Researchers reconstructed the morphology of the river Paglia
Researchers at the Department of Earth Sciences of University of Florence, led by Pilario Costagliola, have reconstructed the physiognomy and morphology of the river Paglia, the main tributary of the Tiber.
By studying the sediments contaminated by the mining activity on Mount Amiata, the researchers identified the different levels of mercury concentration along the river Paglia, assessing the presence of this metal in the river terraces, residues of the mercury extraction and processing activities that occurred on Mount Amiata between the end of the nineteenth century and the early eighties of the twentieth century.
“By drawing on cartographic documentation, mainly maps and aerial photographs, and by carrying out appropriate surveys in the field, we were able to reconstruct the physiognomy of the river, establishing the age of river morphologies”, explained Costagliola.
The study, published in the journal Catena, allowed the researchers to establish the distribution of mercury along the river Paglia and calculate the total mass, estimated to correspond to at least 60 tons of metal fragmented in the sediment.
The research team in Florence also carried out an in-depth study on the impact of mercury in the biosphere. “Luckily, mercury seems to be scarcely bioavailable”, explained researcher Valentina Rimondi, “but some municipalities have banned fishing in the Paglia as an appreciable amount of metal can be detected in the muscle tissue of fish”.