Pub Date : 2024-02-08DOI: 10.1371/journal.pwat.0000181
Helen Y. Buse, Jatin H. Mistry
A strategy for nitrification control within chloraminated drinking water systems (CDWSs) is to temporarily switch from chloramine secondary disinfection to free chlorine, also known as a free chlorine conversion (FCC). However, the long-term and beneficial effects of FCCs are unclear, especially regarding opportunistic pathogen occurrence. In this study, the impacts to microbial and physicochemical parameters were monitored throughout a CDWS implementing a FCC. Water samples were collected weekly for 4–6 weeks before, during, and after a FCC at eight locations: four distribution system and four residential sites. Monochloramine residual (mean±standard deviation) before and after the FCC averaged 1.8±0.9 and 1.6±1.0 parts per million (ppm) for all sites, respectively. Free chlorine levels averaged 2.3±0.9 ppm. There were no significant differences in turbidity and hardness at each location during the three time periods, but some were noted for pH, temperature, and orthophosphate levels across various sites and sampling periods. For all locations, heterotrophic plate count levels were lower during the FCC compared to the periods before and after. All samples from one residence were culture positive for P. aeruginosa which exhibited high levels before the FCC, decreasing levels during, and steadily increasing levels after. Additionally, one week prior to the FCC, sediment samples from two elevated storage tanks, ET-1 and ET-2, were analyzed with ET-1 displaying higher levels of culturable heterotrophic bacteria and molecularly detected total bacteria, Legionella spp., and nontuberculous mycobacteria (NTM), as well as presence of culturable P. aeruginosa and total coliforms compared to ET-2. Fourteen P. aeruginosa and total coliform isolates were whole genome sequenced with genetic differences observed depending on the sampling location and timepoint. Collectively, the observed differences in chemical and microbial parameters advocates for a better understanding of the effects associated with implementing FCCs to determine both their effectiveness and potential risks/rewards to water quality.
{"title":"Microbial and physicochemical water quality changes within distribution and premise plumbing systems during a chlorine conversion","authors":"Helen Y. Buse, Jatin H. Mistry","doi":"10.1371/journal.pwat.0000181","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000181","url":null,"abstract":"A strategy for nitrification control within chloraminated drinking water systems (CDWSs) is to temporarily switch from chloramine secondary disinfection to free chlorine, also known as a free chlorine conversion (FCC). However, the long-term and beneficial effects of FCCs are unclear, especially regarding opportunistic pathogen occurrence. In this study, the impacts to microbial and physicochemical parameters were monitored throughout a CDWS implementing a FCC. Water samples were collected weekly for 4–6 weeks before, during, and after a FCC at eight locations: four distribution system and four residential sites. Monochloramine residual (mean±standard deviation) before and after the FCC averaged 1.8±0.9 and 1.6±1.0 parts per million (ppm) for all sites, respectively. Free chlorine levels averaged 2.3±0.9 ppm. There were no significant differences in turbidity and hardness at each location during the three time periods, but some were noted for pH, temperature, and orthophosphate levels across various sites and sampling periods. For all locations, heterotrophic plate count levels were lower during the FCC compared to the periods before and after. All samples from one residence were culture positive for P. aeruginosa which exhibited high levels before the FCC, decreasing levels during, and steadily increasing levels after. Additionally, one week prior to the FCC, sediment samples from two elevated storage tanks, ET-1 and ET-2, were analyzed with ET-1 displaying higher levels of culturable heterotrophic bacteria and molecularly detected total bacteria, Legionella spp., and nontuberculous mycobacteria (NTM), as well as presence of culturable P. aeruginosa and total coliforms compared to ET-2. Fourteen P. aeruginosa and total coliform isolates were whole genome sequenced with genetic differences observed depending on the sampling location and timepoint. Collectively, the observed differences in chemical and microbial parameters advocates for a better understanding of the effects associated with implementing FCCs to determine both their effectiveness and potential risks/rewards to water quality.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"85 2-3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139851329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-08DOI: 10.1371/journal.pwat.0000181
Helen Y. Buse, Jatin H. Mistry
A strategy for nitrification control within chloraminated drinking water systems (CDWSs) is to temporarily switch from chloramine secondary disinfection to free chlorine, also known as a free chlorine conversion (FCC). However, the long-term and beneficial effects of FCCs are unclear, especially regarding opportunistic pathogen occurrence. In this study, the impacts to microbial and physicochemical parameters were monitored throughout a CDWS implementing a FCC. Water samples were collected weekly for 4–6 weeks before, during, and after a FCC at eight locations: four distribution system and four residential sites. Monochloramine residual (mean±standard deviation) before and after the FCC averaged 1.8±0.9 and 1.6±1.0 parts per million (ppm) for all sites, respectively. Free chlorine levels averaged 2.3±0.9 ppm. There were no significant differences in turbidity and hardness at each location during the three time periods, but some were noted for pH, temperature, and orthophosphate levels across various sites and sampling periods. For all locations, heterotrophic plate count levels were