Search

Background: The consumption of vegetables is increasing in Ethiopia because of their high health benefits. Smallholder farmers who use water from the Akaki River for irrigation meet more than 60% of the vegetable needs of Addis Ababa. However, the Akaki River is severely polluted by anthropogenic impacts. Hence, the intake of vegetables grown in fecally contaminated water can lead to many health problems. Therefore, this study aimed to evaluate microbial contamination of irrigation water and vegetables in Addis Ababa. Methods: This study assessed the quality of water and vegetables collected from the Akaki River. Fresh vegetables, such as Ethiopian kale, lettuce, cabbage, and spinach, were collected from 14 farmlands during the dry and wet seasons. The analysis of E. coli non-E. coli, total coliform (TC), fecal coliform (FC), and total aerobic plate count (TAC) were determined using standard methods. Results: The findings of this study indicated that all fresh vegetables were contaminated with total coliforms, fecal coliforms, and total aerobic plate counts in both dry and wet seasons. The overall mean counts of E. coli and non-E. coli in the water samples were 2.09 and >3.48 log10 CFU 10 mL−1, respectively. The mean counts of TC, FC, and TAC on the sampled vegetables were 3.22, 1.37, and 4.72 in the dry season, and 3.87, 2.57, and 5.09 log10 CFU per gram in the wet season, respectively. Conclusion: The Akaki River has been contaminated with non-E. Coli & E. coli coliforms, and did not meet the WHO guideline criteria for safe irrigation. The microbial contamination of vegetables was found to be high and exceeded the hazard analysis and critical control points for total quality management (HACCPTQM) and International Commission on Microbiological Specifications for Food (ICMSF) limits for safe consumption. Therefore, the local government is responsible for ensuring that farmers can use pollution-reducing irrigation systems and that consumers are aware of the health risks of contaminated vegetables and take appropriate precautions.

Bottled water is potable water that is manufactured, distributed, or offered for sale and intended for human consumption. However, bottled water retailers usually expose bottled water to direct sunlight at the point of sale, and store it for extended periods. Therefore, this study aimed to investigate the effects of sunlight exposure and storage time on the physicochemical properties of bottled water. An experimental observational study design was employed to assess the effect of direct sunlight exposure on selected physicochemical parameters in four water brands (40 samples for both control and exposed) for 28 days in Addis Ababa, Ethiopia. The study's average sunlight intensity and sunshine hours from 3 October to 30/2020 were 197.7 ± 31.8 W/M2 and 7. 3 ± 2. 7 h, respectively. The mean values of the physicochemical parameters of bottled water before and after exposure to sunlight were compared using a paired sample t-test and Wilcoxon signed-rank test with a significance level of 0.05. Approximately 80% of the analysed parameters did not match the labelled value of bottled water. This study showed that the values of pH, F-, and NO3− were decreased from 7.31 to 7.02; 0.20 to 0.15 mg/L, and 3.95 to 3.52 mg/L, respectively. Whereas the level of NO2−, TDS, and turbidity was increased with increasing sunlight exposure from 0.00 to 0.02 mg/L, 82.82 to 85.24 mg/L, and 0.00 to 0.57 NTU, respectively. Statistically significant differences in pH, F−, NO2−, and turbidity levels were found between the exposed and non-exposed groups of bottled water. Apart from the increase or decrease in chemical concentration after sunlight exposure, the physicochemical parameters of the exposed bottled waters were within the recommended standards, except for fluoride and turbidity. However, the fluoride concentration was below the recommended level in both exposed and unexposed samples, with a further reduction in sunlight-exposed bottled water samples. Therefore, regulators should ensure that bottled water is protected against long-term direct exposure to sunlight to provide safe water to consumers.