Incidence of diarrhea and risk factors among wastewater-irrigating urban farmers along Akaki Rivers in Addis Ababa.

The importance of diarrhea risk associated with wastewater exposure in agriculture is almost unknown. This study aimed to examine diarrheal infection and risk factors among farmers using wastewater for irrigation in Addis Ababa. A cross-sectional study was employed among 380 farmers (190 exposed and 190 unexposed farmers). Among these, a cohort of 200 adults (100 wastewater-exposed, 100 unexposed farmers) aged 25-69 years were selected and followed up biweekly for two successive vegetables growing seasons to examine the incidence of diarrhea. The incidence rate of reported diarrhea was 12 episodes per 1,000 person-weeks at risk and a maximum of 17 episodes per 1,000 person-weeks at risk. Strongly associated risk factors include washing body and clothes with wastewater [AOR: 4.2, 95%CI (1, 11.2)], using working clothes at home [AOR: 4.7, 95%CI (0.25, 87)], and wearing protective cloth [AOR: 5.6, 95 CI (0.3, 70)]. Moreover, hand washing after work, washing feet and boots, and on-site hand washing were significant determinants of farmers' diarrhea. Exposure to wastewater significantly contributes to the risk of diarrhea among adults. Significant determinants of diarrhea among farmers include washing the body and clothes with irrigation water, contamination with soil and irrigation water, and on-site hand washing. Increased risk factors include hand contamination, washing vegetables with irrigation water, eating raw vegetables, and using work clothes at home.

Vulnerability Assessment and Protection Zone Delineation for Water Supply Schemes in the Upper Awash Subbasin, Ethiopia, Sub-Saharan Africa.

Water quality issues in Ethiopia necessitate the implementation of the Water Safety Plan (WSP) to safeguard drinking water. Despite its benefits, WSP implementation is underutilized, a situation exacerbated by urbanization, agriculture, pollution, and climate change. This study evaluated water supply system vulnerability and delineated protection zones in the Upper Awash River subbasin. By employing the DRASTIC model, the National WASH Inventory-2 (NWI-2), and qualitative methods, this research aims to integrate the NWI-2 with vulnerability assessments. The study revealed that, among 2864 schemes, only 14.4% had a water safety plan, while 20.7% practiced water safety, and 6% reported the occurrence of waterborne diseases. Over 39.23% of the schemes were in high vulnerability areas, 12.32% were in very high vulnerability areas, and only 8% were in low vulnerability areas. The validation revealed a 61.7% association between the vulnerability indices and nitrate concentration. The strengths of the strategy included coordination and guideline development, but challenges such as institutionalization, catchment protection, the legal framework, and climate information remain for the Water Safety Plan. To promote public health, these findings help to demonstrate and integrate the NWI-2 with vulnerability assessments to protect drinking water sources. The conclusion also calls for all concerned authorities to implement water source protection, emphasizing the use of GIS technology and the adoption of integrated watershed management practices, which encompass regulatory control and conservation strategies. Furthermore, more research on the pollutant time of travel, assimilation capacity, and land use priorities is needed to delineate specific protection zones.

Water Safety Practices Along the Water Service Chain in Addis Ababa: A Cross-Sectional Study in a Cosmopolitan City.

This study investigated water safety practices and risk levels along Addis Ababa's water supply service chain. The data came from 23 random woredas, 384 random households, 115 microbiological water quality tests, and diagnostic inspections from source to point of use. Findings from this study indicate that the surface water sources (53%) and the water source catchments (62%) are characterized by very high-risk and high risk contamination levels respectively. Conversely, the water treatment process (5%) and temporary reservoir (20%) indicates a low risk level. Whereas the water distribution system (40%), water source boreholes (44%), and Household level (29%) water safety practices are identified as medium risk levels. The microbial analysis of the drinking water at the source and point of use indicated low (<11 CFU/100 ml) to high levels (>100 CFU/100 ml) of risk with significant levels of contamination at the household level. Moreover, the household-level water safety practice assessment revealed intermediate to very high levels of risks. The Chi2 test shows that water supply type is significantly associated with occupation(X2(12,384) = 23.44, P < .05) and education(X2(8,384) = 15.4, P < .05). Multinomial regression analysis also showed better occupation is associated with increased access to safe bottled water compared to safe piped water on premises. It can be concluded that the water safety practice encountered low to very high levels of risk of contamination at different components along the water supply service chain and the household level. This study suggests ways to improve Addis Ababa residents' health and well-being through water safety interventions. These include safeguarding water sources, supporting local safe water businesses, providing household water treatment, and handling options, and addressing the barriers and incentives for adopting safe water practices.

