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Radioactive
emission is capable to produce corresponding modifications in the haemopoetic
systems of man and animals as a function of radiation intensity and duration.
When
man is exposed to a dose from I to 10 Gy an acute radiation disease appears.
The hematological syndrome emerges on the 3rd or 4th week in the form of
granulocytopenia, thrombocytopenia and anemia and plays an important role
in the pathogenesis of the diseases (A.E. Ivanov, 1991).
Stable
modifications of quantitative and qualitative parameters of the peripheral
blood and bone marrow, strong modifications of the system of metal proteids
of the blood plasma, reduced concentrations of Fe-transferin and Cu2+-ceruloplasmin
occur during reconvalescence after acute radiation disease and among patients
with the initial stages of depression of haemopoiesis after doses 0.3-1.0
Gy.
Scrutiny
of cultures shows that the haemopoietic function at the level of closest
offsprings of stem cells is retained by the majority of these individuals
(V.G. Babushka et al., 1991).
During
the initial fortnight in the Chernobyl zone the liquidators had transient
leucocytosis, reticulosis, eosinophilia (U.N. Shishmarev et al., 1992),
a greater number of stem nuclear neutrophil leucocytes (L.N. Ljubchenko
et al., 1991; N.M. Oganesjan et al., 1991) and basophils L.N. Ljubchenko
et al., 1991). The nuclei of mononuclears would increase in dimensions
and become less optically dense.
Zverkova
et al. (1991)
indicate that after involvement in the elimination of the Chernobyl consequences
a number of individuals would manifest neutrophilopenia, a leftward shift
of the leucocytary formula, a greater concentration of monocytes.
During
the next 30-50 days in the Chernobyl zone the count of thrombocytes, erythrocytes
and reticulocytes would reduce (U.N. Shishmarev et al., 1992).
Four
or five years later these individuals would manifest absolute lymphocytosis
and monocytosis, reduced index of segmentation of cell nuclei, reduced
concentration of myeloperoxidase in leucocytes (I.E.. Danilov et al., 1992).
Five
or six years later quantitative and qualitative modifications of the leucocytary
link are observed in the form of moderate relative and absolute lymphocytosis,
eosinophilia and neutropenia. Larger radiation doses would produce lymphocytes
and neutrophil leucocytes with a jagged nuclear shape, would cause appearance
of additional nuclei. The number of chromatin outgrowth in neutrophils
would increase (K.P. Zak et al., 1995).
Moreover,
the liquidators showed four years later manifestations of the functional
loss of organization in the hemostasis system: activation of hemocoagulation
and aggregation of thrombocytes against the suppressed activity of fibrolysis
and antithrombogenic features of vascular walls (S.I. Chekalina et al.,
1995).
Like
among adults, the children in the radiation-affected area manifest modifications
of the haemopoietic system. The children in the areas with heavy contamination
have the average concentrations of erythrocytes, hemoglobin validly less
compared with the norm (£.I. Kozorezova et al., 1993). Basically healthy
children evacuated from the city of Pripyat 36-40 hours after the disaster
have manifested a moderate leucocytosis and a higher relative and absolute
concentration of the cells of the granulocytary series (the stem nuclear
and segment nuclear neutrophils, eosinophils).
The leucograms of these children typically show granular lymphocytes (V.G. Bebeshko, 1991) and enlarged neutrophil leucocytes with a toxigen and immature granularity (U.V. Stepanov et al., 1992). Hexagrams of these children did not manifest
any
significant modifications 1-4 years after the disaster. Also, the children
after exposure to small doses of radiation manifest modifications of the
morphological composition of the peripheral blood which have no pathological
nature, such as leucopenia, lymphocytopenia (D.A. Torubarova, G.I. Kovalev,
1991). Suppressed activity of alkaline phosphatase in neutrophil granulocytes
has been revealed among a number of children, together with a significant
rise of the concentration of eosinophil granulocytes (K.P. Zak et al.,
1991).
Analysis
of an extensive bank of data of laboratory hematological examinations of
children and adolescents living in the contaminated areas has revealed
disorders in hexagrams, such as reduction of the number of erythrocytes
accompanied by macrocytosis, leuco- and lymphopenias in a number of cases
(A.F. Tsyb et al., 1996).
