The climate change of the Little Ice Age may have been one of the factors causing the prevalence of rickets in our early 19th-century ancestors, archaeologists have said following a new study of 21 skeletons.
The period from roughly 1550 to 1880 is known as the Little Ice Age due to extended low temperatures and limited sunlight, perhaps linked to a series of volcanic explosions.
The end of this period overlapped with the Industrial Revolution, when Britain’s economy transitioned from one based on agriculture to industry, from roughly 1760 to 1840.
Rickets, when the skeleton does not develop proper strength during childhood, was commonplace in this period. The condition is caused by lack of vitamin D, found in sunlight.
This has traditionally been attributed to the pollution, harsh working conditions and inadequate housing of Britain’s industrial cities.
However, a new Frontiers in Environmental Archaeology study has offered new insights into the causes of rickets prevalence by examining 30 teeth from 21 skeletons in the former Quaker cemetery at Coach Lane in North Shields.
The cemetery was actively used between 1711 and 1829. Around that time, North Shields transformed from a fishing village into an industrial port.
The researchers found that 76% of the individuals showed possible signs of rickets, where dentin, the inner layer of the tooth, fails to fully mineralize during childhood.
Because this didn’t tell the researchers about the calendar years when mineralization failures happened, they used Coach Lane’s burial register. It chronicles ages and years of death for many of the 197 individuals listed, and birth years could be estimated for 109 community members by subtracting age at death from year of death. Because the graves weren’t marked, these dates could not be matched to individuals. However, the data showed that out of the 109 people with known birth years, 91 were born within 10 years after a major volcanic eruption. 41 were born during periods when low solar output and volcanic activity co-occurred.
Dr Ellen Kendall of Durham University, one of the authors of the study, said: “Humans are incredibly complicated. We’re physical creatures defined by our biology. We’re cultural creatures defined by beliefs and the systems they reinforce. And we’re products of our environment. No part overrides another; they all interact. When we assess one aspect of human biology – vitamin D deficiency during the Industrial period – it’s going to be in the context of needing to grapple with the full dynamics of the human experience.”
“We think of climate instability as a modern challenge, but it’s really nothing new as human problems go,” she added. “Whether it’s pandemics, economic crises, or climate change, it’s important to understand the ways that people have adapted to similar issues in the past and use that information to help people thrive in the future.”
