Thorium in occupationally exposed men

摘要

Higher than environmental levels of (sup 232)Th have been found in autopsy211u001esamples of lungs and other organs from four former employees of a thorium 211u001erefinery. Working periods of the subjects ranged from 3 to 24 years, and times 211u001efrom end of work to death ranged from 6 to 31 years. Examination of the 211u001edistribution of thorium among the organs revealed poor agreement with the 211u001edistribution calculated from the dosimetric models in Publication 30 of the 211u001eInternational Commission on Radioprotection (ICRP). Concentrations in the lungs 211u001erelative to pulmonary lymph nodes, bone or liver were much higher than calculated 211u001efrom the model for class Y thorium and the exposure histories of the workers. 211u001eMuch better agreement was found with more recently proposed models in 211u001ePublications 68 and 69 of the ICRP. Radiation doses estimated from the amounts of 211u001ethorium in the autopsy samples were compatible with health studies that found no 211u001esignificant difference in mortality from that of the general population of men in 211u001ethe US.