However, the researchers suggested that soft tissue radiocarbon content would be transferred to, and preserved in, the pupal cases of insects whose larvae feed on these tissues.
Such insects are simply another link in the food chain.
Unlike tooth enamel, soft tissues are constantly being made and remade during life.
Thus, their radiocarbon levels mirror those in the changing environment.
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.
They found that for teeth formed after 1965, enamel radiocarbon content predicted year of birth within 1.5 years.
All the people whose tissues were tested for the study were residents of the United States.