Thus,
the peripheral blood of the children, after protracted exposure to small
doses of radiation, manifests both qualitative and quantitative modifications
in the erythroid series, neutrophil leucocytes, eosinophils, B-lymphocytes,
the pattern and the tendencies of these modifications being dependent upon
the age of the children and the level of general radiation (L.V. Evets
et al., 1992).
No
pronounced rise of the incidence of leukemias or any other diseases of
the myelocytary function has been registered in the affected areas during
the period since the Chernobyl disaster (I.V. Osechinskii et al., 1994).
Yet,
a statistically valid rise of the frequency of chronic lympholeucosis,
paraproteinic hemoblastosis, non-Hodgkin's lymphomas is noteworthy. Moreover,
since 1988 a statistically valid rise of acute non-lymphoblastose leukemias,
chronic myeloleucoses has been registered (I.V. Osechinskii et al., 1991).
The
hemoblastosis incidence is somewhat higher in the areas with mild radioactive
contamination basically due to the number of acute lymphoblastose leukemias,
chronic lympholeucoses and lymphogranulomatoses (I.V. Osechinskii et al.,
1996).
Hence,
the population affected by the Chernobyl disaster has been manifesting
substantial modifications of the haemopoietic system for a number of years.
They are typically related to the quantities of radioisotopes incorporated
by the organism. It is evidenced by the results of evaluation of hematological
examinations of children from the communities with different levels of
soil contamination and different levels of radiation accumulation in the
organism.
A
reverse proportionality exists between the concentration of erythrocytes
in the blood and the quantities of incorporated radioisotopes (Fig. 14)).
The
children from the community of Svetilovichi (15-40 Ci/km2 of
137Cs) manifest the most pronounced reduction of the erythrocyte
count. Yet, the concentration of hemoglobin among these children is much
higher than the control level (Fig. 15). Other groups demonstrate a similar
dependence. The results of clinical examinations and laboratory tests are
corroborated by experimental studies of laboratory animals.
Rats
born during the first months after the disaster would manifest throughout
their life significant modifications of the peripheral blood and the bone
marrow haemopoietic system, such as eosinophilia, lymphopenia, hypersegmentosis
and fragmentation of the nuclei of neutrophils, their giant dimensions,
double and more nuclear lymphocytes, inclusions of the nuclear matter in
the cytoplasm of lymphocytes and erythrocytes, giant shapes of thrombocytes,
porosity of 'the cytoplasm of eosinophils V.0. Pinchuk et al., 1991).
Ultrasound
investigation of the bone marrow cells among male rats kept within the
30-km zone around Chernobyl has revealed significant submicroscopic modifications
of the cells at various stages of maturity, including non-differentiated
regions and mature forms of the cells of the neutrophil, eosinophil, monocytary
and erythrocytary series of haemopoiesis and similar modifications in the
stroma elements of the microenvironment, megakariots and endothelium (V.V.
Afanasjeva et al., 1991).
Feeding
Vistar line rats with oats containing 137Cs in a concentration
445.7 Bq/kg during 20 days would reduce the concentration of erythrocytes
in the blood compared with the control group fed with the grain containing
137Cs in a concentration 44.2 Bq/kg (I.V. Vuevskaja, 1997).
The concentration of 137Cs in the organisms of the rats in the
experimental group amounted to 62.76 3.84
Bq/kg compared with 9.76 1.77 Bq/kg in the control group (p < 0.05).
So,
individuals after exposure to elevated doses of external and internal radiation
manifest suppressed proliferative activity of the haemopoietic function.
Meanwhile the process of saturation of the organism with iron suffers no changes. Yet, there is a number of reports of iron-deficit anemias in several regions which have gone up several times recently (V.I. Ponomarenko et al., 1993).
In
a number of cases evolution of anemias among the children in the areas
contaminated with radiation can be attributed to the disorders of lysis
of transferin as one of the major glycoproteids of the blood plasma. Disorders
of this process have been registered among experimental animals long time
after exposure which unfavorably affects the iron transport in the organism
(N.M. Shilina et al., 1997).
Liver
damage induced by the incorporated 137Cs is one of the causes
of this pathological process (Ju.I. Bandazhevsky, N.E. Fomchenko, 1996)
(Fig. 14).
