Abebe Beyene

An ethnobotanical study of medicinal plants in Wayu Tuka District, East Welega Zone of Oromia Regional State, West Ethiopia

BackgroundThis paper reports an ethnobotanical study that focused on the traditional medicinal plants used by local communities to treat human and livestock ailments. A cross-sectional study was undertaken from September 2009 to June 2010 in Wayu Tuka District of Oromia Region, Ethiopia. The aim of the study is to document medicinal plants used by local people of the study area and the threats currently affecting medicinal plants.MethodsEthnobotanical data were collected using semi-structured interviews, field observations and group discussion in which 63 (41 men & 22 women) randomly selected informants participated. Of which, 11 (10 male and 1 female) were local healers. Paired comparison method, direct matrix ranking and Informant consensus factors (ICF) were used to analyze the importance of some plant species.ResultsA total of 126 medicinal plant species, distributed in 108 genera and 56 families, were collected together with their medicinal uses. Of the 126 species of medicinal plants collected from the study area, eighty six (68%) were obtained from the wild whereas thirty three (26%) were from homegardens. The Fabaceae came out as a leading family with 15 medicinal species while the Solanaceae followed with eight species. Seventy eight (62%) of the medicinal plants were reported as being used for treating human ailments, 23 (18.2%) for the treatment of livestock ailments and 25 (20%) for both. The most frequently used plant parts were leaves (43%), followed by roots (18.5%) while crushing, which accounted for (29%) and powdering (28%) were the widely used methods of preparation of traditional herbal medicines.ConclusionThe number of reported medicinal plants and their uses by the local people of the District indicate the depth of the local indigenous knowledge on medicinal plants and their application. The documented medicinal plants can serve as a basis for future investigation of modern drug.

Urban impact on ecological integrity of nearby rivers in developing countries: the Borkena River in highland Ethiopia

Accelerated pollution and eutrophication of rivers and streams because of human activity are a concern throughout the world and severe in Africa where Ethiopia is case in point. The objective of this study was to assess the urban impact on the ecological integrity of the Borkena River at the eastern escarpment of the central Ethiopian highlands. The water quality status and macroinvertebrate distribution and diversity of the river were assessed during the dry and wet seasons. Diversity indices revealed that a severe decline in the ecological integrity of the Borkena River downstream of Dessie and within Kombolcha towns in terms of macroinvertebrate abundance and composition. Clustering and ordination analysis clearly separated reference sites from urban impacted sites. At the urban-impacted sites, dissolved oxygen was also depleted to 0.5 mg/l and BOD5 values were reached to a level of above 1,000 mg/l, with extremely low biological diversity of pollution-sensitive taxa. These patterns are the result of a combination of rampant dumping of untreated wastes exacerbated by geologic, topographic, climatic and land use factors.

Current state and trends of access to sanitation in Ethiopia and the need to revise indicators to monitor progress in the Post-2015 era.

BackgroundInvestigating the current level and trends of access and identifying the underlying challenges to sanitation system development will be useful in determining directions developing countries are heading as they plan to promote sustainable development goals (post 2015 agenda). This research investigates the status and trends of access to improved sanitation coverage (ISC) in relation to the MDG target in Ethiopia with the aim of identifying prevailing constraints and suggesting the way forward in the post-MDG era.MethodWe examined data from a nationwide inventory conducted in accordance with the sanitation ladder at the national level and from a household survey in randomly selected urban slums in Addis Ababa. The inventory data were analyzed and interpreted using the conceptual model of the sanitation ladder. We used administrative reports and survey results to plot the time trend of the ISC.ResultsThe data from the nationwide inventory of sanitation facilities, which are presented along the sanitation ladder reveal that more than half of the Ethiopian population (52.1%) still used unimproved sanitation facilities in 2014. The majority (35.6%) practiced open defecation, implying that the country is far from the MDG target for access to improved sanitation (56%). Most people in urban slums (88.6%) used unimproved sanitation facilities, indicating that the urban poor did not receive adequate sanitation services. Trend analysis shows that access to ISC has increased, but Central Statistical Authority (CSA) data reveal a decline. This discrepancy is due to differences in data collection methods and tools. Dry pit latrines are the most widely used toilet facilities in Ethiopia, accounting for about 97.5% of the ISC.ConclusionThe sanitation coverage is far from the MDG target and the majority of the population, mainly the urban poor, are living in a polluted environment, exposed to water and sanitation-related diseases. The sanitation coverage estimates might be even lower if proper utilization, regular emptying, and fecal sludge management (FSM) of dry pit latrines were considered as indicators. In order to enhance sanitation services for all in the post-MDG era, urgent action is required that will establish proper monitoring and evaluation systems that can measure real access to ISC.

