
Acute Radiation Syndrome Survivors after Chernobyl Accident:
History of Irradiation, Diagnostic Mistakes and Death Reasons
in Long-term Period
David Belyi*, Alexander Kovalenko and Dimitry Bazyka
State Institution "National Researc h Centre f or Radiation Medicine o f Ukrainian Academ y o f Med ical Sciences",
Mel nikov str. 53, 04 050, Kiev, U kraine
Received 20 March 2013; revised 7 May 2013; accepted 10 May 2013
*David Belyi, MD: State Institution "National Research Centre for Radiation
Medicine of Ukrainian Academy of Medical Sciences"
Melnikov str. 53, 04050, Kiev, Ukraine
E-mail: dbelyi_2000@yahoo.com
Copyright © 2013 by Hirosaki University. All rights reserved.
Review
1. I n t r o d u c t i o n
Patients with a history of acute radiation syndrome
(ARS) constitute a group of most heavily injured of those
exposed to radiation ef fects as a result of Chernobyl
Nuclear Power Plant (CNPP) accident. The health status
of such patients is continuously monitored in Ukraine
by the National Research Centre for Radiation Medicine
(NRCRM). Different phases of such research programs
ha ve been r epor t ed alr ead y1-7 ). Two int erna t ional
projects (1) Joint study project No 3 "Diagnosis and
treatment of patients with acute radiation syndrome"
(1991-1995); and (2) INCO-Copernicus project "Radiation
over-exposed accident victims: eva luation of health
consequences" (1998-1999) have been completed and
their results have already been published8-10).
Ho wever, the nat ure and s pectr um of diseases
developed in ARS sur vivors over a mid- and long-term
period after radiation exposure is still under discussion. In
particular, the role of radiation factor and its magnitude
6 6D. Belyi et al. / R adiation Emergency Medicine 2013 Vol. 2, No. 2 5-12
in the late development of a somatic pathology in ARS
sur vivors should be elucidated. Long-term ef fects on
the cardiovascular system should be studied above all,
as the indications exist about the relationship of the
car diovascular morta lity with radiation exposure11).
An inc r ease in t he i ncide nce and mor ta l ity from
cardiovascular system diseases in a cleanup workers of
the CNPP accident is also registered on an epidemiologic
basis12).
In 95% of ARS survivors, dyscirculatory impairments
of cerebral haemodynamics were f ound during the
first several years after the accident13). The further 20-
year post-accidental monitoring at the NRCRM showed
a high incidence of circulator y diseases. However, no
correlation of the development of cardiovascular diseases
in ARS survivors with the exposure dose or severity of
ARS was found5). Meanwhile, a significant increase in the
incidence of cerebral atherosclerosis and coronary heart
disease (CHD) has been revealed in hibakusha with high
exposure doses in a much later period after irradiation
exposure14). Those facts mean that a lifetime analysis of
the health status of ARS survivors should be carried out.
It is such program of long-term studies what is planned at
NRCRM.
The cohort of ARS survivors has shrunk substantially
over 26 post-accidental years as compared with 1986,
and it will continue to decrease. Some patients got lost
for the follow-up. Nevertheless, the system of mortality
registration in individuals with occupational pathologies
implemented in Ukraine makes it possible to obtain data
on the mortality of ARS survivors. This paper describes
the initial group of patients with ARS diagnosed in 1986,
and thus included in the high priority medical supervision
cohort. The causes of death in the post-accidental period
are also analyzed.
2. Materials and methods
In the first days after CNPP accident, 499 patients with
declared ARS were hospitalized. No clinical or laboratory
signs confirming the diagnosis were found in the majority
of them. In December 1986, it was of ficially stated that
237 patients got ARS of different severity as a result of
the accident at the CNPP. Of those patients, 28 died within
11 to 96 days: 27 patients (20 patients with ARS grade
4 and 7 patients with ARS grade 3) died of extremely
severe radiat ion-induced bone mar row fai lure and
radiation lesions of skin, and one female patient with ARS
grade 2 died of a concomitant disease on a background
of recovered haematopoiesis15). Two more individuals
died within the first day after the accident: one of them
was buried under the ruins of the reactor, and the other
died of fatal thermal burns in several hours af ter the
explosion16). Of 237 patients with ARS, 118 were staying
on treatment in Moscow Clinical Hospital No. 6 and 119 in
several hospitals in Kyiv.
Overdiagnosis of ARS was suggested back in 198617). An
analysis of source documents was made by the Institute
of Biophysics (Moscow) with the participation of experts
fr om NRCR M under the general guidance by prof.
