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Uprety S, Ngo I, Maggos M, Dangol B, Sherchan SP, Shisler JL, Amarasiri M, Sano D, Nguyen TH. Multiple pathogen contamination of water, hands, and fomites in rural Nepal and the effect of WaSH interventions. Int J Hyg Environ Health 2024; 257:114341. [PMID: 38442666 DOI: 10.1016/j.ijheh.2024.114341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 01/23/2024] [Accepted: 02/16/2024] [Indexed: 03/07/2024]
Abstract
Water, Sanitation, and Hygiene (WaSH) interventions are the most effective in reducing diarrheal disease severity and prevalence. However, very few studies have investigated the effectiveness of WaSH intervention in reducing pathogen presence and concentration. In this study, we employed a microfluidic PCR approach to quantify twenty bacterial pathogens in water (n = 360), hands (n = 180), and fomite (n = 540) samples collected in rural households of Nepal to assess the pathogen exposures and the effect of WaSH intervention on contamination and exposure rates. The pathogen load and the exposure pathways for each pathogen in intervention and control villages were compared to understand the effects of WaSH intervention. Pathogens were detected in higher frequency and concentration from fomites samples, toilet handle (21.42%; 5.4,0 95%CI: mean log10 of 4.69, 5.96), utensils (23.5%; 5.47, 95%CI: mean log10 of 4.77, 6.77), and water vessels (22.42%; 5.53, 95%CI: mean log10 of 4.79, 6.60) as compared to cleaning water (14.36%; 5.05, 95%CI: mean log10 of 4.36, 5.89), drinking water (14.26%; 4.37, 85%CI: mean log10 of 4.37, 5.87), and hand rinse samples (16.92%; 5.49, 95%CI: mean log10 of 4.77, 6.39). There was no clear evidence that WaSH intervention reduced overall pathogen contamination in any tested pathway. However, we observed a significant reduction (p < 0.05) in the prevalence, but not concentration, of some target pathogens, including Enterococcus spp. in the intervention village compared to the control village for water and hands rinse samples. Conversely, no significant reduction in target pathogen concentration was observed for water and hand rinse samples. In swab samples, there was a reduction mostly in pathogen concentration rather than pathogen prevalence, highlighting that a reduction in pathogen prevalence was not always accompanied by a reduction in pathogen concentration. This study provides an understanding of WaSH intervention on microbe concentrations. Such data could help with better planning of intervention activities in the future.
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Affiliation(s)
- Sital Uprety
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL, USA; Department of Sanitation, Water and Solid Waste for Development (Sandec), Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Zurich, Switzerland; Department of Civil and Environmental Engineering, Tohoku University Sendai, Japan.
| | - Isaac Ngo
- Department of Microbiology, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Marika Maggos
- Department of Microbiology, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Bipin Dangol
- Environment and Public Health Organization (ENPHO), Kathmandu, Nepal
| | - Samendra P Sherchan
- Environment and Public Health Organization (ENPHO), Kathmandu, Nepal; Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA; BioEnvironmental Science Program Morgan State University, Baltimore, MD, 21251, USA
| | - Joanna L Shisler
- Department of Microbiology, University of Illinois at Urbana Champaign, Urbana, IL, USA; Institute of Genomic Biology, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Mohan Amarasiri
- School of Allied Health Sciences, Kitasato University, Sagamihara, Japan
| | - Daisuke Sano
- Department of Frontier Sciences for Advanced Environment, Tohoku University, Sendai, Japan; Department of Civil and Environmental Engineering, Tohoku University Sendai, Japan
| | - Thanh H Nguyen
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL, USA; Institute of Genomic Biology, University of Illinois at Urbana Champaign, Urbana, IL, USA
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Uprety S, Sherchan SP, Narayanan P, Dangol B, Maggos M, Celmer A, Shisler J, Amarasiri M, Sano D, Nguyen TH. Microbial assessment of water, sanitation, and hygiene (WaSH) in temporary and permanent settlements two years after Nepal 2015 earthquake. Sci Total Environ 2023; 877:162867. [PMID: 36931512 DOI: 10.1016/j.scitotenv.2023.162867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 03/10/2023] [Accepted: 03/10/2023] [Indexed: 05/06/2023]
Abstract