Assessment of composition and generation rate of healthcare wastes in selected public and private hospitals of Ethiopia

In many developing countries, the inadequacy of data regarding the quantity and composition of healthcare waste is one of the major reasons for improper healthcare waste management. We investigated the generation rate and composition of healthcare wastes in six public and three private hospitals. We conducted healthcare waste composition and characterization measurements for seven consecutive days in the selected hospitals following the protocol described by the World Health Organization (WHO). The results revealed that the total generation rate of healthcare wastes of hospitals ranged from 0.25 to 2.77 kg/bed/day with a median value of 1.67 kg/bed/day for inpatients to 0.21–0.65 in kg/patient/day with a median value of 0.31 kg/patient/day for outpatients. The waste generation rate in private hospitals (median 3.9 kg/bed/day) was significantly greater (Kruskal–Wallis test, P < 0.05) than in government hospitals (median 1.5 kg/bed/day). The median values of percent hazardous waste estimated for private and government hospitals were 63.4% and 52.2%, respectively. These figures are about three times greater than the threshold values recommended by the WHO. This situation might be attributed to the improper practice of healthcare waste segregation by health professionals and auxiliary health workers due to inadequate risk perception and lack of enforced public health regulations. The study revealed that the generation rate and proportion of hazardous waste significantly varies between public and private hospitals and number of patients treated per day.

Developing models for the prediction of hospital healthcare waste generation rate

An increase in the number of health institutions, along with frequent use of disposable medical products, has contributed to the increase of healthcare waste generation rate. For proper handling of healthcare waste, it is crucial to predict the amount of waste generation beforehand. Predictive models can help to optimise healthcare waste management systems, set guidelines and evaluate the prevailing strategies for healthcare waste handling and disposal. However, there is no mathematical model developed for Ethiopian hospitals to predict healthcare waste generation rate. Therefore, the objective of this research was to develop models for the prediction of a healthcare waste generation rate. A longitudinal study design was used to generate long-term data on solid healthcare waste composition, generation rate and develop predictive models. The results revealed that the healthcare waste generation rate has a strong linear correlation with the number of inpatients (R2 = 0.965), and a weak one with the number of outpatients (R2 = 0.424). Statistical analysis was carried out to develop models for the prediction of the quantity of waste generated at each hospital (public, teaching and private). In these models, the number of inpatients and outpatients were revealed to be significant factors on the quantity of waste generated. The influence of the number of inpatients and outpatients treated varies at different hospitals. Therefore, different models were developed based on the types of hospitals.

River Water Pollution Status and Water Policy Scenario in Ethiopia: Raising Awareness for Better Implementation in Developing Countries

Despite the increasing levels of pollution in many tropical African countries, not much is known about the strength and weaknesses of policy and institutional frameworks to tackle pollution and ecological status of rivers and their impacts on the biota. We investigated the ecological status of four large river basins using physicochemical water quality parameters and bioindicators by collecting samples from forest, agriculture, and urban landscapes of the Nile, Omo-Gibe, Tekeze, and Awash River basins in Ethiopia. We also assessed the water policy scenario to evaluate its appropriateness to prevent and control pollution. To investigate the level of understanding and implementation of regulatory frameworks and policies related to water resources, we reviewed the policy documents and conducted in-depth interviews of the stakeholders. Physicochemical and biological data revealed that there is significant water quality deterioration at the impacted sites (agriculture, coffee processing, and urban landscapes) compared to reference sites (forested landscapes) in all four basins. The analysis of legal, policy, and institutional framework showed a lack of cooperation between stakeholders, lack of knowledge of the policy documents, absence of enforcement strategies, unavailability of appropriate working guidelines, and disconnected institutional setup at the grass root level to implement the set strategies as the major problems. In conclusion, river water pollution is a growing challenge and needs urgent action to implement intersectoral collaboration for water resource management that will eventually lead toward integrated watershed management. Revision of policy and increasing the awareness and participation of implementers are vital to improve ecological quality of rivers.

