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6. |
What are the medical consequences of the Chernobyl accident? |
The consequences of irradiation may manifest themselves either immediately or in the distant future. The immediate effects are seen when the whole body is exposed to radiation doses exceeding 0.5 Sv* in a few hours or days. Large radiation doses of many Sv induce symptoms of radiation sickness (nausea, vomiting, lost appetite, bleeding, decrease in the amount of white blood cells) which result in increased risk of infection and sometimes death.
| * |
Sievert (Sv) - dose equivalent of radiation which accounts for the biological influence from various types of irradiation (X-ray, gamma-, beta-, alpha-, neutron-radiation) with certain numerical coefficients (1, 1, 1, 20, and 10, respectively). |
It is very difficult to determine the influence of small doses of radiation on the body because their manifestations are not clear.
Small doses of radiation(less than 500 mSv), contrary to popular belief, negatively impact the central nervous system. During the first few months after the accident, it was established that pathological changes in the nervous system have a significant place in the clinical manifestations of radiation exposure in the victims.** Special made it possible to determine malfunctions of the peripheral nervous system, neuroautoimmune changes, and disturbances in neuroendocrine control. It was shown in the clinic and through experiments that the development of these changes depends heavily on the dose of radiation and on psychogenic stresses.
| ** |
Radiation and Health Impact Facts. Technical Steering Panel of the Hanford Environmental Dose Reconstruction Project. Fact Sheet. November 1-May 1989 (Revised February 1992), p-p 1-4 |
Figure 10: Nearly healthy children
About 23.7% of the total number of children under 15 years evacuated from the contaminated territories in 1994 were considered healthy; of children who inhabited the controlled contaminated territories, this amount is 24.64%. Taking into consideration the general health conditions of affected children's population, it should be noted that the rate of incidence increases and continues to increase because of the Chernobyl disaster.
Source: Lukyanova, Ye.M., Clinic and paraclinic aspects of children's health 9 years after the Chernobyl disaster. Proceedings of the Ukrainian Academy of Medical Sciences, Vol. 1, 1995.
The primary disturbances of the peripheral nervous system are changes in cardiovascular control which may lead to pain, irregular heartbeat, and changes in the electrocardiogram. Radiation can be considered a possible risk factor in the development of such diseases as atherosclerosis, hypertension, and ischemia, which are the primary causes of disability and reduced life expectancy.
The pulmonary system is considered to be relatively sensitive to radiation. Changes in the respiratory system depend on the time elapsed from the accident and the duration of inhalation of radionucleotides. Disturbances in respiratory volume and an increase in the number of allergic illnesses were shown for adults and children. It should be noted that atypical cells were seen in a morphological study of the bronchial mucosa of "liquidators" (persons immediately involved in the liquidation and elimination of the consequences of the Chernobyl accident). This allows one to talk not only about the definite sensitivity of the pulmonary system to radiation, but also the increased risk for development of lung cancer in this group of persons.
Fig. 11. Indexes (standardized against age) of the accumulated (during 1986-1991) incidence of chronic non-tumor diseases among the members of liquidator groups who worked in 1986-1987, according to the external irradiation dose (per 1000 persons)..
Disease classification
(MKB-9) |
Dose lower than 25 cGr |
Dose higher than 25 cGr |
| All diseases |
580.60 |
685.10 |
| Diseases of the endocrine system |
74.30 |
72.50 |
| Diseases of the blood and blood-forming organs |
4.64 |
6.57 |
| Psychiatric disturbances |
50.80 |
72.70 |
| Diseases of the nervous system and organs of senses |
168.60 |
190.50 |
| Diseases of circulatory system |
91.80 |
93.20 |
| Diseases of respiratory organs |
30.20 |
38.80 |
| Disease of digestive system |
93.10 |
128.50 |
| Diseases of urogenital system |
8.80 |
9.80 |
| Diseases of skin and subcutaneous fat |
6.30 |
10.00 |
| Diseases of bones and muscles |
42.30 |
52.00 |
Source: "10 years after the accident at Chernobyl"
Particular attention should be given to the destructive effects on the digestive system. In the time after the accident, even those who were expose to small doses of radiation (on the order of 20-50 centigrays) showed various pathological changes in the digestive system. During the first two years, these changes had the nature of inflammation of the duodenum (the first part of the small intestine). In succeeding years, it was shown that there is a tendency toward the transformation to atrophic and erosive processes with spontaneously hyperplastic (thickened) mucous membranes. At present, illnesses of the digestive system are the most frequent type of pathology associated with the Chernobyl Nuclear Power Plant accident.
Fig. 12. The number of illnesses (in 1988-1994) among the liquidator groups after the accident at the Chernobyl Nuclear Power Plant (according to the National Ukrainian Register).
| Disease classification |
The number of diseases per 1000 persons |
| 1988 |
1992 |
1993 |
1994 |
| All diseases |
377.90 |
806.20 |
545.80 |
531.20 |
| Infectious |
3.30 |
5.60 |
4.10 |
4.70 |
| Mass/growth/swelling formations |
3.00 |
6.40 |
5.00 |
4.10 |
| Diseases of endocrine system |
13.40 |
56.30 |
17.00 |
34.00 |
| Diseases of blood and blood-forming organs |
0.55 |
2.50 |
2.00 |
2.30 |
| Psychiatric disturbances |
14.40 |
31.60 |
11.70 |
8.00 |
| Diseases of nervous system and organs of senses |
51.70 |
171.90 |
86.40 |
85.20 |
| Diseases of the circulatory system |
38.60 |
115.10 |
63.90 |
66.20 |
| Diseases of respiratory organs |
139.60 |
159.80 |
149.70 |
147.00 |
| Disease of digestive system |
44.20 |
128.70 |
82.60 |
76.30 |
| Diseases of urogenital system |
6.10 |
14.40 |
12.20 |
12.90 |
| Diseases of skin and subcutaneous fat |
7.90 |
9.10 |
7.80 |
8.10 |
| Diseases of bones and muscles |
26.30 |
72.00 |
60.60 |
60.80 |
| Injury and poisoning |
25.80 |
28.80 |
20.40 |
19.60 |
The annual increase in the number of illnesses was established for the members of liquidator groups during the post-accident period according to chronic diseases of nervous system and organs of the senses, blood-forming system, digestive system, bones and muscles diseases, occasional psychiatric disturbances, blood diseases, endocrine pathology, formation of masses/growths/swelling, and diseases of the urogenital system.
Source: State of health among the various groups of population: Chernobyl disaster, Kiev, Naukova Dumka Publishers, 1995.
The immune system is considered the most sensitive to radiation. Many studies unambiguously indicate that independent of the place of residence and exposed irradiation dose, a large portion of the population exposed to irradiation has symptoms of one or another immune disturbances. These were seen in the decreased immune protection against bacterial and virus infections.
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