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Measuring Atomic Bomb-derived 14C Levels in Human Remains to Determine Year of Birth and/or Year of Death

NCJ Number
Date Published
97 pages
This study determined the utility of using tissue radiocarbon content in order to estimate year-of-birth and year-of-death in human remains for people who lived and died in the past half century.
This technique provides such estimates because of a global environmental phenomenon, namely, a uniform worldwide distribution of atmospheric radiocarbon whose level changes measurably on a yearly basis. Between 1955 and 1963, above-ground nuclear testing generated high concentrations of radioactive carbon (14C) in the earth's atmosphere. After a 1964 moratorium on above-ground testing, atmospheric levels of 14C began declining as the radioactivity passed from the atmosphere into the oceans and the biosphere. Virtually every organism living since the 1950s has higher than normal levels of 14C, including humans. The rapid year-to-year change in atmospheric levels of 14C within this time frame, combined with rapid transfer of atmospheric 14C into the food chain via photosynthesis, mean that the distribution of bomb-derived 14C within the humans depends upon birth-year, diet, and the dynamics of tissue replacement within the human body. The radiocarbon content of tissues is fixed at the time of death. Thus, the distribution of 14C in various tissue compartments can potentially be used to determine year-of-birth and/or year-of-death for people who lived and died in the past half century. This study measured 14C levels in postmortem tissues from 36 humans whose birth and death dates were known. A total of 276 measurements were completed on 9 different tissue fractions: tooth enamel, bone apatite, bone collagen, bone lipid, skin collagen, skin lipid, hair, nails, and blood. The method predicted year-of-birth within 1.5 years of actual birth for 8 of 15 individuals; however, inaccuracies increased up to 5 years for people were born in the 1950s. Extensive tables and figures, 28 references, and a listing of venues for the dissemination of research findings

Date Published: January 1, 2009