Reliability analysis of roof rainwater harvesting systems in a semi-arid region of sub-Saharan Africa: case study of Mekelle, Ethiopia

ABSTRACT Curbing water scarcity problems in semi-arid regions is a top priority for economic and social development. Alternative strategies for sustainable domestic water supply are therefore required to augment water supply with affordable cost and technology. Scant research findings in sub-Saharan Africa have, however, reported inefficiency in adapting to water scarcity problems in the region. Therefore, an investigation of domestic rainwater harvesting (RWH) reliability is important to identify factors affecting the system. We found that rainwater harvesting with the existing traditional RWH systems in Mekelle city was unreliable. Unreliability was attributed to inefficient design (the systems were installed without considering deterministically the stochastic nature of rainfall), family size, water demand, rooftop area and storage tank size. Editor M.C. Acreman; Associate editor S. Kanae

Assessment of the quality of drinking water in storage tanks and its implication on the safety of urban water supply in developing countries

BackgroundWater quality problems are one of the manifestations of poverty and most developing countries including Ethiopia suffering a lot of health problems associated with consumption of contaminated water. Although communities living in urban areas of Ethiopia have access to piped water supply, cross-contamination in the distribution system and unsafe storage are the major source of water borne diseases hence they are mostly overlooked by water professionals.ResultsAll water samples collected from drinking water storage tanks were positive for total coliforms and faecal coliforms. The result of this study showed that the drinking water was microbially contaminated in all sampling points. The level of microbial contamination increased from before entering the storage tank to after leaving the storage tank indicating that the presence of leakage in the distribution system and contamination at the storage tanks. The turbidity was found in the safe water quality range (2.1–2.9 NTU).ConclusionThe current study indicated that all water samples were bacteriologically contaminated and none of them met the WHO maximum permissible limit of drinking water quality. The unsafe piped-water supply was attributed to both leakage and contamination in the distribution system or unsafe storage. Thus, detail risk assessment should be conducted from treatment to distribution including storage and safe handling of water at the point of use in order to provide complete intervention strategies in tackling waterborne diseases.

Estimation of environmental optima and tolerances of diatoms using multifactor multiplicative modeling

Abstract We demonstrated the use of a multifactor multiplicative regression model to study the ecology of diatoms. A dataset of 174 samples of diatoms matched with environmental variables, which were collected from similar typology streams of three major watersheds in Ethiopia was used to build the model. Tropical rivers experience wet and dry season dynamics with highest levels of pollution at low water levels. In extreme polluted sites, diatoms are still present whereas other bio-indicator groups such as fishes, macrophytes and even macro-invertebrates are absent. The distribution of selected model diatom taxa (widely known pollution tolerant and sensitive taxa) in relation to environmental descriptors was studied by fitting non-parametric multiplicative regression (NPMR) to species relative abundances. A local mean estimator and Gaussian kernel functions were used to construct the models. The models reported here are those showing the best fit for particular number of predictors. Predictors were added until the cross-validated coefficient of multiple determination (× R 2 ) increased at least by 5% so that the model with the highest number of predictors had the highest × R 2 . We used bootstrap sampling to validate the model. NPMR a powerful model to study autoecology allows us to question the assumption that a suitable indicator species exhibits approximately bell-shaped curve with a single optimum for the probability density function of a species along environmental gradients. Only a few number of taxa showed such an optima whereas multi-interaction of diatom species could cause linear, skewed or non-unimodal, bimodal and multimodal responses. Therefore, modeling of species response to environmental gradients can be best explored without predefining the response curve and considering simultaneous multiple factor interaction in a multiplicative way.

Effect of brewery spent diatomite sludge on trace metal availability in soil and uptake by wheat crop, and trace metal risk on human health through the consumption of wheat grain

Soil plays a crucial role in food safety as it determines the composition of food at the beginning of the food chain. However, the quality of soil resources in terms of their potential impact on human health caused by harmful elements is poorly understood in Ethiopia due to lack of reliable and appropriate experimental data. In this study, a field experiment was conducted to evaluate trace metal accumulation in soils amended with brewery spent diatomite sludge (BSDS) in comparison to control, recommended inorganic fertilizers (RIF) and integrated BSDS & RIF (BSDS:RIF). Trace metals uptake by wheat crop and the degree of soil contamination, and human health risk were investigated. BSDS application significantly increased the concentration of trace metals (Cu, Zn, Pb and Ni) in soil compared to that in the control, the RIF, and BSDS:RIF applications. It also significantly increased the concentration of Cu, Zn, Pb and Ni in the wheat grain compared to that in the control and the RIF, but the increase was not significantly different from that in BSDS:RIF amendment. All trace metal concentrations in soil and wheat grain (except Pb in wheat grain) were below the maximum permissible limits in some European countries of agricultural soils, and the maximum permissible limit of FAO/WHO. The degree of soil contamination from each of the treatments was below the maximum acceptable degree of contamination. The Health Risk Index (HRI) was <1 for all metals in all treatments. Thus, we conclude that consumption of wheat grain grown on soils amended with BSDS and BSDS:RIF has no human risks and has low likelihood of human exposure to trace metals.