Organochlorine pesticides (OCPs) and stable isotopes were measured in muscle from 4 bird and 5 fish species from the Ethiopian Rift Valley region where DDT is used for malaria control and vast agricultural activities are carried out. We investigated the bioaccumulation of OCPs such as DDTs, HCHs, chlordanes, and heptachlors between the species, and examined the potential risk posed by these compounds for bird species. Significant differences in contaminant profiles and levels were observed within the species. Levels of total OCPs ranged from 3.7 to 148.7 μg/g lipid in bird and 0.04 to 10.9 μg/g lipid in fish species. DDTs were the predominant contaminant, and a positive relationship between δ15N and ΣDDT concentrations was found. The main DDT metabolite, p,p′-DDE was the most abundant and significantly greater concentrations in bird species (up to 138.5 μg/g lipid), which could have deleterious effects on survival and/or reproduction of birds.

Faecal indicator bacteria (FIB) are used for the assessment of faecal pollution and possible water quality deterioration. There is growing evidence that FIB used in temperate regions are not adequate and reliable to detect faecal pollution in tropical regions. Hence, this study evaluated the adequacy of FIB, including total coliforms (TC), Escherichia coli (EC), Enterococci (IEC), and Clostridium perfringens (CP) in the high-altitude, tropical country of Ethiopia. In addition to FIB, for microbial source tracking (MST), a ruminant-associated molecular marker was applied at different water types and altitudes, and faecal pollution risk mapping was conducted based on consensus FIB. The performances of the indicators were evaluated at 22 sites from different water types. The results indicate that EC cell enumeration and CP spore determination perform well for faecal contamination monitoring. Most of the sub-basins of Lake Tana were found to be moderately to highly polluted, and the levels of pollution were demonstrated to be higher in the rainy season than in the post-rainy season. Markers associated with ruminants (BacR) were identified in more than three quarters of the sites. A bacterial pollution risk map was developed for sub-basins of Lake Tana, including the un-gauged sub-basins. We demonstrate how bacterial pollution risk mapping can aid in improvements to water quality testing and reduce risk to the general population from stream bacteria.

In order to assess metal contamination on the Mediterranean coast of Egypt, 45 sediment samples, seawaters and bivalve specimens were collected from Rosetta coastal area for Mg, Al, K, Fe, Sr, Zn, Pb, Mn, As, Ce, Ni, Cr and Zr analyses by Inductively Coupled Plasma-Mass Spectrometer. The Enrichment Factor (EF), the Geoaccumulation Index (Igeo) and the Contamination Factor (CF) indicated that the coastal sediments of Rosetta area were severely enriched, strongly polluted with As, Pb and very highly contaminated with As, Pb, Ni, Ce, mostly as a result of anthropogenic inputs. Comparison with other samples from the Arabian Gulf, Red Sea and abroad coasts suggested that the studied samples have higher concentrations of Fe, Pb, As, Zn and Ni. The natural sources of heavy metals in the study area are attributed to weathering and decomposition of mountain ranges of the Sudan and Ethiopia, while the anthropogenic ones are the metals produced from industrial, sewage, irrigation and urban runoff.

Although many variables that have adverse impacts on the sustainable environment are investigated from many aspects, some variables are missing. In this study, it will be simultaneously focused on the relation between refugees, governance, sustainable environment, economic growth, energy consumption, and supplementary explanatory variables, HDI, the trade deficit, and financial development, for Bangladesh, Ethiopia, Jordan, Lebanon, Pakistan, Sudan, and Uganda using the panel quantile autoregressive distributed lag (PQARDL) and causality methods for the 1996–2019 period. Long-run coefficients found by PQARDL method showed the evidence of the long-run relationship between the sustainable environment, refugee population, governance, economic growth, energy consumption, and explanatory variables. Both traditional and Dumitrescu and Hurlin (2012) causality tests determined the evidence of a unidirectional causality from political and economic governance to greenhouse gas (GHG) emissions and deforestation, as well as a unidirectional causality from refugees to GHG emissions and deforestation.

