Doses of the Whole Body Irradiation in Belarus As a Result of the Chernobyl
Accident
M. V. Malko
Joint Institute of Power and Nuclear Research-Sosny,
National Academy of Sciences, Minsk, Belarus

Abstracts An assessment of the collective and mean individual doses of the whole body
irradiation as a result of the Chernobyl accident for children, adults and total population ofBelarus are described in the present report. The assessment was carried out on the basis of dataon the surface contamination of Belarus and empirical data on contribution of internal exposure
to the total irradiation of the whole body. It was found that in case the mixed population ofBelarus collective and individual doses achieve some plateaus after 1990. The mean value of thecollective dose of the mixed population in the period 1986-2004 is about 2.3·104 person-Sv. The
mean individual dose of the whole body irradiation of the Belarusian population in this period oftime is about 2.3 mSv. In case of the childhood population the whole body irradiation doses
decrease since 1990. As a result of this decrease, collective and population doses of children of
Belarus decrease to some fractions of background irradiation doses at 2004. The different
temporal patterns of the whole body irradiation of different Belarusian subpopulations are
determined by demographic factors such as birth, achieving of a definite age by children, deathand external and internal migration.
Materials and Methods.
Assessment of the whole body irradiation doses was carried out on the basis of normalized doses of thewhole body irradiation. The normalized doses are based on using normalized exposition doses in free air,P γ (t ) that is a function of radioactive contamination of territory. The following expression determines
normalized doses:−1*h (t ) = µ ⋅ C1 ⋅ C 2 ⋅ F1 ⋅ [F 2 + (1 − F 2 ) ⋅ F 3] ⋅ Pγ (t ).

(1)Here, h* (t ) - the normalized equivalent dose delivered to the whole body at the time t ,µ - the contribution factor of external irradiation to the total dose,
C1 - the conversion factor for transfer from exposition dose to tissue-absorbed dose,C 2 - the conversion factor for transfer from tissue-absorbed dose to equivalent dose,
F1 - the correction coefficient (considers different factors that can influence the exposition dose inair, for example such as soil cultivation etc.),
F 2 - the outdoor occupancy factor (fraction of time spent outside buildings),
F 3 - shielding factor of buildings,

Pγ (t ) -the exposition dose in a free air at the height 1 meter above the ground at the time testimated for contamination level in the isotope 137Cs equal to 37 kBq/m2 at the end of April 1986.
Data on exposition doses in free air assessed in the report [1] for so-called “caesium spot” wereused in the present report for calculation of normalized doses. They were estimated for real composition of- 136 -

radionuclides deposited in Belarus as a result of the Chernobyl accident [2]. In the process calculating

Pγ (t ) values, all radionuclides that gave some measurable contribution to the total exposition in 1986
were considered [1]. They are 131I, 132Te, 103Ru, 106Ru, 140Ba, 134Cs and 137Cs. According to data [1] theshort-lived isotopes 131I, 132Te, 103Ru, 106Ru, 140Ba and 134Cs determined approximately 85% of thesummary exposition dose in the period from 26 April 1986 to 31 August 1986, while approximately 20%
in the period from 26 April 1986 to 31 December 1986. The isotope 137Cs was taken after the accident at
the Chernobyl NPP as an indicator of the radioactive contamination. Therefore, only this isotope ismentioned here and below by characterizing of radioactive contamination despite the fact that contributionof other isotopes to irradiation doses is also included.
Individual dose at any arbitrary level of radioactive contamination of territory can be assessed byusing of the formula:137

h(t ) = A0 ⋅ h* (t ).
(2)37Here, h(t ) is the equivalent dose of the whole body irradiation on the territory with contaminationin the isotope 137Cs equal to A137
kBq/m2 at the end of April 1986 delivered at the time t. It is the0arithmetic mean dose of the whole body irradiation of population living on the territory contaminated with
the isotope 137Cs to the level A137
kBq/m2. This is the mean individual dose for this territory.
0
Multiplication of h(t ) with the number of irradiated persons gives the collective equivalent dose of thewhole body irradiation delivered at the time t:Coll
H t = h(t ) ⋅ N t .

