1
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Jang CS, Liu CC. Integrating quantitative microbiological risk assessment and disability-adjusted life years to evaluate the effects of urbanization on health risks for river recreationists. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 932:172667. [PMID: 38677423 DOI: 10.1016/j.scitotenv.2024.172667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 04/19/2024] [Accepted: 04/19/2024] [Indexed: 04/29/2024]
Abstract
Urban rivers provide an excellent opportunity for water recreation. This study probabilistically assessed health risks associated with water recreation in urban rivers in the Bitan Scenic Area, Taiwan, by employing quantitative microbial risk assessment and disability-adjusted life years (DALYs). Moreover, the effects of urbanization on the health risks of river recreation induced by waterborne pathogenic Escherichia coli (E. coli) were investigated. First, data on river E. coli levels were collected in both the Bitan Scenic Area and the upstream river section, and model parameters were obtained through a questionnaire administered to river recreationists. Monte Carlo simulation was then employed to address parameter uncertainty. Finally, DALYs were calculated to quantify the cumulative effects in terms of potential life lost and years lived with disability. The results indicated that the 90 % confidence intervals for the disease burden (DB) were 0.2-74.1 × 10-6, 0.01-94.0 × 10-6, and 0.3-128.9 × 10-6 DALY per person per year (pppy) for canoeing, swimming, and fishing, respectively, in the Bitan Scenic Area. Furthermore, urbanization near the Bitan Scenic Area approximately doubled the DB risks to river recreationists in upstream rural areas. At the 95th percentile, the DB risks exceeded the tolerances recommended by the World Health Organization (1 × 10-6) or U.S. Environmental Protection Agency (1 × 10-4). The findings suggest that the simultaneous implementation of effluent sewer systems and best management practices can reduce health risks to river recreationists by at least half, reducing the DALY levels below 1 × 10-4 or even 1 × 10-5 pppy.
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Affiliation(s)
- Cheng-Shin Jang
- Department of Leisure and Recreation Management, Kainan University, Taoyuan City 338, Taiwan.
| | - Chu-Chih Liu
- Department of Leisure and Recreation Management, Kainan University, Taoyuan City 338, Taiwan
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2
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Carpio Vallejo E, Düker U, Meyer F, Berding U, Nogueira R. Microbiological water quality and derived health risks from exposure to ornamental water fountains in the city of Hannover. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2024; 44:24-39. [PMID: 37067226 DOI: 10.1111/risa.14145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 03/04/2023] [Accepted: 03/09/2023] [Indexed: 06/19/2023]
Abstract
Ornamental fountains are attractive urban infrastructures helping cities to cope with global warming, as water sprays have great cooling effects due to evaporative properties; however, exposure to microbiologically impaired water from ornamental fountains during recreational activities may result in adverse health outcomes for the exposed population. This study assesses the microbial water quality of four ornamental water fountains (Blätterbrunnen, Körtingbrunnen, Klaus-Bahlsen-Brunnen, and Marstallbrunnen) and performs a quantitative microbial risk assessment (QMRA) for children using Escherichia coli, Enterococci, and Salmonella to quantify the probability of gastrointestinal illnesses and Pseudomonas aeruginosa to quantify the risk of dermal infections. Samples were collected fortnightly in two campaigns in 2020 and 2021 and processed to determine bacterial concentrations. Data on exposure time were obtained during field observations on the selected fountains; a total of 499 people were observed of which 30% were children. Mean bacterial concentrations ranged from 1.6 × 101 to 6.1 × 102 most probable number (MPN)/100 mL for E. coli, 1.2 × 101 -1.2 × 103 MPN/100 mL for Enterococci, 8.6 × 103 -3.1 × 105 CFU/100 mL for Salmonella, and 2.5 × 103 -3.2 × 104 MPN/100 mL for P. aeruginosa. The results of the QMRA study showed that the USEPA illness rate of 36 NEEAR-gastrointestinal illnesses/1000 was exceeded for Enterococci at the Körtingbrunnen, Klaus-Bahlsen-Brunnen, and Marstallbrunnen fountains and for Salmonella and P. aeruginosa at the Körtingbrunnen fountain, suggesting that exposure to microbiologically contaminated water from ornamental fountains may pose a health risk to children. The scenario analysis shows the importance of keeping low bacterial concentrations in ornamental fountains so that the risk of illness/infection to children does not exceed the USEPA illness rate benchmark.
