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García-Gil Á, Abeledo-Lameiro MJ, Gómez-Couso H, Marugán J. Kinetic modeling of the synergistic thermal and spectral actions on the inactivation of Cryptosporidium parvum in water by sunlight. WATER RESEARCH 2020; 185:116226. [PMID: 32738603 DOI: 10.1016/j.watres.2020.116226] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/20/2020] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
Water contamination with the enteroprotozoan parasite Cryptosporidium is a current challenge worldwide. Solar water disinfection (SODIS) has been proved as a potential alternative for its inactivation, especially at household level in low-income environments. This work presents the first comprehensive kinetic model for the inactivation of Cryptosporidium parvum oocysts by sunlight that, based on the mechanism of the process, is able to describe not only the individual thermal and spectral actions but also their synergy. Model predictions are capable of estimating the required solar exposure to achieve the desired level of disinfection under variable solar spectral irradiance and environmental temperature conditions for different locations worldwide. The thermal contribution can be successfully described by a modified Arrhenius equation while photoinactivation is based on a series-event mechanistic model. The wavelength-dependent spectral effect is modeled by means of the estimation of the C. parvum extinction coefficients and the determination of the quantum yield of the inactivation process. Model predictions show a 3.7% error with respect to experimental results carried out under a wide range of temperature (30 to 45 °C) and UV irradiance (0 to 50 W·m-2). Furthermore, the model was validated in three scenarios in which the spectral distribution radiation was modified using different plastic materials common in SODIS devices, ensuring accurate forecasting of inactivation rates for real conditions.
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Affiliation(s)
- Ángela García-Gil
- Department of Chemical and Environmental Technology (ESCET), Universidad Rey Juan Carlos, C / Tulipán s/n, 28933 Móstoles, Madrid, Spain
| | - María Jesús Abeledo-Lameiro
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, Campus Vida, 15782 Santiago de Compostela, A Coruña, Spain; Research Institute on Chemical and Biological Analysis, University of Santiago de Compostela, 15782 Santiago de Compostela, A Coruña, Spain
| | - Hipólito Gómez-Couso
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, Campus Vida, 15782 Santiago de Compostela, A Coruña, Spain; Research Institute on Chemical and Biological Analysis, University of Santiago de Compostela, 15782 Santiago de Compostela, A Coruña, Spain
| | - Javier Marugán
- Department of Chemical and Environmental Technology (ESCET), Universidad Rey Juan Carlos, C / Tulipán s/n, 28933 Móstoles, Madrid, Spain.
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Polo-López MI, Martínez-García A, Abeledo-Lameiro MJ, H Gómez-Couso H, E Ares-Mazás E, Reboredo-Fernández A, Morse TD, Buck L, Lungu K, McGuigan KG, Fernández-Ibáñez P. Microbiological Evaluation of 5 L- and 20 L-Transparent Polypropylene Buckets for Solar Water Disinfection (SODIS). Molecules 2019; 24:molecules24112193. [PMID: 31212699 PMCID: PMC6600371 DOI: 10.3390/molecules24112193] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 06/04/2019] [Accepted: 06/07/2019] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Solar water disinfection (SODIS) is an appropriate technology for household treatment of drinking water in low-to-middle-income communities, as it is effective, low cost and easy to use. Nevertheless, uptake is low due partially to the burden of using small volume polyethylene terephthalate bottles (1.5-2 L). A major challenge is to develop a low-cost transparent container for disinfecting larger volumes of water. (2) Methods: This study examines the capability of transparent polypropylene (PP) buckets of 5 L- and 20 L- volume as SODIS containers using three waterborne pathogen indicators: Escherichia coli, MS2-phage and Cryptosporidium parvum. (3) Results: Similar inactivation kinetics were observed under natural sunlight for the inactivation of all three organisms in well water using 5 L- and 20 L-buckets compared to 1.5 L-polyethylene-terephthalate (PET) bottles. The PP materials were exposed to natural and accelerated solar ageing (ISO-16474). UV transmission of the 20 L-buckets remained stable and with physical integrity even after the longest ageing periods (9 months or 900 h of natural or artificial solar UV exposure, respectively). The 5 L-buckets were physically degraded and lost significant UV-transmission, due to the thinner wall compared to the 20 L-bucket. (4) Conclusion: This work demonstrates that the 20 L SODIS bucket technology produces excellent bacterial, viral and protozoan inactivation and is obtained using a simple transparent polypropylene bucket fabricated locally at very low cost ($2.90 USD per unit). The increased bucket volume of 20 L allows for a ten-fold increase in treatment batch volume and can thus more easily provide for the drinking water requirements of most households. The use of buckets in households across low to middle income countries is an already accepted practice.