(3)

The total collective dose of irradiation delivered to the whole body during some time period canbe determined by summing data estimated with the formula (3). It is to be noticed here that in case oflong-term irradiation some special procedure has to be used for correct estimation of the collective doses
received by irradiated population for some time period. The use of direct summing of data estimated on
the basis of the formula (3) can cause a significant overestimation of the collective dose delivered in somefinite time. Data on population numbers given in statistical handbooks [3-6] were used in the present
report by estimation of collective doses.
Results and discussion.
Irradiation doses.
All contaminated territories in Belarus were divided after the accident at the Chernobyl NPP in clean

territories, characterized by contamination level in 137Cs at the end of April 1986, A137
0 , less than 37
kBq/m2 (1 Ci/km2), and contaminated territories, characterized by contamination level in 137Cs equal or
higher than 37 kBkBq/m2 (1 Ci/km2) [7]. Contaminated territories in Belarus were then divided infollowing categories: 37 ≤ A137
≤ 185 kBq/m2, 185 ≤ A137
≤ 555 kBq/m2, 555 ≤ A137
≤ 1,4800002kBq/m2, A137
0 > 1,480 kBq/m .

Table 1 gives annual total (external plus internal) individual dose of the whole body irradiation ofrural inhabitants living in areas with these levels (fourth, fifth and sixth column) and specific values of- 137 -

contamination. The second column is doses of irradiation of rural inhabitants living in areas with thecontamination level in 137Cs equal to 3.7 kBq/m2, which is approximately the same contamination with137
Cs existed in Belarus before the Chernobyl accident. It was resulted from the atmospheric test of atomic
weapon [8]. The third column of Table 1 gives the mean individual doses of the whole body irradiation for
the territory with the contamination level equal to 37 kBq/m2 or normalized doses assessed for rural
inhabitants of Belarus.
Table 1. Annual mean individual equivalent doses of the whole body irradiation of rural inhabitantsof Belarus (mSv/a).
Level of 137Cs contamination, kBq/m2 (Ci/km2)
Year37-185185-555555-1,4801,48037
3.7 (0.1)(1-5)(5-15)(15-40)
( 40)
(1)
1986
0.0972
0.9719
2.896
8.339
23.62
51.22
1987
0.04680.4681
1.395
4.016
11.37
24.67
1988
0.0296
0.29570.8812
2.537
7.186
15.58
1989
0.01810.1806
0.5382
1.549
4.388
9.517
1990
0.01040.10420.31040.8938
2.531
5.490
1991
0.00890.08850.26390.7597
2.152
4.666
1992
0.00790.07720.2302
0.6628
1.877
4.071
1993
0.00690.06860.20430.5883
1.666
3.614
1994
0.00620.06210.18490.5324
1.508
3.270
1995
0.00570.05700.16980.48901.385
1996
0.00530.05310.15830.45561.290
1997
0.00490.04950.14750.42471.203
1998
0.00470.04690.13970.4021
1.139
1999
0.00440.04430.13190.37991.076
2000
0.00430.04250.12670.36471.033
2001
0.00410.04050.1206
0.34720.983
2002
0.00390.03890.11600.33390.946
2003
0.00380.0382
0.11380.32770.928
2004
0.0036
0.03620.10780.31040.879
1986-2004
0.27642.76398.236423.7141
67.162110.555

