title: Micronuclei in lymphocytes from currently active uranium miners.
abstract: Micronuclei can be used as markers of past radiation exposure, but only few studies have dealt with uranium miners. In this paper, we report on micronuclei in lymphocytes from individuals currently working at Rožná, Czech Republic, the last functioning uranium mine in the European Union. A modified micronucleus-centromere test was applied to assess the occurrence of micronuclei in stimulated lymphocytes, as well as their content in terms of whole chromosomes or fragments. Compared with unexposed individuals, the miners had higher frequencies of micronucleus-containing lymphocytes and higher percentages of micronuclei without centromeres, and the differences were significant for both parameters (0.74 ± 0.60 vs. 0.50 ± 0.42, p = 0.017 and 49 ± 44 vs. 12 ± 21, p = 0.0002; means ± standard deviations). There were also significant correlations between one or other of these parameters on the one hand and various dose values on the other, in particular with a 'retrievable' dose, that is, a dose whose effect should still be recognisable in lymphocytes assuming a half-life of 3 years. The 'retrievable' dose at which a doubling of the micronucleus frequency was observed was around 35 mSv, corresponding to a total dose of 90 mSv received while working in the mines. Altogether, our data show that the micronucleus-centromere test is a valuable tool for the assessment of past radiation exposure in uranium miners. The scatter in the data is of course far too great to allow individual dosimetry, but for groups of a few dozen exposed individuals, the method can be used to monitor doses clearly below 100 mSv.
authors.affiliation: Department of Radiology and Toxicology, Faculty of Health and Social Studies, University of South Bohemia in České Budějovice, České Budějovice, Czech Republic. zoelzer@zsf.jcu.cz
authors.forename: Friedo
authors.initials: F
authors.lastname: Zölzer
authors.forename: Zdeněk
authors.initials: Z
authors.lastname: Hon
authors.forename: Zuzana Freitinger
authors.initials: ZF
authors.lastname: Skalická
authors.forename: Renata
authors.initials: R
authors.lastname: Havránková
authors.forename: Leoš
authors.initials: L
authors.lastname: Navrátil
authors.forename: Jozef
authors.initials: J
authors.lastname: Rosina
authors.forename: Jiří
authors.initials: J
authors.lastname: Škopek
mesh_terms: D002503:Centromere / Q000235:genetics / Q000528:radiation effects; D018153:Czech Republic; D006801:Humans; D008214:Lymphocytes / Q000473:pathology* / Q000528:radiation effects*; D048629:Micronuclei, Chromosome-Defective / Q000528:radiation effects*; D015162:Micronucleus Tests; D008906:Mining; D016273:Occupational Exposure / Q000009:adverse effects* / Q000032:analysis; D014501:Uranium / Q000009:adverse effects*
chemical_list: D014501:Uranium