Why is carbon 14 useful in radioactive dating
The researchers found that year-of-death determinations based on nails were accurate to within three years.
The generally poor post-mortem preservation of soft tissues would be a limiting factor to this approach.
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.
Before the nuclear age, the amount of radiocarbon in the environment varied little in the span of a century.
Carbon-12 and carbon-14 are two isotopes of the element carbon.
The difference between carbon-12 and carbon-14 is the number of neutrons in each atom.
The researchers found that if they assumed tooth enamel radiocarbon content to be determined by the atmospheric level at the time the tooth was formed, then they could deduce the year of birth.
Traditional radiocarbon dating is applied to organic remains between 500 and 50,000 years old and exploits the fact that trace amounts of radioactive carbon are found in the natural environment.
The researchers found that certain soft tissues — notably blood, nails and hair — had radiocarbon levels identical to the contemporary atmosphere.