Conversion factors C1 and C 2 used for assessment of normalized doses were taken from the report[9]. The coefficient F 1 = 0.368 was accepted for the period 1990-2004. This value was assessed in thereport [1] on the basis of empirical data. For the period 1986-1990, the value of the factor F 1 wasassumed to linearly change from 1 to 0.368. The coefficient F 2 equal to 0.295 was accepted as theoccupancy factor of rural inhabitants of Belarus [10,11]. The value of shielding factor for rural inhabitantsin Belarus was taken equal to 0.212. It was also assessed on the basis of empirical data [1]. The
coefficient µ characterizing contribution of the external irradiation equal to 0.736 was used inassessments. This value was assessed on the basis of empirical data given in the report [12].
Estimation of mean individual doses of rural inhabitants living in territories with contaminationlevels 37-185, 185-555 and 555-1480 kBq/m2 (fourth, fifth and sixth columns of Table 1) was performedon the basis of respective average contamination levels. They are 110.2, 317.5 and 899.1 kBq/m2,
respectively, at the end of April 1986. These values were estimated on the basis of data given in the report[1] on the basis of empirical data [13].
Data given in the sixth column of Table 1 allow to assess the individual dose of the whole body
irradiation accumulated in the period 1986-1995 for persons living in the area with the level ofcontamination 555-1480 kBq/m2. It is 57.7 mSv.
- 138 -

The Russian specialists [14] estimated the cumulative dose of the whole body irradiation of rural
inhabitants lived in 1986-1995 in territories with the same level of contamination equal to approximately
60 mSv. This is practically the same as irradiation dose estimated for rural inhabitants of Belarus living in
the area with the level of contamination 555-1480 kBq/m2.
A very good agreement in data assessed for the Belarusian rural inhabitants and data estimated by
the Russian specialists [14], which used more sophisticated model, justifies the simplified method of thewhole body irradiation described in the present report.
As can be seen from Table 1, assessment of irradiation doses for inhabitants of the territory with thelevel of contamination 1,480 kBq/m2 was performed only for the period 1986-1994. This was because allresidents of territories contaminated with 1,480 kBq/m2 and higher were resettled to clean areas in Belarus
in 1990-1994 [15]. According to our assessment, the mean individual dose accumulated by them before
resettlement is approximately 100 mSv.
Data presented in Table 1 show that mean arithmetic individual doses of the whole body
irradiation of rural inhabitants of Belarus accumulated in 1986-2004 vary from some fractions of
millisivert to hundreds of millisivert. In some cases inhabitants of the Belarusian rural settlements
accumulated much higher doses of the whole body irradiation for much shorter periods of time.
Assessment made on the basis of the method described in this report gives for inhabitants of the rural
settlement Vysoki Borak the population dose of the whole body irradiation equal to 135 mSv. This dose
was accumulated in the period 1986-1990. The population dose of the whole body irradiation in the same
period in case of inhabitants of the rural settlement Chudzyany is approximately 295 mSv. The settlement
Vysoki Borak is situated in the Krasnopolie district of the Mogilev region approximately 230 kilometersfrom the Chernobyl NPP. The settlement Chudzyany is situated in the Cherikov district of the Mogilev
region approximately 250 kilometers from the Chernobyl NPP. The average contamination of thesettlement Vysoki Borak was 2,480 kBq/m2 and of the settlement Chudzyany 5,420 kBq/m2 [13].
It is well known that maximum individual doses often exceed the mean dose by a factor of 3-5[16]. This means that some inhabitants of the rural settlement Chudziany received doses of the whole body
irradiation up to 1,500 mSv. In this respect they are comparable with atomic bomb survivors.
Table 2 presents collective doses of rural and urban inhabitants of Belarus in 1986-2004,
collective doses of the total population of Belarus (sixth column) as well as mean individual doses of thewhole body irradiation of the entire Belarusian population in this period (seventh column). The data in theseventh column of Table 2 were calculated by dividing the data given in the sixth column by the total
population of Belarus.
The following simplified method was used for assessment of data presented in Table 2. The entire
Belarusian population was divided into two subpopulations: rural and urban subpopulations. Normalized
doses of the whole body irradiation of rural and urban subpopulations were assessed separately for these
two subpopulations. In case of rural subpopulation the same values of coefficients F 2 and F 3 as inprevious assessment (Table 1) were taken. For assessment of the normalized doses for urban inhabitants ofBelarus coefficient F 2 equal to 0.2 and coefficient F 3 equal to 0.1 were used [11].
Calculation of population doses for urban subpopulation was performed for an averagecontamination of the Belarusian territory equal to 78.42 kBq/m2. This value was estimated from the total
amount of the 137Cs isotope deposited in Belarus [1]. Values of collective doses of the urban population ofBelarus were calculated for the average contamination equal to 37 kBq/m2 [11].