Disaster-induced displacement often causes people to live in temporary settlements that have limited infrastructure and access to water, sanitation, and hygiene (WaSH). Reducing the risk of diarrheal diseases in such situations requires knowing how housing influences the presence of pathogens in water and the interaction between human settlements and exposure to pathogens. A cross-sectional study was conducted in May 2017 in two communities hard-hit by the Nepal 2015 earthquake: one recovered with newly reconstructed houses, and one recovered with residents still living in sheet metal temporary shelters constructed after the earthquake. We collected 60 water (30 drinking water and 30 cleaning water), 30 hand rinse, and 90 environmental swab samples (30 toilet handles, 30 utensils, and 30 water vessels) from selected households in each location and quantified 22 bacterial pathogens using microfluidic quantitative polymerase chain reaction (mfqPCR). A total of 59 samples were randomly selected for amplicon-based sequencing of the 16S rRNA, and it identified bacterial community profiles between these two settlements and their association with target genes of pathogenic bacteria. Target genes like uidA of Escherichia coli and the mip gene of Legionella pnuemophila showed significantly high frequency in specific sample types in temporary settlements than in permanent settlements. A significantly high concentration was observed in temporary settlements for Enterococcus spp. and S. typhimurium, specifically in swab samples. There was a sharp distinction of microbial community profiles between water and hand rinse samples with environmental swab samples, with a large abundance of potentially pathogenic bacteria in swab samples in both settlements. This observation highlighted that fomite could be an important transmission route for pathogens in rural settings and designing key interventions to target different stages of transmission pathways is essential. Overall findings from this study suggest that the recovered settlement with higher quality housing may be less impacted by fecal contamination than recovering settlements and that interventions should be designed to disrupt multiple transmission pathways to reduce pathogen exposure.
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Affiliation(s)
- Sital Uprety
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL, USA; Department of Sanitation, Water and Solid Waste for Development (Sandec), Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Zurich, Switzerland; Department of Civil and Environmental Engineering, Tohoku University, Sendai, Japan.
| | - Samendra P Sherchan
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, New Orleans, LA, USA; Department of Biology, Morgan State University, Baltimore, MD, USA
| | - Preeti Narayanan
- Department of Chemistry, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Bipin Dangol
- Environment and Public Health Organization (ENPHO), Kathmandu, Nepal
| | - Marika Maggos
- Department of Microbiology, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Alex Celmer
- Department of Microbiology, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Joanna Shisler
- Department of Microbiology, University of Illinois at Urbana Champaign, Urbana, IL, USA; Institute of Genomic Biology, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Mohan Amarasiri
- Department of Health Science, School of Allied Health Sciences, Kitasato University, Sagamihara, Japan
| | - Daisuke Sano
- Department of Civil and Environmental Engineering, Tohoku University, Sendai, Japan
| | - Thanh H Nguyen
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL, USA; Institute of Genomic Biology, University of Illinois at Urbana Champaign, Urbana, IL, USA
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Yadav D, Dangol B, Shrestha N, Pandit S, Nepal A. Post-tonsillectomy Hemorrhage in Patients Receiving Ketorolac Analgesic. Kathmandu Univ Med J (KUMJ) 2023; 21:3-6. [PMID: 37800417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/07/2023]
Abstract
Background Ketorolac, the non-steroidal anti-inflammatory drug, is thought to have less sedation as well as postoperative nausea and vomiting in comparison to opioids, but with higher risk of post-tonsillectomy hemorrhage as reported in some of the literatures. There is no consensus till date in the use of ketorolac in the management of pain following tonsil and adenoid related surgeries. Objective To find out the incidence of hemorrhage following tonsil and adenoid related surgeries in patients receiving ketorolac in postoperative period. Method This is a retrospective chart review of patients undergoing tonsil and adenoid related surgeries who had received ketorolac during April, 2013 to May, 2019 at department of ENT-HNS, Patan Academy of Health Sciences (PAHS), Lalitpur, Nepal. Post-tonsillectomy hemorrhage rate was calculated in pediatric and adult patients. Result During the study period, 103 patients (male - 50 and female - 53) received ketorolac in postoperative period. Tonsillectomy and adenotonsillectomy were performed in 71and 32 patients respectively. Forty-five patients were < 18 years whereas 58 were ≥ 18 years. Most common indication for surgery was recurrent tonsillitis (66/103) followed by adenotonsillar hypertrophy (31/103). Post-tonsillectomy hemorrhage was observed in 15 patients; among them, four out 45 were < 18 years and 11 out of 58 ≥ 18 years. All five patients out of 15, who required surgical intervention for post-tonsillectomy hemorrhage, were ≥ 18 years and were operated for recurrent tonsillitis. Rest of the patients (10/15) were managed conservatively. None of the patients required blood transfusion. Conclusion Ketorolac is not associated with increased risk of post-tonsillectomy hemorrhage in children and can safely be administered. Whereas in adults, recurrent tonsillitis being the most common indication for tonsillectomy, it should be used cautiously.