Public health risks associated with drinking water consumption in the upper Awash River sub-basin, Ethiopia, sub-Saharan Africa.

The Upper Awash sub-basin characterized by urban, industrial, agricultural and population growth, has impacted the quality of its water sources. This study focuses on the assessment of public health risks associated with drinking water sources in the sub-basin. In accordance with WHO guidelines, 120 water samples were collected from 60 water supply schemes in dry and wet seasons located in areas with low and high water pollution risk (WPR). Multi-meter, Photometer, Digital Arsenator, and Microbiological test kit measured the concentration of parameters. The assessment uses methods of hazard identification, exposure and dose-response analysis, and risk characterization, including Hazard Quotient (HQ), Cancer Risk (CR), Hazard Index (HI), and probability of infection. Monte Carlo simulation analyzes non-cancer risks from Nitrite, Nitrate, Chromium, Iron, Fluoride, and Arsenic, and CRs from Chromium and Arsenic, and infection risks from Escherichia coli (E.coli). As a result, the Hazard Quotient (HQ) of Nitrate was beyond unity (HQ > 1) in the dry season for all groups. HQ of Chromium was HQ > 1 for Women (1.1E+00) and Children (1.4E+00) in the wet season in the high WPR area. Chromium HQ > 1 for children (1.4E+00) in the wet season and Fluoride (HQ > 1) for Children (3.2E+00) in the dry season in the low WPR area. Arsenic CR was above 1 in 10,000 persons for children in the dry season, for all groups, and for women and children in the wet season in the high WPR areas. The CR of chromium ranged from 1 in 1000 persons, which is beyond the limit. Moreover, the Hazard Index (HI) was higher than the unity (HI > 1) for most cases. All E coli infection risks daily and annually exceeded the acceptable risks. Therefore, Public health concerns in the Sub-basin were quantified, and evidences were generated for risk management to undertake source protection through integrated watershed management and appropriate water treatment technologies.

Rural community perceptions and practices toward the novel coronavirus (COVID-19) prevention in Konso Zone, Southern Ethiopia: a lesson for the next pandemic.

Background: Corona Virus Disease (COVID-19) has provided a lesson on preparedness and coping mechanisms for similar pandemics to different community segments. To control and prevent the spreading of COVID-19, people need to possess the correct attitude and perception to follow the appropriate practices against the causative agent. Therefore, this study aimed to assess the rural community's perceptions and practices toward COVID-19 prevention among southern Ethiopia's Konso zone rural communities. Methods: A community-based cross-sectional study conducted from April to May 2022 on 605 study participants in the Kena district of the Konso zone of Ethiopia. Participants were recruited using simple random sampling techniques. Face-to-face interviews were conducted to collect data using structured questionnaires developed from the World Health Organization guide and related literature. A logistic regression model was used to identify determinants of perception and practice. Results: Among the 564 participants, 296 (52.5%) believed they would go to the healthcare facility if they contracted COVID-19. About 276 (48.9%) perceived that COVID-19 is not a stigma and should not be concealed. About 233 (41.3%) perceived COVID-19 would be controlled. However, the majority, 451 (80%), 440 (78%), 384 (68.1%), 381 (67.6%), 337 (59.8%), and 317 (56.2%) perceived that the cause of COVID-19 is sin, eating some food items were effective against the virus, no cases in their locality, living far away from COVID-19 area, the virus does not exist, respectively. Overall, only 22.5% of the study participants have good perceptions. About 58.5% practiced handwashing to prevent COVID-19, and 45.2% covered their mouth and nose while coughing/sneezing. Among the participants, 39.8% were vaccinated, and about a quarter (24.8%) of the respondents had good prevention practices. Participants with better educational status, use of social media as a source of information, and those with better income levels are found to be protective factors while being married is a risk factor. Conclusion: The status of the participant's perception and preventive practices toward COVID-19 was meager. There was a substantial magnitude of wrong perceptions about controlling such pandemics. High inaccurate perceptions and low preventive practice need an urgent and sustained improvement strategy to tackle similar pandemics or epidemics.

