| 1. |
- Amin, Nuhu, et al.
(author)
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Dependency of sanitation infrastructure on the discharge of faecal coliform and SARS-CoV-2 viral RNA in wastewater from COVID and non-COVID hospitals in Dhaka, Bangladesh
- 2023
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In: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 867
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Journal article (peer-reviewed)abstract
- The detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) RNA in wastewater can be used as an indicator of the presence of SARS-CoV-2 infection in specific catchment areas. We conducted a hospital-based study to explore wastewater management in healthcare facilities and analyzed SARS-CoV-2 RNA in the hospital wastewater in Dhaka city during the Coronavirus disease (COVID-19) outbreak between September 2020-January 2021. We selected three COVID-hospitals, two non-COVID-hospitals, and one non-COVID-hospital with COVID wards, conducted spot-checks of the sanitation systems (i.e., toilets, drainage, and septic-tank), and collected 90 untreated wastewater effluent samples (68 from COVID and 22 from non-COVID hospitals). E. coli was detected using a membrane filtration technique and reported as colony forming unit (CFU). SARS-CoV-2 RNA was detected using the iTaq Universal Probes One-Step kit for RT-qPCR amplification of the SARS-CoV-2 ORF1ab and N gene targets and quantified for SARS-CoV-2 genome equivalent copies (GEC) per mL of sample. None of the six hospitals had a primary wastewater treatment facility; two COVID hospitals had functional septic tanks, and the rest of the hospitals had either broken onsite systems or no containment of wastewater. Overall, 100 % of wastewater samples were positive with a high concentration of E.coli (mean = 7.0 log10 CFU/100 mL). Overall, 67 % (60/90) samples were positive for SARS-CoV-2. The highest SARS-CoV-2 concentrations (median: 141 GEC/mL; range: 13-18,214) were detected in wastewater from COVID-hospitals, and in non-COVID-hospitals, the median SARS-CoV-2 concentration was 108 GEC/mL (range: 30-1829). Our results indicate that high concentrations of E. coli and SARS-CoV-2 were discharged through the hospital wastewa-ter (both COVID and non-COVID) without treatment into the ambient water bodies. Although there is no evidence for transmission of SARS-CoV-2 via wastewater, this study highlights the significant risk posed by wastewater from health care facilities in Dhaka for the many other diseases that are spread via faecal oral route. Hospitals in low-income settings could function as sentinel sites to monitor outbreaks through wastewater-based epidemiological surveillance systems. Hospitals should aim to adopt the appropriate wastewater treatment technologies to reduce the discharge of pathogens into the environment and mitigate environmental exposures.
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| 2. |
- Haque, Rehnuma, et al.
(author)
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Wastewater surveillance of SARS-CoV-2 in Bangladesh : Opportunities and challenges
- 2022
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In: CURRENT OPINION IN ENVIRONMENTAL SCIENCE & HEALTH. - : Elsevier BV. - 2468-5844. ; 27, s. 100334-
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Journal article (peer-reviewed)abstract
- The ongoing pandemic of the coronavirus disease 2019 (COVID-19) is a public health crisis of global concern. The progression of the COVID-19 pandemic has been monitored in the first place by testing symptomatic individuals for SARS-CoV-2 virus in the respiratory samples. Concurrently, wastewater carries feces, urine, and sputum that potentially contains SARS-CoV-2 intact virus or partially damaged viral genetic materials excreted by infected individuals. This brings significant opportunities for understanding the infection dynamics by environmental surveillance. It has advantages for the country, especially in densely populated areas where individual clinical testing is difficult. However, there are several challenges including: 1) establishing a sampling plan and schedule that is representative of the various catchment populations 2) development and validation of standardized protocols for the laboratory analysis 3) understanding hydraulic flows and virus transport in complex wastewater drainage systems and 4) collaborative efforts from government agencies, NGOs, public health units and academia.
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| 3. |
- Jolly, Yeasmin N., et al.
(author)
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Evaluation of surface water quality near pollution sources in Buriganga River and deciphering their probable emergence, ecological, and health risk aspects
- 2023
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In: Regional Studies in Marine Science. - : Elsevier BV. - 2352-4855. ; 63
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Journal article (peer-reviewed)abstract
- Potentially toxic elements (PTEs) contamination in Buriganga river water, provoked by the point and non-point sources, has recently become a major health concern. Concentration, pollution degree, drinking and irrigation water potentiality, and associated health risks are the factors considered for this study. This study ascertained a mean pH, EC, TDS, and salinity value of 6.96, 86.25 mu S/cm, 51.86 mg/L, and 86.56%, respectively, revealing that it is safe for drinking and agricultural purposes. Furthermore, the mean value of major anion (NO-23: 1.16, SO-24 : 13.40, PO-34 : 0.66, Cl-1 : 14.71 mg/L) and major cations (Na+1 : 16.95, K+1 : 4.26, Ca+2 : 17.63, and Mg+2 : 5.47 mg/L) also estimated safe for human consumption and agricultural use. Trace element evaluation index (TEI) value was found to vary among the sites and ranging from 4.40 to 10.50, indicating moderate pollution and risk imposed by the single PTEs can be ranked as Mn>Fe>Pb>As>Cu>Zn. Nemerow index and comprehensive pollution index value stipulated an insignificant to moderate pollution by the studied elements. Consequently, no ecological risk was posed via elements studied in the proposed sites. The emerging sources for PTEs are confined to both anthropogenic and lithogenic derivations. Non-carcinogenic risk assessment stipulated that the river water was safe for adults and children as the estimated Hazard Quotient (HQ) and Hazard Index (HI) value was found below the threshold value (HQ/HI<1). Total carcinogenic risk was calculated at 7.44E-08 and 1.60E-08 for adults and children, respectively, specifying no risk, and water from the sites was evaluated as suitable for agricultural irrigation purposes on the basis of estimated indices.
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