Angelina Guskova in the period from 1986 through 1989.
Confirmation (exclusion) criteria were based on typical
dynamics of hematological indices uppermost neutrophil
granulocytes and thromboc ytes during acute phase
followed the ir radiation, and clinical symptoms as well
(Table 1)17, 18).
Diagnosis of ARS was cancelled in 103 patients (10
patients treated in Moscow Clinical Hospital No. 6 and
93 patients treated in Ukrainian medical centres) due
to incompliance of the clinical and laboratory data with
radiation bone marrow syndrome or because of lack of
medical data that would make it possible to confirm the
diagnosis (Table 2). Thus, the number of patients with
ARS reduced to 134 individuals. The rest of patients
with unconfirmed diagnosis (ARS NC) were considered
as definitely suf fered from a radiation exposure, which,
however, did not result in the development of classical
radiation-induced bone marrow syndrome.
Taking in account that the ma jority of Chernobyl
victi ms was liv ing in Ukraine NRCRM hav e been
established in Kyiv on October 1986. Star ting from this
date 190 patients residing in Ukraine have been under
regular medical supervision and treatment in the clinic
of NRCRM. During a first five-year period before a
collapse of the USSR most of Ukrainians, two Russian
and two Belarusian patients had been followed up also
at Moscow Clinical Hospital No. 6 of the Institute of
Biophysics. Therefore, data on first recovery period after
ARS published by Kyiv and Moscow groups are almost
identical. Since 1991 clinical analysis and treatment are
performed by national centres.
Male patients prevailed among those exposed to
irradiation: male patients comprised 89.3% of unconfirmed
ARS diagnosis group, 92.7% of ARS grade 1 group, 96.0%
of ARS grade 2 group, 100% of ARS grade 3 group and
95.2% of ARS grade 4 group (Table 3). The professional
radiation anamnesis showed that among patients with
confirmed ARS grade 1 to 4 there were 70 workers of
the CNPP, 12 guardians of the plant (servicemen of the
internal military forces of the Ministry of Internal Affairs
of the USSR), 21 construction workers of the 5th and 6th
new power blocks, 19 fire-fighters, 4 so-called "liquidators"
(clean-up staff) and 6 individuals occasionally exposed to
radioactive irradiation. Occupation of 2 died patients was
unknown, therefore, such patients were not included in
any of the aforementioned categories of injured persons18).
The rectified data available now in the archives of CNPP
and Chernobyl National Museum, make it possible to
7 7D. Belyi et al. / R adiation Emergency Medicine 2013 Vol. 2, No. 2 5-12
categorize all individuals injured during the Chernobyl
disaster by their occupation as shown in Table 3.
The follow-up included regular full clinical examinations
and laboratory check-ups for ever yone. The check-up
protocols included full blood count, biochemical tests
(basic metabolic panel, chemical pathology and liver
function tests), immunological prof ile (humoral and
cellular indicators), thyroid tests (ultrasound and TSH,
FT4), urinalysis, full physical examination, and various
instrumental tests as necessar y (electrocardiogram,
electroencephalogram, ophthalmological tests, gastro-
or duodenoscopy, chest X-ray, functional lung test etc.
When necessary, patients were consulted by specialists
(hema tol ogist, endocrinol ogist, neur opa t holog ist ,
oph t h a l m o l ogis t , p u l m o n olog i s t , ca r d i o l o gis t ,
gastroenterologist, dermatologist, psychiatrist, urologist
or gynecologist ). Fur ther, more complex diagnostic
methods were applied under indications, including CT
scans, biopsy, cardio-stress-ECG, colonoscopy, serological
tests for specific causes, e.g. hepatitis A, B or C viruses,
Table 2. Distribution of the patients subject to ARS grade before the diagnosis was confirmed and after this
ARS
grade
ARS was diagnosed in 1986 ARS was confirmed in 1989
Russia, Moscow Ukraine, Kyiv Russia, Moscow Ukraine, Kyiv
ARS NC 10 93
1 31 100 23 18
2 46 13 44 6
3 21 5 21 1
4 20 1 20 1