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Affiliation(s)
| | - Urda Düker
- Institut für Siedlungswasserwirtschaft und Abfalltechnik, Leibniz University, Hannover, Germany
| | - Franziska Meyer
- Institut für Siedlungswasserwirtschaft und Abfalltechnik, Leibniz University, Hannover, Germany
| | - Ulrich Berding
- Plan Zwei Stadtplanung und Architektur, Hannover, Germany
| | - Regina Nogueira
- Institut für Siedlungswasserwirtschaft und Abfalltechnik, Leibniz University, Hannover, Germany
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3
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Gitter A, Mena KD, Lisle JT. Informing ASR Treatment Practices in a Florida Aquifer through a Human Health Risk Approach. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:6833. [PMID: 37835103 PMCID: PMC10572346 DOI: 10.3390/ijerph20196833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/05/2023] [Accepted: 09/21/2023] [Indexed: 10/15/2023]
Abstract
Aquifer storage and recovery (ASR) can augment water supplies and hydrologic flows under varying climatic conditions. However, imposing drinking water regulations on ASR practices, including pre-treatment before injection into the aquifer, remains arguable. Microbial inactivation data-Escherichia coli, Pseudomonas aeruginosa, poliovirus type 1 and Cryptosporidium parvum-were used in a human health risk assessment to identify how the storage time of recharged water in the Floridan Aquifer enhances pathogen inactivation, thereby mitigating the human health risks associated with ingestion. We used a quantitative microbial risk assessment to evaluate the risks for a gastrointestinal infection (GI) and the associated disability-adjusted life years (DALYs) per person per year. The risk of developing a GI infection for drinking water no longer exceeded the suggested annual risk threshold (1 × 10-4) by days 31, 1, 52 and 80 for each pathogen, respectively. DALYs per person per year no longer exceeded the World Health Organization threshold (1 × 10-6) by days 27, <1, 43 and 72. In summary, storage time in the aquifer yields a significant reduction in health risk. The findings emphasize that considering microbial inactivation, caused by storage time and geochemical conditions within ASR storage zones, is critical for recharge water treatment processes.
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Affiliation(s)
- Anna Gitter
- Department of Epidemiology, Human Genetics and Environmental Sciences, University of Texas Health Science Center-Houston School of Public Health, Houston, TX 77030, USA;
| | - Kristina D. Mena
- Department of Epidemiology, Human Genetics and Environmental Sciences, University of Texas Health Science Center-Houston School of Public Health, Houston, TX 77030, USA;
| | - John T. Lisle
- U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL 33701, USA;
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4
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Goh SG, Haller L, Ng C, Charles FR, Jitxin L, Chen H, He Y, Gin KYH. Assessing the additional health burden of antibiotic resistant Enterobacteriaceae in surface waters through an integrated QMRA and DALY approach. JOURNAL OF HAZARDOUS MATERIALS 2023; 458:132058. [PMID: 37459761 DOI: 10.1016/j.jhazmat.2023.132058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 06/15/2023] [Accepted: 07/12/2023] [Indexed: 07/26/2023]
Abstract
Antibiotic resistant Enterobacteriaceae pose a significant threat to public health. However, limited studies have evaluated the health risks associated with exposure to antibiotic-resistant bacteria (ARB), especially in natural environments. While quantitative microbial risk assessment (QMRA) assesses microbial risks in terms of the probability of infection, it does not account for the severity of health outcomes. In this study, a QMRA-DALY model was developed to integrate QMRA with health burden (disability-adjusted life years (DALY)) from infections caused by ARB. The model considers uncertainties in probability of infection and health burden assessment using Monte Carlo simulations. The study collected antimicrobial resistance (AMR) surveillance data from surface waters with different land uses. Results revealed water bodies with agricultural land use to be the main AMR hotspots, with the highest additional health burden observed in infections caused by meropenem-resistant E. coli (∆DALY = 0.0105 DALY/event) compared to antibiotic-susceptible E. coli. The estimated ∆DALY for antibiotic-resistant K. pneumoniae was lower than for antibiotic-resistant E. coli (highest ∆DALY = 0.00048 DALY/event). The study highlights the need for better evaluation of AMR associated health burden, and effective measures to mitigate the risks associated with antibiotic-resistant bacteria in natural environments.