lower during the FCC compared to the periods before and after. All samples from one residence were culture positive for P. aeruginosa which exhibited high levels before the FCC, decreasing levels during, and steadily increasing levels after. Additionally, one week prior to the FCC, sediment samples from two elevated storage tanks, ET-1 and ET-2, were analyzed with ET-1 displaying higher levels of culturable heterotrophic bacteria and molecularly detected total bacteria, Legionella spp., and nontuberculous mycobacteria (NTM), as well as presence of culturable P. aeruginosa and total coliforms compared to ET-2. Fourteen P. aeruginosa and total coliform isolates were whole genome sequenced with genetic differences observed depending on the sampling location and timepoint. Collectively, the observed differences in chemical and microbial parameters advocates for a better understanding of the effects associated with implementing FCCs to determine both their effectiveness and potential risks/rewards to water quality.
{"title":"Microbial and physicochemical water quality changes within distribution and premise plumbing systems during a chlorine conversion","authors":"Helen Y. Buse, Jatin H. Mistry","doi":"10.1371/journal.pwat.0000181","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000181","url":null,"abstract":"A strategy for nitrification control within chloraminated drinking water systems (CDWSs) is to temporarily switch from chloramine secondary disinfection to free chlorine, also known as a free chlorine conversion (FCC). However, the long-term and beneficial effects of FCCs are unclear, especially regarding opportunistic pathogen occurrence. In this study, the impacts to microbial and physicochemical parameters were monitored throughout a CDWS implementing a FCC. Water samples were collected weekly for 4–6 weeks before, during, and after a FCC at eight locations: four distribution system and four residential sites. Monochloramine residual (mean±standard deviation) before and after the FCC averaged 1.8±0.9 and 1.6±1.0 parts per million (ppm) for all sites, respectively. Free chlorine levels averaged 2.3±0.9 ppm. There were no significant differences in turbidity and hardness at each location during the three time periods, but some were noted for pH, temperature, and orthophosphate levels across various sites and sampling periods. For all locations, heterotrophic plate count levels were lower during the FCC compared to the periods before and after. All samples from one residence were culture positive for P. aeruginosa which exhibited high levels before the FCC, decreasing levels during, and steadily increasing levels after. Additionally, one week prior to the FCC, sediment samples from two elevated storage tanks, ET-1 and ET-2, were analyzed with ET-1 displaying higher levels of culturable heterotrophic bacteria and molecularly detected total bacteria, Legionella spp., and nontuberculous mycobacteria (NTM), as well as presence of culturable P. aeruginosa and total coliforms compared to ET-2. Fourteen P. aeruginosa and total coliform isolates were whole genome sequenced with genetic differences observed depending on the sampling location and timepoint. Collectively, the observed differences in chemical and microbial parameters advocates for a better understanding of the effects associated with implementing FCCs to determine both their effectiveness and potential risks/rewards to water quality.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":" 35","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139791234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-05DOI: 10.1371/journal.pwat.0000125
Fabian Mendez, Laura E. Piedrahita-Gómez, Andrés Fernando Toro, Juliana Salazar-Benitez, Helmer Zapata, Miguel Peña
Modernization is marked by an increase in pollution-related health risks due to the rapid economic and technological growth. In the Global South, there is concern regarding the disease burden attributable to chemical contaminants released into the environment, especially in river basins, where populations are exposed through multiple pathways. While significant research exists linking chemical exposure to disease, mostly in occupational settings, less data is available for the open environment. Emerging pollutants have shown ecotoxicological and genotoxic effects at low concentrations in both terrestrial and aquatic ecosystems, with humans at the apex. Despite such evidence, water quality standards focus primarily on communicable diseases risks, and the burden of disease method mainly includes gastrointestinal and respiratory infections. Therefore, the use of DALYs as a prioritization strategy needs to be evaluated to suggest alternatives for integrated analysis. Our aim was to enhance the comprehension of watersheds as socioecological entities that necessitate inclusive indicators to display the intricate and diverse links between water, health, and the resultant inequities. Based on previous research and information collected in a tropical Andean watershed at southwestern Colombia, we characterized drivers of pollution and health hazards. Using standardized methods for calculating DALYs, we estimated the water-related environmental burden of communicable and noncommunicable diseases. Estimates of disease burden were analyzed to find out disparities driven by ethnic, gender and socioeconomic status. Results indicate that significant inequalities persist affecting the most vulnerable populations for preventable communicable diseases. Furthermore, the impact of noncommunicable diseases, which are linked to chemical pollution from individual substances and their cocktail effect, remains largely invisible due to insufficient data and research. The econometric approach of the DALY addition effect needs to be expanded with historical and critical perspectives to expose the profound social and health inequities present in the socioecological systems of the Global South.