Total 118 119 118 119
Table 1. Diagnostic criteria of ARS in different periods of its development
Indices ARS grade (severity)
1 (mild) 2 (moderate) 3 (severe) 4 (very severe)
Range of absorbed dose
(Gy) 1-2 2-4 4-6 6-10
Period of primary reaction
Vomiting
in 2 hours and later, single in 1-2 hours, recurrent in 30-60 min, multiple in 5-20 min, intractable
Diarrhea
absent absent absent or probable probable
Headache
short-term moderate moderate intensive
Consciousness
clear clear clear mental confusion
Body temperature
normal subfebrile subfebrile high (38-39)
Skin and visible
mucous membrane
normal mild transitory hyperemia moderate transitory
hyperemia
apparent transitory
hyperemia
Duration of primary
reaction
Some hours Up to 1 day Up to 2 days
>
2-3 days
Latent period
Peripheral blood lymphocytes on
3-6 day (x109 1-1)
1.0-0.6 0.5-0.3 0.2-0.1 0.1
Peripheral blood leukocytes
on 8-9 day (x109 1-1)
4.0-3.0 2.9-2.0 1.9-0.5 ≤ 0.5
Diarrhea starting from 7-9 day
absent absent absent apparent
Epilation, time of onset
invisible may be on 15-20 day iin majority of patients on
10-15 day
in majority of patients on
7-10 day
Argranulocytosis onset
(granulocytes ≤ 1.0×l09 1-1)
absent or starts after 30
day 20-30 day 8-20 day 6-8 day
Thrombocytes decrease
below 40×109 1-1)
absent or starts after 25-
28 day 17-24 day 10-16 day before 10 day
Duration of latent period
30 days 15-25 days 8-17 days absent or
6-8 days
Period of manifestation
Clinical syndromes
asthenia infectious complication,
hemorrhagic diathesis,
epilation
infectious complication,
hemorrhagic diathesis,
epilation
intoxication, fever,
gastrointestinal
syndrome, hypotonia
Leukocytes count (×109 l-1)
3.0-1.5 1.5-0.5 0.5-0.1 < 0.5 or a patient dies
earlier
Thrombocytes count (×109 l-1)
100-60 50-30 less than 30 < 20 or a patient dies
earlier
ESRa, mm h-1
10-25 25-40 40-80 60-80
Note: a – erythrocyte sedimentation rate
8 8D. Belyi et al. / R adiation Emergency Medicine 2013 Vol. 2, No. 2 5-12
bone marrow tests etc.
3. Results
The histor y of irradiation
The CNPP workers formed the biggest cohort of
patients with ARS of different grade – 52.2%. The second
biggest cohort (15.7%) comprised the builders of the 5th
and 6th power units, and the third biggest cohort (14.9%)
fire fighters. Other injured included the guardians (8.2%),
occasionally exposed persons (6.0%) and liquidators (3.0%),
i.e., those persons who were sent by their enterprises to
participate in accident rescue operations in the CNPP
zone. Of 28 died persons, 20 were the workers of CNPP, 6
fire fighters and 2 – occasionally exposed.
Amongst employers there was both the CNPP night
shift and personnel arrived at the plant in the morning of
April 26, 1986 after the reactor explosion. They took an
active part in emergency and rescue operations into the
plant shops and therefore were ir radiated in high level
doses.
The CNPP military guard watched the plant perimeter.
The of ficers, who stood guard at the time of reactor
destroying, suffered from irradiation if their posts turned
out on the way of nuclear fallout. Several persons had
nausea and vomiting minutes-hours after the explosion
and was substit uted by anot her of ficers, who was
undergone to high dose irradiation too.
Together with militar y guard builders were exposed
to radiation due to radionuclides on the ground sur face
near mobile workers' locker rooms. Until the construction
workers of night shift worked inside the premises of 5th
and 6th reactors the exposure at the first hours after the
accident was lower because of distance and wall shielding
factors. However when the workers came back to their
locker rooms early in the morning they were heavily
exposed to the external irradiation and ground radiation
sources (pieces of graphite and nuclear fuel) that led to
combination of bone marrow syndrome with local skin
radiation lesions of lower extremities.
The main task of fire fighters that reached the CNPP
after fire alarm was to stop fire spreading along the
roof of 4th reactor building directly to other plant shops.