- 139 -

Table 2. Annual normalized and collective irradiation doses of the Belarusian population as a resultof the Chernobyl accident.
Year
Rural population
Urban population
Total Population
Normalized Collective Normalized Collective Collective Individual
dose, mSv dose, PSv dose, mSv dose, PSvdose, PSv dose, mSv
1986
0.97197,749
0.6133
3,818
11,567
1.1583
1987
0.4681
3,732
0.29541,839
5,571
0.5547
1988
0.29572,358
0.1866
1,162
3,520
0.34891989
0.18061,440
0.1140709
2,149
0.21171990
0.1042617
0.0657409
1,026
0.1007
1991
0.0886491
0.0559348
839
0.0823
1992
0.0773400
0.0488303
703
0.06891993
0.0686330
0.0433269
599
0.05851994
0.0621275
0.0392244
519
0.0507
1995
0.0570232
0.0360224
456
0.0447
1996
0.0531216
0.0335209
425
0.04181997
0.0495201
0.0312
194395
0.03891998
0.0469191
0.0296184
375
0.0372
1999
0.0443180
0.0279174
354
0.0352
2000
0.0425173
0.0268167
340
0.03392001
0.0405165
0.0255159324
0.0324
2002
0.0389158
0.0246153
311
0.0313
2003
0.0382156
0.0241150
306
0.03092004
0.0362147
0.0228142289
0.02931986-2004
2.763919,2111.7442
10,85730,0682.9900

Data presented in the sixth column of Table 2 gives for the period 1986-1995 the collective dose of
the whole body irradiation as a result of the Chernobyl accident 26,949 PSv. This value is by 28,7%
higher than the collective doses assessed for Belarus for the same period in the report [12]. The authors[12] carried out detailed study of irradiation doses in different regions of Belarus and estimated the totalcollective dose of the whole body irradiation of the Belarusian population equal to 20,940 PSv. However,they studied only inhabitants of rural and urban settlements situated in territories with the contaminationlevel with 137Cs equal or higher than 37 kBq/m2. On the contrary, data shown in Table 2 were assessed for
all contaminated territories of Belarus. Our assessment included also areas with the contamination level
less than 37 kBq/m2. Additionally, the method of assessment described in the present report consideredalso on an indirect way the irradiation of persons that worked as liquidators in the 30-km zone in 19861989. This was done by including radioactive nuclides deposited in the Belarusian part of the 30-km zone
for the estimation of the average contaminated level in case of rural inhabitants of Belarus. Excluding of
the 30-km zone as well as areas contaminated to levels less than 37 kBq/m2 gives practically the samecollective dose as it was estimated by authors [12].
The very good agreement between the data assessed in this report and the data estimated in reports[12,14] allows to conclude that reliable data characterizing irradiation of affected inhabitants of Belarus
are established.
Data in the sixth and seventh column of Table 2 can be used for estimation of cumulative collective
and individual doses of the whole body irradiation of the Belarusian population for any period of interest.
Direct summing of data presented in these columns, however, does not give correct doses unless two
opposite processes for dose accumulation are taken into consideration. The first process is positive
accumulation of irradiation doses year by year. The second process is loosing of already delivered doses
as a result of demographic processes. The influence of demographic processes can be demonstrated for- 140 -

irradiation of the Belarusian population in 2004. According to the data of Table 2, the collective dose of
the whole body irradiation of the Belarusian population in 2004 was approximately 289 person-Sv. The
cumulative mean individual dose for the period 1986-2004 was 2.99 mSv (seventh column of Table 2).
140,064 persons died in Belarus in this year. It is well known that older people give the main contribution
to the mortality in each country. Therefore it is possible to assume that all people that did in Belarus werealive at the time of the Chernobyl accident. This means that the individual dose accumulated by persons
who died in 2004 is practically the same as the cumulative the dose delivered in the period 1986-2004,
which is 2.99 mSv (seventh column of Table 2). Multiplying of this value with a number of people thatdied in 2004 gives the collective dosed loosed by the Belarusian population in 2004 equal to 418.8
persons-Sv. This is by 129.8 person-Sv larger than that delivered to the whole Belarusian population in
2004.
The influence of demographic processes on the cumulative irradiation doses can be much moresignificant in case of “truncated” populations that include persons with some definite age. The populationof children gives an example of such populations. It contains only persons at the age less than 15 years.
Consequently, the children’s subgroup in 2004 contained only children who were born after 1989 whendoses of the whole body irradiation in Belarus were much lesser than in 1986-1989. The loosing of high-

