Cytogenetic monitoring of industrial radiographers using the micronucleus assay.
Industrial radiography is the process of using either gamma-emitting radionuclide sources or X-ray machines to examine the safety of industrial materials. Industrial radiographers are among the radiation workers who receive the highest individual occupational radiation doses. To assess occupationally induced chromosomal damage, we performed the cytokinesis-block micronucleus (CBMN) assay in peripheral lymphocytes of 29 male industrial radiographers, exposed to ionizing radiation for 12.8 years+/-11.2, in comparison with 24 gender-, age-, and smoking habits-matched controls. The CBMN assay was combined with fluorescent in situ hybridization with a pan-centromeric DNA probe in 17 exposed subjects and 17 controls randomized from the initial populations. The mean cumulative equivalent dose, recorded by film dosimeters, was 67.2 mSv+/-49.8 over the past 5 years. The mean micronucleated binucleated cell rate (MCR) was significantly higher in the industrial radiographers than in the controls (10.7 per thousand +/-5.2 versus 6.6 per thousand +/-3.1, P=0.009); this difference was due to a significantly higher frequency of centromere-negative micronuclei (C-MN) in exposed subjects than in controls (8.5 per thousand +/-4.9 versus 2.2 per thousand +/-1.6, P<0.001). The two populations did not significantly differ in centromere-positive micronuclei (C+MN) frequency. These findings demonstrate a clastogenic effect in lymphocytes of industrial radiographers. MCR significantly positively correlated with age in the two groups. After correction for the age effect, MCR did not correlate with duration of occupational exposure. No correlation between radiation doses and MCR, C-MN, and C+MN frequencies was observed. In addition to physical dosimetry records, the enhanced chromosomal damage in lymphocytes of industrial radiographers emphasizes the importance of radiation safety programs.
Sari-Minodier
I
I
Service de Médecine et Santé au Travail, Laboratoire de Biogénotoxicologie et Mutagenèse Environnementale (EA 1784-IFR PMSE 112), Faculté de Médecine, Université de la Méditerranée, 13385 Marseille Cedex 05, France. irene.sari-minodier@medecine.univ-mrs.fr
Orsière
T
T
Bellon
L
L
Pompili
J
J
Sapin
C
C
Botta
A
A
D000328:Adult; D000367:Age Factors; D002503:Centromere / Q000235:genetics; D020732:Cytogenetic Analysis; D015342:DNA Probes; D005720:Gamma Rays; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008214:Lymphocytes / Q000502:physiology / Q000528:radiation effects*; D008297:Male; D015162:Micronucleus Tests / Q000379:methods*; D008875:Middle Aged; D016273:Occupational Exposure; D011834:Radiation Monitoring; D011859:Radiography; D011897:Random Allocation; D012016:Reference Values; D012907:Smoking; D013679:Technology, Radiologic; D000078329:Workforce
D015342:DNA Probes