Six men, who extinguished the fire on the roof, got
unviable general and local radiation damages. Several
fire fighters spent on the roof less time and were far
Table 4. Death reasons in patients with ARS NC and ARS survivors in the post-accidental years
ARS grade
Death reasons
Cardiovascular
diseases
Oncological and
oncohaematological
diseases
Somatic, nervous and
infectious diseases Traumas and accidents Total
ARS NC 5 9 2 2 18
1 32128
2 4 3 3 0 10
3 22116
Total 14 16 7 5 42
Table 3. Distribution of the ARS and ARS NC patients by age, gender, professional and absorbed doses
Indices
ARS grade
ARS NC 1 2 3 4
Gender: f / m 11 / 92 3 / 38 2 / 48 0 / 22 1 / 20
Professional activity at the irradiation:
CNPP employers 29 19 21 17 13
CNPP guardians 2 8 3 - -
builders 6 3 15 3 -
fire-fighters 34 6 7 1 6
clean-up staff 12 1 3 - -
occasionally irradiated persons 20 4 1 1 2
Age at the irradiation, years na=103 n=41 n=50 n=22 n = 21
М ± SDb36.4±10.4 34.1±8.5 37.9±13.5 37.4±13.5 31.8±9.2
min – max 18.4 - 60.3 17.6 - 56.3 17.9 - 79.3 20.4 - 72.6 23.2 - 53.6
95% CI с34.4 - 38.5 31.4 - 36.8 34.1 - 41.7 31.4 - 43.4 27.6 - 36.0
Absorbed dose, Gy n=18 n=34 n= 44 n= 18 n = 18
М ± SD 0.4±0.3 1.0±0.6 2.4±0.9 5.1±1.5 9.9±2.2
min – max 0.1 - 1.0 0.1 - 3.3 0.5 - 4.9 2.9 - 8.2 6.4 - 13.7
95% CI 0.2 - 0.5 0.8 - 1.2 2.1 - 2.7 4.4 - 5.8 8.8 - 11.0
Note: a – number of patients in the sample
b – mean ± standard deviation
c – confidence interval
9 9D. Belyi et al. / R adiation Emergency Medicine 2013 Vol. 2, No. 2 5-12
from destroyed part of the roof. They sur vived mild
and moderate ARS. ARS was incor rectly diagnosed in
firemen who (a) was near their cars and controlled water
supply for extinguishing the fire, (b) inspected the CNPP
territor y for seats of fire, (c) pumped out water from
under the destroyed 4th reactor on May 6-8, 1986 and (d)
distinguished a fire in the tunnel between 3rd and 4th block
on May 22, 1986.
Cleanup staff is a name of voluminous cohort of people
who were directed by their enterprises for emergency
and rescue operations at the CNPP and 30 km radioactive
zone. P rof essionally it was drivers, medical sta f f,
engineers, servicemen and policemen.
The category "occasionally irradiated persons" included
dif ferent people that could not be attributed to any
afore-mentioned groups. T hese people never contact
wit h radiation professionally and didn't take par t in
emergency and rescue operations at the CNPP, but they
were exposed to irradiation nevertheless. For example,
just before the accident, 3 engineers of Kharkov T urbine
Works had been sent to CNPP in order to perform testing
of a turbine manufactured at the said Turbine Works.
During the accident, they were staying in close vicinity
to the ruined reactor. Two of them died of ARS grade 4,
whereas one of them sur vived ARS grade 3. A worker
who operated with ref rigerates in the NPP cafeteria
sur vived ARS grade 2. ARS grade 1 developed in two
women worked on their vegetable gardens that were on
the way of nuclear fallout. Two men also sur vived ARS
grade 1 because of they were at the plant in a mission.
ARS NC was diagnosed in town Pr ypyat inhabitants who
stayed closely to the CNPP.
Patients with ARS grade 1 to 3 and patients with
unconfir med A R S were act uall y of the sa me age
group, while mean values of exposure doses dif fered
significantly (P < 0.001).
The reasons of mistakable ARS
At diagnoses re-evaluation 45.5% of ARS diagnoses
initially established havent been confirmed. Analysis
demonstrated that the main criteria for retrospective
decline of diagnosis were incompleteness or atypical
character of the early laboratory data.
The diagnosis of the ARS in 27 of 93 patients was
declined due to the incompleteness of early laboratory
investigation data. Periphera l blood counts in such
patients within first 40 to 60 days after exposure were
either absent or insufficient for estimation of the severity
of bone marrow failure. Owing to dif ferent objective
emergency f amily or work circumstances, patients
were beyond medical supervision during the period of a
possible manifestation of the disease. They usually have
asked medical care after resolving personal problems
during a recover y period when it was impossible to
esta blish diagnosis usi ng haema tol ogica l criteria.
Accounting for the lack of laboratory data, diagnosis of
ARS was made in 1986 on the basis of (1) a confirmation
of a formal fact of staying in the zone of high irradiation
in the initial period and (2) a history of a primary reaction
with clinical symptoms described16, 17, 19). Exposure doses
in 4 of those 27 patients were determined within the
subsequent months by chromosome aberrations assay
and were equal to 0.2, 0.3, 0.8 and 1.0 Gy.
