Heavy Metals in Fish Muscle from an Ethiopian Rift-Valley Lake (Hawassa) and a Neighboring Stream (Boicha): Assessment of Human Health Risks

Concentrations of heavy metals (Cr, Co, Fe, Ni, Cu, Zn, As, Se, Pb and Hg) in muscle tissues of two fish species (Clarias gariepinus and Oreochromis niloticus) in an Ethiopian rift-valley lake (Hawassa) and a neighboring stream (Boicha) were determined. Target hazard quotients (THQ), hazard index (HI) and target cancer risk (TCR) were used as indices to evaluate potential human health risks from fish consumption. Average concentrations of metals decreased in the order Zn>Fe>Se>Cu>Hg>As>Ni>Cr>Co>Pb and Zn>Fe>Se>Cu>As>Hg>Cr>Ni>Pb>Co in muscle tissues of C. gariepinus and O. niloticus, respectively. Mean concentrations of Hg (0.34+0.04 mg kg-1) in muscle tissues of C. gariepinus from Lake Hawassa, and As (0.18+0.05 mg kg-1) as well as Hg (0.46+0.03 mg kg-1) in muscle tissues of C. gariepinus from Boicha stream were above the safety limits set by WHO/FAO. Likewise, mean concentrations of As (0.31+0.03 mg kg-1) and Hg (0.19+0.05 mg kg-1) in muscle tissues of O. niloticus from Lake Hawassa and Cr (0.19+0.03 mg kg-1), As (0.33 +0.04 mg kg-1), and Hg (0.34+0.09 mg kg-1) in O. niloticus from Boicha stream were also above safety limits. From the results of human health risk assessments it was concluded that Cr, Cu, Hg and As pose potential health risks due to consumption of the two fish species from both water bodies. Moreover, effects of all heavy metals put together may affect human health as indicated by the high HI. Effluents from industries are assumed to be the main sources of the heavy metals. Therefore, regular monitoring of the water bodies and policy interventions with respect to waste disposal are recommended to protect the health of the ecosystem and the public. Keywords: Fish consumption, health risk, heavy metals, Lake Hawass

Heavy Metals Contamination of Soil in the Vicinity of Hawassa Industrial Zone, Ethiopia

Industrial effluents, containing heavy metals, drain directly into downstream water sources within the Hawassa Industrial Zone. These, water sources are used for irrigation, drinking water and other domestic purposes. The load of pollutants, environmental risks and potential human impacts are generally, unknown for soil in Ethiopia. Therefore, the aim of this study was to determine the extent of heavy metal pollution of soil within the Hawassa Industrial Zone and to evaluate environmental impacts using contamination factor (CF), degree of contamination (Cd), modified degree of contamination (mCd), ecological risk factor (Er), ecological risk index (ERI) and pollution load index (PLI) analyses. Seven heavy metals: Cr, Ni, Cu, Zn, As, Cd and Pb were determined in soil samples from three different sites by inductively coupled plasma mass spectrometry (ICP-MS). Average concentration of metals decreased in the order of Zn>Cu>Cr>Ni>Pb>As>Cd consistent with the normal order of abundance in non-polluted soils. One way ANOVA revealed significant differences (P<0.05) in the concentrations of Cu, As, Cd and Pb among the sampling sites. Pearson\u2019s correlation, principal component and cluster analyses revealed that heavy metals are originating from different sources. Within the industrial area, the CF increased in the order of Pb<Cd<Zn<As<Cu<Cr<Ni. The result of Cd revealed that there was considerable to very high contamination of the soil. The mCd index showed moderate contamination of the soils. The Er increased in the order of Zn<Cr<Pb<Cu<Ni<As<Cd and the result of the ERI value revealed considerable ecological risk for the soils. Overall, the study showed that the soils within the Hawassa Industrial Zone are highly contaminated with heavy metals. Therefore, regular monitoring of heavy metals concentration in soil and policy interventions with respect to waste disposal are recommended

Heavy Metals in Fish Muscle from an Ethiopian Rift-Valley Lake (Hawassa) and a Neighboring Stream (Boicha): Assessment of Human Health Risks

