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Assessments of disease burden are important to inform national, regional, and global strategies and to guide investment. We aimed to estimate the drinking water, sanitation, and hygiene (WASH)-attributable burden of disease for diarrhoea, acute respiratory infections, undernutrition, and soil-transmitted helminthiasis, using the WASH service levels used to monitor the UN Sustainable Development Goals (SDGs) as counterfactual minimum risk-exposure levels.

Estimates of the effectiveness of water, sanitation, and hygiene (WASH) interventions that provide high levels of service on childhood diarrhoea are scarce. We aimed to provide up-to-date estimates on the burden of disease attributable to WASH and on the effects of different types of WASH interventions on childhood diarrhoea in low-income and middle-income countries (LMICs).

Schistosomiasis is a debilitating chronic disease with great socioeconomic and public health impact affecting the poor rural populations who lack access to sanitation, and safe water supply. The high cost of synthetic molluscicides, their toxicity to non-target organisms, and their persistence in the environment have forced the research of plant-derived molluscicides. Although plant molluscicides are cheap, biodegradable, ecofriendly and less toxic to higher animals, unregulated applications could affect non˗target organisms. Therefore, ecotoxicological studies are essential to assess the toxicity of these substances to economically and ecologically significant fish species and to establish safe dosage level. This study is intended to investigate the acute toxicity of a molluscicidal plant Achyranthes asperato Nile tilapia fingerlings, Oreochromis niloticus(O. niloticus) (n = 7) were exposed to serial dilutions of A. asperaleaf aqueous extract using maceration method for 96 h in triplicate setup. Phytoconstituents were identified by GC-MS. Mortality data were analyzed by probit regression to determine lethal concentrations. The NOAEC was ascertained through hypothesis testing based on survival data. The respective piscicidal LC1and LC10values were 897.43 and 1063.87 mg/L while the LC50is 1310.74 mg/L. In addition, the NOAEC was 1100 mg/L (p > 0.05). This piscicidal toxicity is much lower than its molluscicidal potency may be due to the presence of rotenones and triterpenoides which are commonly found in piscicidal natural products. The GC-MS analysis revealed 12 phytoconstituents including a monoterpene. This study indicates that A. asperahas low toxicity to Nile tilapia could be due to monoterpenes are nontoxic. The findings of this study demonstrate that, at this dose, the plant is safe to the test fish. Thus it can be effective, eco-friendly and sustainable alternative for the development of molluscicides for snail control.

ABSTRACTThe tourism-food security relationship is one of the most critical yet overlooked areas of sustainable tourism development policy, particularly for developing countries. With a view to casting light on the tourism-food security relationship, this paper presents an analysis of Ethiopia’s tourism development, with a focus on tourism policies and strategies that are linked to food security. The paper reveals that while eradicating pervasive food insecurity is a priority development concern of Ethiopia, existing tourism policy does not directly reference food security concerns. Rather, employment, income and poverty reduction are the foci of tourism policy and can be considered as, at best, implicit policy pathways to food security. The paper argues that for more effective food security, the tourism sector needs to be guided by policy prescription and instruments that mainstream food security concerns into practice.

Freeze desalination, i.e., desalination of water by freezing it, may be an option to treat polluted water at individual household level. Taking into account the widespread fluoride contamination of Ethiopian water resources and with the reason that most households in semi-urban and urban areas do have easier accessibility of refrigerators, this study aimed to investigate the defluoridation capacity of freeze desalination and its energy consumption for different water sources. For this purpose, synthetic solutions that emulate the major ion compositions of natural waters (hereafter called simulated water), tap water, and double-distilled water to which variable concentrations of fluoride ions were added were evaluated using home-use insulated refrigerator (BEKO, RRN 2650). The effects of conditions such as initial fluoride concentration, multi-ion existence, fraction of ice frozen, volume of the container, and freezing duration were evaluated in relation to the produced ice quality. It was found that nearly 48% and 62% removal of fluoride were achieved from tap water spiked with 10 mg/L F−and 10 mg/L F−aqueous solutions, respectively, with a total water recovery of 85 to 90%. The energy consumption predicted to produce the ice from tap water spiked with 10 mg/L F−and double-distilled water alone was found to be 93.9 and 91.8 kJ/L, respectively. The results showed that freeze desalination can be a potential technique for fluoride removal from water to be used as drinking water at household level in semi-urban and urban areas as well as in colder regions.

Eight horizontal subsurface flow pilot scale artificial wetlands were constructed to evaluate their effectiveness in the removal of antibiotic-resistant bacteria from hospital wastewater. A total of 40 composite samples were collected from the inlet and outlet of wetlands, transported and processed for enumeration of indicator organisms, bacteriological identification and susceptibility testing following standard procedure. The treatment wetlands achieved 7.1 logs10 and 5.1 logs10 removal of total and fecal coliforms. Among the total samples, 159 bacterial isolates were detected, of these 45 (28.3%) were from hospital wastewater and 114 (71.7%) from the outlets of wetlands. The most frequently isolated bacteria from hospital wastewater samples were found to be Staphylococcus sp12 (26.6%) followed by E.coli11(24.4%), Klebsiella sp9(20%) and Shigella sp5(11.1%). Similarly, the overall isolates in treated wastewater samples were E.coli45(39.5%), Staphylococcus(35.1%) and Klebsiella sp35 (30.7%). Among bacterial isolates from hospital wastewater, 100% of Salmonellaisolates were found to be resistant to ampicillin and 75% to doxycycline, erythromycin, ceftazidime, cefoxitin, and chloramphenicol. E.coliwas also found to be 81.8% resistant to ampicillin and 72.7% to cotrimoxazole and amoxicillin-clavulanic acid. Significantly (P < 0.005) higher removal (80.8% to 93.2%) of antibiotic-resistant bacteria was recorded in vegetated wetlands. In contrary, no significant difference between the vegetated and non-vegetated wetlands was observed in the removal of indicator and pathogenic bacteria. Constructed wetlands could help to solve the problem of the cost-effective disposal of hospital wastewater and be promoted in a strategy to reduce water pollution in low-income countries like Ethiopia.

