Assessment of the metal contamination evolution in the Loire estuary using Cu and Zn stable isotopes and geochemical data in sediments. (June 2019)

• Record Type: Journal Article
• Authors: Araújo, Daniel F.; Ponzevera, Emmanuel; Briant, Nicolas; Knoery, Joël; Sireau, Teddy; Mojtahid, Meryem; Metzger, Edouard; Brach-Papa, Christophe
• Is Part Of: Marine pollution bulletin. Volume 143(2019)
• Page Start: 12
• Page End: 23
• Publication Date: 2019-06
• Subjects: Coastal pollution -- Coastal biogeochemistry -- Geochemical tracers -- Metal isotopes -- Trace metal -- Anthropogenic contamination; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2019.04.034
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: In this work, a multi-elemental approach combining Cu and Zn stable isotopes is used to assess the metal contamination evolution in the Loire estuary bulk sediments. Elemental geochemical data indicate an increase of metal concentrations from the beginning of the industrial period peaking in the 1990s, followed by an attenuation of metal contamination inputs to the estuary. Zinc isotope compositions suggest a binary mixing process between Zn derived from terrigenous material and multi-urban anthropogenic sources. Copper isotope systematics indicate a single natural dominant source represented by weathered silicate particles from soils and rocks. This work demonstrates the applicability of Zn isotopes to identify anthropogenic Zn sources in coastal systems, even under a low to moderate degree of contamination. Further studies are required to constrain Cu sources and to elucidate possible effects of grain-size and mineralogy in the Cu isotope composition of sediment in the Loire estuary. Highlights: Geochemical data and Cu and Zn isotopes were investigated in the Loire estuary. Cu and Zn isotope compositions of sediments vary in spatial and temporal scales. Zinc isotopes suggest a mixing process between terrigenous and urban sources. Cu isotopes indicate a natural dominant source represented by weathered material.