Another group of patients with unconfirmed ARS
comprised 76 individuals. Haematological data were not
uniform in that group. In particular, blood counts were
within the normal values in 2 patients during the first 60
days after exposure, whereas 4 patients showed the signs
of transient anaemia, 1 patient had lymphocytopenia and 3
patients – lymphocytopenia in combination with transient
anaemia. Nevertheless, those 10 patients had symptoms
of the primary reaction, including vomiting in 5 patients;
and moderate radiation burns of feet were diagnosed in
one patient. Somatic pathologies that would explain the
observed changes in the blood analyses were found in
none of the patients during their staying at the hospital.
Dynamics of neutrophilic granulocytes and platelets
in the peripheral blood of the other 66 of 76 injured
persons was not typical for the bone marrow syndrome
such as a gradual or sharp, depending on the exposure
dose, decrease down to the minimum level followed with
an increase corresponding to a recovery of the blood
count level. Dif ferences between the haematological
characteristics of those patients included the dif ferent
extent of granulocytopenia and thrombocytopenia and
the number of cases of the decrease in granulocyte and
platelet levels beyond the lower limit of the physiological
range. Following the exposure, granulocyte levels in
the peripheral blood decreased beyond the lower limits
in 51 patients and platelet levels in 61 patients. During
the first 10 days af ter exposure, lymphocyte coun ts
were reduced in 51 patients. Eventual nonrecurring
reduction of either granulocyte or platelet levels was
observed in 4 patients only, and granulocytopenia was
combined with lymphocytopenia and erythrocytopenia
in one of such patients. Nonrecurring granulocytopenia
and thrombocytopenia was obser ved in 3 patients in
combination with lymphocytopenia and erythrocytopenia.
In other patients with ARS NC from 2 to 29 (5 on average)
episodes of granulocytopenia and 2 to 16 (4 on average)
episodes of thrombocytopenia were obser ved in the
period from 5 to 60 days after exposure.
One can assent to an opinion that diagnostic mistakes
were related to lack of knowledge and experience20).
Indeed, shor t sporadic episodes of cyt openia w er e
frequently taken as the manifestations of bone marrow
failure in patients with a history of stay in high radiation
fields in a close vicinity to the ruined 4th reactor. However,
10 10D. Belyi et al. / R adiation Emergency Medicine 2013 Vol. 2, No. 2 5-12
one should also account for that none of the injured
persons of this initial accident period were provided
by individual dosimeters designed for high levels of
irradiation, and no information was available for health
care staf f about a possible patient doses calculated on
the basis of route lists (such calculations were made
substantially later). Therefore, physicians followed a
conservative strategy: they would rather make a mistake
and diagnose more severe condition than miss a diagnosis
of a real disease.
A retrospective analysis of haematological parameters
of patients with ARS NC showed substantial differences
as co m p a r e d wi t h pa t ie n t s wi t h A R S grade 1.
Individual haemograms of patients with ARS NC did
not comply with those typical for ARS supporting the
absence of typical bone mar row f ailur e syndrome.
Meanwhi le, episodes of r ed uced perip heral blood
levels of granulocytes and platelets, minimum levels of
granulocytopenia and thrombocytopenia, actual terms of
their onset and lymphocytopenia in the first 10 days after
exposure testified to the substantial radiation-induced
haematological injury.
T.Fliedner and W.Nothdurft21) believe that a single
dose of 0.5 Gy or lower may induce a damage of the
hematopoietic tissue in a cer tain region of the bone
marrow. G.Gruzdiev22) shares their opinion having found
that ir radiation dose of 0.5 Gy may induce a reduction
of the level of myeloid cells in the bone marrow down
to 58% of the physiological level, and a reduction of the
peripheral blood neutrophils down to subnormal values.
HLA phenotype studies performed in ARS grade 1-2 in
comparison with ARS NC with the similar known doses
of exposure have suggested also possibility of association
of atypical bone marrow changes with different subjects
radiosensiti vit y23). Of course there still exist ot her
uncertainties.
Thus, we can suggest that signs of radiation damage
of hematopoietic tissue confirmed with haematological
or dosimetric characteristics were observed in 73.8% of
patients with unconfirmed ARS.
The reasons of death during long-term period
Only 209 individuals were still alive by the end of
1986, including 106 ARS survivors and 103 patients with
unconfirmed ARS. Of those individuals, 190 were living in
the territory of Ukraine, and the residual 19 persons – in
other republics of the former Soviet Union.
For study of the late health effects of radiation exposure
the identical criteria and approaches of the assessment of
health data were used irrespectively of the results of the
1989-th re-evaluation of diagnoses.