0.9

3.6
corrected
noncorrected

a)

3.2
3.0
2.8
2.6
2.4
2.2
2.0
1.8
1.6
1.4

0.7
0.6
0.5
0.4
0.3
0.2
0.1

1.2
1.0

0.0

1986 1988 1990 1992 1994 1996 1998 2000 2002 2004

1986 1988 1990 1992 1994 1996 1998 2000 2002 2004

Years

Years

1.8

0.50

corrected
noncorrectedc)Collective dose / 10,000 PSv

1.7

Collective dose / 10,000 PSv

corrected
noncorrected

b)

0.8

Collective dose / 10,000 PSv

Collective dose / 10,000 PSv

3.4

1.6
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6

corrected
noncorrected

d)

0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00

1986 1988 1990 1992 1994 1996 1998 2000 2002 2004

1986 1988 1990 1992 1994 1996 1998 2000 2002 2004

Years

Years

Fig.1. Collective equivalent doses of the whole body irradiation in Belarus as a result of theChernobyl accident: a) total population of Belarus, b) children of Belarus, c) total populationof the Gomel region, d) children of the Gomel region.

- 141 -

irradiated children decreases the cumulative doses of the subgroup of children.
As can be seen from here, different concepts of cumulative doses have to be distinguished in case ofchronic irradiation. The first concept is a cumulative dose that was delivered to the population living onsome contaminated territory. In the second concept, cumulative dose was possessed by the population
during certain time when they live on some contaminated territory. In the first concept one needs only todetermine the sum of doses delivered in the period of interest. In the second concept, cumulative doses ofirradiation are some functions of time one needs to take into account about demographic processes. Fig.1
and Fig.2 demonstrate collective and population doses of irradiation of the entire Belarus and of theGomel region assessed for these two different concepts.
In case of the Gomel region the same method of assessment as in case of the entire Belarus wasused in estimation of the data presented in Fig.1 and Fig.2. It was also assumed that normalized doses of
the whole body irradiation are the same for children as for adolescents and adults.
Figure 1 demonstrates influence of demographic processes on collective doses of the whole body
irradiation of the entire population of Belarus as a result of the Chernobyl accident. The subscript“corrected” in Fig.1 refers to data assessed by considering of demographic processes mentioned above.
The subscript “noncorrected” denotes in case of the entire Belarus data assessed by simple summing up
values presented in Table 2.
The influence of the natural demographic processes on mean individual doses of Belarus and the
3.4
3.2

corrected
noncorrected

a)

2.8

Population dose, mSv / a

Population dose, mSv / a

3.0

2.6
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0

3.4
3.2
3.0
2.8
2.6
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2

corrected
noncorrectedb)1986 1988 1990 1992 1994 1996 1998 2000 2002 2004

1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006

Years

Years

13
corrected
noncorrected

c)

13
12

11

11

10

10

Population dose, mSv / a

Population dose, mSv / a

12

9
8
7
6
5

corrected
noncorrected

d)

9
8
7
6
5
4
3
2

4

1

3
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006

0
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006

Years

Years

Fig.2. Mean individual (population) equivalent doses of the whole body irradiation in Belarus asa result of the Chernobyl accident: a) total population of Belarus, b) children of Belarus, c) total
population of the Gomel region, d) children of the Gomel region.