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Affiliation(s)
- D Yadav
- Department of ENT-HNS, Patan Hospital, Patan Academy of Health Sciences, Lagankhel, Lalitpur, Nepal
| | - B Dangol
- Department of ENT-HNS, Patan Hospital, Patan Academy of Health Sciences, Lagankhel, Lalitpur, Nepal
| | - N Shrestha
- Department of ENT-HNS, Patan Hospital, Patan Academy of Health Sciences, Lagankhel, Lalitpur, Nepal
| | - S Pandit
- Consultant Radiation Oncologist, Kathmandu Cancer Center, Tathali, Nala Road, Bhaktapur, Nepal
| | - A Nepal
- Department of ENT-HNS, Patan Hospital, Patan Academy of Health Sciences, Lagankhel, Lalitpur, Nepal
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Mueller B, Dangol B, Ngai TKK, Hug SJ. Kanchan arsenic filters in the lowlands of Nepal: mode of operation, arsenic removal, and future improvements. Environ Geochem Health 2021; 43:375-389. [PMID: 32974885 DOI: 10.1007/s10653-020-00718-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Accepted: 09/03/2020] [Indexed: 06/11/2023]
Abstract
In the lowlands of Nepal (Terai), the WHO drinking water guideline concentration of 10 μg/L for arsenic (As) is frequently exceeded. Since their introduction in 2006, iron-assisted bio-sand filters (Kanchan filters) are widely used to treat well water in Nepal. The filters are constructed on the basis of As-removal with corroding zero-valent iron (ZVI), with water flowing through a filter bed of iron nails placed above a sand filter. According to several studies, the performance of Kanchan filters varies greatly and depends on the size of the iron nails, filter design, water composition, and operating conditions, leading to concerns about their actual efficiency. This study examined 38 Kanchan household filters for which insufficient As-removal was reported, to evaluate the reasons for limited removal efficiency and to define measures for improved performance. The measured arsenic removal ranged from 6.3% to 98.5%. The most relevant factors were the concentrations of As and Fe in the raw water, with the best removal efficiency observed for water with low As (123 µg/L) and high Fe (5.0 mg/L). Although the concentrations of other elements, pH, flow rates, and contact time with ZVI also played a role, the combined evidence indicated that the reactivity of the frequently drying nail beds between filtrations was insufficient for efficient As-removal. Optimized filters with added top layers of sand and raised water outlets with flow restrictions to keep nails permanently immersed and to increase contact times, should be able to achieve higher and more consistent arsenic removal efficiencies.
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Affiliation(s)
- Barbara Mueller
- Bamugeobiochem, Horbenstrasse 4, 8356, Ettenhausen, Switzerland.
| | - Bipin Dangol
- ENPHO, Environment and Public Health Organization, New Baneshwor, Kathmandu, Nepal
| | - Tommy K K Ngai
- CAWST, Center for Affordable Water and Sanitation Technology, B12, 6020 - 2Street SE, Calgary, AB, T2H 2L8, Canada
| | - Stephan J Hug
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600, Duebendorf, Switzerland
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Uprety S, Dangol B, Nakarmi P, Dhakal I, Sherchan SP, Shisler JL, Jutla A, Amarasiri M, Sano D, Nguyen TH. Assessment of microbial risks by characterization of Escherichia coli presence to analyze the public health risks from poor water quality in Nepal. Int J Hyg Environ Health 2020; 226:113484. [DOI: 10.1016/j.ijheh.2020.113484] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/07/2020] [Accepted: 02/09/2020] [Indexed: 02/01/2023]
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Brabec JL, Wright J, Ly T, Wong HT, McClimans CJ, Tokarev V, Lamendella R, Sherchand S, Shrestha D, Uprety S, Dangol B, Tandukar S, Sherchand JB, Sherchan SP. Arsenic disturbs the gut microbiome of individuals in a disadvantaged community in Nepal. Heliyon 2020; 6:e03313. [PMID: 32051876 PMCID: PMC7002857 DOI: 10.1016/j.heliyon.2020.e03313] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 12/18/2019] [Accepted: 01/24/2020] [Indexed: 01/15/2023] Open
Abstract
