Uranium and Thorium Isotopes and Their State of Equilibria in Lungs from Uranium Miners
| Autor: | Geno Saccomanno, Narayani P. Singh, McDonald E. Wrenn |
|---|---|
| Rok vydání: | 1983 |
| Předmět: |
Male
Lung Neoplasms Epidemiology Health Toxicology and Mutagenesis Population chemistry.chemical_element Radiation Dosage Mining Humans Radiology Nuclear Medicine and imaging education Lung Postural Balance Aged education.field_of_study Radionuclide Radiochemistry Isotope Thorium Middle Aged Uranium Carnotite Occupational Diseases chemistry Conventional PCI Carcinoma Squamous Cell Dose rate Carcinoma in Situ Isotopes of thorium |
| Zdroj: | Health Physics. 44:385-389 |
| ISSN: | 0017-9078 |
| DOI: | 10.1097/00004032-198306001-00036 |
| Popis: | Radiochemical analysis of seven lungs obtained at autopsy show that concentrations ranged between 6 and 63 pCi/kg for 238U and 6-66 pCi/kg, for 234U. Similarly, 230Th ranged from 17 to 54 pCi/kg, two orders of magnitude higher than 230Th observed in the lungs of the general population from the Western mining region. For individual lungs, 238U and 234U were close to equilibrium with an average ratio of 238U/234U of 0.94 and a range of 0.80-1.02. Surprisingly, 230Th was close to equilibrium with 234U with a 230Th/234U ratio of 1.1 and a range from 0.54 to 2.6. Equilibrium between U and Th isotopes is in contrast to the disequilibrium reported in beagles which chronically inhaled carnotite, where the 230Th/234U ratio was observed to range from 5.4 to 7.4 with an average of 6.3. The average radiation dose rate to lung from each of the three radionuclides was calculated as follows: D = 18.7 CE where D = dose rate in mrad/year, C = activity concentration in tissue in pCi/g and E = energy absorbed per disintegration in MeV. The combined radiation dose rate (at death) due to three long-lived radionuclides 238U, 234U and 230Th varied from 2.5 to 14.2 mrad/yr with a mean of 9.6 mrad/yr. The concentration of 226Ra and daughters in the lung was not determined. An upper limit to the dose rate from the whole chain, calculated assuming 226Ra through 210Po are in equilibrium with 238U, 234U and 230Th, would be 30 mrad/yr. |
| Databáze: | OpenAIRE |
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