During three years after CNPP disaster 190 patients
residing in Ukraine under went medical examination
in NRCRM, but by the end of 2012, the actual number
of followed-up patients reduced to 118 (ARS NC 61,
ARS grade 1–27, ARS grade 2–24, and ARS grade 3 6).
Altogether, 42 patients, including 18 pat ient s with
unconfirmed ARS and 24 ARS survivors, died during 26
years after CNPP accident. Thirty individuals, including
20 patients with unconfirmed ARS and 10 ARS survivors,
were lost for medical supervision.
Eighteen patients with ARS NC and 24 ARS survivors
died during the period from 1987 to 2012. Oncological
and oncohematological pathologies prevailed among the
causes of those deaths (Table 4). Blood disorders included
a case of hypoplasia of hematopoiesis (D61.9 according to
International Classification of Diseases of 10th revision) in
1987, acute myelomonoblastic leukaemia (C92.5) in 1998,
three cases of myelodysplastic syndrome (D46) in 1993,
1998 and 2002, and a case of polycythemia vera (D45) in
2011. Two patients died of stomach cancer (C16.8) in 2004
and 2005 and two of colon cancer (C18.9) in 2001 and 2005.
Lar yngeal cancer (C13.9) in 2001, prostate cancer (C61)
in 2003, urinary bladder cancer (C67.8) in 2008, maxillary
sinus cancer (C31.0) in 2010 and mandible malignant
neurinoma (schwannoma) (C47) in 2004 caused the death
in one patient each. One patient with unconfirmed ARS
died of femoral soft tissue sarcoma (C49.2) in 1993.
Cardiovascular diseases placed the second (after
oncological pathologies) prevailing cause of long-term
mortality after exposure (Table 4). In the period from
1986 to 2012, sudden cardiac death was the cause of
death of 9 persons (I46.1). Either essential hypertension
(I10, I11) or/and coronar y hear t disease (I20.1, I25.0,
I25.1) were diagnosed in all such died persons. Post-
mortem examination of none of them showed any signs
of myocardial inf arction or anot her acute pathology
that might be the cause of death. Fatal heart rhythm
disorders could result in lethal outcome. Three more
patients with underlying essential hypertension died of
acute cerebrovascular disease (1991, 2006, 2008) (I61,
I63). Chronic heart failure (I50.1) and acute myocardial
infarction (I21) were the causes of death of one patient in
2007 and another in 2010 respectively.
We have found no correlation between the cases
of oncological or cardiac death and dose of radiation
exposure or ARS grade.
Other somatic pathology, in particular, pulmonary
gangrene (J85.0), liver cirrhosis (K74) caused death
in 1 patient (in 1987) and 2 patients (in 1995 and 1998),
correspondingly. One patient with unconfirmed ARS
died of encephalomyelitis with bulbar paralysis in 1988,
and two ARS survivors (1995, 2004) and one patient with
unconfirmed ARS (2006) died of tuberculosis (A15).
Injuries suffered in a traffic or other accidents were
lethal in five persons (in 1986, 1995, 1995, 2002 and 2010).
Average age of died patients was 58.8±13.7 years; on
the date of death, the youngest had 26.3 years of age
11 11D. Belyi et al. / R adiation Emergency Medicine 2013 Vol. 2, No. 2 5-12
(patient with ARS grade 1, sudden cardiac death), and
the oldest – 87.3 years (patient with ARS grade 3). Nine
patients died in the age below 50 years, and among the
other patients, 13 individuals died in the age below 60.
Thus, the share of malignant tumours in the causes
of long-term mortality was 23.8% (10 patients, average
age: 61.4±13.0 years), blood and hematopoietic tissue
diseases – 14.3% (6 patients; average age 56.8±6.8 years)
and cardiovascular pathologies, including stroke, – 33.3%
(14 patients; average age 61.9±15.7 years).
Of 75991 victims of atomic bombing of Hiroshima
enr olled in the program of t he L ife Span Study at
the Radiation Ef fects Research Founda tion, 28737
persons died during the period from 1950 to 198514).
The aforementioned diseases were the cause of death
in 20.7% (5936 patients), 0.5% (146 patients) and 38.8%
(11164 patients) of those patients, correspondingly. The
period of follow-up of exposed people in Japan was twice
as large as our period of follow-up, never theless, the
relative numbers of patients died of malignant tumours
and cardiovascular diseases were actually similar in both
studies.