Analysis of Achyranthes aspera leaf extract and acute toxicity study on fingerlings of Nile tilapia, Oreochromis niloticus.

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 aspera to Nile tilapia fingerlings, Oreochromis niloticus (O. niloticus) (n = 7) were exposed to serial dilutions of A. aspera leaf 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 LC1 and LC10 values were 897.43 and 1063.87 mg/L while the LC50 is 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. aspera has 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.

Prevalence and risk factors of childhood diarrhea among wastewater irrigating urban farming households in Addis Ababa.

INTRODUCTION: Childhood diarrhea is one of the major contributors to the morbidity of under-five children in Ethiopia. Although researchers determine the risk factors varyingly, the exposure route to the pathogens is usually complicated. This study aims to investigate the prevalence and risk factors of diarrhea among children under the age of five among wastewater irrigation farming households in Addis Ababa, Ethiopia. METHODS: Cross-sectional study was conducted among 402 farming households from November 2021 to February 2022. Data was collected using a face-to-face interviewer-administered questionnaire. Stata version 14 software was used to analyze data. Factors associated with the prevalence of diarrhea was identified using binary logistic regression. Multivariable analysis was carried out to determine an adjusted odds ratio at a confidence level of 95% and level of significance at 0.05. RESULTS: The overall prevalence of under-five children diarrheal cases was 22.3%. The odds of diarrhea are associated with a multitude of variables. Major wastewater-related determinants associated with diarrhea are body washing with irrigation water [AOR: 37.7, 95%CI (3.1, 358)], contaminated cloth with irrigation water [AOR:10.8,95%CI(0.6, 205)], use of protective clothing during farm work [28.9,95%CI (3.9, 215)], use of farm work cloths at home [AOR: 31.7, 95%CI (4.4, 226)], and bringing unwashed farm tools to home [94 (5.7, 1575)]. CONCLUSION: The high prevalence of under-five children diarrheal disease among wastewater irrigation households was strongly associated with factors related to occupational exposure. Thus, to decrease childhood diarrheal among urban agriculture farmers, appropriate precautions need to be taken.

Trihalomethanes and physicochemical quality of drinking water in Addis Ababa, Ethiopia.

Background: Trihalomethanes (THMs) are the most dominant fraction of all the byproducts formed during chlorination of water. Disinfection by product (DBP) formation in water is a function of numerous factors, including pH, temperature, residual chlorine, source water characteristics, and organic matter. No study has determined the THM level in the drinking water supply of Addis Ababa, Ethiopia. Methods: A cross-sectional design was conducted to collect water samples in the water supply distribution networks of Addis Ababa, Ethiopia. Twenty-one (21) sampling stations yielded a total of one hundred twenty (120) samples of drinking water. The sample handling and collection procedures were carried out in accordance with USEPA guidelines. A DB-5 capillary column was used to separate the THMs, which were detected using GC-ECD (gas chromatography-electron capture detector). Spectrophotometric and in situ methods were used for physicochemical parameters. Redundancy analysis (RDA) was used for data analysis of trihalomethanes and environmental variables using CANOCO 4.5. Results: The mean concentration of total trihalomethanes in drinking water in Addis Ababa was 76.3 µg/L. The concentration of chloroform in the drinking water supply in Addis Ababa, Ethiopia, ranged between 4.03 and 79.4 µg/L. The mean total THMs in the Legedadi and Gefersa water supply systems were 77.4 µg/L and 69.66 µg/L, respectively. The residual chlorine, phosphates, UV absorbance at 254 nm, and combined chlorine had positive correlations with THM formation. However, electron conductivity had a negative correlation with THM formation. Conclusions: Chloroform contributed the most to TTHMs in nearly all samples. The residual chlorine, UV absorbance, phosphate and hardness as calcium, and electron conductivity were found to be the main predictors determining the abundance and distribution of trihalomethanes. The monitoring and regulation of the THMs is required on a regular basis to analyse trends and guide the water treatment and distribution system.

Micropollutant Removal Efficiency of Advanced Wastewater Treatment Plants: A Systematic Review.

