The proverbial good old times!
"Abnormally high levels of lead in the teeth of a brown bear, which died 1000 years ago down a cave shaft in the Southern Carpathian mountains, represent the earliest known evidence of human-induced heavy metal pollution in a wild animal. The finding pushes back the date of such pollution affecting terrestrial wildlife by several centuries before the Industrial Revolution began around 1760. ...
Analyses of sediment cores revealed such pollution had already begun at low levels at the onset of the Bronze Age 5200 years ago in northern Greece. Then, 2150 years ago the pollution intensified, aligning with when the Roman Empire began to occupy Ancient Greece.
However, although historic heavy metal pollution likely affected ecosystems, little is known about its impacts due to a lack of direct evidence. Now, palaeontologist[s] ... have found the earliest evidence yet of lead pollution in a wild animal after analysing the teeth of a bear that lived around 1000 years ago. ..."
From the highlights and abstract:
"Highlights
• multi-elemental concentration maps of the dentition of a sub-fossil brown bear from the Carpathian Mountains.
• Anomalous concentrations of heavy metals (lead, zinc, lithium) are detected in the last deposited layers of dentine.
• Radiocarbon data of the sampled bone indicate the individual is 1000 BP-year-old, at a time and place known for ore smelting.
• Earliest-known evidence for anthropogenic pollution on the wildlife.
Abstract
Effects of past anthropogenic metal pollution on the wildlife are understudied. We investigate trace element incorporation in the dentition of a 1000 BP-year-old brown bear from the Romanian Carpathians, an area known historically for strong metallurgical activities.
Background values as well as unnatural high lead (Pb), lithium (Li) and zinc (Zn) levels in a circa 5‒6-year-old brown bear male were detected using trace element maps across its functional dentition.
High-resolution elemental transects and histological sections reveal the seasonal extent of lead intake, which occurred during five recorded summers, i.e. when the animal was actively foraging.
We interpret the elevated Pb, Li and Zn concentrations in the terminal growth lines as evidence for the earliest-known anthropogenic heavy metal pollution in a wild animal.
Our study underlines the impact of early industrial activities in a large terrestrial omnivore, demonstrating that anthropogenic threats on wildlife were not solely driven by hunting or landscape modification during the most recent decades."
This 20m vertical shaft is the only way in or out of the cave where the bears’ remains were found
Graphical abstract
No comments:
Post a Comment