The spread of antimicrobial-resistant pathogens is a global health concern. Most studies report high levels of antimicrobial resistance genes (ARGs) in the aquatic environment; however, levels associated with sediments are limited. This study aimed to investigate the distribution of ARGs in the sediments and water of the Akaki river in Addis Ababa, Ethiopia. The diversity and abundance of 84 ARGs and 116 clinically important bacteria were evaluated from the sediments and water collected from five sites in the Akaki river. Most of the ARGs were found in the city close to anthropogenic activities. Water samples collected in the middle catchment of the river contained 71–75% of targeted ARGs, with genes encoding aminoglycoside acetyltransferase (aac(6)-Ib-cr), aminoglycoside adenylyl transferase (aadA1), β-lactamase (blaOXA₋₁₀), quinolone resistance S (qnrS), macrolide efflux protein A (mefA), and tetracycline resistance (tetA), were detected at all sampling sites. Much fewer ARGs were detected in all sediments, and those near the hospitals had the highest diversity and level. Despite the lower levels and diversity, there were no unique ARGs detected in the sediments that were also not detected in the waters. A wide range of clinically relevant pathogens were also detected in the Akaki river. The findings suggest that the water phase, rather than the sediments in the Akaki river, is a potential conduit for the spread of ARGs and antibiotic-resistant bacteria.

Developing strategies that counter the ongoing homogenization trends of home-garden agroforestry systems is required to maintain diversity and sustainability. This study aimed to map and characterize traditional enset-based home-garden agroforestry for managing sustainability in the Gurage socioecological landscape in Ethiopia. We generated plots and land use land cover (LULC) spatial data from orthophotomosaic and collected household survey data of the field. Five home-garden types were identified explicitly through integrating the home-garden composition, functional structure, and agroecological zones. Most home-garden types had similar horizontal functional structures in which perennial crops were planted close to homesteads, annual crops grew in outer fields, and woodlots were located at the end of the parcel. Diverse woody species, crop varieties, and plot sizes were identified in individual household parcels, and these varied across the home-garden types. Enset-based home-garden agroforestry production has been declining in the Ethiopian landscape because of socioeconomic changes and a lack of technological inputs. These challenges may compromise the community’s food security with loss of the product diversity provided by the home-garden system. Thus, technological adoptions and scaling up of agroforestry practices according to the home-garden types are necessary for the continue provision of multiple contributions. This study demonstrated site-specific spatial characterization of the agroforestry systems by considering a holistic approach to reduce the local challenges and support the development of sustainable landscape management in an altering socioecological landscape.

Tropospheric ozone can have a detrimental effect on vegetation, including reducing the quantity of crop yield. This study uses modelled ozone flux values (POD₃IAM; phytotoxic ozone dose above 3 nmol m⁻² s⁻¹, parameterised for integrated assessment modelling) for 2015, together with species-specific flux-effect relationships, spatial data on production and growing season dates to quantify the impact of ozone on the production of common wheat (Triticum aestivum) and common beans (Phaseolus vulgaris) across Sub-Saharan Africa (SSA). A case study for South Africa was also done using detailed data per province. Results suggest that ozone pollution could decrease wheat yield by between 2 and 13%, with a total annual loss of 453,000 t across SSA. The impact on bean production depended on the season; however, estimated yield losses were up to 21% in some areas of SSA, with an annual loss of ~300,000 t for each of the two main growing seasons. Production losses tended to be greater in countries with the highest production, for example, Ethiopia (wheat) and Tanzania (beans). This study provides an indication of the location of areas at high risk of crop losses due to ozone. Results emphasise that efforts to reduce ozone precursors could contribute to reducing the yield gap in SSA. More stringent air pollution abatement policies are required to reduce crop losses to ozone in the future.