Introduction: Various review papers have been published regarding the occurrence and fate of micropollutants (MPs). MPs in the aquatic environment are still not well reviewed to generate comprehensive summaries with a special focus on their removal from wastewater using conventional and advanced treatment processes. Therefore, this review aimed to provide a synopsis of the efficiency of the advanced wastewater treatment plants in the removal of MPs. Materials and methods: A systematic search of published literature was conducted on the National Library of Medicine (NLM) database, Web of Science, Joanna Briggs Institute (JBI) database, Scopus, and Google Scholar, based on studies with evidence of removal of MPs in the wastewater treatment process. Screening of the published articles was made using pre-specified inclusion and exclusion criteria. Results: Amongst the 1545 studies searched, 21 full-length articles were analyzed that showed 7 treatment options related to the removal of MPs from wastewater. MPs from wastewater effluents were successfully and effectively removed by advanced treatment techniques. Advanced Oxidation Processes (AOPs), membrane processes, and adsorption processes have all been shown to be potential solutions for the removal of MPs in advanced treatment plants (WWTPs). But, there are 2 critical issues associated with the application of the advanced treatment options which are high operational cost and the formation of dangerous by-products and concentrated residues. Conclusion: This study identified that the removal of MPs using WWTPs was commonly incomplete with varying removal efficiency. Therefore, the adaptation and scale-up of the cost-effective and efficient combined wastewater treatment technology are vital to creating an absolute barrier to MPs emissions.

Depth profile of reservoir water quality in the Southwest of Ethiopia.

The objective of this research was to investigate the variation of water quality parameters at different depths of the Gilgel Gibe I reservoir in Oromia Jimma zone during wet seasons. Five stations within the reservoir were selected, and water quality parameters were determined at four different depths (surface, 5 m, 10 m, and 15 m). Water quality parameters were analyzed on-site using a HACH, HQ40d portable multi-meter, and turbidity was measured using Wag tech turbidity meter and in the laboratory using the standard method. Comparison of water quality parameters among depths were conducted using one-way ANOVA and Tukey's pairwise comparisons with 5% significance level. The probable contributing source of the investigated physicochemical water quality parameters at different depth was identified using Principal components analysis. The results show that depth wise except for total suspended solids (TSS), total dissolved solids (TDS), total phosphorus (TP) and soluble reactive phosphorus (SRP) the rest showed statistically significant difference at p < 0.05 level. Negative correlations were found between depth and dissolved oxygen (DO), water temperature, pH, nitrate (N03-) and chlorophyll a (Chl.a) while positive correlations were found between electrical conductivity (EC), biochemical oxygen demand (BOD5), turbidity and N03-. The study revealed that the release of nutrients associated with increased concentration of BOD5 at the bottom depth caused low concentration of dissolved oxygen due to oxygen consumption. This was further aggravated through the decomposition of organic matter, indicating organic pollution resulting from runoff from the catchment. The presence of dense masses of blue-green algae in the pelagic zone of Gilgel Gibe I reservoir suggested the presence of ample nutrients for its blooming and significant reduction of water quality, indicating possible eutrophic conditions. Therefore, catchment management is required to protect aquatic life and the reservoir function as a whole from reservoir water quality degradation.

Evaluating the relationship between community water and sanitation access and the global burden of antibiotic resistance: an ecological study.

BACKGROUND: Antibiotic resistance is a leading cause of death, with the highest burden occurring in low-resource settings. There is little evidence on the potential for water, sanitation, and hygiene (WASH) access to reduce antibiotic resistance in humans. We aimed to determine the relationship between the burden of antibiotic resistance in humans and community access to drinking water and sanitation. METHODS: In this ecological study, we linked publicly available, geospatially tagged human faecal metagenomes (from the US National Center for Biotechnology Information Sequence Read Archive) with georeferenced household survey datasets that reported access to drinking water sources and sanitation facility types. We used generalised linear models with robust SEs to estimate the relationship between the abundance of antibiotic resistance genes (ARGs) in human faecal metagenomes and community-level coverage of improved drinking water and sanitation within a defined radii of faecal metagenome coordinates. FINDINGS: We identified 1589 metagenomes from 26 countries. The mean abundance of ARGs, in units of log10 ARG fragments per kilobase per million mapped reads classified as bacteria, was highest in Africa compared with Europe (p=0·014), North America (p=0·0032), and the Western Pacific (p=0·011), and second highest in South-East Asia compared with Europe (p=0·047) and North America (p=0·014). Increased access to improved water and sanitation was associated with lower ARG abundance (effect estimate -0·22, [95% CI -0·39 to -0·05]) and the association was stronger in urban (-0·32 [-0·63 to 0·00]) than in rural (-0·16 [-0·38 to 0·07]) areas. INTERPRETATION: Although additional studies to investigate causal effects are needed, increasing access to water and sanitation could be an effective strategy to curb the proliferation of antibiotic resistance in low-income and middle-income countries. FUNDING: Bill & Melinda Gates Foundation.