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Affiliation(s)
- Shin Giek Goh
- NUS Environmental Research Institute, National University of Singapore, Singapore 117411, Singapore
| | - Laurence Haller
- NUS Environmental Research Institute, National University of Singapore, Singapore 117411, Singapore
| | - Charmaine Ng
- NUS Environmental Research Institute, National University of Singapore, Singapore 117411, Singapore
| | - Francis Rathinam Charles
- NUS Environmental Research Institute, National University of Singapore, Singapore 117411, Singapore
| | - Lim Jitxin
- NUS Environmental Research Institute, National University of Singapore, Singapore 117411, Singapore
| | - Hongjie Chen
- NUS Environmental Research Institute, National University of Singapore, Singapore 117411, Singapore
| | - Yiliang He
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Karina Yew-Hoong Gin
- NUS Environmental Research Institute, National University of Singapore, Singapore 117411, Singapore; Department of Civil & Environmental Engineering, National University of Singapore, Singapore 117576, Singapore.
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5
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Cui B, An D, Li H, Luo X, Zhu H, Li M, Ai X, Ma J, Ali W, Yan C. Evaluating the threshold limit value of acceptable exposure concentration for exposure to bioaerosols in a wastewater treatment plant: Reverse-quantitative microbial risk assessment and sensitivity analysis. JOURNAL OF HAZARDOUS MATERIALS 2023; 452:130687. [PMID: 36989774 DOI: 10.1016/j.jhazmat.2022.130687] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 12/13/2022] [Accepted: 12/26/2022] [Indexed: 05/03/2023]
Abstract
Agitation operations produce numerous pathogenic bioaerosols in WWTPs1. QMRA2 can determine risks of persons exposed to these bioaerosols. However, QMRA framework cannot help stakeholders in immediately deciding whether a risk is intolerable. Thus, evaluating threshold of acceptable exposure concentration is an urgent issue but is still rarely addressed in WWTPs. This study analyzed TLV3 benchmarks of E. coli and S. aureus bioaerosols emitted from a WWTP by reverse-QMRA. Furthermore, variance of input parameters was clarified by sensitivity analysis. Results showed that, under conservative and optimistic estimates, TLV of technicians was 1.52-2.06 and 1.26-1.68 times as large as those of workers, respectively; wearing mask drive TLV up to 1-2 orders of magnitude; TLV of M4 was at most 1.33 and 1.31 times as large as that of RD5, respectively. For sensitivity analysis, removal fraction by equipping PPE enlarge TLV for effortlessly obtaining an acceptable assessment result; exposure time was dominant when without PPE excepting the scenario of technicians exposed to E. coli bioaerosol. This study helps establish threshold guidelines for bioaerosols in WWTPs and contribute innovative perspectives for stakeholders.
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Affiliation(s)
- Beibei Cui
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, PR China; Hubei Key Laboratory of Environmental Water Science in the Yangtze River Basin, China University of Geosciences, Wuhan 430074, PR China
| | - Dongzi An
- China Construction Eco-Environmental Group Co., Ltd, Beijing 100037, PR China
| | - Haojun Li
- Yunnan Design Institute Group Co., Ltd, Kunming 650100, PR China
| | - Xi Luo
- Yangtze Ecology and Environment Co., Ltd, Wuhan 430062, PR China
| | - Hao Zhu
- POWERCHINA Hubei Electric Engineering Co., Ltd, Wuhan 430040, PR China
| | - Ming Li
- POWERCHINA Hubei Electric Engineering Co., Ltd, Wuhan 430040, PR China
| | - Xiaojun Ai
- POWERCHINA Hubei Electric Engineering Co., Ltd, Wuhan 430040, PR China
| | - Jiaxin Ma
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, PR China
| | - Wajid Ali
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, PR China
| | - Cheng Yan
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, PR China; Hubei Key Laboratory of Environmental Water Science in the Yangtze River Basin, China University of Geosciences, Wuhan 430074, PR China.
