Nuclear Testing Has Left Evidence of Age in Teeth
From Times Staff and Wire Reports
Carbon-14 fallout from above-ground nuclear weapons testing in the 1950s is embedded in tooth enamel, allowing scientists to estimate age to within 1.6 years, Jonas Frisen of the Karolinska Institute in Stockholm reported this week in the journal Nature. Tooth enamel contains 0.4% carbon. Concentrations in teeth thus reflect the amount in the atmosphere when the enamel was formed. It does not work for individuals born before 1943 because their teeth formed before nuclear tests began.