Burden of disease attributable to unsafe drinking water, sanitation, and hygiene in domestic settings: a global analysis for selected adverse health outcomes.

BACKGROUND: 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. METHODS: We assessed the WASH-attributable disease burden of the four health outcomes overall and disaggregated by region, age, and sex for the year 2019. We calculated WASH-attributable fractions of diarrhoea and acute respiratory infections by country using modelled WASH exposures and exposure-response relationships from two updated meta-analyses. We used the WHO and UNICEF Joint Monitoring Programme for Water Supply, Sanitation and Hygiene public database to estimate population exposure to different WASH service levels. WASH-attributable undernutrition was estimated by combining the population attributable fractions (PAF) of diarrhoea caused by unsafe WASH and the PAF of undernutrition caused by diarrhoea. Soil-transmitted helminthiasis was fully attributed to unsafe WASH. FINDINGS: We estimate that 1·4 (95% CI 1·3-1·5) million deaths and 74 (68-80) million disability-adjusted life-years (DALYs) could have been prevented by safe WASH in 2019 across the four designated outcomes, representing 2·5% of global deaths and 2·9% of global DALYs from all causes. The proportion of diarrhoea that is attributable to unsafe WASH is 0·69 (0·65-0·72), 0·14 (0·13-0·17) for acute respiratory infections, and 0·10 (0·09-0·10) for undernutrition, and we assume that the entire disease burden from soil-transmitted helminthiasis was attributable to unsafe WASH. INTERPRETATION: WASH-attributable burden of disease estimates based on the levels of service established under the SDG framework show that progress towards the internationally agreed goal of safely managed WASH services for all would yield major public-health returns. FUNDING: WHO and Foreign, Commonwealth & Development Office.

Fecal Contamination in the Wastewater Irrigation System and its Health Threat to Wastewater-Based Farming Households in Addis Ababa, Ethiopia.

Due to rapidly growing demand, the production of vegetables is increasing along the Akaki Rivers. The objective of this study was to examine the degree of fecal contamination and levels of fecal contamination and dissemination throughout the wastewater irrigation system. Irrigation water, irrigated soil, and leafy vegetables were collected twice during 2 vegetable growing seasons, at the maturity period of the growing season, from 19 sampling points along the 2 Akaki Rivers. Composite samples were taken from all sampling points and E.coli was enumerated. The mean E.coli load in wastewater and non-wastewater sources were 1.16±5.53 CFU/100 ml and 2.232±1.292 CFU/100 ml respectively. All counts of E. coli in the wastewater exceeded the WHO's standards indicating that the irrigation water quality was unacceptable. In the wastewater-irrigated and non-wastewater-irrigated soil, the mean E.coli were 3.62 ±1.582 CFU/g and 1.322±87.1 CFU/g respectively. Meanwhile, the mean E.coli counts on the lettuce and Swiss chard were 78 ± 2 CFU/g and 44 ±3CFU/g respectively. The E.coli count on the leafy vegetables was found to be associated with the E.coli in the wastewater and soil. The production of leafy vegetables using wastewater with unacceptably high levels of E.coli and high occupational exposure introduces high levels of risk to the farming communities and to the consumers. Leafy, low-growing raw edible vegetables need careful treatment during food production and harvesting procedures or activities.

Menstrual hygiene management practices and determinants among schoolgirls in Addis Ababa, Ethiopia: The urgency of tackling bottlenecks - Water and sanitation services.

