Baseline study on trace and rare earth elements in marine sediments collected along the Namibian coast

• Published in: Marine pollution bulletin 2018-06, Vol.131 (Pt A), p.386-395
• Main Authors: Orani, Anna Maria, Vassileva, Emilia, Wysocka, Irena, Angelidis, Michael, Rozmaric, Martina, Louw, Deon
• Format: Article
• Language: English
• Subjects: Anthropogenic factors; Baseline studies; Benguela; Cadmium; Coastal environments; Coasts; Copper; Correlation analysis; Diamonds; Earth; Enrichment; Environmental assessment; Environmental impact; Environmental Monitoring - methods; Fluorite; Geologic Sediments - analysis; Heavy metals; Human influences; Isotope ratios; Isotopes; Lead; Marine environment; Marine sediments; Metal industry; Metals, Heavy - analysis; Metals, Rare Earth - analysis; Namibia; Pb isotope ratios; Pollutant load; Pollution; Pollution index; Pollution load; Pollution sources; Principal components analysis; Rare earth elements; Ratios; REEs; Sediment; Sediments; Surface sediments; Trace elements; Uranium; Water Pollutants, Chemical - analysis; Zinc
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2018.04.021

Namibia is a fast-growing country with extensive mineral extraction activities used in diamond, fluorspar, uranium, and metals production. To assess the impact of land based human activities on the Namibian coastal marine environment, 25 elements were analyzed in 22 surface sediments samples collected along the coast. After applying a variety of pollution assessment indices (Enrichment Factor, Igeo and Pollution Load Indexes) was concluded that As, Cd and Sb were considerably enriched in the sediments from several sites, while Cu, Pb and Zn showed very high enrichment near the Walvis Bay harbor. Pearson's correlation and Principal Component Analysis were used to investigate common metal sources. Additionally, the determination of Pb isotope ratios confirmed the contribution of land based human activities at Walvis Bay and Lüderitz as sources of pollution. The analysis of REEs did not reveal any important enrichment due to anthropogenic activities, but provides a needed baseline for further investigations. [Display omitted] •A baseline monitoring study for Namibian cost is proposed.•Trace elements were determined after analysis of 22 surface sediments.•Lead isotope ratios results provided a tool to trace the pollution sources.•The first REEs evaluation for this area was also object of the present study.•The areas around Walvis Bay and Lüderitz revealed the highest trace elements enrichment.