FOLLOW-UP-STUDY OF CHROMOSOME-ABERRATIONS IN LYMPHOCYTES IN-HOSPITAL WORKERS OCCUPATIONALLY EXPOSED TO LOW-LEVELS OF IONIZING-RADIATION

In the present study we analyzed and followed up on the cytogenetic ef fects of low levels of ionizing X-radiation on hospital workers at 72 h cultures. Samples of peripheral blood were collected from 10 hospita l workers exposed to 1.84 mSv/year, and from 10 non exposed individual s, who were screened simultaneously and used as controls. The chromoso mes were prepared using standard techniques. After 12 months, we under took a second evaluation, this time with exposure to the same workers of 1.67 mSv/year. We observed 100 metaphases per subject, and there wa s a high percentage of altered metaphases (29.2% in the first sample a nd 26% in the second samples) The chromosome analysis in the second mi totic division, show aberrations such as gaps, breaks and acentric fra gments, as well as other alterations such as dicentrics and rings, as well as chromosome variants (double minutes) in the exposed workers vs . the controls, and the difference was statistically highly significan t (p < 0.001). There is no statistically significant difference betwee n the first sample of exposed workers with the second one (p > 0.05). The findings in this study are interesting, because the workers were e xposed to doses well below the accepted standards for exposure to radi ations, Because of these unusual findings, our results could have pote ntially major consequences on our views on standards of exposure to ra diation.