Chernobyl: Clean-up workers (Lithuania) (Lazutka 1996)

Scenario

Accident of Chernobyl NPP contaminated large area of Belarus, Ukraine and Russia. Approximately 600,000 people from all republics of former Soviet Union (USSR) have bee involved in the post-Chernobyl clean-up. Of these, more than 6,000 clean-up workers were from Lithuania. The cytogenetic examinations of Lithuania clean-up workers were approved by Lithuania Ministry of Health Care and started in early 1992.

A total of 210 male donors were chromosomally examined between 1992 and 1994 (i.e., 4-6 year after the accident). Of these, 183 civilians who individually spent, on average, between 1 and 6 months at Chernobyl and were allowed to receive up to 0.25 Gy of external gamma-irradiation.

For 107 clean-up workers, the individual doses of external gamma-irradiation estimated by local dosimeter services at Chernobyl were available. The dose estimations ranged from 0.08 to 0.36 Gy (mean 0.14 Gy). However for a significant proportion of clean-up workers had no personal dosimeters and their doses were estimated on the basis of the time spent in zones with different radioactive contamination levels.

Of the clean-up workers analyzed, 23 workers were selected in which the chromosome analysis was possible in enough number of cells (i.e., more than 300 cells). The frequencies of chromosome aberrations in clean-up workers were compared with those of 27 controls.

Reference

Lazutka, J. R. (1996): Chromosome aberrations and rougue cells in lymphocytes of Chernobyl clean-up workers. Mutation Res., 350:315-329.

Chromosome aberration analysis

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	Subject	No. of	Chromatid-type aberrations					Chromosome-type aberrations
	ID	cells	chromatid breaks	isochromatid breaks	quadriradials	triradials	ace*	acentric rings	dicentrics+centric rings	translocations
	62	300	7	0	0	0	15	1	5	0
	101	1,220	10	1	2	0	6	1	2	1
	129	848	19	1	2	0	17	1	3	1
	157	370	12	1	0	1	13	0	4	0
	158	470	8	0	1	1	8	0	2	0
	174	900	19	0	1	0	10	1	3	2
	180	685	9	0	4	0	10	0	3	0
	184	1,100	19	0	2	0	5	0	5	1
	208	530	5	0	0	0	5	0	2	0
	221	600	20	0	1	1	6	0	7	1
	315	800	7	1	1	0	5	0	2	0
	316	1,110	28	0	0	0	21	0	2	0
	401	1,050	13	1	2	0	13	2	2	0
	431	1,000	13	0	4	1	11	0	3	2
	457	1,020	14	0	1	0	16	0	4	1
	462	800	9	0	3	0	9	0	3	0
	471	426	6	0	3	0	7	1	3	0
	481	600	4	0	2	0	14	0	4	1
	486	500	8	0	1	1	7	0	3	0
	491	650	9	0	3	0	7	2	6	1
	510	605	22	0	4	0	13	0	1	0
	513	710	11	1	3	0	8	0	4	0
	532	400	6	0	0	1	8	0	2	1
	Total	16,694	278	6	40	6	234	9	75	12
	Controls**	5,370	58	1	3	1	31	2	11	1
	*) definition unclear. Acentric fragments?
	**) Controls: 27 controls (apparently the same age: 31.7±8.9 years).
	Highlighed values are significantly higher frequencies than those of controls (p<0.05) by χ2 test with Yates correction.										.
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