Background: Menstrual hygiene management (MHM) service provision and improving schoolgirls' hygienic practices in schools are among the major challenges for low and middle income countries, including Ethiopia, in meeting the 2030 Sustainable Development Goals. This study was conducted to assess schoolgirls' MHM practices and what influences those practices in Addis Ababa, the capital city of Ethiopia. Methods: A cross-sectional study was conducted on 401 adolescent schoolgirls and 98 school directors that were selected using a multistage sampling method. Pretested semi-structured interviewer-administered questionnaires and observational checklists were used to collect data. Results: During menstruation, about 90% of schoolgirls used commercially made disposable sanitary pads. However, only 45.9% of girls had access to emergency pads from their schools. Of the 98 directors, 79 (80.6%) responded that they had MHM provisions for schoolgirls. However, 42 (42.9%) schools had no water and soap in the pad changing rooms/toilets, and 70% lacked a covered dustbin for disposal/storage of soiled sanitary pads. Besides, more than 55% of the schools practiced open burning and dumping to dispose of used menstrual materials. More than half of the schools had no sanitary pad changing rooms, three-quarters of them lack MHM education, and only 2.5% had a bathing area. The location of schools (AOR = 5.44, 95% CI: (2.34-12.66)), health club availability (AOR = 3.14, 95% CI: (1.53, 6.42)), being informed about MHM before menarche (AOR = 2.04, 95% CI: (1.04, 4.00)), and availability of emergency sanitary pad at schools (AOR = 2.59, 95% CI: (1.36, 4.91)) were significantly associated with the status of schoolgirls menstrual hygiene practices. Conclusions: About one-quarter of the schoolgirls had poor menstrual hygiene practices. Being a student in inner-city schools, attending a school that had a health club, being informed about MHM before menarche, and having access to emergency pads from schools were the determinant factors for good menstrual hygiene practices. However, most schools lack water, soap, and a covered dustbin in the pad changing rooms/toilets. Moreover, only a few schools provided MHM education and emergency pads. Improving water and sanitation services along with tailored MHM education are urgently needed to circumvent unsafe MHM practices among adolescent schoolgirls.

Aflatoxin contamination of animal feeds and its predictors among dairy farms in Northwest Ethiopia: One Health approach implications.

Background: In dairy farming, animal feed is the first line of food safety. Animal feed can become contaminated and spoiled on farms or in storage facilities due to the diverse microorganisms that are naturally present around or on various animal feeds. This study aims to assess the level of aflatoxin and predictors in animal feeds among dairy farms in the South Gondar Zone of Ethiopia. Methods: A total of 100 samples of each animal feed ingredient (atella, hay, commercial concentrates, and cut and carry pasture) were obtained. A total of 400 animal feed ingredient samples were tested separately among 100 randomly chosen dairy farmers for aflatoxin analysis. Simultaneously, swabs from cow udders and water samples were also collected. Using a structured and pretested questionnaire, the knowledge and practices of animal feed administrators responsible for managing animal feed were also evaluated. Descriptive statistics and logistic regression models were used to identify determinants. Results: From the total animal feed analyzed, 96% was positive for aflatoxins. Feed storage facilities, feed storage duration, education of animal feed administrators, mixed concentrates, and previous training were found to be associated with aflatoxin contamination levels in animal feeds. Conclusions: The levels of aflatoxin contamination in animal feeds were found to be higher than the recommended limit; these findings suggest the spread of aflatoxin contamination between humans and animals. Furthermore, the occurrence of aflatoxins in the environment results from milk becoming contaminated with aflatoxins. A One Health strategy should therefore receive special consideration to tackle such problems and safeguard consumer safety.

Exposure and carcinogenic risk assessment of trihalomethanes (THMs) for water supply consumers in Addis Ababa, Ethiopia.

