Thorium in human tissues. Formal report 1 Sep 76-31 Mar 80
The content of Th-228, Th-230 and Th-232 was investigated in human tissue from the general public without known occupational exposure. Twenty-two sets of human tissues from Grand Junction, Colorado and ten sets from Washington, DC were analyzed. Organs included were lung, pulmonary lymph nodes, liver, kidney, spleen and bone. A radiochemical method was developed for the determination of environmental levels of alpha-emitting isotopes of thorium in tissue consisting of tissue digestion, separation of thorium isotopes by solvent extraction, electro-deposition, followed by alpha-spectrometric measurement using a surface barrier silicon diode. The method utilizes Th-229 as an internal tracer for radiochemical recoveries, and Th-228, Th-230, and Th-232 are measured simultaneously. Concentrations of Th-230 and Th-232 decrease in the following order: lymph nodes > lung > bone > kidney > liver, and Th-228: lymph nodes > bone > lung > kidney > liver. As expected, Th-230 and Th-232 were distributed similarly with about 11-27% of the body content in lung, and 55-70% in the skeleton. Th-228 was distributed differently with about 80% in the skeleton and only 5% in the lungs. Thorium-230 and 232 concentrations in bone were found to increase approximately linearly with age. The observed distribution of thorium among the organs is in good agreement with that recently adopted by the ICRP (ICRP 30, 1979). The total accumulation of thorium in the human body was equivalent to the average amount of natural thorium in 1 to 6 gms of soil. The highest median radiation dose rate for the groups studied from all 3 isotopes of Th was 5 and 0.6 mrad/year delivered to pulmonary lymph nodes and bone respectively.
- Research Organization:
- New York Univ., NY (USA). Inst. of Environmental Medicine
- OSTI ID:
- 5387950
- Report Number(s):
- NUREG/CR-1227
- Country of Publication:
- United States
- Language:
- English
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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
BODY
CHEMICAL ANALYSIS
COLORADO
DIGESTIVE SYSTEM
EVEN-EVEN NUCLEI
FEDERAL REGION VIII
GLANDS
HEAVY NUCLEI
HUMAN POPULATIONS
ISOTOPES
KIDNEYS
LIVER
LUNGS
LYMPH NODES
LYMPHATIC SYSTEM
MONITORING
NORTH AMERICA
NUCLEI
ORGANS
POPULATIONS
QUANTITATIVE CHEMICAL ANALYSIS
RADIATION MONITORING
RADIOCHEMICAL ANALYSIS
RADIOISOTOPES
RESPIRATORY SYSTEM
SKELETON
SPLEEN
THORIUM 228
THORIUM 230
THORIUM 232
THORIUM ISOTOPES
USA
WASHINGTON DC
YEARS LIVING RADIOISOTOPES