According to Y.Shimizu et al.24), higher lethality rate
caused by circulatory system diseases was obser ved in
persons below 40 years of age on the date of exposure or
in persons with exposure dose above 2 Gy according to
dosimetric model DS86. A lack of significant correlation
between cardiac death and exposure dose in our study
may be explained, f irst, with a smaller number of
deceased subjects because of a shorter follow-up period,
and second, with a smaller group of examined patients as
compared with the cohort exposed in Japan.
4. Conclusion
A study of the late health ef fects in the group of
survivors after ARS diagnosed in 1986 was performed
by the st andardized criter ia ir respectiv ely of t he
results of the diagnoses re-evaluation in 1989. Analysis
demonstrated that the main criteria for retrospective
decline of diagnosis in 27 patients with typical clinical
symptoms were incompleteness of early haematological
data, and in 76 – the atypical character of haematological
parameters recovery after their initial decrease. During
the 1986-2012 follow -up period 42 of 190 pat ients
deceased from the number of persons who followed up in
NRCRM. The prevailing causes of death were malignant
tumours, including oncohaematological patholog y,
and cardiovascular diseases. These data coincide with
obtained in A-bomb survivors. No dose dependency of
mortality and no dif ference between ARS and ARS NC
were demonstrated at the study period.
References
1. Bebeshko V G, et al. (1989) Rehabilitation of victims of acute
radiation sickness. In: Medical aspects of the Chernobyl accident.
p 267. IAEA, Vienna.
2. Bebeshko V, et al. (1995) Health effects of the Chernobyl accident.
In: Te ylor M ed. Proceedings of the Twentieth international
symposium "Uranium and Nuclear Energy: 1995". pp. 67–73. The
Uranium Institute, London.
3. Bebeshko V, Kovalenko A and Belyi D (1996) Long term follow-
up of irradiated persons: rehabilitation process. In: K araoglou
A, Desmet G, Kelly GN and Menzel HG eds. The Radiological
Consequences of the Chernobyl Accident. pp. 607–609. European
Commission, Brussels.
4. Bebeshko VG, et al. (1999) R adiation cata racts in high dose
liquidators who developed acute radiation syndrome. In: Junk
AK, Kundiev Y, Vitte P and Worgul BV eds. Ocular radiation risk
assessment in populations exposed to environmental radiation
contamination. pp. 51–56. Kluwer Academic Publishers, Dordrecht.
5. Belyi DA, Bebeshko VG, Weiss M and Fliedner TM (2002) The
cardiovascular system: observations in Chernobyl accident victims.
In: Fliedner TM, Feinendegen LE and Hopewell JW eds. Chronic
Irradiation: Tolerance and Failure in Complex Biological Systems.
pp. 258–264. The British Institute of Radiology, London.
6. Bebeshko V, Belyi D, Kovalenko A and Gergel O (2002) Health
consequences in the Chernobyl emergency workers surviving
after confirmed acute radiation sickness. In: Follow-up of delayed
health consequences of acute accidental radiation exposure. pp.
5–26. IAEA, Vienna.
7. Bebeshko VG, et al. (2003) Medical monitoring results of survivors
wit h acute radiation s yndr ome after Chernoby l disaster. In:
Shibata Y, Yamashita S, Wa tanabe M and Tomonaga M eds.
Radiation and humankind. pp. 115–122. Elsevier, Amsterdam.
8. Gottlober P, et al. (2001) The outcome of local radiation injuries: 14
years of follow-up after the Chernobyl accident. J Radiat Res 155:
409–416.
9. Steinert M, et al (2003) Delayed effects of accidental cutaneous
radiation exposure: fif teen years follow-up after the Chernobyl
accident. J Am Acad Dermatol 49: 417–423.
10. Boehm BO, et al. (2009) Thyroid examination in highly radiation-
exposed workers after the Chernobyl accident. Eur J Endocrinol
160: 625–630.
11. Preston DL, et al. (2003) Studies of mortalit y of atomic bomb
survivors. Report 13: Solid cancer and noncancer disease mortality:
1950–1997. J Radiat Res 160: 381–407.
12. Bebeshko VG, Bazyka DA and Buzunov V (2007) Chornobyl:
current situation of non-cancer diseases. In: Shibata Y, Namba H,
Suzuki K and Tomonaga M eds. Radiation Risk Perspectives: Proc.
of the Second Nagasaki Symp. of Int. Consortium for Medical Care
of Hibakusha and Radiation Life Science (Nagasaki) (International
Congress Series, vol 1299). pp. 54–59. Elsevier, Nagasaki.
13. Gorban NG and Torubarov FS (1990) Cerebral hemodynamics
in acute radiation disease in the victims of the accident at the
Chernobyl nuclear power station. Med Radiol (Mosk) 35: 20–23 (In
Russian)
14. Effects of A-bomb radiation on the human body (1995) Shigematsu
I, Ito C, Kamada N, Akiyama M, Sasaki H and Harrison B eds.
