Your search found 3 records
1 Pantha, K.; Acharya, K.; Mohapatra, S.; Khanal, S.; Amatya, N.; Ospina-Betancourth, C.; Butte, G.; Shrestha, S. D.; Rajbhandari, P.; Werner, D. 2021. Faecal pollution source tracking in the holy Bagmati River by portable 16S rRNA gene sequencing. npj Clean Water, 4:12. [doi: https://doi.org/10.1038/s41545-021-00099-1]
Water pollution ; Faecal pollution ; Coliform bacteria ; Faecal coliforms ; Biological contamination ; Rivers ; Water quality ; Sewage ; Wastewater treatment plants ; Sanitation ; Public health ; Indicators ; Monsoons / Nepal / Kathmandu Valley / Bagmati River
(Location: IWMI HQ Call no: e-copy only Record No: H050276)
(2.02 MB) (2.02 MB)
A suitcase laboratory was used for 16S rRNA amplicon sequencing to assess microbial water quality in the holy Bagmati River, Kathmandu, Nepal. SourceTracker analysis and Volcano plots revealed that microbial communities in the downstream part of the river were mainly contributed by untreated sewage. Seasonal variability in the sewage microbiome was reflected in the downstream river water quality. The bacterial genera Acidovorax, Geobacillus and Caulobacter predominated in the upstream sites, while genera containing putative human pathogens and gut bacteria, such as Clostridium, Prevotella, Arcobacter, Lactobacillus, Enterococcus and Streptococcus become prominent in the downstream sites. Marker gene qPCR assays for total bacteria, total coliforms, Human E. coli, Arcobacter butzleri and Vibrio cholerae confirmed the sequencing data trends. Even though basic sanitation provision is nowadays near universal in Nepal, our findings show how inadequate wastewater management may turn an urban river into an open sewer, which poses a public health risk.
2 Butte, G.; Niwagaba, C.; Nordin, A. 2021. Assessing the microbial risk of faecal sludge use in Ugandan agriculture by comparing field and theoretical model output. Water Research, 197:117068. [doi: https://doi.org/10.1016/j.watres.2021.117068]
Faecal sludge ; Agriculture ; Biological contamination ; Risk assessment ; Treatment plants ; Pathogens ; Escherichia coli ; Waste management ; Risk reduction ; Vegetables ; Crops ; Fertilizers ; Farmers ; Models / Uganda / Kampala
(Location: IWMI HQ Call no: e-copy only Record No: H050481)
https://www.sciencedirect.com/science/article/pii/S0043135421002669/pdfft?md5=8d175bb8c32e02db26ee505950926fb9&pid=1-s2.0-S0043135421002669-main.pdf
https://vlibrary.iwmi.org/pdf/H050481.pdf
https://vlibrary.iwmi.org/pdf/H050481.pdf
(1.80 MB) (1.80 MB)
Reuse of faecal sludge in agriculture has many potential benefits, but also poses risks to human health. To better understand the potential risks, Quantitative Microbial Risk Assessment (QMRA) was performed for three population groups in Kampala, Uganda: wastewater and faecal sludge treatment plant workers; farmers using faecal sludge; and consumers of faecal sludge-fertilised vegetables. Two models were applied for farmers and consumers, one based on pathogen concentrations from field sampling of sludge, soils and vegetables, and one based on theoretical pathogen contribution from the last sludge application, including decay and soil to crop transfer of pathogens. The risk was evaluated for two pathogens (enterohaemorrhagic E. coli (EHEC) and Ascaris lumbricoides). The field data on sludge, soil and vegetables indicated that the last application of faecal sludge was not the sole pathogen source. Correspondingly, the model using field data resulted in higher risks for farmers and consumers than the theoretical model assuming risk from sludge only, except when negligible for both. For farmers, the yearly risk of illness, based on measured concentrations, was 26% from EHEC and 70% from Ascaris, compared with 1.2% and 1.4%, respectively, considering the theoretically assumed contribution from the sludge. For consumers, the risk of illness based on field samples was higher from consumption of leafy vegetables (100% from EHEC, 99% from Ascaris) than from consumption of cabbages (negligible for EHEC, 26% from Ascaris). With the theoretical model, the risk of illness from EHEC was negligible for both crops, whereas the risk of illness from Ascaris was 64% and 16% for leafy vegetables and cabbage, respectively. For treatment plant workers, yearly risk of illness was 100% from EHEC and 99.4% from Ascaris. Mitigation practices evaluated could reduce the relative risk by 30-70%. These results can help guide treatment and use of faecal sludge in Kampala, to protect plant workers, farmers and consumers.
3 Hiruy, A. M.; Mohammed, J.; Haileselassie, M. M.; Acharya, K.; Butte, G.; Haile, Alemseged Tamiru; Walsh, C.; Werner, D. 2022. Spatiotemporal variation in urban wastewater pollution impacts on river microbiomes and associated hazards in the Akaki Catchment, Addis Ababa, Ethiopia. Science of the Total Environment, 826:153912. [doi: https://doi.org/10.1016/j.scitotenv.2022.153912]
Municipal wastewater ; Water pollution ; River water ; Biological contamination ; Bacteria ; Faecal pollution ; Faecal coliforms ; Water quality standards ; Antimicrobial resistance ; Microbiological risk assessment ; Extended spectrum beta-lactamases ; Real time PCR ; Surface water ; Catchment areas ; Irrigation ; Effluents ; Health hazards / Ethiopia / Addis Ababa / Akaki River / Akaki Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H051034)
https://www.sciencedirect.com/science/article/pii/S004896972201004X/pdfft?md5=e4136acb70d545e2d44e8f9069c0a381&pid=1-s2.0-S004896972201004X-main.pdf
https://vlibrary.iwmi.org/pdf/H051034.pdf
https://vlibrary.iwmi.org/pdf/H051034.pdf
(2.34 MB) (2.34 MB)
In Addis Ababa and its environs, most urban wastewater is discharged into rivers without treatment. This study related urban wastewater characteristics to the prevalence of faecal, antibiotic resistant, and potentially pathogenic bacteria in rivers of the Akaki catchment across six locations, for the dry and wet season. Spatiotemporal variation in bacterial hazards across the catchment was up to 6 log10 units. Cooccurrence of sewage pollution marker gene HF183 in all river samples testing positive for the Vibrio cholerae marker gene ompW, and high levels of these two genes in untreated wastewater, identified human sewage as the likely source of Vibrio cholerae hazards in the catchment. Levels of the marker genes rodA for E. coli, HF183 for human host associated Bacteroides, ciaB for Arcobacter, and ompW for Vibrio cholerae were all higher in the dry season than in the wet season. Marker gene gyrB for Pseudomonas aeruginosa was not detected in the samples. From the sequencing data, notable bacterial genera in the dry season included wastewater pollution indicators Arcobacter and Aeromonas, whereas soil erosion may explain the greater prominence of Legionella, Vicinamibacter, and Sphingomonas during the wet season. Except for the most upstream location, all faecal coliform (FC) counts exceeded WHO standards of 1000 CFU/100 mL for unrestricted irrigation. Concerningly, 0.6–20% of FC had ESBL producing antimicrobial resistance traits. In conclusion, multiple bacterial hazards were of concern for river water users in the Akaki catchment, and elevated in the dry season, when the river water is being used for irrigation of vegetable fields that supply the markets of Addis Ababa. This reflects inadequate treatment and limited dilution of urban wastewater by the natural river flows during periods of low rainfall.
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