Toxic metal concentration and ecotoxicity test of sediments from dense populated areas of Congo River, Kinshasa, Democratic Republic of the Congo

Environmental Chemistry and Ecotoxicology

Georgette N. Ngweme¹  Dhafer Mohammed M. Al Salah²  Guillaume M. Kiyombo³  Henry K. Mata⁴  Joel N. Konde⁴  Crispin K. Mulaji⁴  John W. Poté⁴ 

[1] King Abdulaziz City for Science and Technology, Joint Centers of Excellence Program, Prince Turki the 1st st, Riyadh 11442, Saudi Arabia;Department F.-A, Forel for Environmental and Aquatic Sciences and Institute of Environmental Sciences, Earth and Environmental Science Section, Faculty of science, University of Geneva, 66 Boulevard Carl-Vogt, CH-1211 Geneva 4, Switzerland;University of Kinshasa (UNIKIN), Faculty of Sciences, Department of Chemistry, B.P. 190. Kinshasa XI, Democratic Republic of the Congo;University of Kinshasa (UNIKIN). Faculty of Medicine, School of Public Health, B.P. 11850. Kinshasa I, Democratic Republic of the Congo;

关键词: River pollution;    Sediments;    Toxic metals;    Toxicity test;    Anthropogenic activity and risk;    Congo River;   

DOI  :  

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown