Lead in teeth can tell a body's tale

July 31, 2014 by Julia Glum

Your teeth can tell stories about you, and not just that you always forget to floss.

A study led by University of Florida geology researcher George D. Kamenov showed that trace amounts of lead in modern and historical human teeth can give clues about where they came from. The paper will be published in the August issue of Science of The Total Environment.

The discovery could help police solve cold cases, Kamenov said. For instance, if an unidentified decomposed body is found, testing the lead in the teeth could immediately help focus the investigation on a certain geographic area. That way, law enforcement can avoid wasting resources checking for missing persons in the wrong places.

"We can use this pollution signal to figure out where these people came from," he said.

Lead is composed of four variants, called isotopes. The amount of those isotopes fluctuates in different rocks, soils and ores – and, therefore, regions of the world.

Mining and other pollution-causing activities release that lead into the environment, and it accumulates in children's bodies as they grow because kids inhale dust and ingest soil when they put their hands in their mouths.

Tooth enamel, which develops during childhood, locks in the lead signals and preserves them.

"When you grow up, you record the signal of the local environment," Kamenov said. "If you move somewhere else, your isotope will be distinct from the local population."

Even different teeth can reveal certain facts.

First molar enamel is finished forming by age 3, so it provides information about birth and toddler years. Incisor and canine enamel starts later and finishes around age 5, so it gives insight into early childhood. The third molar enamel does not start forming until age 8, so it indicates late childhood residences.

Lead analysis can also tell what time period a body is from.

Modern and historical teeth have different signals, according to the study. The natural composition of lead changed over the past century because of mining and the use of leaded gasoline, so there's a clear distinction between modern and historical human exposure.

Using that information, archaeologists can identify early European bodies in New World areas.

"You can go back in time, look at archaeological sites and try to reconstruct human migration," Kamenov said.

But modern American teeth are like no others in the world, according to the study. Whereas available data for areas such as South America overlap with Europe, American can be identified anywhere due to usage of ores with distinct isotope signals in the United States.

"What's in the environment goes into your body," Kamenov said.

Explore further: Exploring dental enamel thickness of giant ape by using high-resolution CT

Related Stories

Recommended for you

48-million-year-old horse-like fetus discovered in Germany

October 7, 2015

A 48 million year-old horse-like equoid fetus has been discovered at the Messel pit near Frankfurt, Germany according to a study published October 7, 2015 in the open-access journal PLOS ONE by Jens Lorenz Franzen from Senckenberg ...

Chimpanzees shed light on origins of human walking

October 6, 2015

A research team led by Stony Brook University investigating human and chimpanzee locomotion have uncovered unexpected similarities in the way the two species use their upper body during two-legged walking. The results, reported ...

How much for that Nobel prize in the window?

October 3, 2015

No need to make peace in the Middle East, resolve one of science's great mysteries or pen a masterpiece: the easiest way to get yourself a Nobel prize may be to buy one.

The dark side of Nobel prizewinning research

October 4, 2015

Think of the Nobel prizes and you think of groundbreaking research bettering mankind, but the awards have also honoured some quite unhumanitarian inventions such as chemical weapons, DDT and lobotomies.

Who you gonna trust? How power affects our faith in others

October 6, 2015

One of the ongoing themes of the current presidential campaign is that Americans are becoming increasingly distrustful of those who walk the corridors of power – Exhibit A being the Republican presidential primary, in which ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.