{"title":"The invisibility of health effects associated with water pollution within disease burden estimates: Analysis from a Colombian Andean watershed","authors":"Fabian Mendez, Laura E. Piedrahita-Gómez, Andrés Fernando Toro, Juliana Salazar-Benitez, Helmer Zapata, Miguel Peña","doi":"10.1371/journal.pwat.0000125","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000125","url":null,"abstract":"Modernization is marked by an increase in pollution-related health risks due to the rapid economic and technological growth. In the Global South, there is concern regarding the disease burden attributable to chemical contaminants released into the environment, especially in river basins, where populations are exposed through multiple pathways. While significant research exists linking chemical exposure to disease, mostly in occupational settings, less data is available for the open environment. Emerging pollutants have shown ecotoxicological and genotoxic effects at low concentrations in both terrestrial and aquatic ecosystems, with humans at the apex. Despite such evidence, water quality standards focus primarily on communicable diseases risks, and the burden of disease method mainly includes gastrointestinal and respiratory infections. Therefore, the use of DALYs as a prioritization strategy needs to be evaluated to suggest alternatives for integrated analysis. Our aim was to enhance the comprehension of watersheds as socioecological entities that necessitate inclusive indicators to display the intricate and diverse links between water, health, and the resultant inequities. Based on previous research and information collected in a tropical Andean watershed at southwestern Colombia, we characterized drivers of pollution and health hazards. Using standardized methods for calculating DALYs, we estimated the water-related environmental burden of communicable and noncommunicable diseases. Estimates of disease burden were analyzed to find out disparities driven by ethnic, gender and socioeconomic status. Results indicate that significant inequalities persist affecting the most vulnerable populations for preventable communicable diseases. Furthermore, the impact of noncommunicable diseases, which are linked to chemical pollution from individual substances and their cocktail effect, remains largely invisible due to insufficient data and research. The econometric approach of the DALY addition effect needs to be expanded with historical and critical perspectives to expose the profound social and health inequities present in the socioecological systems of the Global South.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"18 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139804988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-05DOI: 10.1371/journal.pwat.0000127
Mair L. H. Thomas-Possee, Andrew A. Channon, Robert E. S. Bain, James A. Wright
Given nearly one third of sub-Saharan Africa’s population lack access to an improved water source that is available when needed, service continuity restricts access to safely managed services. Household surveys, water regulators, and utilities all gather data on service continuity, but few studies have integrated these disparate datasets to quantify continuity-related risk factors and inequalities. This study aimed to assess the added value of utility and regulator data for international monitoring by assessing factors affecting piped water availability in urban and peri-urban Zambia. Household ‘user’ data from the 2018 Demographic and Health Survey (n = 3047) were spatially linked to provider data from an international utility database and regulator reports. Multilevel modelling quantified provider-related and socio-economic risk factors for households reporting water being unavailable for at least one day in the previous fortnight. 47% (95% CI: 45%, 49%) of urban and peri-urban households reported water being unavailable for at least one full day, ranging from 18% (95% CI: 14%, 23%) to 76% (95% CI: 70%, 81%) across providers. Controlling for provider, home ownership (odds ratio (OR) = 1.31; p <0.01), speaking Luvale, Kaonde, Lunda (OR = 2.06; p <0.05) or Tonga (OR = 1.78; p <0.1) as an ethnicity proxy, and dry season interview dates (OR = 1.91; p <0.05) were associated with household-reported interruptions. Households using a neighbour’s tap (OR = 1.33; p <0.1) and in mid-wealth neighbourhoods (OR = 4.31; p <0.1) were more likely to report interruptions. For every $1000 increase in utility-level GDP per capita, the odds of an interruption were 0.51 times less (p<0.01). Substantial inequalities in drinking-water availability were found between provider coverage areas. Spatial integration of user, provider and regulator data enriches analysis, providing a finer-scale perspective than otherwise possible. However, wider use of utility or regulator data requires investment in monitoring of small-scale community supply intermittency and utility coverage area data.
