Copper, zinc and lead isotope signatures of sediments from a mediterranean coastal bay impacted by naval activities and urban sources

Abstract

Toulon bay is severely impacted by metal contamination induced by past and recent naval activities. In this work, Cu, Zn and Pb isotope compositions and elemental concentrations of fifty-five surface sediments were determined in order to map the spatial distribution of anthropogenic and natural sources along this land-sea continuum. Two subsystems of Toulon Bay, the Small and Large bays, showed wellmarked patterns on metal contamination levels and isotope signatures for Cu and Pb. The Small bay had the highest metal concentrations, and displayed average Pb and Cu isotope compositions of 1.1664 ± 0.0043 (1s, expressed as 206Pb/207Pb ratios) and −0.17 ± 0.19‰ (1s, expressed as δ65CuNIST values), respectively. It contrasted with the Large bay, with moderate to pristine metal concentrations and average Pb and Cu isotope compositions of 1.1763 ± 0.0079 (1s) and +0.08 ± 0.23‰ (1s), respectively. Lead isotope systematics indicated a binary source mixing process involving industrial and natural sources, while Cu isotope systematics showed a ternary mixing process involving two distinct anthropogenic signatures, interpreted as associated to new diffuse anthropogenic sources and old warfare material. In contrast, Zn isotope compositions in the Small and Large bays were practically the same: +0.06 ± 0.05‰ and +0.06 ± 0.11‰ (1s, expressed δ66ZnJMC values), respectively, denoting an overlap between isotope signatures of natural and anthropogenic sources. This study presents the first detailed spatial distributions of Cu and Zn isotope compositions for an aquatic system, and demonstrates the feasibility to use Cu isotopes as tracers of anthropogenic sources in coastal environments. Highlights ► Cu isotope systematic show a mixing process of natural and anthropogenic sources. ► Low Cu contaminated sediments display δ 65 CuNIST values ranging from 0.0 to +0.2‰. ► Contaminated sediments by diffuse sources tend to negative δ 65 CuNIST values. ► Pb isotopes reveal mixing process involving industrial and natural sources. ► Zn isotope system does not allow identifying mixing source processes. Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site.

Copper, Zinc and Lead Isotopic Delta Values and Isotope Ratios of Various Geological and Biological Reference Materials

“…Lead isotopic ratios of marine sediment RMs such as MESS‐3 and PACS‐2 have been reported (Araújo et al . 2019). However, these two materials are no longer commercially available and have been replaced by MESS‐4 and PACS‐3.…”

Evaluating Spatiotemporal Resolution of Trace Element Concentrations and Pb Isotopic Compositions of Honeybees and Hive Products as Biomonitors for Urban Metal Distribution

“…These include Zn, Cd, or Cu isotopes, all potentially useful for identifying anthropogenic processes by observing isotopic compositions that deviate from geologic ones. While Pb isotopic compositions of environmental samples are overwhelmingly governed by the two major endmembers (Broken Hill and southeast Missouri ores) of the global gasoline mixing line, use of another isotope system can aid in source apportionment by revealing other potential point sources of pollution (e.g., Araújo et al, 2019). Furthermore, bee pollen and bee tissues may be more suitable for laboratories without access to mass spectrometers, since the higher TE concentrations will result in less challenging concentration measurements (e.g., by ICP-AES) for specific low-level TE useful in anthropogenic sourcing studies (e.g., Cd, Sb, and Sn).…”

Elemental and isotopic compositions in blank filters collecting atmospheric particulates

“…Recently, multi-isotope (Zn and Pb isotopes) studies have been initiated to determine the origin of contamination source in aerosols and to evaluate the individual contribution of these pollution sources (Araújo et al 2019;Souto-Oliveira et al 2018, 2019Schleicher et al 2020). Although multi-isotope approach allows us to shed light on the origin and contribution of potential anthropogenic sources in the atmospheric particulates, there is a limitation to apply them due to little isotope data for potential anthropogenic sources.…”