Abstract

Abstract The objective of the present research was to evaluate the contamination level and potential risks at a part of a large and important river in Central Africa, the Congo River. Surface sediments were collected from seven stations located in Maluku-Kinsuka section, at the vicinity of Kinshasa, capital city of Democratic Republic of the Congo. The concentration of toxic metals (Cr, Co, Ni, Cu, Zn, As, Cd and Pb) in sediment samples were determined using Inductive Coupled Plasma-Mass Spectroscopy (ICP-MS). The Hg analysis was carried out using Advanced Mercury Analyzer (AMA). The evaluation of the pollution degree was based on Sediment Quality Guidelines (SQGs), Enrichment Factor (EF), Geoaccumulation Index (Igeo), and using toxicity test based on exposing Ostracods to the sediment samples. The result revealed high metal concentrations in sediments from the 4 densely populated areas (Kinkole, Kauka fishermen, Demoulin, Chanic), reaching the values (mg kg−1) of of 95.5, 14.3, 37.1, 139.9, 281.5, 4.8, 6.6, 200.9 and 4.9 mg kg−1 for Cr, Co, Ni, Cu, Zn, As, Cd, Pb and Hg, respectively. These values are above SQGs and probable effect levels. In these sites, Igeo and EF values showed heavily to extremely polluted and severe enrichment to extremely severe enrichment for analysed metals. Additionally, Ostracods exposed to sediments resulted in 100% mortality rates after 6 days of incubation, demonstrating the sediment toxicity as well as potential risks for aquatic living organisms. The pollution in these sites may be explained by local intense human activities with various commercial, presence of uncontrolled landfills in riverbank and industrial settlements, as well as by the construction of boats for the regular navigation along the river. This research presents useful tools for evaluating sediments quality and risk, which can be applied to similar environments.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.