Natural coagulants, especially those from Moringa oleifera Lam., have been employed since ancient times (200 B.C.) in the treatment of drinking water. The aim of this study was to extract natural coagulants from tubers of Maerua subcordata (Gilg.) DeWolf and seeds of Moringa stenopetala (Baker f.) Cufod, both native to Ethiopia, and to examine their potential utility in water treatment in the future. The coagulation activity of the extracts was measured in natural turbid river water and synthetic water made of a kaolin clay suspension. The turbidity removal efficiency was tested using a jar test and spectrophotometric-based assays. Proteins from the extracts were visualized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and gel staining. Relevant parameters affecting the effectiveness of coagulation (pH, extraction time, type/concentration of the extracting solvents, and storage duration/conditions) were also investigated. A wide range of abundant proteins, with molecular weights of 10, 15, 35, and 40 kDa, were found in the crude extracts. However, only the proteins with molecular weights of 10 and 15 kDa were resistant to prolonged heat at 95°C for 5 h. Interestingly, using synthetic turbid water, the tuber extracts from M. subcordata showed 90.5% coagulation activity within 3 h of contact, whereas the seed extracts from M. stenopetala showed only 83.5% coagulation activity. The removal efficiency of M. subcordata and M. stenopetala in turbid river water was 80% and 83%, respectively. Both the M. subcordata and M. stenopetala extracts showed the most efficient coagulation activity at pH = 8. Increasing the extraction time negatively affected the removal efficiency of the coagulation. In conclusion, coagulant proteins from these native species could provide a means of water treatment for communities living in rural areas, enabling access to adequate supplies of safe drinking water.

Conventional chemical water treatment systems which involve a series of steps are not feasible in rural areas, where a dispersed population is found. Moreover, it is extremely costly for investment in developing countries. Hence, improving drinking water quality at a household level is believed to be effective in fighting waterborne diseases. For this purpose, we investigated the performance of indigenous plant species locally used for turbid water treatment in Ethiopia. Batch coagulation and microbial reduction experiments were carried out on surface river waters found in Ethiopia having initial turbidities of 20, 45, 46, 80, and 195 nephelometric turbidity unit (NTU) with the flocculent dosages of 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100 mg/l. Tubers of Maerua subcordata(Gilg.) DeWolf and seeds of Moringa stenopetala(Baker f.) Cufod. were used for this study, and they were able to achieve appreciable removal efficiency (up to 98 %) of turbidity at an optimum dose range of 20 to 80 mg/l in 6 h of settling time. About 99.9 % of microbial load removal were observed for both M. subcordataand M. stenopetala, which is comparable with chlorine disinfection. The experimental result revealed that these plant coagulants were able to meet World Health Organization (WHO) standards of drinking water quality (<5 NTU). This implies that with further optimization, M. subcordataand M. stenopetalacan be used as an alternative to household-level water treatment in low-income countries.

AbstractThe Gilgel Gibe reservoir, which was built to fulfill the energy demand and the electricity export ambitions of Ethiopia, was characterized by low macroinvertebrate diversity mainly due to water level fluctuations, trampling of the littoral zone by cattle, nutrient input, and siltation from the catchment flow. The downstream river system was also affected by the dam due to a strongly decreased discharge as the water is diverted to Gilgel Gibe II hydropower plant through a 25 km underground tunnel. The study was based on seasonal macroinvertebrate sampling, water quality analyses, measurement of daily water level fluctuation, and recording of major anthropogenic activities. Hierarchical cluster analysis and canonical correspondence analysis were performed to determine relationships between the macroinvertebrate community composition and the environmental variables in the reservoir. The cluster analysis, Kruskal-Wallis ANOVA, and MANOVA permutation tests, revealed that differences in physicochemical water quality parameters and ecological quality metrics based on macroinvertebrates existed between the samples taken during periods with low, medium, and high water level seasons. Remedial actions could be important at basin and reservoir level to solve the identified problems and to improve the ecological water quality.

Underpinned by sustainable livelihood thinking, this study investigated community stakeholders' perspectives on the impacts of tourism on food security in two rural tourism destinations: Debarq and Meket in Ethiopia. Semi-structured interviews and focus group discussions were conducted with a range of stakeholders to solicit their perspectives, revealing the complexity of the tourism and food security relationship. Although tourism had brought about some small changes to food availability, access and utilisation, there were limitations around its contribution to food stability. This was primarily due to the nature of tourism employment and lack of linkages between tourism and local agriculture. Tourism was not strong enough nor properly integrated with existing livelihoods to support the local communities' food security, generally only offering a minor contribution. This research highlights the challenges for tourism to contribute to local communities' food security, offering policy-relevant guidance for addressing the food security challenges of tourism destinations.