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6
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van der Wielen PWJJ, Dignum M, Donocik A, Prest EI. Influence of Temperature on Growth of Four Different Opportunistic Pathogens in Drinking Water Biofilms. Microorganisms 2023; 11:1574. [PMID: 37375076 DOI: 10.3390/microorganisms11061574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 06/08/2023] [Accepted: 06/10/2023] [Indexed: 06/29/2023] Open
Abstract
High drinking water temperatures occur due to climate change and could enhance the growth of opportunistic pathogens in drinking water systems. We investigated the influence of drinking water temperatures on the growth of Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Mycobacterium kansasii and Aspergillus fumigatus in drinking water biofilms with an autochthonous microflora. Our results reveal that the growth of P. aeruginosa and S. maltophilia in the biofilm already occurred at 15.0 °C, whereas M. kansasii and A. fumigatus were able to grow when temperatures were above 20.0 °C and 25.0 °C, respectively. Moreover, the maximum growth yield of P. aeruginosa, M. kansasii and A. fumigatus increased with increasing temperatures up to 30 °C, whereas an effect of temperature on the yield of S. maltophilia could not be established. In contrast, the maximum ATP concentration of the biofilm decreased with increasing temperatures. We conclude from these results that high drinking water temperatures caused by, e.g., climate change can result in high numbers of P. aeruginosa, M. kansasii and A. fumigatus in drinking water systems, which poses a possible risk to public health. Consequently, it is recommended for countries with a more moderate climate to use or maintain a drinking water maximum standard temperature of 25 °C.
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Affiliation(s)
- Paul W J J van der Wielen
- KWR Water Research Institute, 3433 PE Nieuwegein, The Netherlands
- Laboratory of Microbiology, Wageningen University & Research, 6708 WE Wageningen, The Netherlands
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7
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Denissen J, Reyneke B, Waso-Reyneke M, Havenga B, Barnard T, Khan S, Khan W. Prevalence of ESKAPE pathogens in the environment: Antibiotic resistance status, community-acquired infection and risk to human health. Int J Hyg Environ Health 2022; 244:114006. [PMID: 35841823 DOI: 10.1016/j.ijheh.2022.114006] [Citation(s) in RCA: 66] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/30/2022] [Accepted: 06/30/2022] [Indexed: 01/10/2023]
Abstract
The ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) pathogens are characterised by increased levels of resistance towards multiple classes of first line and last-resort antibiotics. Although these pathogens are frequently isolated from clinical environments and are implicated in a variety of life-threatening, hospital-associated infections; antibiotic resistant ESKAPE strains have been isolated from environmental reservoirs such as surface water, wastewater, food, and soil. Literature on the persistence and subsequent health risks posed by the ESKAPE isolates in extra-hospital settings is however, limited and the current review aims to elucidate the primary reservoirs of these pathogens in the environment, their antibiotic resistance profiles, and the link to community-acquired infections. Additionally, information on the current state of research regarding health-risk assessments linked to exposure of the ESKAPE pathogens in the natural environment, is outlined.
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Affiliation(s)
- Julia Denissen
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Brandon Reyneke
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Monique Waso-Reyneke
- Faculty of Health Sciences, University of Johannesburg, PO Box 17011, Doornfontein, 2028, South Africa
| | - Benjamin Havenga
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Tobias Barnard
- Water and Health Research Centre, University of Johannesburg, PO Box 17011, Doornfontein, 7305, South Africa
| | - Sehaam Khan
- Faculty of Health Sciences, University of Johannesburg, PO Box 17011, Doornfontein, 2028, South Africa
| | - Wesaal Khan
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa.
