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Hellar-Kihampa, H.; Potgieter-Vermaak, S.; De Wael, K.; Lugwisha, E.; van Espen, P.; Van Grieken, R. |
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Title |
Concentration profiles of metal contaminants in fluvial sediments of a rural-urban drainage basin in Tanzania |
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A1 Journal article |
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Year  |
2014 |
Publication |
International journal of environmental analytical chemistry |
Abbreviated Journal |
Int J Environ An Ch |
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Volume |
94 |
Issue |
1 |
Pages |
77-98 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
This study investigated concentration profiles of trace, rare earth and platinum group metals in fluvial sediments from the Pangani river basin (43,650 km2), one of the largest river basins in Tanzania, to assess its environmental quality. Sediment samples were collected in two distinct seasons from 12 representative sites of diverse land-use practices and characterised by ICP-MS after optimised microwave digestion. Ecological risks were assessed by evaluation of pollution index and comparison with legislated sediment quality guidelines (SQG). The results revealed contamination by some trace metals (e.g. Pb, V, Cu, Cr, Ni, Cd, As, Co, Mn and Zn) in concentrations ranging from 0.7 to 2940 mg kg−1, and four rare earth elements (Y, Ce, Nd, Yb) in concentrations ranging from 0.9 (Yb) to 500 mg kg−1 dry weight (Ce), which significantly exceeded the estimated background values at some stations. Palladium was the only platinum group element that was detected in quantifiable concentrations (0.33.5 mg kg−1). Concentrations of some trace metals exceeded the SQGs at some localised areas. Principal component analysis and multivariate correlations indicated geochemical characteristics of the area as the major control of metal concentrations and spatial variability. Organic matter and clay contents also played a significant role in metal distributions. Assessment of land-use practices upstream of the sampling locations was used to trace potential anthropogenic sources of metal enrichments, where highest levels were found in areas close to urban centres and agricultural activities. The study provides baseline data for future monitoring programs, and highlights the need for more comprehensive analysis involving a wider spatio-temporal scale and ecotoxicological risk assessment. |
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000329774500007 |
Publication Date |
2013-05-24 |
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0306-7319 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.208 |
Times cited |
5 |
Open Access |
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Notes |
; The participants of this research gratefully acknowledge the financial support of the Belgian Development Agency (BTC). The contribution of the Pangani Basin Water Board (PBWB), especially Ms Arafa Maggidi in provision of valuable information and assistance with the sampling campaigns is greatly appreciated. We sincerely acknowledge the assistance of Mr. Elisa Dunstan Kiwelu of Ardhi University, Dar es Salaam, Tanzania in mapping the study area; Mr Peter Machibya of the Department of Geology, University of Dar es Salaam, Tanzania in sediment characterisation; and Dr Valentine Kayawe Mubiana of the Department of Biology, University of Antwerp in ICP-MS analysis. The contributions of six anonymous reviewers, which greatly improved the manuscript for this paper, are highly appreciated. ; |
Approved |
Most recent IF: 1.208; 2014 IF: 1.295 |
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Call Number |
UA @ admin @ c:irua:109234 |
Serial |
5547 |
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Author |
Hellar-Kihampa, H.; De Wael, K.; Lugwisha, E.; Govindan, M.; Covaci, A.; Van Grieken, R. |
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Title |
Spatial monitoring of organohalogen compounds in surface water and sediments of a rural-urban river basin in Tanzania |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
The science of the total environment |
Abbreviated Journal |
Sci Total Environ |
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Volume |
447 |
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Pages |
186-197 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre |
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Abstract |
The presence of persistent organic pollutants in Tanzanian environment is not well monitored despite the existing pollution potential from a number of sources. In this study, we investigated for the first time, the concentration profiles of different organohalogen compounds such as organochlorine pesticide residues (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in environmental samples (water and sediments) from the Pangani river basin (PRB). The PRB is one of the largest drainage basins in Tanzania, with its watershed exposed to multiple input sources of trace organic contaminants. Surface water and sediments were sampled from 12 representative stations of diverse characteristics and land-use practices, in three distinct seasons, and extracted by liquidliquid and Soxhlet extraction methods, respectively. Water samples were analyzed by GC-ECD for OCPs only, while sediment samples were analyzed