{"title":"Household, neighbourhood and service provider risk factors for piped drinking-water intermittency in urban and peri-urban Zambia: A cross-sectional analysis","authors":"Mair L. H. Thomas-Possee, Andrew A. Channon, Robert E. S. Bain, James A. Wright","doi":"10.1371/journal.pwat.0000127","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000127","url":null,"abstract":"Given nearly one third of sub-Saharan Africa’s population lack access to an improved water source that is available when needed, service continuity restricts access to safely managed services. Household surveys, water regulators, and utilities all gather data on service continuity, but few studies have integrated these disparate datasets to quantify continuity-related risk factors and inequalities. This study aimed to assess the added value of utility and regulator data for international monitoring by assessing factors affecting piped water availability in urban and peri-urban Zambia. Household ‘user’ data from the 2018 Demographic and Health Survey (n = 3047) were spatially linked to provider data from an international utility database and regulator reports. Multilevel modelling quantified provider-related and socio-economic risk factors for households reporting water being unavailable for at least one day in the previous fortnight. 47% (95% CI: 45%, 49%) of urban and peri-urban households reported water being unavailable for at least one full day, ranging from 18% (95% CI: 14%, 23%) to 76% (95% CI: 70%, 81%) across providers. Controlling for provider, home ownership (odds ratio (OR) = 1.31; p <0.01), speaking Luvale, Kaonde, Lunda (OR = 2.06; p <0.05) or Tonga (OR = 1.78; p <0.1) as an ethnicity proxy, and dry season interview dates (OR = 1.91; p <0.05) were associated with household-reported interruptions. Households using a neighbour’s tap (OR = 1.33; p <0.1) and in mid-wealth neighbourhoods (OR = 4.31; p <0.1) were more likely to report interruptions. For every $1000 increase in utility-level GDP per capita, the odds of an interruption were 0.51 times less (p<0.01). Substantial inequalities in drinking-water availability were found between provider coverage areas. Spatial integration of user, provider and regulator data enriches analysis, providing a finer-scale perspective than otherwise possible. However, wider use of utility or regulator data requires investment in monitoring of small-scale community supply intermittency and utility coverage area data.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"97 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139804553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-05DOI: 10.1371/journal.pwat.0000125
Fabian Mendez, Laura E. Piedrahita-Gómez, Andrés Fernando Toro, Juliana Salazar-Benitez, Helmer Zapata, Miguel Peña
Modernization is marked by an increase in pollution-related health risks due to the rapid economic and technological growth. In the Global South, there is concern regarding the disease burden attributable to chemical contaminants released into the environment, especially in river basins, where populations are exposed through multiple pathways. While significant research exists linking chemical exposure to disease, mostly in occupational settings, less data is available for the open environment. Emerging pollutants have shown ecotoxicological and genotoxic effects at low concentrations in both terrestrial and aquatic ecosystems, with humans at the apex. Despite such evidence, water quality standards focus primarily on communicable diseases risks, and the burden of disease method mainly includes gastrointestinal and respiratory infections. Therefore, the use of DALYs as a prioritization strategy needs to be evaluated to suggest alternatives for integrated analysis. Our aim was to enhance the comprehension of watersheds as socioecological entities that necessitate inclusive indicators to display the intricate and diverse links between water, health, and the resultant inequities. Based on previous research and information collected in a tropical Andean watershed at southwestern Colombia, we characterized drivers of pollution and health hazards. Using standardized methods for calculating DALYs, we estimated the water-related environmental burden of communicable and noncommunicable diseases. Estimates of disease burden were analyzed to find out disparities driven by ethnic, gender and socioeconomic status. Results indicate that significant inequalities persist affecting the most vulnerable populations for preventable communicable diseases. Furthermore, the impact of noncommunicable diseases, which are linked to chemical pollution from individual substances and their cocktail effect, remains largely invisible due to insufficient data and research. The econometric approach of the DALY addition effect needs to be expanded with historical and critical perspectives to expose the profound social and health inequities present in the socioecological systems of the Global South.
