Polycyclic aromatic hydrocarbon record in an urban secondary carbonate deposit over the last three centuries (Paris, France)

Julia Garagnon; Yves Perrette; Emmanuel Naffrechoux; Edwige Pons-Branchu

doi:10.1016/j.scitotenv.2023.167429

Polycyclic aromatic hydrocarbon record in an urban secondary carbonate deposit over the last three centuries (Paris, France)

Sci Total Environ. 2023 Dec 20:905:167429. doi: 10.1016/j.scitotenv.2023.167429. Epub 2023 Sep 27.

Authors

Julia Garagnon¹, Yves Perrette², Emmanuel Naffrechoux², Edwige Pons-Branchu³

Affiliations

¹ LSCE/IPSL, UMR 8212CEA-CNRS-UVSQ, Université Paris-Saclay, Orme des Merisiers, F-91191 Gif-sur-Yvette, France; EDYTEM (CNRS/USMB/MCC), Bâtiment Pole Montagne, Campus Scientifique, 73376 Le Bourget du Lac Cedex, France. Electronic address: julia.garagnon@lsce.ipsl.fr.
² EDYTEM (CNRS/USMB/MCC), Bâtiment Pole Montagne, Campus Scientifique, 73376 Le Bourget du Lac Cedex, France.
³ LSCE/IPSL, UMR 8212CEA-CNRS-UVSQ, Université Paris-Saclay, Orme des Merisiers, F-91191 Gif-sur-Yvette, France.

PMID: 37774882
DOI: 10.1016/j.scitotenv.2023.167429

Abstract

Preserving water resources and limiting pollution are central environmental issues in the current context of intense anthropization. Among organic pollutants, polycyclic aromatic hydrocarbons (PAHs) are commonly analysed as part of water quality assessments. After being emitted into the atmosphere, these persistent organic pollutants are deposited on the continental surface, where they are transported to the aquatic environment by run-off and infiltration waters. Mainly due to anthropogenic emissions, PAHs can therefore be considered as a proxy for human activities. Urban secondary carbonate deposits (USCDs), similar to cave speleothems, have recently been studied for their potential as natural archives of water quality. However, USCDs have never been used to trace water organic pollution and only a few studies on PAHs in speleothems are available. This study focuses on a well-dated USCD covering the last 300 years from the Great Aqueduct of Belleville (north-east of Paris, France). The aim is to determine the nature and variation of trapped organic compounds over time and to discuss their origin, transport, and link with changes in soil occupation due to human activities. To do so, high-resolution solid-phase UV fluorescence imaging analyses were combined with chemical analyses of PAHs and organic carbon carried out on low-weight samples. The results show that PAHs have been present in urban surface water for 300 years. Over the last few decades, a 7-fold increase is observed, accompanied by a change in the pollution source, enriched in high-molecular-weight PAHs, probably linked to urban dust. This study also reveals modes of transport directly influenced by changes in the soil occupation that are very different from those usually encountered in natural environments. This work thus paves the way for a better long-term understanding of the impact of human activity on the transfer of pollutants to sub-surface waters.

Keywords: Anthropization; Organic geochemistry; Organic matter; PAH; Speleothems; Urbanisation.