for OCPs, PCBs and PBDEs by GC/MS. Seven compounds, dominated by HCH isomers (5104460 pg/L) and DDT analogs (1601460 pg/L),were detected in the water samples. These concentrations are far below the WHO guidelines for drinking water quality. A total of 42 compounds (8 OCPs, 28 PCB congeners and 6 PBDE congeners) were detected in the sediment samples. Their respective total concentration ranges were 24510,230; 35711,000 and 382175 pg/g dry weight. The spatial distribution patterns and Hierarchical Cluster Analysis reflected the impact of historical agricultural usage in sugarcane plantations (OCPs), and urbanization (PCBs and PBDEs). Risk assessment using sediment quality guidelines indicated no ecotoxicological risks. The results we have found provide preliminary data on levels of the organic contaminants in Pangani river basin as a new insight on the environmental quality of the area. |
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000317538100022 |
Publication Date |
2013-02-05 |
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ISSN |
0048-9697 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.9 |
Times cited |
42 |
Open Access |
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Notes |
; This research project was funded by the International Foundation for Science (IFS, Project Number W/4945-1). The authors wish to acknowledge the contribution of the Pangani Basin Water Office (PBWO) in Moshi, Tanzania; especially Ms. Arafa Maggidi in provision of valuable information and assistance with the sampling campaigns, and Salim Lyimo in mapping of the study area. The contributions of Mr. Peter Machibya of the Department of Geology, University of Dar es Salaam, Tanzania in sediment characterization; and Mr. Emmanuel Gwae, of the Government Chemists Laboratory Agency (GCLA) Dar es Salaam, Tanzania, for instrumental analysis of the water samples, are highly appreciated. Harieth Hellar-Kihampa acknowledges financial support from the Belgian Technical Agency (BTC). Govindan Malarvannan and Adrian Covaci acknowledge financial support from the University of Antwerp. ; |
Approved |
Most recent IF: 4.9; 2013 IF: 3.163 |
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Call Number |
UA @ admin @ c:irua:105260 |
Serial |
5836 |
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Author |
Hellar-Kihampa, H.; De Wael, K.; Lugwisha, E.; Van Grieken, R. |
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Title |
Water quality assessment in Pangani river basin, Tanzania : natural and anthropogenic influences on concentrations of nutrients and inorganic ions |
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A1 Journal article |
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Year |
2013 |
Publication |
International journal of river basin management |
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Volume |
11 |
Issue |
1 |
Pages |
55-75 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The ongoing rapid expansions of human activities and population dynamics have potential impact on the environmental quality of the Pangani river basin, one of the largest water resources in Tanzania, including possible loadings of different kinds of micro-contaminants. However, specific extents of the impacts are rather not well investigated. In this work, we assessed the environmental quality of the basin, based on seasonal characterisation of physicochemical water and sediments parameters, dissolved inorganic ions and nutrient loads. The contributions of geochemical processes and land-use practices were evaluated by multivariate correlations and principal component analysis (PCA). Hierarchical cluster analysis was used to classify similar water quality stations and identify the most and least enriched ones. Surface waters were slightly alkaline, characterised by low total dissolved solids (48652 mg/L). Extremely low oxygen concentration (2.0 mg/L) was also a cause of concern at one station. The Na+ and HCO3 − ions provided the dominant cation and anion, respectively. PCA identified weathering of carbonate and Na+ bearing rocks, gypsum dissolution and atmospheric deposition of sea-salt as the major factors controlling the ionic composition, contributing more than 60% of the spatial variance. Concentration profiles of the chemical species showed a generally low level of anthropogenic inputs, except at a few locations where nitrate and nitrite were significantly enriched above the limits of safe exposure, with patterns indicating influences of farming and livestock keeping. A seasonal difference was observed, with lower ion concentrations during the rainy season, likely due to the dilution effect of increased water discharge. The study provides new insights into the environmental quality of the basin, and indicates the need for continuous monitoring and assessment of the chemical species in the area. |
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Wos |
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Publication Date |
2013-01-07 |
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Edition |
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ISSN |
1571-5124 |
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Additional Links |
UA library record |
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Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:104621 |
Serial |
5909 |
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