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8
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Proctor C, Garner E, Hamilton KA, Ashbolt NJ, Caverly LJ, Falkinham JO, Haas CN, Prevost M, Prevots DR, Pruden A, Raskin L, Stout J, Haig SJ. Tenets of a holistic approach to drinking water-associated pathogen research, management, and communication. WATER RESEARCH 2022; 211:117997. [PMID: 34999316 PMCID: PMC8821414 DOI: 10.1016/j.watres.2021.117997] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 12/13/2021] [Accepted: 12/19/2021] [Indexed: 05/10/2023]
Abstract
In recent years, drinking water-associated pathogens that can cause infections in immunocompromised or otherwise susceptible individuals (henceforth referred to as DWPI), sometimes referred to as opportunistic pathogens or opportunistic premise plumbing pathogens, have received considerable attention. DWPI research has largely been conducted by experts focusing on specific microorganisms or within silos of expertise. The resulting mitigation approaches optimized for a single microorganism may have unintended consequences and trade-offs for other DWPI or other interests (e.g., energy costs and conservation). For example, the ecological and epidemiological issues characteristic of Legionella pneumophila diverge from those relevant for Mycobacterium avium and other nontuberculous mycobacteria. Recent advances in understanding DWPI as part of a complex microbial ecosystem inhabiting drinking water systems continues to reveal additional challenges: namely, how can all microorganisms of concern be managed simultaneously? In order to protect public health, we must take a more holistic approach in all aspects of the field, including basic research, monitoring methods, risk-based mitigation techniques, and policy. A holistic approach will (i) target multiple microorganisms simultaneously, (ii) involve experts across several disciplines, and (iii) communicate results across disciplines and more broadly, proactively addressing source water-to-customer system management.
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Affiliation(s)
- Caitlin Proctor
- Department of Agricultural and Biological Engineering, Division of Environmental and Ecological Engineering, Purdue University, West Lafayette, IN, USA
| | - Emily Garner
- Wadsworth Department of Civil & Environmental Engineering, West Virginia University, Morgantown, WV, USA
| | - Kerry A Hamilton
- School of Sustainable Engineering and the Built Environment and The Biodesign Centre for Environmental Health Engineering, Arizona State University, Tempe, AZ, USA
| | - Nicholas J Ashbolt
- Faculty of Science and Engineering, Southern Cross University, Gold Coast. Queensland, Australia
| | - Lindsay J Caverly
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI, USA
| | | | - Charles N Haas
- Department of Civil, Architectural & Environmental Engineering, Drexel University, Philadelphia, PA, USA
| | - Michele Prevost
- Department of Civil, Geological and Mining Engineering, Polytechnique Montreal, Montreal, Quebec, Canada
| | - D Rebecca Prevots
- Epidemiology Unit, Laboratory of Clinical Immunology and Microbiology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Amy Pruden
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, VA USA
| | - Lutgarde Raskin
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Janet Stout
- Department of Civil & Environmental Engineering, University of Pittsburgh, and Special Pathogens Laboratory, Pittsburgh, PA, USA
| | - Sarah-Jane Haig
- Department of Civil & Environmental Engineering, and Department of Environmental & Occupational Health, University of Pittsburgh, Pittsburgh, PA, USA.
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9
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Practitioners’ Perspective on the Prevalent Water Quality Management Practices for Legionella Control in Large Buildings in the United States. WATER 2022. [DOI: 10.3390/w14040663] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Managing building water systems is complicated by the need to maintain hot water temperatures high enough to control the growth of Legionella spp. while minimizing the risk of scalding. This study assessed water quality management practices in large buildings in the United States. Surveys conducted with building water quality managers found that more than 85% of buildings have hot water temperatures that are consistent with scald risk mitigation guidelines (i.e., <122 °F/50 °C). However, nearly two thirds and three quarters of buildings do not comply with the common temperature guidance for opportunistic pathogen control, i.e., water heater setpoint > 140 °F (60 °C) and recirculation loop > 122 °F (50 °C), respectively; median values for both setpoint and recirculation loop temperatures are 10 °F (6 °C) or more below temperatures recommended for opportunistic pathogen control. These observations suggest that many buildings are prone to Legionella spp. risk. The study also found that 27% of buildings do not comply with guidelines for time to equilibrium hot water temperature, over 33% fail to monitor temperature in the recirculation loop, more than 70% fail to replace or disinfect showerheads, more than 40% lack a written management plan, and only a minority conduct any monitoring of residual disinfectant levels or microbiological quality. Given the rise in Legionellosis infections in recent years, coupled with highlighted water quality concerns because of prolonged water stagnation in plumbing, such as in buildings closed due to COVID-19, current management practices, which appear to be focused on scald risk, may need to be broadened to include greater attention to control of opportunistic pathogens. To accomplish this, there is a need for formal training and resources for facility managers.
