Identifying unknown corpses is one of the most difficult things that the forensic pathologist and the forensic anthropologist must do. This is particularly true in situations of mass disaster where there are so many bodies to deal with or in circumstances where the body is severely decayed and there is little left to deal with but bones. The size, the sex, and the age of the skeletal remains narrow the possible identities. If the skeleton is intact, the size and the sex of the victim is usually easily ascertained but the exact age of the person is more difficult.
If the remains are those of a child it is usually easier since the development of the bones and teeth follow a pattern that is recognizable and more or less predictable. But once someone reaches adulthood this becomes more problematic. The teeth are often the best bet but once the wisdom teeth have completely erupted it is difficult to ascertain age. Hard to distinguish the skeletal remains of a 20 year old from a 35 year old.
Enter carbon-14. Carbon-14 is the radioactive isotope of carbon and is present in the residual of all organic materials. It has not been a useful forensic tool simply because it is too blunt and can only narrow down the age of the carbonaceous material to a century or so. So it is very good for determining if something is 500 years old or 5000 years old but not much help with a more recently deceased unidentified corpse.
A new technique has appeared that shows promise. A Swedish research team has begun looking at carbon 14 in tooth enamel and have found that it is highly accurate in determining the year of birth in anyone under 50 or 60 years of age. This technique uses the carbon-14 that was released into the atmosphere during the nuclear testing that was so common during the 1950s and 1960s. It’ll be interesting to follow this new technique and see if it really pans out to be as useful as hoped.