Pollution, an older problem than we expected

Humans have been polluting nature since ancient times, this is the conclusion of a study. Human-caused environmental contamination with lead in the Aegean region began approximately 5,200 years ago, about 1,200 years earlier than previously thought, according to research that also reveals that the expansion of the Roman Empire in Ancient Greece contributed significantly to this pollution. These are the main findings of the study carried out by several German research centers led by the University of Heidelberg and published in the journal Communications and Environment, taken over by the EFE agency. The research, based on the study of samples collected from the bottom of the Aegean Sea, demonstrates that humans contaminated the environment with lead in a very early era of Antiquity, first by the Greek civilization and then by the powerful Roman Empire. The research team, led by Andreas Koutsodendris from Heidelberg University, analyzed the lead content of 14 marine sediment samples taken between 2001 and 2021 in the Aegean Sea, coastal regions of the sea and the Tenaghi Philippon peatland in northeastern Greece. The same team analyzed the pollen and spore content of several samples and combined it with the lead content data to try to find out how and to what extent the ecosystems of the region may have been affected by the social and cultural transformations of the era. They found that the first indication of probable human-caused lead contamination dates back to about 5,200 years ago in the Tenaghi Philippon core, about 1,200 years earlier than the earliest evidence of human-caused lead contamination in peatlands on the Balkan Peninsula. "Since lead was released, among other things, during the production of silver, evidence of increasing lead concentrations in the environment is at the same time an important indicator of socio-economic change," explains Andreas Koutsodendris. The lead and pollen sediment samples analyzed also allowed the research team members to reconstruct the development of vegetation in the Aegean region, as the amount of pollen shows how the land was used. They found that during the Roman expansion in Ancient Greece, around 2,150 years ago, a significant concentration of lead appeared, which was accompanied by intense deforestation. This period was marked by a significant increase in the extraction of gold, silver and other metals for use in coins and other items, an activity that at the same time required large amounts of wood. "These changes coincide with the conquest of Hellenistic Greece by the Romans, who later claimed the region's rich resources for themselves," notes Joseph Maran, an archaeologist and co-author of the study. Since then, lead contamination has been evident in all sediments of the Aegean Sea. The authors conclude that the Aegean Sea is the site of the first probable lead contamination recorded in a marine environment.