- 142 -

Gomel region is shown on Fig.2.
As can be seen from Fig. 1, collective doses of the whole body irradiation in case of total
populations of Belarus as well as the Gomel region increase up to 1991 and then remain practicallyconstant showing some plateaus in the time period 1991-2004. Our assessment shows that the same
temporal patterns demonstrate also collective doses of the whole body irradiation of entire populations ofother regions of Belarus.
On the contrary, “noncorrected” collective equivalent doses in case of total populations of Belarus
and the Gomel region demonstrate the further increase after 1990 although it is much slower than in 19861990. Comparison of “corrected” and “noncorrected” collective doses assessed for the entire population ofBelarus as well as for the Gomel region shows that “noncorrected” collective doses in 2004 are byapproximately 20% higher than “corrected” doses. This difference correlates with number of people thatdied in the period 1987-2004. Assessment on the basis of statistical handbooks [5,6] shows that 2,239,782
persons died in Belarus in this period. This is about 22.7% from the total number of the Belarusian
population averaged for the period 1987-2004 (approximately 10,000,000 persons).
Quite different situation arises in case of children’s population. Here “corrected” collective
equivalent doses increases up to 1989 and then decreases rapidly to very small values after 2000. For
example, “corrected” collective equivalent doses of children’s populations of Belarus and the Gomel
region in 2004 were by one order in magnitude less than in 1989. Such significant decrease of collective
doses resulted from the “loss” of persons who were children in 1986-1989 and left the children’s
population before 2004 as a result of their transition to the population of adolescents and adults.
The same temporal patterns demonstrate mean individual doses of the whole body irradiation,
which can be seen on Fig.2. Such temporal patterns of irradiation doses of children indicate that possible
medical effects of the Chernobyl accident in children have to be expected only immediately after this
accident. Table 3 contains cumulative collective and population doses of the whole body irradiationassessed for children, adults and the mixed population of Belarus for the period 1986 –2004 by
considering the described correction procedure.
Table 3. Collective and mean individual doses of the whole body irradiation of different subgroups
in Belarus as a result of the Chernobyl accident.
Children doses
Adults doses
Whole population
Year Collective Individual Collective Individual Collective
Individual
4
4
4
mSv
/10 PYSv
mSv/10 PYSv
mSv/10 PYSv
1986
0.25691.12200.8936
1.15671.1505
1.15201987
0.3722
1.61071.32551.7091
1.69771.69051988
0.42971.84571.60142.05452.03112.01301989
0.4501
1.92301.77672.26912.22672.19341990
0.4396
1.8772
1.86332.37442.30292.2602
1991
0.42281.8132
1.93342.45912.35622.3123
1992
0.3863
1.6696
1.93802.45232.32432.27911993
0.34891.5254
1.94902.45092.29782.24521994
0.31091.38181.96242.46002.27332.2192
195
0.28211.28042.00562.50972.28762.24041996
0.2516
1.17232.04382.55042.29532.2554
1997
0.2192
1.05312.08202.59072.30112.26891998
0.18430.91972.11962.62792.30382.28261999
0.1471
0.76312.15562.65952.30272.29232000
0.10970.58982.19262.69212.30232.29792001
0.07710.43182.22522.71872.30232.3045
2002
0.05880.34452.24002.72602.29882.3102- 143 -

