Chernobyl Liquidators' Health
as a Psycho-Social Trauma
2.4.4. Estimations of the irradiation dose received by the liquidators
The liquidators are considered to be the most irradiated group of the affected (Chernobyl'skaya katastrofa 1995: 393—396). Their doses vary within a very broad range, for the participation in radiation-hazardous works varied from a short-time visit to the inhabited territory within 30-km zone to continuous work at the vicinity of the exploded unit 4. The authors consider it sensible to classify the liquidators according to such indicators as:
— period of participation,
— localisation of the workplaces and the degree of their radiation danger,
— (non-radiation) conditions of work,
— the Department/Ministry, to which of the liquidator was affiliated.
As for the period of participation, the authors outline, in descending order of radiation danger, the following periods:
1) April-May 1986;
2) June-November 1986 (until the date of completion of the Sarcophagus, as it is given in (Chernobyl'skaya katastrofa 1995: 42)); these two first period were considered to be the most radiation-dangerous;
3) Until the spring of 1987 (most dangerous work were clean-up of the roof of unit 3 and burial of highly-radioactive wastes);
4) Until the end of 1987 — middle of 1988 (mainly decontamination of the settlements in the 30-km zone);
5) Since the end of 1987; stay in the 30-km zone was not connected with any significant irradiation, except for single cases, for the personal doses during one shift, measured with individual dosimeters, did not exceed 0.1 mZv (Chernobyl'skaya katastrofa 1995: 394) (that is 0.01 R (= 10 mR) of the exposure dose, or 0.01 centiGy of the absorbed dose, under the conditions mentioned in Ch.220.127.116.11).
The localisation of the workplaces is considered to be of crucial importance for the dose obtained during the participation in the mitigation works. The authors distinguish, in descending order of radiation danger:
— the work at the NPP territory (the most dangerous);
— work on burial of the radioactive wastes, including elimination of the Red Forest;
— decontamination of the town of Prypjat and settlements, adjacent to the NPP;
— work and stay outside the 10-km zone around the NPP (in particular, in the town of Chernobyl and villages at the south of the 30-km zone), which was not considered as connected with irradiation, dangerous for the health (Chernobyl'skaya katastrofa 1995: 394).
As for the profession and the Department/Ministry of the liquidator, which largely predetermined the period, the place and the conditions of the work, the liquidators may be subdivided into the following groups (Chernobyl'skaya katastrofa 1995: 393—396):
1. The NPP personnel and the firemen, who participated in extinguishing the fire at the NPP (about 4000 persons), whose doses are within a wide range, with the upper limit of 1—3 Zv.
2. Professionals (miners, builders, scientists etc.) sent to the zone to mitigate the disaster at its first stage, who got substantial doses (e.g., miners, who worked under the reactor, got 0.1—0.3 Zv (10—30 R, under the conditions mentioned in Ch.18.104.22.168).
3. Regular military officers, soldiers and workers of the Soviet Army, Interior Forces, KGB and militia (police), who participated in the evacuation from 30-km zone and carried on security and entry regime service in the zone. Their doses are within a rather wide range; the authors consider that, as a rule, they are not high.
4. Workers of the organisations of the 30-km zone, who were shift-working in the zone since the end of the summer — autumn of 1986, whose doses were well-controlled and did not exceed permissible limits.
5. Reservists of the Soviet Army, drafted from the reserve for “the special military training”. Doses of this group, which is one of the most numerous (Chernobyl'skaya katastrofa 1995: 395), are the most vague. The dosimetric control in the regiments was inadequate; in a series of cases the doses were distorted, that is under-stated in order not to exceed the permissible one. Basing upon the character and localisation of the works, the authors assume that actual irradiation doses of this group were significantly higher than those officially registered.
A different classification of the liquidators depending the value of the irradiation dose is also suggested (Chernobyl'skaya katastrofa 1995: 263—264): the Chernobyl-irradiated are subdivided into 3 groups:
A — those who got acute irradiation injury by the dose of total, more or less uniform irradiation of 1—1.2 Gy (100—120 R) and more (ARS of various degrees), or 0.5—1.0 Gy (50—100 R) (acute radiation reaction), received in a short period (hours, days); the group, according to the source, is “of 150 persons as for the order of magnitude”;
B — with very approximate doses 25—100 cGy (25—100 R) of sub-acute irradiation during several days or weeks, of the liquidators of 1986 and evacuated from the 30-km zone, of 10,000's persons in total (I would consider this latter figure an underestimation), and
C — chronically irradiated during months and years, the doses unclear (though apparently less than for group B. — S. M.); embraces mostly liquidators of 1987—1988 and inhabitants of the “strict control” areas, in total of hundreds of thousands of persons.
Amirazajan (1999) accepts that an absolute majority of the liquidators have actually received less than 30 cGy (30 R), and refers to the following data: the dose of 30 cGy on the crystalline lens of eye is considered (by the International Committee on Radiological Protection and UN Scientific Committee on the Effects of Atomic Radiation) to be a threshold of deterministic effects of irradiation upon this organ; this effect in liquidators has not been reported. This logic presupposes that the crystalline lens has similar dose as the rest of the body.
Summing up the literature data upon the numerical values of the doses, one can conclude that there are sensible grounds to state that a vast part of the liquidators, embracing hundreds of thousands of people, have received doses which are insufficient to produce classical, distinct radiation injuries, that is, not exceeding several 10's R of the exposure dose (or several 10's cGy of the absorbed dose, or several 10's cZv of the equivalent dose).
Design by: M.Opalev
Studio ARWIS Kharkov, 2001