Concentrations of heavy metals (Cr, Co, Fe, Ni, Cu, Zn, As, Se, Pb and Hg) in muscle tissues of two fish species ( Clarias gariepinus and Oreochromis niloticus ) in an Ethiopian rift-valley lake (Hawassa) and a neighboring stream (Boicha) were determined. Target hazard quotients (THQ), hazard index (HI) and target cancer risk (TCR) were used as indices to evaluate potential human health risks from fish consumption. Average concentrations of metals decreased in the order Zn>Fe>Se>Cu>Hg>As>Ni>Cr>Co>Pb and Zn>Fe>Se>Cu>As>Hg>Cr>Ni>Pb>Co in muscle tissues of C. gariepinus and O. niloticus, respectively. Mean concentrations of Hg (0.34\ub10.04 mg kg-1) in muscle tissues of C. gariepinus from Lake Hawassa, and As (0.18\ub10.05 mg kg-1) as well as Hg (0.46\ub10.03 mg kg-1) in muscle tissues of C. gariepinus from Boicha stream were above the safety limits set by WHO/FAO. Likewise, mean concentrations of As (0.31\ub10.03 mg kg-1) and Hg (0.19\ub10.05 mg kg-1) in muscle tissues of O. niloticus from Lake Hawassa and Cr (0.19\ub10.03 mg kg-1), As (0.33 \ub10.04 mg kg-1), and Hg (0.34\ub10.09 mg kg-1) in O. niloticus from Boicha stream were also above safety limits. From the results of human health risk assessments it was concluded that Cr, Cu, Hg and As pose potential health risks due to consumption of the two fish species from both water bodies. Moreover, effects of all heavy metals put together may affect human health as indicated by the high HI. Effluents from industries are assumed to be the main sources of the heavy metals. Therefore, regular monitoring of the water bodies and policy interventions with respect to waste disposal are recommended to protect the health of the ecosystem and the public

Water Quality Monitoring: A comparative case study of municipal and Curtin Sarawak’s lake samples

In this study, particle size distribution and zeta potential of the suspended particles in municipal water and lake surface water of Curtin Sarawak's lake were compared and the samples were analysed using dynamic light scattering method. High concentration of suspended particles affects the water quality as well as suppresses the aquatic photosynthetic systems. A new approach has been carried out in the current work to determine the particle size distribution and zeta potential of the suspended particles present in the water samples. The results for the lake samples showed that the particle size ranges from 180nm to 1345nm and the zeta potential values ranges from -8.58 mV to -26.1 mV. High zeta potential value was observed in the surface water samples of Curtin Sarawak's lake compared to the municipal water. The zeta potential values represent that the suspended particles are stable and chances of agglomeration is lower in lake water samples. Moreover, the effects of physico-chemical parameters on zeta potential of the water samples were also discussed

Using lake sediment cores to improve records of volcanism at Aluto volcano in the main Ethiopian rift

info:eu-repo/semantics/publishe

Heavy Metals Contamination of Soil in the Vicinity of Hawassa Industrial Zone, Ethiopia

Industrial effluents, containing heavy metals, drain directly into downstream water sources within the Hawassa Industrial Zone. These, water  sources are used for irrigation, drinking water and other domestic purposes. The load of pollutants, environmental risks and potential human impacts are generally, unknown for soil in Ethiopia. Therefore, the aim of this study was to determine the extent of heavy metal pollution of soil within the Hawassa Industrial Zone and to evaluate environmental impacts using contamination factor (CF), degree of contamination (Cd), modified degree of contamination (mCd), ecological risk factor (Er), ecological risk index (ERI) and pollution load index (PLI) analyses. Seven heavy metals: Cr, Ni, Cu, Zn, As, Cd and Pb were determined in soil samples from three different sites by inductively coupled plasma mass spectrometry (ICP-MS). Average concentration of metals decreased in the order of Zn>Cu>Cr>Ni>Pb>As>Cd consistent with the normal order of abundance in non-polluted soils. One way ANOVA revealed significant differences (P<0.05) in the concentrations of Cu, As, Cd and Pb among the sampling sites. Pearson’s correlation, principal component and cluster analyses revealed that heavy metals are originating from different sources. Within the industrial area,  the CF increased in the order of Pb<Cd<Zn<As<Cu<Cr<Ni. The result of Cd revealed that there was considerable to very high contamination of the soil. The mCd index showed moderate contamination of the soils. The Er increased in the order of Zn<Cr<Pb<Cu<Ni<As<Cd and the result of the ERI value revealed considerable ecological risk for the soils. Overall, the study showed that the soils within the Hawassa Industrial Zone are highly contaminated with heavy metals. Therefore, regular monitoring of heavy metals concentration in soil and policy interventions with respect to waste disposal are recommended. Keywords: Heavy metals, potential ecological risks, pollution load index, soi