Background: Trihalomethanes (THMs), a class of DBPs (disinfection byproducts) that includes chloroform, bromodichloromethane (BDCM), chlorodibromomethane (CDBM), and bromoform. To the best of authors' knowledge, no study has addressed the relationship between the concentration of THMs and lifetime cancer risks (LCR) in drinking water supply system in Addis Ababa, Ethiopia. Therefore, this study aimed to determine the lifetime cancer risks of exposure to THMs in Addis Ababa, Ethiopia. Method: A total of 120 duplicate water samples were collected from 21 sampling points in Addis Ababa, Ethiopia. The THMs were separated by a DB-5 capillary column and detected by an electron capture detector (ECD). Cancer and non-cancer risk assessments were performed. Results: The average total THMs (TTHMs)concentration in Addis Ababa, Ethiopia, was 76.3 µg/L. Chloroform was the most dominant THM species identified. The total cancer risk for males was higher than that for females. The average LCR for TTHMs via ingestion in drinking water in this study was unacceptably high risk 93.4 × 10 - 2 . An average LCR through dermal routes was also of unacceptably high risk 4.3 × 10 - 2 . The LCR by chloroform contributes the highest (72%) of the total risk, followed by BDCM (14%), DBCM (10%) and bromoform (4%). Conclusions: The cancer risk of drinking water due to THMs in Addis Ababa was higher than the level recommended by the USEPA. The total LCR from the targeted THMs was higher via the three exposure routes. Males were at higher THM cancer risk than females. The hazard index (HI) indicated that the dermal route caused higher HI values than the ingestion route. It is essential to apply alternatives to chlorine, i.e., chlorine dioxide (ClO2), ozone and ultraviolet radiation, in Addis Ababa, Ethiopia. The monitoring and regulation of the THMs is required on a regular basis to analyse the trends and guide the water treatment and distribution system. Availability of data and materials: The datasets generated for this analysis are available from the corresponding author upon reasonable request.

Determination of pesticide residues in the serum of flower farm workers: A growing occupational hazards in low income countries.

Ethiopia is one the major exporter of cut flowers in East Africa. However, the sector is blamed for the intensive use of pesticides which leads to exposure of workers. This study aims to investigate the level of pesticides in blood serum of flower farm workers as a predictor to occupational exposure. A cross-sectional laboratory based study was conducted in central Ethiopia among 194 flower farm workers. Blood sample were collected from 100 study participants (50 from farm workers and 50 civil servants as control). Blood-serum separation, extraction, and clean-up was performed following standard analytical methods. Ten organochlorine pesticides (OCPs) (o,p'-DDT, p,p'-DDD, p,p'-DDE, p,p'-DDT, heptachlor, heptachlor epoxide, endosulfan, dieldrin, methoxychlor, dibutychloridate), and three pyrethroids (cypermethrin, permethrin and deltamethrin) were detected in the serum of the study participants. From the detected pesticides p,p'-DDT and p,p'-DDE were observed at high mean concentration (81.5 ± 83.5, and 12.5 ± 6.7 ng/mL),(38.0 ± 31.8 and 6.84 ± 7.4 ng/mL) in the flower farm and controls, respectively. From the Mann-Whitney U-test, there is a significant difference for total DDT (P < 0.02), p,p'-DDE (P < 0.001), cypermethrin (P < 0.001), heptachlor (P < 0.04), heptachlor-epoxide (P < 0.001) and dibutyl chlorendate (P < 0.01) among the flower farm workers and controls. Multinomial regression revealed, being flower farm worker is a significant predictor of moderate to high residues of p,p'-DDE, total DDT, heptachlor-epoxide and dibutyl chlorendate. The pesticides under study were detected more frequently in the flower farm workers than controls which is an indicative for occupational exposure to pesticides and strict regulation is important for the safety of workers.

Prevalence and Trends of Drinking Water Disinfection Byproducts-Related Cancers in Addis Ababa, Ethiopia.

Background: Disinfection byproducts (DBPs) from chlorinated drinking water have been linked to an increased risk of cancer in the bladder, stomach, colon, and rectum. No studies showed the independent trends and prevalence of these cancers in Ethiopia. Therefore, this study aimed to determine the prevalence and trends of disinfection byproducts-related cancers in Addis Ababa, Ethiopia. Methods: Data were collected from the Addis Ababa Cancer Registry. Spatial data sets were produced and classified into households receiving chlorinated surface water and less chlorinated groundwater. The Cochran-Armitage trend test was used to evaluate whether there was a disinfection byproducts-related cancers (DBRCs) trend among communities receiving chlorinated water. Negative binomial regression was used to analyze the incidence rate. Results: A total of 11, 438 cancer cases were registered between 2012 and 2016, and DBRCs accounted for approximately 17%. The majority of the total cancer cases were female; 7,706 (67%). The prevalence of DBRCs was found to be higher in communities supplied with chlorinated water. From 2012 to 2016, the trend of colon cancer increased (ß = 10.3, P value = .034); however, esophageal cancer decreased (ß = -6.5, P value = .018). Approximately 56% of colorectal cancer patients and 53% of stomach cancer patients are known to be using chlorinated surface water for drinking regularly. In addition, approximately 57.1% and 54% of kidney and bladder cancer patients, respectively, used chlorinated surface water. Conclusion: The prevalence of DBRCs in this study was found to be high. The colon cancer trend increased substantially from 2012 to 2016. The prevalence of DBRCs was higher in communities supplied with chlorinated surface water. Similarly, the prevalence of DBRCs was higher among males than females. Further study is required to validate the association between DBRCs and water chlorination.

