Old Cemetery Teeth Reveal Climate Shocks May Have Fueled Past Disease

In short: A new study suggests that shifts in climate related to volcanic activity and low solar output helped drive vitamin D deficiencies in children during England's Industrial Revolution. The evidence comes from a single study examining teeth and records from one historical cemetery.

Can a cold volcanic past leave clues inside human teeth? A new study suggests that shifting weather long ago might have made past children more vulnerable to disease.

What happened, in plain words

Researchers from Durham University looked at teeth and old written records from a long-disused Quaker cemetery in north-east England called Coach Lane. During the Industrial Revolution, England changed from a farming-based economy to an industrial one, while experiencing an extended cooling period known as the Little Ice Age. The scientists studied thirty teeth from twenty-one unidentified people to check for failures in how dentin, the inner layer of the tooth, turns into hard tissue. By combining these dental clues with birth years estimated from the cemetery's burial register, the team found that many individuals were born shortly after major volcanic eruptions or during times of low solar output. The authors propose that climate shifts reducing sunlight availability may have acted as an additional driver of vitamin D deficiencies, such as rickets, alongside well-known factors like pollution and poor housing.

Key points

Studying teeth from old graves: Researchers examined thirty teeth from twenty-one unidentified individuals to look for growth issues in the inner layer of the tooth. These flaws can point to vitamin D shortages when they happen at regular intervals during childhood.
Matching dental flaws to history: Scientists used a burial register to estimate birth years for people in the community as a whole because individual graves were unmarked. They discovered that most of these individuals were born within ten years after a major volcanic eruption.
A new piece of the health puzzle: While poor housing, work conditions, and pollution are known causes of past illnesses, the authors argue that environmental climate factors should also be considered to get the full picture of human health.

Terms explained

Dentin — The inner layer of a tooth located just beneath the hard outer enamel. Example: If you chip your tooth deeply, the yellowish layer you might see underneath the hard outer shell is dentin.
Rickets — A medical condition in growing children where bones fail to properly harden due to a lack of vitamin D. Example: A child with soft and weak leg bones that bend under their weight might be diagnosed with rickets.
Little Ice Age — An extended cooling period in history marked by cooler temperatures and volcanic activity. Example: Rivers freezing over during winters that are much colder than normal over many decades represent a mini ice age period.

Critical analysis

What is encouraging. The work cleverly connects historical written records with biological clues from teeth to explore a neglected angle of past human health. By looking at the community as a whole through careful archival data, the researchers attempt to piece together environmental pressures that are normally hard to track.

What deserves caution:

Unmarked individual graves. Because the specific graves were not marked, the researchers could not link individual teeth directly to specific birth and death years on the paper register. They had to analyze the community as an overall group instead of matching exact timelines for each person.
A single historical site. The study relies entirely on material from one specific Quaker cemetery in north-east England. It is unclear if these findings apply to other regions, different social groups, or urban populations elsewhere.
Correlation is not direct proof. Finding that many people were born after volcanic events does not automatically prove that volcanic dust or lower sunlight directly caused their tooth flaws. Other hidden stresses or local factors might have played a larger role.

Bottom line: While teeth and old records suggest climate shifts may have worsened past vitamin D shortages, this single study cannot confirm a direct cause-and-effect link.

What we still don't know

The source does not provide direct proof that climate factors caused the observed tooth flaws in specific individuals, as the graves were unmarked and dates were estimated for the community as a whole. It also remains unknown if these patterns apply outside of this specific north-east England cemetery.

Based on reporting from Frontiers Science News. This is an independent explainer, written in our own words with AI assistance; Frontiers Science News has not reviewed or endorsed it. Read the original for the full details.