Carbon dating study
Barring any future nuclear detonations, this method should continue to be useful for year-of-birth determinations for people born during the next 10 or 20 years.
Everyone born after that would be expected to have the same level of carbon-14 that prevailed before the nuclear testing era.
Their recent analysis of sediment from the largest freshwater lake in northeast China showed that its carbon clock stopped ticking as early as 30,000 years ago, or nearly half as long as was hitherto thought.
However, more testing is needed to confirm that belief. 269, March 2012NCJ 237722 Philip Bulman is a writer and editor at NIJ.
Danielle Mc Leod-Henning is a program manager and physical scientist at NIJ.
The researchers found that certain soft tissues — notably blood, nails and hair — had radiocarbon levels identical to the contemporary atmosphere.
Therefore, the radiocarbon level in those tissues post-mortem would indicate the year of death.