Arsenic is ubiquitous in nature, highly toxic, and is particularly abundant in Southern Asia. While many studies have focused on areas like Bangladesh and West Bengal, India, disadvantaged regions within Nepal have also suffered from arsenic contamination levels, with wells and other water sources possessing arsenic contamination over the recommended WHO and EPA limit of 10 μg/L, some wells reporting levels as high as 500 μg/L. Despite the region's pronounced arsenic concentrations within community water sources, few investigations have been conducted to understand the impact of arsenic contamination on host gut microbiota health. This study aims to examine differential arsenic exposure on the gut microbiome structure within two disadvantaged communities in southern Nepal. Fecal samples (n = 42) were collected from members of the Mahuawa (n = 20) and Ghanashyampur (n = 22) communities in southern Nepal. The 16S rRNA gene was amplified from fecal samples using Illumina-tag PCR and subject to high-throughput sequencing to generate the bacterial community structure of each sample. Bioinformatics analysis and multivariate statistics were conducted to identify if specific fecal bacterial assemblages and predicted functions were correlated with urine arsenic concentration. Our results revealed unique assemblages of arsenic volatilizing and pathogenic bacteria positively correlated with increased arsenic concentration in individuals within the two respective communities. Additionally, we observed that commensal gut bacteria negatively correlated with increased arsenic concentration in the two respective communities. Our study has revealed that arsenic poses a broader human health risk than was previously known. It is influential in shaping the gut microbiome through its enrichment of arsenic volatilizing and pathogenic bacteria and subsequent depletion of gut commensals. This aspect of arsenic has the potential to debilitate healthy humans by contributing to disorders like heart and liver cancers and diabetes, and it has already been shown to contribute to serious diseases and disorders, including skin lesions, gangrene and several types of skin, renal, lung, and liver cancers in disadvantaged areas of the world like Nepal.
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Affiliation(s)
- Jeffrey L Brabec
- Department of Biology, Juniata College, Huntingdon, PA, 16652, USA
| | - Justin Wright
- Department of Biology, Juniata College, Huntingdon, PA, 16652, USA
| | - Truc Ly
- Department of Biology, Juniata College, Huntingdon, PA, 16652, USA
| | - Hoi Tong Wong
- Department of Biology, Juniata College, Huntingdon, PA, 16652, USA
| | | | - Vasily Tokarev
- Department of Biology, Juniata College, Huntingdon, PA, 16652, USA
| | | | - Shardulendra Sherchand
- Department of Microbiology, Immunology & Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, 70112, USA
| | | | - Sital Uprety
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL, United States
| | - Bipin Dangol
- Environment and Public Health Organization, Kathmandu, Nepal
| | - Sarmila Tandukar
- Public Health Research Laboratory, Tribhuvan University Teaching Hospital, 1524, Kathmandu, Nepal
| | - Jeevan B Sherchand
- Public Health Research Laboratory, Tribhuvan University Teaching Hospital, 1524, Kathmandu, Nepal
| | - Samendra P Sherchan
- Department of Global Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana, 70112, USA
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Ogata R, Dangol B, Sakamoto M. Sustainability assessment of long-term, widely used household Kanchan Arsenic Filters in Nepal. J Environ Sci Health A Tox Hazard Subst Environ Eng 2020; 55:517-527. [PMID: 31903841 DOI: 10.1080/10934529.2019.1710414] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 06/10/2023]
Abstract
This study revealed the status of 2833 Kanchan Arsenic Filters (KAFs), aged 2 months to over 10 years, distributed in Nepal. Thirty percent of the filters were being used, but usage status generally declined 4 years after installation. Lack of use was mostly due to breakage or leaks (74%), which users did not know how to repair. Some 1283 filters (65%) were abandoned, and users returned to drinking arsenic-contaminated water. Water quality tests showed that the average KAF arsenic removal rate was 75%, and 87 and 62% of the samples met Nepal's drinking water quality standards and World Health Organization guidelines, respectively. The KAF arsenic removal amount was significantly influenced by the arsenic and iron concentrations of influent water and KAF type. The concrete square type showed the best performance in usage status and arsenic removal capacity, namely 57 and 83%, respectively. Long-term use of KAFs (more than 4 years) was assumed to be a cause of the decreasing capacity of iron nails to supply ferric hydroxide to influent water, which led to decreased arsenic removal capacity. Thus, replacement of older iron nails may restore the arsenic removal capacity of KAFs.