This paper examines households’ preferences, willingness to pay, and determinants of adopting improved cook stoves in rural Ethiopia. The study uses primary household data selected randomly from three districts in Ethiopia’s Oromia region. The data was collected using a mix of contingent and choice experiment methods of valuation. The former used a double-bounded value elicitation method, while the latter used a fractional factorial design to efficiently generate an attribute and level combination for the improved cook stoves. The study also used various discrete choice models for data analysis and also used models which account for scale and preference heterogeneity. The findings show that the sample households were aware of the effects of using traditional cook stoves and the benefits of using improved cook stoves. However, they were constrained by the availability of the new technology and discouraged by the low-quality of the products that they had used so far. The estimated mean willingness to pay ranged from about 150 Birr to 350 Birr which is lower than the market price of the improved cook stoves. Emission reduction, reducing fire risks, and the durability of the cook stove positively affected its adoption, while price discouraged its use. Higher levels of education, higher incomes, non-farm employment, and having more livestock increased the probability of adopting the new gas stoves. The study recommends that policymakers and product designers should use the mean willingness to pay and marginal rate of substitution for the different attributes as a benchmark for product design and pricing that fit households’ preferences and ability to pay. The lower mean willingness to pay means that a public subsidizing policy is needed for effectively disseminating improved cook stoves in rural Ethiopia.

In recent years, an enormous amount of sludge is generated every day from zero liquid discharge treatment plant due to rapid expansion of industrial parks in Ethiopia. About 30,000 tons of partially dried sludge discharged to the environmental without proper waste management from all industrial parks. Thus, posing serious environmental problems. One of the most plausible means to recycle the excess sludge resource is converting it into energy-efficient brick by combining with clay. Bricks were prepared by incorporating textile sludge at different proportions (10–40%) and temperature (600, 900 and 1200 °C). Clay and sludge samples were collected from the Addis Ababa brick factory PLC and Hawassa Industrial Park. Results revealed that 10 and 20% sludge bricks satisfied criteria of class “A” bricks as per Ethiopia standards, with the compressive strength of 30.43 and 29.10 Mpa, respectively, at 1200 °C. About 26 and 50% of energy were saved during firing of 10 and 20% sludge-containing bricks, respectively, compared with pristine clay bricks. Moreover, too low concentrations of selected heavy metals found in the brick leachate, showing the sludge, were effectively stabilized in the burnt clay bricks. Thus, based on the results, we suggest the rapid utilization of huge amount of partially dried sludge resources for low-cost and efficient large-scale brick production. This will mutually benefit both the industrial parks and brick production industries. In addition, this will create thousands of jobs to the local people. Above all, the solid waste will be managed properly at textile industrial parks.

Pesticides are widely used chemicals in the agricultural sector to control pests, diseases, and other plant pathogens. This study aimed to assess the storage conditions of pesticides, the community perception, and health risk of pesticide exposure. The study was conducted in three different zonal cities in Ethiopia, East Africa, namely Mekelle, Aksum, and Alamata. Community perception was studied in a community living near a pesticide stockpile with a cross-sectional study of 384 randomly selected households. In addition, questionnaires were administered, a field investigation was conducted, and focused group discussions with responsible bodies were held to assess storage condition. Accidental ingestion and inhalation were considered to determine average daily exposure (ADE) and incremental lifetime cancer risk (ILCR). This study reveals that all obsolete and banned hazardous pesticides were stored in one area. The storage sites were only secured with simple locks and exposed to rain, sunlight, and temperature variation. The majority of the residents perceived that pesticides pose risk to human health (46.6%), to the environment (28.4%), and to animals (25%). The association between residence proximity of respondents to the store and side effect of obsolete pesticides is statistically significant (p = 0.008). Children aged 2 years and below have higher ADE when exposed to the same concentration of contaminant via inhalation. The probability of a person developing cancer was very low with a risk value of 2.54E−08 and 1.65E−07 as a result of exposure to air containing heptachlor and dichlorodiphenyltrichloroethane (DDT), respectively.