Biomaterial Database

Chromosomal aberrations after exposure to low doses of ionizing radiation. 2009

S Milacic

University of Belgrade, Faculty of Medicine, Institute of Occupational Medicine and Radiological Protection, Belgrade, Serbia. m.masha@beotel.net

OBJECTIVE To compare the incidence of chromosomal aberrations (CA) in healthy medical workers occupationally exposed to ionizing radiation (IR) and in non-exposed healthy population. METHODS This was a 4-year study with 462 subjects, mean age 42.3 years, occupationally exposed to IR (exposed group - E), and 95 subjects, mean age 35.2 years, not exposed to IR (control group - C), during the same time period and from the same territory. Thermoluminescence dosimeters (TLD) were used for assessment of IR exposure. Modified Moorhead's micro method for peripheral blood lymphocytes and conventional cytogenetic technique of CA was used for analysis of CA. The karyotype of 200 lymphocytes in metaphase was analysed by immersion light microscope. RESULTS The average annual absorbed dose measured by TLD was 14.5 mSv in group E and 2.8 mSv in group C exposed to natural level of radioactivity. The incidence of CA was 21.6% in group E and 2.1% in group C (p <0.05), while non-specific chromosomal lesions (gaps, breaks, elongations) were equal in both groups (22%). In group E, the highest incidence was found in nuclear medicine workers (42.6%), then in orthopedic surgeons (27.08%). Highly significant difference (p <0.001) was found in the number of aberrant cells and the sum of CA between group E and C. The sum of CA and the number of aberrant cells were positively correlated with the duration of exposure (p < 0.001), and to a lesser degree with age (p < 0.05) in group E. In group C, this correlation was negative and insignificant. In group E, subjects with duration of occupational exposure (DOE) up to 15 years (subgroup E I=327) had significantly less number of aberrant cells and CA in comparison with the subjects with DOE over 15 years (subgroup E II=135) (p < 0.01). CONCLUSIONS Long-term occupational exposure to low doses IR contributes to the development and increased frequency of specific CA (like dicentrics), but varies in relation to different working places. The majority of subjects had no other genetic modifications (non-specific chromosomal lesions) affected by low doses of IR.

UI	MeSH Term	Description	Entries
D008214	Lymphocytes	White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.	Lymphoid Cells,Cell, Lymphoid,Cells, Lymphoid,Lymphocyte,Lymphoid Cell
D011832	Radiation Injuries	Harmful effects of non-experimental exposure to ionizing or non-ionizing radiation in VERTEBRATES.	Radiation Sickness,Radiation Syndrome,Injuries, Radiation,Injury, Radiation,Radiation Injury,Radiation Sicknesses,Radiation Syndromes,Sickness, Radiation,Sicknesses, Radiation,Syndrome, Radiation,Syndromes, Radiation
D011834	Radiation Monitoring	The observation, either continuously or at intervals, of the levels of radiation in a given area, generally for the purpose of assuring that they have not exceeded prescribed amounts or, in case of radiation already present in the area, assuring that the levels have returned to those meeting acceptable safety standards.	Monitoring, Radiation
D011839	Radiation, Ionizing	ELECTROMAGNETIC RADIATION or particle radiation (high energy ELEMENTARY PARTICLES) capable of directly or indirectly producing IONS in its passage through matter. The wavelengths of ionizing electromagnetic radiation are equal to or smaller than those of short (far) ultraviolet radiation and include gamma and X-rays.	Ionizing Radiation,Ionizing Radiations,Radiations, Ionizing
D002869	Chromosome Aberrations	Abnormal number or structure of chromosomes. Chromosome aberrations may result in CHROMOSOME DISORDERS.	Autosome Abnormalities,Cytogenetic Aberrations,Abnormalities, Autosome,Abnormalities, Chromosomal,Abnormalities, Chromosome,Chromosomal Aberrations,Chromosome Abnormalities,Cytogenetic Abnormalities,Aberration, Chromosomal,Aberration, Chromosome,Aberration, Cytogenetic,Aberrations, Chromosomal,Aberrations, Chromosome,Aberrations, Cytogenetic,Abnormalities, Cytogenetic,Abnormality, Autosome,Abnormality, Chromosomal,Abnormality, Chromosome,Abnormality, Cytogenetic,Autosome Abnormality,Chromosomal Aberration,Chromosomal Abnormalities,Chromosomal Abnormality,Chromosome Aberration,Chromosome Abnormality,Cytogenetic Aberration,Cytogenetic Abnormality
D004307	Dose-Response Relationship, Radiation	The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.	Dose Response Relationship, Radiation,Dose-Response Relationships, Radiation,Radiation Dose-Response Relationship,Radiation Dose-Response Relationships,Relationship, Radiation Dose-Response,Relationships, Radiation Dose-Response
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D016273	Occupational Exposure	The exposure to potentially harmful chemical, physical, or biological agents that occurs as a result of one's occupation.	Exposure, Occupational,Exposures, Occupational,Occupational Exposures
D018570	Risk Assessment	The qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards or from the absence of beneficial influences. (Last, Dictionary of Epidemiology, 1988)	Assessment, Risk,Benefit-Risk Assessment,Risk Analysis,Risk-Benefit Assessment,Health Risk Assessment,Risks and Benefits,Analysis, Risk,Assessment, Benefit-Risk,Assessment, Health Risk,Assessment, Risk-Benefit,Benefit Risk Assessment,Benefit-Risk Assessments,Benefits and Risks,Health Risk Assessments,Risk Analyses,Risk Assessment, Health,Risk Assessments,Risk Benefit Assessment,Risk-Benefit Assessments