title: Analysis of chromosome damage in circulating lymphocytes of radiological workers affected by thyroid nodules.
abstract: The aim of our study was to assess whether or not thyroid nodularity in combination with occupational exposure to low levels of ionising radiation would be correlated with chromosome damage in peripheral lymphocytes. Conventional chromosome-aberration analysis was performed on a group of 92 hospital workers with or without thyroid nodules. On the basis of measurements of their exposure levels, the workers were classified into a low (mean total level=0.03 mSv), medium (mean total level=1.04 mSv) or high (mean total level=8.60 mSv) exposure category. Our results indicate that among workers with thyroid nodules, the high-exposed workers showed significantly higher levels of both total (2.35+/-0.34 per 100 cells) and chromosome-type aberrations (1.46+/-0.20 per 100 cells) than medium-exposed (0.98+/-0.42 and 0.68+/-0.25 per 100 cells, respectively) or low-exposed workers (1.11+/-0.29 and 0.58+/-0.17 per 100 cells, respectively). Workers without thyroid nodules had comparable frequencies of chromosome aberrations among the three exposure categories. To our knowledge, this is the first study revealing a slight, but significant increase of chromosome damage in peripheral lymphocytes from hospital workers who developed thyroid nodules under conditions of occupational exposure to radiation well below the threshold limit for the workplace. The existence of a possible association between chromosome aberrations and development of thyroid nodularity will be discussed.
authors.affiliation: Dipartimento di Scienze dell'Uomo e dell'Ambiente, University of Pisa, Via San Giuseppe 22, 56100, Pisa, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Scarpato
authors.forename: Alessandro
authors.initials: A
authors.lastname: Antonelli
authors.forename: Michela
authors.initials: M
authors.lastname: Ballardin
authors.forename: Monica
authors.initials: M
authors.lastname: Cipollini
authors.forename: Poupak
authors.initials: P
authors.lastname: Fallahi
authors.forename: Antonio
authors.initials: A
authors.lastname: Tomei
authors.forename: Claudio
authors.initials: C
authors.lastname: Traino
authors.forename: Roberto
authors.initials: R
authors.lastname: Barale
mesh_terms: D000704:Analysis of Variance; D002869:Chromosome Aberrations / Q000528:radiation effects*; D004249:DNA Damage / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008214:Lymphocytes / Q000473:pathology* / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D011839:Radiation, Ionizing; D011859:Radiography / Q000009:adverse effects*; D016606:Thyroid Nodule / Q000209:etiology* / Q000235:genetics*; D014916:Whole-Body Irradiation