Effectiveness of interventions to improve drinking water, sanitation, and handwashing with soap on risk of diarrhoeal disease in children in low-income and middle-income settings: a systematic review and meta-analysis.

BACKGROUND: 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). METHODS: In this systematic review and meta-analysis, we updated previous reviews following their search strategy by searching MEDLINE, Embase, Scopus, Cochrane Library, and BIOSIS Citation Index for studies of basic WASH interventions and of WASH interventions providing a high level of service, published between Jan 1, 2016, and May 25, 2021. We included randomised and non-randomised controlled trials conducted at household or community level that matched exposure categories of the so-called service ladder approach of the Sustainable Development Goal (SDG) for WASH. Two reviewers independently extracted study-level data and assessed risk of bias using a modified Newcastle-Ottawa Scale and certainty of evidence using a modified Grading of Recommendations, Assessment, Development, and Evaluation approach. We analysed extracted relative risks (RRs) and 95% CIs using random-effects meta-analyses and meta-regression models. This study is registered with PROSPERO, CRD42016043164. FINDINGS: 19 837 records were identified from the search, of which 124 studies were included, providing 83 water (62 616 children), 20 sanitation (40 799 children), and 41 hygiene (98 416 children) comparisons. Compared with untreated water from an unimproved source, risk of diarrhoea was reduced by up to 50% with water treated at point of use (POU): filtration (n=23 studies; RR 0·50 [95% CI 0·41-0·60]), solar treatment (n=13; 0·63 [0·50-0·80]), and chlorination (n=25; 0·66 [0·56-0·77]). Compared with an unimproved source, provision of an improved drinking water supply on premises with higher water quality reduced diarrhoea risk by 52% (n=2; 0·48 [0·26-0·87]). Overall, sanitation interventions reduced diarrhoea risk by 24% (0·76 [0·61-0·94]). Compared with unimproved sanitation, providing sewer connection reduced diarrhoea risk by 47% (n=5; 0·53 [0·30-0·93]). Promotion of handwashing with soap reduced diarrhoea risk by 30% (0·70 [0·64-0·76]). INTERPRETATION: WASH interventions reduced risk of diarrhoea in children in LMICs. Interventions supplying either water filtered at POU, higher water quality from an improved source on premises, or basic sanitation services with sewer connection were associated with increased reductions. Our results support higher service levels called for under SDG 6. Notably, no studies evaluated interventions that delivered access to safely managed WASH services, the level of service to which universal coverage by 2030 is committed under the SDG. FUNDING: WHO, Foreign, Commonwealth & Development Office, and National Institute of Environmental Health Sciences.

Contamination and ecological risk assessment of toxic metals in Awetu watershed stream waters and sediments, Ethiopia.

The study analyzed the contamination level and ecological risk assessment of toxic metals Awetu watershed streams. A total of 20 water and 20 sediment samples were collected and analyzed for the toxic metals of Arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), tin (Sn), and zinc (Zn). Sediment samples showed severe contamination levels based on ranges in sediment quality guidelines (SQGs). Water samples showed high grades of contamination factor and potential ecological risk factor by toxic metals. The synergistic effects of toxic metals in the sampling sites were evaluated by Nemerow pollution index, potential ecological risk index and modified degree of contamination and were found to have similar results. Dololo stream (D1, D2, D3, and D4) and Kito (K1, K2, and K3) were found at 'toxic' contamination and 'severe' ecological risk. Cd, Mn, Ni, Pb, and Sn contributed to the highest ecological risk. Toxic metal contamination in Dololo stream is attributed to institutions carrying out various anthropogenic activities along the stream bank, including traditional metal plating, garages, laboratory effluents, extensive agriculture, carwash, irresponsible waste disposal, and urban population growth. The result shows Awetu watershed streams are seriously contaminated by toxic metals. Therefore, future pollution control and management plans should accentuate the strict regulation of discharge of wastes from these anthropogenic activities.