Carbon dating objects
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.It was while working in the Kent Laboratory building in the 1940s that researchers developed radiocarbon dating—an innovative method to measure the age of organic materials.Scientists soon used the technique on materials ranging from the dung of a giant sloth from a Nevada cave; seaweed and algae from Monte Verde, Chile, the oldest archaeological site in the Western Hemisphere; the Shroud of Turin; and the meteorite that created the Henbury Craters in northern Australia.The new method is based on the fact that over the past 60 years, environmental levels of radiocarbon have been significantly perturbed by mid-20th-century episodes of above-ground nuclear weapons testing.
Danielle Mc Leod-Henning is a program manager and physical scientist at NIJ.
The researchers wanted to find out if they could identify a person's year of birth or year of death using precise measurements of carbon-14 levels in different post-mortem tissues.
They measured carbon-14 levels in various tissues from 36 humans whose birth and death dates were known.
To determine year of birth, the researchers focused on tooth enamel.
Adult teeth are formed at known intervals during childhood.