Microplastics are invading nearly every corner of the globe, but now the tiny particles threaten to wipe out part of human history.
Researchers at the UK’s University of York discovered the first evidence of microplastics at two archaeological sites in York that have produced significant findings from the Roman and Viking periods.
Microplastics, smaller than five millimeters in length, enter our bodies through plastic packaging, certain food, tap water and even the air we breathe – and have been linked to cancer and fertility issues.
But the foreign objects pulled from the ground in the UK could potentially compromise preserved remains, making them worthless to science.
The team found more than 25,000 microplastics in the samples, which were likely a direct result of of human activity, such as industry, agriculture, transportation and daily life.
The site at Wellington Row is linked to the Viking period, archaeologists have uncovered give tons of animal bones, a quarter million pieces of pottery and 20,000 other interesting objects
The Roman site excavation at the Queen’s Hotel revealed remains of an ancient wall, suggesting that the area could have been of major significance to ancient empire
Microplastics have gained much attention recently due to their prevalence and abundance in our everyday lives.
They have also been found in nearly every part of the world – from the deepest place on the planet, the Mariana Trench to the top of Mount Everest.
Professor John Schofield from the University of York’s Department of Archaeology, said in a statement: ‘This feels like an important moment, confirming what we should have expected: that what were previously thought to be pristine archaeological deposits, ripe for investigation, are in fact contaminated with plastics, and that this includes deposits sampled and stored in the late 1980s.
‘We are familiar with plastics in the oceans and rivers.
‘But here we see our historic heritage incorporating toxic elements.
‘To what extent this contamination compromises the evidential value of these deposits, and their national importance is what we’ll try to find out next.’
Microplastics, smaller than five millimeters in length, enter our bodies through plastic packaging, certain food, tap water and even the air we breathe – and have been linked to cancer and fertility issues
The team found more than 25,000 microplastics in the samples, which were likely a direct result of of human activity, such as industry, agriculture, transportation and daily life
The team analyzed soil samples taken from Wellington Row in 1989 and the Queen’s Hotel in York in the same year and 1990 – a total of three samples from each.
The earliest deposits from Wellington Row were revealed as being late first or early second century and extended to the 19th and 20th centuries.
And those from the Queen’s Hotel date to the late first century to the 20th century.
Wellington had the highest concentration, with 20,588 microplastics per kilogram and samples from the Queen’s Hotel site contained 5,910 per kilogram.
At the site linked to the Viking period, archaeologists have uncovered give tons of animal bones, a quarter million pieces of pottery and 20,000 other interesting objects.
The Roman site excavation at the Queen’s Hotel revealed remains of an ancient wall, suggesting that the area could have been of major significance to ancient empire.
The team used a technique called Fourier-transform infrared (FTRI) spectroscopy, which can identify unknown plastics in materials.
The device picked up tens of thousands of microplastics across the six small soil samples – and 16 could not be categorized.
The plastics that could be included are ethylene-vinyl and polyalkene, which are used in food packaging.
Polyethylene, found in water bottles, polypropylene, used in jars, and hydrocarbon resin, which is added to rubbers printing inks and adhesives – other plastics were also uncovered.
However, 57 percent of the microplastics found were categorized as Polytetrafluoroethylene (PTFE) – or what is commonly known as Teflon which is used in nonstick-coated cookware.
Approximately 17 different microplastics were identified in the soil samples
The team has speculated that the tiny particles were introduced to the archaeological sites when they were excavated in the 1980s.
‘The plastic storage buckets (PP), coring tubes (polymethacrylate), as well as a week-long air sample from the archive storage facility identified different predominant polymer types relative to those characterized in the archived sediments,’ the researchers wrote in the study.
The team said this work was a pilot study to see if microplastics have made their way into treasured sites and noted that ‘if replicated across the UK, then many heritage assets are potentially at risk from increased deterioration and loss of information potential.’
Because plastics have slow degradation, the particles could impact the chemical and physical makeup of the soil.
‘ The potential for radiocarbon dating or residue/trace element analysis may be compromised by the presence of [microplastics], and again requires further investigation to identify whether these are real risks,’ reads the published study.
‘The loss of information potential may be the greater threat to in situ preservation.’