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10
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Are carbon water filters safe for private wells? Evaluating the occurrence of microbial indicator organisms in private well water treated by point-of-use activated carbon block filters. Int J Hyg Environ Health 2021; 238:113852. [PMID: 34627100 DOI: 10.1016/j.ijheh.2021.113852] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 09/09/2021] [Accepted: 09/28/2021] [Indexed: 11/21/2022]
Abstract
Point-of-use (POU) water treatment is highly relevant to private well users vulnerable to chemical contamination, but uncertainty remains around the effects of activated carbon based POU devices on the microbial quality of the treated water. In this study, under-sink activated carbon block water filters were installed in 17 homes relying on private well water in North Carolina. The influent and effluent water in each home was evaluated for bacterial and viral microbial indicator organisms monthly for five months. Multiple logistic regression was used to identify water quality and water usage variables that were significant predictors of each indicator organism occurring in the filter effluent. The odds of total coliforms occurring in the effluent decreased by 84% with each 1-log10 increase in the influent HPC (p < 0.05), suggesting a protective effect by native heterotrophic bacteria, but increased by over 50 times with low cumulative water use (p < 0.05). The filters were not protective against coliphages in the influent and viral shedding may occur after periods of increased virus concentrations in the raw well water. Specific bacteria were also found to increase in the effluent, causing a shift in the bacterial community composition, although potential opportunistic pathogens were detected in both the influent and the effluent. Overall, under normal conditions of use, the filters tested in this study did not represent a significant additional risk for well users beyond the existing exposures from undisinfected well water alone.
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11
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Reyneke B, Hamilton KA, Fernández-Ibáñez P, Polo-López MI, McGuigan KG, Khan S, Khan W. EMA-amplicon-based sequencing informs risk assessment analysis of water treatment systems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 743:140717. [PMID: 32679496 DOI: 10.1016/j.scitotenv.2020.140717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 06/29/2020] [Accepted: 07/01/2020] [Indexed: 06/11/2023]
Abstract
Illumina amplicon-based sequencing was coupled with ethidium monoazide bromide (EMA) pre-treatment to monitor the total viable bacterial community and subsequently identify and prioritise the target organisms for the health risk assessment of the untreated rainwater and rainwater treated using large-volume batch solar reactor prototypes installed in an informal settlement and rural farming community. Taxonomic assignments indicated that Legionella and Pseudomonas were the most frequently detected genera containing opportunistic bacterial pathogens in the untreated and treated rainwater at both sites. Additionally, Mycobacterium, Clostridium sensu stricto and Escherichia/Shigella displayed high (≥80%) detection frequencies in the untreated and/or treated rainwater samples at one or both sites. Numerous exposure scenarios (e.g. drinking, cleaning) were subsequently investigated and the health risk of using untreated and solar reactor treated rainwater in developing countries was quantified based on the presence of L. pneumophila, P. aeruginosa and E. coli. The solar reactor prototypes were able to reduce the health risk associated with E. coli and P. aeruginosa to below the 1 × 10-4 annual benchmark limit for all the non-potable uses of rainwater within the target communities (exception of showering for E. coli). However, the risk associated with intentional drinking of untreated or treated rainwater exceeded the benchmark limit (E. coli and P. aeruginosa). Additionally, while the solar reactor treatment reduced the risk associated with garden hosing and showering based on the presence of L. pneumophila, the risk estimates for both activities still exceeded the annual benchmark limit. The large-volume batch solar reactor prototypes were thus able to reduce the risk posed by the target bacteria for non-potable activities rainwater is commonly used for in water scarce regions of sub-Saharan Africa. This study highlights the need to assess water treatment systems in field trials using QMRA.