Assessment on the basis of data presented in the sixth column of Table 3 gives for the period 19902004 the mean time-averaged collective dose of the whole body irradiation of the Belarusian population asa result of the Chernobyl accident equal to 2.3·104 person-Sv. Data shown in the seventh column of Table
3 gives as the mean time-averaged mean individual dose of the whole body irradiation for this period
equal to 2.28 mSv.
It is evident that the described method of correction can not give fully correct doses of the wholebody irradiation because it does not take in account other important factors that influence the accuracy ofassessed values. Significant influence on the correctness of dose assessment has internal (movement toother regions of Belarus) and external (movement to other countries) migration of inhabitants ofcontaminated areas. It began soon after the Chernobyl accident. As a result, a large fraction of people
migrated from territories affected by the Chernobyl accident. For example, one sixth of inhabitants of the
Slavhorod district (Mogilev oblast) left their contaminated settlements during the first three years after theaccident [17]. The similar situation arose in other contaminated districts of the Mogilev oblast. The
process of migration was even more pronounced in contaminated areas of the Gomel oblast [18].
According to the official information, the number of people that changed their place of residence inborders of Belarus in 1986-2000 reached 1,500,000, while the averaged total number of people in thisperiod in Belarus equal to 10 millions. 675.1 thousand of people migrated in 1990-2000 from Belarus toother countries of the world. Out of this number, 524 thousand of people migrated to countries of theCommunity of Independent States (CIS) and 151.1 thousand of people immigrated to countries beyond thebounds of the former USSR. For example, approximately 130 thousand of persons of the Jewish
nationality immigrated to Israel from the contaminated areas in Belarus and the Ukraine [19]. About 50%
persons from this number have immigrated to Israel from Belarus.
The internal migration from the contaminated areas of Belarus was occurring with a partial
assistance of the state. On this way approximately 135,000 persons had left the territories strongly affectedby the Chernobyl accident with the support of the state [20]. About 200,000 persons migrated fromcontaminated areas without assistance of the state [20].
The external and internal migration causes significant incorrectness in assessment of irradiation
doses carried out by using the method based on contamination levels. The external migration decreases
collective and population doses of the affected populations because of a transfer of irradiation doses toother countries. This transfer means a “loss” of radiation risk for Belarus. This means that using doses
presented in Table 3 assessed without taking in account the loss of some fractions of doses will cause anunderestimation of radiation risks.
The internal migration does not cause such underestimation of radiation risk because the transfer ofirradiation doses between different regions of Belarus causes only leveling of radiation risk in different
regions of Belarus. However, the internal migration causes decrease of statistical power of analysis
because it disturbs the correlation between levels of contamination and incidence rates of analyzed
diseases. The effect of internal migration can even exclude the possibility of using of standard method ofanalysis based on comparison of incidence rates in contaminated and not contaminated regions.
Conclusions
Collective and individual doses of the whole body irradiation of the Belarusian population were assessedon the basis of contamination of Belarus caused by the accident at the Chernobyl NPP. Assessment was
carried for the period 1986-2004 years. The influence of such demographic factors as birth, achieving of
the age 15 years by children as well as death was taken into account in course of assessment. Estimated- 144 -