Information synthesis to identify water quality issues and select applicable in-stream water quality model for the Awash River basin in Ethiopia: A perspective from developing countries

In the sub-Saharan countries, stream water quality is declining due to many human activities. In-stream water quality models help to prepare effective planning strategy to tackle the problem and understand pollutant dynamics in the stream system. In this study, water quality issues of the Awash basin were reviewed to select an applicable in-stream model. The key sources of pollutants were considered and the availability, appropriateness and quality of related data were assessed and the capacity of model users was also evaluated. The identified opportunities and limitations were analyzed to present options of applicable models simulating the status quo in the basin's streams, and also, the changes needed for the existing settings. The model selection was done using a set of criteria based on assumptions useful for enabling environment and improvement in the future. Land covers, surficial geologies, and urban and industries along streams are found major issues to be addressed. Though the poor capacity of the governmental model users is a concern, the available hydrological, monitoring, and meteorological information are opportunities to capitalize the usage of in-stream modeling. QUAL2KW and INCA models are found more applicable for the present conditions, while in the future the WASP model may well be useful to conduct detailed analysis. The identification process applied in this study is based on the context of the Awash basin and it can be a replicated and support local model practitioners in creating improvement in water quality managements

Determinants of vaccine acceptance, knowledge, attitude, and prevention practices against COVID‐19 among governmental healthcare workers in Addis Ababa and Adama, Ethiopia: A cross‐sectional study

Abstract Background and Aims COVID‐19 vaccines are vital tools for infection prevention and control of the pandemic. However, coronavirus immunization requires acceptance among healthcare workforces and by the community. In Ethiopia, studies focused on determinants of vaccine acceptance, knowledge, attitude, and prevention practices (KAP) contrary to the novel coronavirus among healthcare staff are limited. Hence, closing this gap requires research. Methods A cross‐sectional study was conducted on 844 governmental healthcare workers. A stratified, simple random sampling technique was used to select the respondents. Data were collected using a structured questionnaire. Binary and multivariable logistic regression statistical models were used to analyze the data. Results This study indicated that only 57.9% of the participants had good COVID‐19 vaccine acceptance, meaning they took at least a dose of the vaccine themselves. We found that 65%, 60.9%, and 51.3% of the participants had good knowledge, prevention practices, and attitude against the pandemic. The novel coronavirus vaccine acceptance rate was 2.19 times more likely among females (adjusted odds ratio [AOR] = 2.19 with 95% confidence interval [CI]: 1.54–3.10) than among male participants. Further, respondents who did not report having any chronic diseases were 9.40 times higher to accept COVID‐19 vaccines (AOR = 9.40 with 95% CI: 4.77, 18.53) than those who reported having a chronic condition. However, healthcare workers who had a habit of chewing khat at least once per week were 4% less likely to take the vaccine (AOR = 0.04 with 95% CI: 0.01, 0.32) than those who had no habit of chewing khat. Conclusion Many core factors influencing COVID‐19 vaccine acceptance were identified. A significant number of participants had poor vaccine acceptance, KAP against COVID‐19. Therefore, the government should adopt urgent and effective public health measures, including public campaigns to enhance public trust in COVID‐19 vaccines. In addition, continuous, timely, and practical training should be provided to healthcare workers