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Affiliation(s)
- B Reyneke
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch 7602, South Africa
| | - K A Hamilton
- School for Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85281, United States; The Biodesign Institute Center for Environmental Health Engineering, Arizona State University, Tempe, AZ 85281, United States
| | - P Fernández-Ibáñez
- Plataforma Solar de Almeria-CIEMAT, P.O. Box 22, Tabernas, Almería, Spain; Nanotechnology and Integrated BioEngineering Centre, School of Engineering, University of Ulster, Newtownabbey, Northern Ireland, United Kingdom
| | - M I Polo-López
- Plataforma Solar de Almeria-CIEMAT, P.O. Box 22, Tabernas, Almería, Spain
| | - K G McGuigan
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - S Khan
- Faculty of Health Sciences, University of Johannesburg, PO Box 17011, Doornfontein 2028, South Africa
| | - W Khan
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch 7602, South Africa.
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12
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Julien R, Dreelin E, Whelton AJ, Lee J, Aw TG, Dean K, Mitchell J. Knowledge gaps and risks associated with premise plumbing drinking water quality. ACTA ACUST UNITED AC 2020. [DOI: 10.1002/aws2.1177] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Ryan Julien
- Department of Biosystems and Agricultural EngineeringMichigan State University East Lansing Michigan
| | - Erin Dreelin
- Department of Fisheries and WildlifeMichigan State University East Lansing Michigan
| | - Andrew J. Whelton
- Lyles School of Civil Engineering and Environmental and Ecological EngineeringPurdue University West Lafayette Indiana
| | - Juneseok Lee
- Department of Civil and Environmental EngineeringManhattan College Riverdale New York
| | - Tiong Gim Aw
- Department of Environmental Health Sciences, School of Public Health and Tropical MedicineTulane University New Orleans Louisiana
| | - Kara Dean
- Department of Biosystems and Agricultural EngineeringMichigan State University East Lansing Michigan
| | - Jade Mitchell
- Department of Biosystems and Agricultural EngineeringMichigan State University East Lansing Michigan
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13
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Ahmed J, Wong LP, Chua YP, Channa N, Mahar RB, Yasmin A, VanDerslice JA, Garn JV. Quantitative Microbial Risk Assessment of Drinking Water Quality to Predict the Risk of Waterborne Diseases in Primary-School Children. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17082774. [PMID: 32316585 PMCID: PMC7215448 DOI: 10.3390/ijerph17082774] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/11/2020] [Accepted: 04/13/2020] [Indexed: 01/13/2023]
Abstract
Primary-school children in low- and middle-income countries are often deprived of microbiologically safe water and sanitation, often resulting in a high prevalence of gastrointestinal diseases and poor school performance. We used Quantitative Microbial Risk Assessment (QMRA) to predict the probability of infection in schoolchildren due to consumption of unsafe school water. A multistage random-sampling technique was used to randomly select 425 primary schools from ten districts of Sindh, Pakistan, to produce a representative sample of the province. We characterized water supplies in selected schools. Microbiological testing of water resulted in inputs for the QMRA model, to estimate the risks of infections to schoolchildren. Groundwater (62%) and surface water (38%) were identified as two major sources of drinking water in the selected schools, presenting varying degrees of health risks. Around half of the drinking-water samples were contaminated with Escherichia coli (49%), Shigella spp. (63%), Salmonella spp. (53%), and Vibrio cholerae (49%). Southern Sindh was found to have the highest risk of infection and illness from Campylobacter and Rotavirus. Central and Northern Sindh had a comparatively lower risk of waterborne diseases. Schoolchildren of Karachi were estimated to have the highest probability of illness per year, due to Campylobacter (70%) and Rotavirus (22.6%). Pearson correlation was run to assess the relationship between selected pathogens. V. cholerae was correlated with Salmonella spp., Campylobacter, Rotavirus, and Salmonella spp. Overall, the risk of illness due to the bacterial infection (E. coli, Salmonella spp., V. cholerae, Shigella, and Campylobacter) was high. There is a dire need for management plans in the schools of Sindh, to halt the progression of waterborne diseases in school-going children.
