Distribution of mercury in the sediments of some freshwater bodies in Ethiopia

Mekonnen, Kebede Nigussie; Ambushe, Abayneh A.; Chandravanshi, Bhagwan Singh; Abshiro, M. R.; McCrindle, Robert; Panichev, Nikolay

doi:10.1080/02772248.2012.728602

Cited by 14 publications

(6 citation statements)

References 30 publications

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“…In the present study, the lake water used for irrigation had a Hg content ranging from 60 to 110 μ g·kg −1 , with an average value of 90 μ g·kg −1 . These levels are higher than the previously reported Hg load in the lake sediment by Mekonnen et al [ 51 ]. In contrast, Woldetsadik et al [ 52 ] found lower levels of metals in irrigation water collected from ten sampling sites of Addis Ababa vegetable farms.…”

Section: Resultscontrasting

confidence: 68%

“…This could be due to the use of an irrigation method where pumped lake water flows in long furrows constructed up to the vegetable farms, causing dilution of the heavy metals. In a study conducted by Mekonen et al [ 51 ], who examined the distribution of mercury (Hg) in sediments from various freshwater bodies, it was reported that the concentration of Hg in ten sampling sites of Lake Ziway ranged from 17 to 119 μ g·kg −1 , with an average value of 44 μ g·kg −1 . The authors attributed the higher concentrations of Hg in the sediments of Lake Ziway to the presence of small and large-scale horticultural farms near the lake.…”

Section: Resultsmentioning

confidence: 99%

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Level of Heavy Metals and Potential Ecological Risks in Irrigated Horticultural Farms in the Vicinity of Lake Ziway, Central Ethiopian Rift Valley Region

Yimer

2024

Journal of Toxicology

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Research on heavy metal pollution in horticultural farms located around lakes in the Central Ethiopian Rift Valley Region has focused on measuring the levels of heavy metals and their health implications. However, the ecological risks of horticultural farms contaminated with heavy metals in this region have not been studied. The current study addresses this gap by providing information on the degree of heavy metal contamination and the ecological risk associated with horticultural farms around Lake Ziway, using various pollution indices. An inductively coupled plasma optical emission spectrometer (ICP-OES) was used to measure the concentrations of nine heavy metals (As, Cd, Co, Cu, Cr, Ni, Pb, Hg, and Zn) in a total of 30 composite soil and irrigation water samples, each consisting of a mix of six subsamples. The results indicated that the mean concentrations of Hg, Cd, Pb, and Zn in soils collected from all the sampling sites exceeded the FAO/WHO maximum permissible limit (MPL). The values of both the contamination factor (CF) and contamination degree (Cd) of the heavy metals ranged from 0.04 to 2.66 and 2.81 to 6.14, respectively, indicating a low to medium level of contamination for both indices. The pollution load index (PLI) values of 0.451, 0.449, and 0.157 for sites 2, 1, and 3, respectively, indicate “unpolluted” to “moderately polluted” levels of heavy metal pollution. However, the ecological risk indices (ERIs) at sites 2 and 1 (158.92 and 141, respectively) showed a potentially high ecological risk due to soil pollution. Therefore, close monitoring and early intervention mechanisms must be in place to control pollution in the study area.

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Section: Resultscontrasting

confidence: 68%

Section: Resultsmentioning

confidence: 99%

Level of Heavy Metals and Potential Ecological Risks in Irrigated Horticultural Farms in the Vicinity of Lake Ziway, Central Ethiopian Rift Valley Region

Yimer

2024

Journal of Toxicology

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“…Monitoring of trace metals in sediment is extremely important as it can serve as sources of information about the long term trends in geological and ecological conditions of the aquatic ecosystem and the corresponding catchment area (Mekonnen et al 2012;Dhanakumar et al 2015). The occurrence of high levels of these pollutants in sediments can be a good indicator of anthropogenic pollution, rather than natural enrichment of the sediment by geological weathering.…”