results demonstrate that in case of children collective and individual doses increase in the period 19861989 and then decrease practically to fractions of collective and population doses of the background
irradiation. The collective and individual doses in case of adults of Belarus demonstrate a significant
increase in the period 1986-1989 and changed with some weak increase after 1990. The collective andindividual doses of the whole population of Belarus increase in the period 1989-1989 and then remain
practically constant up to 2004.
References.
1. Malko, M.V. Assessment of the Chernobyl radiological consequences. In the report; Research
activities about radiological consequences of the Chernobyl NPS accident and social activities to assist
the sufferers by the accident. Edited by Imanaka T. Research Reactor Institute. Kyoto University,
Japan. KURRI-KR-21. ISSN 1342-0852, 1998, p.65-85.
2. Chernobyl Radioactive Contamination of Natural Environments. Edited by Yu.A.Izrael. Leningrad.
Hydrometeoizdat. 1990 (in Russian).
3. Ministry of Statistics and Analysis of the Republic of Belarus. Population of the Republic of Belarus
by Sex, Age and Marital Status. Minsk, 2000.
4. Ministry of Statistics and Analysis of the Republic of Belarus. Population of the Republic of Belarus.
Minsk, 2003.
5. Ministry of Health Care of the Republic of Belarus. Public health in the Republic of Belarus. An
official statistical collection, 2003. Minsk, 2004.
6. Ministry of Health Care of the Republic of Belarus. Public health in the Republic of Belarus. An
official statistical collection, 2004. Minsk, 2005.
7. Ministry of Emergency Situations and Protection of Population from Consequences of the Catastrophe
at the Chernobyl NPP of the Republic of Belarus. Academy of Sciences of Belarus. Consequences of
the Chernobyl Catastrophe in the Republic of Belarus. National Report. Editors.: Konoplya E.F.,
Rolevich I.V. Minsk, 1996, p.11.
8. UNSCER. Ionizing Radiation: Sources and Biological Effects. United Nations Scientific Committee
on the Effects of Atomic Radiation 1982 Report to the General Assembly, with annexes, United
Nations, New York. 1982, p.221.
9. UNSCER. Sources, Effects and Risks of Ionizing Radiation. United Nations Scientific Committee on
the Effects of Atomic Radiation 1988 Report to the General Assembly, with annexes, United Nations,
New York. 1988, p.320.
10. Malko M.V. Assessment of population doses of rural inhabitants of Belarus irradiation as a result of
the accident at the Chernobyl NPP. In: Materials of the international conference of leading specialists,
young scientists and students “Sacharov’s Readings 2003: Ecological problems of the XXI century”.
Minsk, 19-20 May, 2003. Ministry of Education of the Republic of Belarus, A.D.Sachorov
International State Ecological University. Minsk, 2003, p. 49-50 (in Russian).
11. Malko M.V. Assessment of the collective equivalent dose of the Belarusian population irradiated as aresult of the accident at the Chernobyl NPP. In: Materials of the international conference of leading
specialists, young scientists and students “Sacharov’s Readings 2003: Ecological problems of the XXI
century”. Minsk, 19-20 May 2003. Ministry of Education of the Republic of Belarus, A.D.Sachorov
International State Ecological University. Minsk, 2003, p. 50-52 (in Russian).
12. Minenko V.F., Drozdovich V.V., Tretiakovich S.S. et al. Irradiation of the population of Belarus after
the Accident at the chernobyl NPP: collective doses and prognoses of stochastic effects. Medicobiologicheskie aspecty avarii na ChAES. Minsk. № 4, 1996 p 50-65 (in Russian).

- 145 -

13. State Committee of Hydrometeorology of the USSR. Date of radioactive contamination of settlementsof the Belorussian SSR with Caesium-137 and Strontium-90 (status of June 1989). M.
“Hydrometeoizdat”, 1989 (in Russian).
14. Ministry of Russian Federation on Civil Defence, Emergency and Elimination of Consequences of
Natural Disasters (EMERCOM of Russia). Chernobyl Accident:Ten Years On. Problems and resultsof Elimination of the Consequences of the Accident in Russia. Russian National Report. Moscow,
1996.
15. Ministry of Emergency Situation of the Republic of Belarus. Belarus and Chernobyl: the second
decade. Editor: I.A.Kenik. Baranovichi. 1998.
16. UNSCER. Sources and Effects of Ionizing Radiation. United Nations Scientific Committee on the
Effects of Atomic Radiation. UNSCEAR 2000 Report to the General Assembly with Scientific
Annexes, United Nations, New York. 2000, p.482.
17. Simurov A., Ulitenok A. Belarusian zone. Newspaper of the Central Committee of the CP of USSR
“Pravda”. M., № 205 (25,923), 24 June 1989.
18. Committee on Problems of Consequences of the Catastrophe at the Chernobyl NPP of the Council of
Ministers of the Republic of Belarus. Consequences of Chernobyl in Belarus: 17 years after.
Belarusian National Report. Edited by V.E.Shevchuk, V.G.Gurachevski. Minsk, 2003, p.18.
19. Goldsmith J.R., Kordysh E., Quastel M.R., Merkin L., Poljak S., Levy Y., Gorodisher R., Barki Y.,
Wynberg J. Elevated TSH in children who emigrated to Israel from Belarus and the Ukraine near
Chernobyl. Proceedings of the International Conference held in Vienna, 8-12 April 1996 “One decade
after Chernobyl: Summing up the consequences of the accident”, Poster presentations – Volume 1, p.
69 – 72. IAEA, September 1967.
20. Pastayalka L.A. Medical consequences of the Chernobyl catastrophe in Belarus: problems andperspective. Meditsinskiya Novosti. Minsk. No 11, 2004, p.3-17 (in Russian).

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