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Affiliation(s)
| | | | - Maria Jesus Abeledo-Lameiro
- Laboratory of Parasitology, Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
| | - Hipolito H Gómez-Couso
- Laboratory of Parasitology, Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
- Institute of Food Research and Analysis, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
| | - Elvira E Ares-Mazás
- Laboratory of Parasitology, Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
| | - Aurora Reboredo-Fernández
- Laboratory of Parasitology, Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
| | - Tracy D Morse
- Department of Civil and Environmental Engineering, University of Strathclyde, Glasgow G1 1XQ, UK.
| | - Lyndon Buck
- School of Art, Design and Performance, Buckinghamshire New University, High Wycombe HP11 2JZ, UK.
| | - Kingsley Lungu
- Department of Environmental Health, University of Malawi, Malawi.
| | - Kevin G McGuigan
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland (RCSI), DO2 YN77 Dublin, Ireland.
| | - Pilar Fernández-Ibáñez
- NIBEC, School of Engineering, Ulster University, Newtownabbey BT37 0QB, Northern Ireland, UK.
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Nelson KL, Boehm AB, Davies-Colley RJ, Dodd MC, Kohn T, Linden KG, Liu Y, Maraccini PA, McNeill K, Mitch WA, Nguyen TH, Parker KM, Rodriguez RA, Sassoubre LM, Silverman AI, Wigginton KR, Zepp RG. Sunlight-mediated inactivation of health-relevant microorganisms in water: a review of mechanisms and modeling approaches. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2018; 20:1089-1122. [PMID: 30047962 PMCID: PMC7064263 DOI: 10.1039/c8em00047f] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Health-relevant microorganisms present in natural surface waters and engineered treatment systems that are exposed to sunlight can be inactivated by a complex set of interacting mechanisms. The net impact of sunlight depends on the solar spectral irradiance, the susceptibility of the specific microorganism to each mechanism, and the water quality; inactivation rates can vary by orders of magnitude depending on the organism and environmental conditions. Natural organic matter (NOM) has a large influence, as it can attenuate radiation and thus decrease inactivation by endogenous mechanisms. Simultaneously NOM sensitizes the formation of reactive intermediates that can damage microorganisms via exogenous mechanisms. To accurately predict inactivation and design engineered systems that enhance solar inactivation, it is necessary to model these processes, although some details are not yet sufficiently well understood. In this critical review, we summarize the photo-physics, -chemistry, and -biology that underpin sunlight-mediated inactivation, as well as the targets of damage and cellular responses to sunlight exposure. Viruses that are not susceptible to exogenous inactivation are only inactivated if UVB wavelengths (280-320 nm) are present, such as in very clear, open waters or in containers that are transparent to UVB. Bacteria are susceptible to slightly longer wavelengths. Some viruses and bacteria (especially Gram-positive) are susceptible to exogenous inactivation, which can be initiated by visible as well as UV wavelengths. We review approaches to model sunlight-mediated inactivation and illustrate how the environmental conditions can dramatically shift the inactivation rate of organisms. The implications of this mechanistic understanding of solar inactivation are discussed for a range of applications, including recreational water quality, natural treatment systems, solar disinfection of drinking water (SODIS), and enhanced inactivation via the use of sensitizers and photocatalysts. Finally, priorities for future research are identified that will further our understanding of the key role that sunlight disinfection plays in natural systems and the potential to enhance this process in engineered systems.