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Affiliation(s)
- Jamil Ahmed
- Centre for Epidemiology and Evidence-Based Practice, Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
- US- Pakistan Center for Advanced Studies in Water, Mehran University of Engineering & Technology, Jamhsoro 76062, Pakistan; (N.C.); (R.B.M.)
- Correspondence: (J.A.); (L.P.W.)
| | - Li Ping Wong
- Centre for Epidemiology and Evidence-Based Practice, Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
- Correspondence: (J.A.); (L.P.W.)
| | - Yan Piaw Chua
- Institute of Educational Leadership, Level 11, Wisma R & D, UM, University of Malaya, Jalan Pantai Baru, Kuala Lumpur 59000, Malaysia;
| | - Najeebullah Channa
- US- Pakistan Center for Advanced Studies in Water, Mehran University of Engineering & Technology, Jamhsoro 76062, Pakistan; (N.C.); (R.B.M.)
| | - Rasool Bux Mahar
- US- Pakistan Center for Advanced Studies in Water, Mehran University of Engineering & Technology, Jamhsoro 76062, Pakistan; (N.C.); (R.B.M.)
| | - Aneela Yasmin
- Department of Biotechnology, Sindh Agriculture University, Tandojam 70060, Sindh, Pakistan;
| | - James A. VanDerslice
- Department of Family and Preventive Medicine, University of Utah, Salt Lake City, UT 84112, USA;
| | - Joshua V. Garn
- School of Community Health Sciences, University of Nevada, Reno, NV 89557, USA;
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Reverse QMRA as a Decision Support Tool: Setting Acceptable Concentration Limits for Pseudomonas aeruginosa and Naegleria fowleri. WATER 2019. [DOI: 10.3390/w11091850] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Opportunistic premise plumbing pathogens such as Pseudomonas aeruginosa and Naegleria fowleri are a growing concern in building water systems because of their potential risks to human health. The aim of this study was to determine the critical concentrations of P. aeruginosa and N. fowleri in water that are associated with meaningful public health risks. To determine these concentrations, a reverse quantitative microbial risk assessment (QMRA) was conducted. Environmental concentrations of P. aeruginosa and N. fowleri corresponding to the risk target of one micro-disability-adjusted life year (DALY) per person per year and 10−4 annual risks of illness were calculated for several applicable exposure scenarios. To calculate the concentration of P. aeruginosa, cleaning contact lenses with potentially contaminated tap water in the absence of an appropriate cleaning solution was considered. For N. fowleri, two exposure scenarios, recreational exposure (swimming) and nasal cleansing (via the use of a neti pot™ or similar device) were considered. The highest critical concentration for P. aeruginosa was found to be 33 CFU/L with a 95% confidence interval of (2.0, 118) for the drop exposure scenario using the 10−4 annual risk target. For N. fowleri, based on the DALY approach, critical concentrations were 0.000030 N. fowleri/L for swimming and 0.00000060 N. fowleri/L for neti pot™ use scenario. Considering heat inactivation, the critical concentration limits for P. aeruginosa using the DALY approach and the 10−4 annual risk target approach were found to be 0.55 CFU/L and 55 CFU/L, respectively. For N. fowleri, the 10−4 annual risk target approach resulted in 0.022 N. fowleri/L and the DALY approach resulted in 0.00000064 N. fowleri/L for the neti pot™ scenario. For P. aeruginosa, N50 (the median infective dose) and alpha (α) contributed the most and contact rates the least to the variability and uncertainty of the estimates for all the scenarios. For N. fowleri, N50 and contact rates contributed the most and α the least to the variability and uncertainty to calculate the concentrations for all the scenarios. The QMRA framework implemented in this research can be used to incorporate more information regarding opportunistic pathogens to inform management decisions, and to prioritize the best interventions regarding estimated reduction in infections caused by opportunistic pathogens.
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