title: REPLACEMENT RATES FOR HUMAN TISSUE FROM ATMOSPHERIC RADIOCARBON.
abstract: Carbon-14, derived from the testing of thermonuclear weapons in the atmosphere of the Northern Hemisphere during 1961-62, has been found in human tissues including the brain in amounts which reflect the atmospheric concentration of carbon-14 as of several months earlier. In collagen of cartilage, the rate of uptake of carbon-14 is much slower than in other tissues; essentially no radioactive carbon was found in the collagen of 70-year-old adults that had been exposed to the comparatively high concentrations of carbon-14 in the atmosphere during the years 1954 to 1964. Individuals from the Southern Hemisphere show little increase in the carbon-14 content of their tissues at present, and detailed tests with individuals traveling to the Northern Hemisphere from the Southern allow closer scrutiny of the tissue replacement rates.
mesh_terms: D000328:Adult; D001272:Atmosphere; D001769:Blood; D001921:Brain; D002244:Carbon; D002245:Carbon Dioxide; D002247:Carbon Isotopes; D002250:Carbon Radioisotopes; D003094:Collagen; D005853:Geriatrics; D006801:Humans; D008660:Metabolism; D011847:Radioactive Fallout
chemical_list: D002247:Carbon Isotopes; D002250:Carbon Radioisotopes; D011847:Radioactive Fallout; D002245:Carbon Dioxide; D002244:Carbon; D003094:Collagen
keywords: BLOOD; BRAIN; CARBON DIOXIDE; CARBON ISOTOPES; COLLAGEN; GERIATRICS; METABOLISM; RADIOACTIVE FALLOUT