Section: Introductionmentioning

confidence: 99%

Distribution and ecological risk assessment of trace metals in surface sediments from Akaki River catchment and Aba Samuel reservoir, Central Ethiopia

et al. 2018

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Background: Due to fast urban expansion and increased industrial activities, large quantities of solid and liquid wastes contaminated by trace metals are released into the environment of the Addis Ababa city, most often untreated. This study was conducted to investigate spatial distribution, seasonal variations and ecological risk assessment of selected trace metals (Cd, Cr, Cu, Fe, Mn, Pb, Ni and Zn) in the surface sediments from Akaki River catchment and Aba Samuel reservoir, Central Ethiopia. Methods: Twenty-two surface sediment samples were collected, digested using the Mehlich-3 procedure and analyzed quantitatively using inductively coupled plasma optical emission spectrometer. Results: The trace metals occurred in varying concentrations along the course of the sampling stations. The decreasing order of trace metal concentrations in the dry season was: Mn > Fe > Pb > Cr > Zn > Ni > Cu > Cd and in the rainy season was Mn > Fe > Pb > Cr > Ni > Zn > Cu > Cd. Little Akaki River contained a higher load of trace metals than the other regions, which is due to the existence of most of the industrial establishments and commercial activities. Relatively lower levels of trace metals were recorded at Aba Samuel reservoir due to the lower residence time of the sediment (reservoir rehabilitated recently). Ecological risk assessment using USEPA sediment guidelines, geo-accumulation index, contamination factor and pollution load index revealed the widespread pollution by Cd and Pb. These were followed by Mn, Ni and Zn. Conclusion: The concentrations of Pb, Cd, Mn, Ni and Zn in sediments were relatively greater and at levels that may have adverse biological effects to the surrounding biota. Therefore, regular monitoring of these pollutants in water, sediment and biota would be required.

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“…Water, sediment and fish are often exposed to toxic substances such as trace metals. Thus, quantification of trace metals in water, sediment and fish is extremely important (Kebede et al, 2012). Sediments provide important information about the long-term trends (Kebede et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

“…Thus, quantification of trace metals in water, sediment and fish is extremely important (Kebede et al, 2012). Sediments provide important information about the long-term trends (Kebede et al, 2012). Fish are notorious for their ability to concentrate trace metals in their muscles (Olowu et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Evaluation and risk Assessment of potentially toxic trace metals in water, sediment and fish from the City of Addis Ababa, Central Ethiopia

Berhanu¹,

Berhanu²,

Okonkwo³

et al. 2019

EJWST

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Because of fast urban expansion and increased industrial activities, large quantities of solid and liquid wastes contaminated by trace metals are released into the nearby water bodies situated in Addis Ababa. Greater Akaki River (GAR) and Little Akai River (LAR), which join at Aba Samuel Reservoir, are the main rivers draining the city. Eleven (11) water, 11 sediment and 18 fish samples were taken and tested for the level of trace metals content, distribution, pollutionlevel, bioaccumulation, possible sources of pollutants and associated ecological risk. Trace metals were tested using an Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). USEPA guideline values, geo-accumulation index, contamination factor, and pollution load index were used to evaluate contamination levels and eco-toxicity. The results indicated that the mean concentration of Cr, Fe, Mn and Ni in water samples and Cd, Pb, Mn, Ni and Zn insediment samples exceeded their respective background values. Besides, the levels of Cr, Fe, Mn, Ni and Pb in the muscle of Clarias gariepinus were above the permissible limits for human consumption. Furthermore, ecological risk assessments using sediment samples revealed the widespread pollution by Cd and Pband moderate pollution by Mn, Ni and Zn. A comparison with similar studies revealed that sediments from the study area had the highest average value of Pb. Generally, the study indicated that Akaki River catchment and Aba Samuel Reservoir were found to be moderately to strongly contaminated by heavy metals and thus posed high ecological risks.

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Distribution of mercury in the sediments of some freshwater bodies in Ethiopia

Cited by 14 publications

References 30 publications

Level of Heavy Metals and Potential Ecological Risks in Irrigated Horticultural Farms in the Vicinity of Lake Ziway, Central Ethiopian Rift Valley Region

Level of Heavy Metals and Potential Ecological Risks in Irrigated Horticultural Farms in the Vicinity of Lake Ziway, Central Ethiopian Rift Valley Region

Distribution and ecological risk assessment of trace metals in surface sediments from Akaki River catchment and Aba Samuel reservoir, Central Ethiopia

Evaluation and risk Assessment of potentially toxic trace metals in water, sediment and fish from the City of Addis Ababa, Central Ethiopia

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