Bunkodo Co., Tokyo.
15. Gus'kova AK, et al. (1989) Acute effects of radiation exposure
following the Chernobyl accident: immediate results of radiation
sickness and outcome of treatment. In: Medical aspects of the
Chernobyl accident. pp. 233–256. IAEA, Vienna.
16. Gus'kova AK, et al. (1987) Acute radiation effects in victims of
the accident at the Chernobyl nuclear power station. Med Radiol
12 12D. Belyi et al. / R adiation Emergency Medicine 2013 Vol. 2, No. 2 5-12
(Mosk) 32: 3–18 (In Russian).
17. Mettler Jr FA, Gus'kova AK and Gusev I (2007) Health effects in
those with acute radiation sickness from the Chernobyl accident.
Health Phys 93: 462–469.
18. Belyi DA, Khomenko VI and Bebeshko VG (2009) Emergency
preparedness of Research Center for Radiation Medicine and
its hospital to admit and treat t he patients with signs of acute
radiation sickness. Radiat Prot Dosimetry 134: 159–163.
19. A nn o GH, Baum SJ , Wi t he rs HR and You ng RW (1 98 9)
Symptomatology of acute radiation effects in humans af ter
exposure to doses 0.5 - 30 Gy. Health Phys. 56: 821–838.
20. Khalyav ko IGand Boichuk RR (1992) Retrospective analysis
of acute radiation sickness diagnosis: criteria and mistakes. In:
Accident at the Chernobyl NPP: radiation monitoring, clinical
problems, social and psychological aspects, demographic situation,
low doses of ionizing radiation (Information bulletin, issue 2, vol 2).
pp. 129–138. Kiev (In Russian).
21. Fliedner TM and Nothdur ft W (1986) Cytological indicators
haematopoietic effects. In: Biological indicators for radiation dose
assessment. pp. 123–152. MMV Medizin, Munich.
22. Gruzdev GP (1988) Acute radiation bone marrow syndrome.
Medicine, Moscow (In Russian).
23. Minchenko J (1998) Genetic systems of blood. In: Kovalenko ON
ed. Acute radiation sickness. pp. 76–84. Ivan Fedorov, Kyiv (In
Ukrainian).
24. Shimizu Y, Kato H, Schull WJ and Hoel DG (1992) Studies of the
mortality of A-bomb survivors. 9. Mortality, 1950-85: Part 3. Non-
cancer mortality based on the revised dose (DS86). J Radiat Res
130: 249–266.
... The incidence of MDS among the ChNPP accident clean-up workers tended to exceed a respective value among population of Ukraine examined at the same period (4.58 vs. 3.70%) [4]. Monitoring of the cohort of acute radiation syndrome (ARS) survivors in the post-accidental period of the Chornobyl accident at the National Research Centre for Radiation Medicine (NRCRM) was performed since 1986 [5]. Three cases of MDS were diagnosed whereupon among the ARS patients. ...
... It was officially stated that 237 patients had got an ARS of different severity as a result of the Chornobyl accident. Until 1989 the ARS diagnosis was confirmed for 134 persons, including those 28 people, who had died within 11 to 96 days [5]. Three mentioned above MDS cases in ARS patients were diagnosed in remote period after the irradiation due to CHNPP accident, namely the RA after 113 months (9.4 years), the U-MDS after 125 months (10.4 years), and the RARS after 49 months (4.1 years). ...
... Cardiovascular and renal disease are two manifestations of DEARE that have been studied clinically and experimentally at targeted radiation exposures !10 Gy. Cardiovascular disease has been identified as a major cause of death in survivors of atomic bombs and nuclear accidents (1)(2)(3)(4)(5)(6). Radiation nephropathy is associated with cardiovascular disease after total-body irradiation (TBI) (6,7), and has been shown to cause myocardial and coronary vascular disease after local as well as total-body exposures (8,9), suggesting a causal link between the renal and cardiovascular DEARE. ...
... Although radiation doses at significantly less than 10 Gy may raise the risk of cardiovascular disease in both humans and animal models (2,4,10), there is a paucity of information related to the time course of cardiovascular disease progression, the specific mechanisms which mediate the progression of vasculopathy, and their association with renal disease. Chronic inflammation and persistent oxidative stress are considered to have major roles in the development of DEARE in multiple organs (11,12), and are believed by some to be due to radiation-induced damage to vascular endothelium. ...
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