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Affiliation(s)
- Kara L Nelson
- Civil and Environmental Engineering, University of California, Berkeley, CA, USA.
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Climate change-induced increases in precipitation are reducing the potential for solar ultraviolet radiation to inactivate pathogens in surface waters. Sci Rep 2017; 7:13033. [PMID: 29026153 PMCID: PMC5638896 DOI: 10.1038/s41598-017-13392-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 09/22/2017] [Indexed: 11/09/2022] Open
Abstract
Climate change is accelerating the release of dissolved organic matter (DOM) to inland and coastal waters through increases in precipitation, thawing of permafrost, and changes in vegetation. Our modeling approach suggests that the selective absorption of ultraviolet radiation (UV) by DOM decreases the valuable ecosystem service wherein sunlight inactivates waterborne pathogens. Here we highlight the sensitivity of waterborne pathogens of humans and wildlife to solar UV, and use the DNA action spectrum to model how differences in water transparency and incident sunlight alter the ability of UV to inactivate waterborne pathogens. A case study demonstrates how heavy precipitation events can reduce the solar inactivation potential in Lake Michigan, which provides drinking water to over 10 million people. These data suggest that widespread increases in DOM and consequent browning of surface waters reduce the potential for solar UV inactivation of pathogens, and increase exposure to infectious diseases in humans and wildlife.
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Montecino-Latorre D, Li X, Xiao C, Atwill ER. Elevation and vegetation determine Cryptosporidium oocyst shedding by yellow-bellied marmots (Marmota flaviventris) in the Sierra Nevada Mountains. INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2015; 4:171-7. [PMID: 25834788 PMCID: PMC4365143 DOI: 10.1016/j.ijppaw.2015.02.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 02/12/2015] [Accepted: 02/21/2015] [Indexed: 11/25/2022]
Abstract
Yellow-bellied marmots of Sierra Nevada Mountain shed Cryptosporidium oocysts. Oocysts loads are low compared to other mammals in California. Shedding of oocysts is associated with altitude and vegetation type. Cryptosporidium oocysts were 99.9%–100% match to Cryptosporidium parvum.
Wildlife are increasingly recognized as important biological reservoirs of zoonotic species of Cryptosporidium that might contaminate water and cause human exposure to this protozoal parasite. The habitat range of the yellow-bellied marmot (Marmota flaviventris) overlaps extensively with the watershed boundaries of municipal water supplies for California communities along the foothills of the Sierra Nevada. We conducted a cross-sectional epidemiological study to estimate the fecal shedding of Cryptosporidium oocysts by yellow-bellied marmots and to quantify the environmental loading rate and determine risk factors for Cryptosporidium fecal shedding in this montane wildlife species. The observed proportion of Cryptosporidium positive fecal samples was 14.7% (33/224, positive number relative to total number samples) and the environmental loading rate was estimated to be 10,693 oocysts animal-1 day-1. Fecal shedding was associated with the elevation and vegetation status of their habitat. Based on a portion of the 18s rRNA gene sequence of 2 isolates, the Cryptosporidium found in Marmota flaviventris were 99.88%–100% match to multiple isolates of C. parvum in the GenBank.
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Affiliation(s)
- Diego Montecino-Latorre
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA ; Current address: Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA
| | - Xunde Li
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA ; Western Institute for Food Safety and Security, University of California, Davis, CA, 95616, USA
| | - Chengling Xiao
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA
| | - Edward R Atwill
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA ; Western Institute for Food Safety and Security, University of California, Davis, CA, 95616, USA
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Dissection of the hierarchy and synergism of the bile derived signal on Cryptosporidium parvum excystation and infectivity. Parasitology 2012; 139:1533-46. [DOI: 10.1017/s0031182012000984] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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