Researchers identified 16 different microplastic polymer types across both contemporary and archived samples. Credit: York Archaeology
Key points:
- Researchers found evidence of microplastic contamination in archaeological soil samples.
- The team identified 16 different polymer types across their samples and dated the infiltration of these particles back to the 1960s’ post-war boom in plastic production.
- Scientists are reconsidering how they manage historical sites to try to eliminate the impact of microplastics on preserved remains.
For the first time, researchers have found evidence of microplastic contamination in archaeological soil samples. The study, published in Science of the Total Environment, outlines the team’s discovery of tiny microplastic particles in deposits more than seven meters deep – dating back to the first or early second century and excavated in the late 1980s.
Researchers identified 16 different microplastic polymer types across both contemporary and archived samples. The team also determined that the infiltration of particles into archaeological deposits likely dates back to the 1960s and the post-war boom in plastic production. The presence of these microplastics can change the chemistry of the soil by introducing elements that cause organic remains to decay.
To date, preserving archaeology in situ has been the preferred approach for managing historical sites. However, these new findings may prompt scientists to reconsider how they manage historical sites as microplastics may compromise preserved remains.
“This feels like an important moment, confirming what we should have expected,” explained John Schofield, professor at the University of York. “What were previously thought to be pristine archaeological deposits, ripe for investigation, are in fact contaminated with plastics.”
The team plans to determine the extent to which contamination compromises the evidential value and importance of these deposits.
“Where this becomes a concern for archaeology is how microplastics may compromise the scientific value of archaeological deposits,” said David Jennings, chief executive of York Archaeology. “If that is the case, preserving archaeology in situ may no longer be appropriate.”