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Affiliation(s)
- Ryuji Ogata
- Japan International Cooperation Agency (JICA), Amman, Jordan and The University of Tokyo, Kashiwa, Japan
| | - Bipin Dangol
- Environment and Public Health Organization, Kathmandu, Nepal
| | - Maiko Sakamoto
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan
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Uprety S, Hong PY, Sadik N, Dangol B, Adhikari R, Jutla A, Shisler JL, Degnan P, Nguyen TH. The Effect of the 2015 Earthquake on the Bacterial Community Compositions in Water in Nepal. Front Microbiol 2017; 8:2380. [PMID: 29270153 PMCID: PMC5724148 DOI: 10.3389/fmicb.2017.02380] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 11/17/2017] [Indexed: 11/13/2022] Open
Abstract
We conducted a study to examine the effect of seasonal variations and the disruptive effects of the 2015 Nepal earthquake on microbial communities associated with drinking water sources. We first characterized the microbial communities of water samples in two Nepali regions (Kathmandu and Jhapa) to understand the stability of microbial communities in water samples collected in 2014. We analyzed additional water samples from the same sources collected from May to August 2015, allowing the comparison of samples from dry-to-dry season and from dry-to-monsoon seasons. Emphasis was placed on microbes responsible for maintaining the geobiochemical characteristics of water (e.g., ammonia-oxidizing and nitrite-oxidizing bacteria and archaea and sulfate-reducing bacteria) and opportunistic pathogens often found in water (Acinetobacter). When examining samples from Jhapa, we identified that most geobiochemical microbe populations remained similar. When examining samples from Kathmandu, the abundance of microbial genera responsible for maintaining the geobiochemical characteristics of water increased immediately after the earthquake and decreased 8 months later (December 2015). In addition, microbial source tracking was used to monitor human fecal contamination and revealed deteriorated water quality in some specific sampling sites in Kathmandu post-earthquake. This study highlights a disruption of the environmental microbiome after an earthquake and the restoration of these microbial communities as a function of time and sanitation practices.
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Affiliation(s)
- Sital Uprety
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL, United States
| | - Pei-Ying Hong
- Water Desalination and Reuse Center, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Nora Sadik
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL, United States
| | - Bipin Dangol
- Environment and Public Health Organization, Kathmandu, Nepal
| | | | - Antarpreet Jutla
- Department of Civil and Environmental Engineering, West Virginia University, Morgantown, WV, United States
| | - Joanna L. Shisler
- Department of Microbiology, University of Illinois at Urbana Champaign, Urbana, IL, United States
| | - Patrick Degnan
- Department of Microbiology, University of Illinois at Urbana Champaign, Urbana, IL, United States
| | - Thanh H. Nguyen
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL, United States
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Dangol B. Internship: a closer look at its prospects. Kathmandu Univ Med J (KUMJ) 2008; 6:141-143. [PMID: 18604132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Ngai TKK, Shrestha RR, Dangol B, Maharjan M, Murcott SE. Design for sustainable development--household drinking water filter for arsenic and pathogen treatment in Nepal. J Environ Sci Health A Tox Hazard Subst Environ Eng 2007; 42:1879-1888. [PMID: 17952789 DOI: 10.1080/10934520701567148] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
In the last 20 years, the widespread adoption of shallow tubewells in Nepal Terai region enabled substantial improvement in access to water, but recent national water quality testing showed that 3% of these sources contain arsenic above the Nepali interim guideline of 50 microg/L, and up to 60% contain unsafe microbial contamination. To combat this crisis, MIT, ENPHO and CAWST together researched, developed and implemented a household water treatment technology by applying an iterative, learning development framework. A pilot study comparing 3 technologies against technical, social, and economic criteria showed that the Kanchan Arsenic Filter (KAF) is the most promising technology for Nepal. A two-year technical and social evaluation of over 1000 KAFs deployed in rural villages of Nepal determined that the KAF typically removes 85-90% arsenic, 90-95% iron, 80-95% turbidity, and 85-99% total coliforms. Then 83% of the households continued to use the filter after 1 year, mainly motivated by the clean appearance, improved taste, and reduced odour of the filtered water, as compared to the original water source. Although over 5,000 filters have been implemented in Nepal by January 2007, further research rooted in sustainable development is necessary to understand the technology diffusion and scale-up process, in order to expand access to safe water in the country and beyond.
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Affiliation(s)
- Tommy K K Ngai
- Centre for Affordable Water and Sanitation Technology, Calgary, Alberta, Canada.
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