{"title":"The invisibility of health effects associated with water pollution within disease burden estimates: Analysis from a Colombian Andean watershed","authors":"Fabian Mendez, Laura E. Piedrahita-Gómez, Andrés Fernando Toro, Juliana Salazar-Benitez, Helmer Zapata, Miguel Peña","doi":"10.1371/journal.pwat.0000125","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000125","url":null,"abstract":"Modernization is marked by an increase in pollution-related health risks due to the rapid economic and technological growth. In the Global South, there is concern regarding the disease burden attributable to chemical contaminants released into the environment, especially in river basins, where populations are exposed through multiple pathways. While significant research exists linking chemical exposure to disease, mostly in occupational settings, less data is available for the open environment. Emerging pollutants have shown ecotoxicological and genotoxic effects at low concentrations in both terrestrial and aquatic ecosystems, with humans at the apex. Despite such evidence, water quality standards focus primarily on communicable diseases risks, and the burden of disease method mainly includes gastrointestinal and respiratory infections. Therefore, the use of DALYs as a prioritization strategy needs to be evaluated to suggest alternatives for integrated analysis. Our aim was to enhance the comprehension of watersheds as socioecological entities that necessitate inclusive indicators to display the intricate and diverse links between water, health, and the resultant inequities. Based on previous research and information collected in a tropical Andean watershed at southwestern Colombia, we characterized drivers of pollution and health hazards. Using standardized methods for calculating DALYs, we estimated the water-related environmental burden of communicable and noncommunicable diseases. Estimates of disease burden were analyzed to find out disparities driven by ethnic, gender and socioeconomic status. Results indicate that significant inequalities persist affecting the most vulnerable populations for preventable communicable diseases. Furthermore, the impact of noncommunicable diseases, which are linked to chemical pollution from individual substances and their cocktail effect, remains largely invisible due to insufficient data and research. The econometric approach of the DALY addition effect needs to be expanded with historical and critical perspectives to expose the profound social and health inequities present in the socioecological systems of the Global South.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"56 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139864772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-05DOI: 10.1371/journal.pwat.0000127
Mair L. H. Thomas-Possee, Andrew A. Channon, Robert E. S. Bain, James A. Wright
Given nearly one third of sub-Saharan Africa’s population lack access to an improved water source that is available when needed, service continuity restricts access to safely managed services. Household surveys, water regulators, and utilities all gather data on service continuity, but few studies have integrated these disparate datasets to quantify continuity-related risk factors and inequalities. This study aimed to assess the added value of utility and regulator data for international monitoring by assessing factors affecting piped water availability in urban and peri-urban Zambia. Household ‘user’ data from the 2018 Demographic and Health Survey (n = 3047) were spatially linked to provider data from an international utility database and regulator reports. Multilevel modelling quantified provider-related and socio-economic risk factors for households reporting water being unavailable for at least one day in the previous fortnight. 47% (95% CI: 45%, 49%) of urban and peri-urban households reported water being unavailable for at least one full day, ranging from 18% (95% CI: 14%, 23%) to 76% (95% CI: 70%, 81%) across providers. Controlling for provider, home ownership (odds ratio (OR) = 1.31; p <0.01), speaking Luvale, Kaonde, Lunda (OR = 2.06; p <0.05) or Tonga (OR = 1.78; p <0.1) as an ethnicity proxy, and dry season interview dates (OR = 1.91; p <0.05) were associated with household-reported interruptions. Households using a neighbour’s tap (OR = 1.33; p <0.1) and in mid-wealth neighbourhoods (OR = 4.31; p <0.1) were more likely to report interruptions. For every $1000 increase in utility-level GDP per capita, the odds of an interruption were 0.51 times less (p<0.01). Substantial inequalities in drinking-water availability were found between provider coverage areas. Spatial integration of user, provider and regulator data enriches analysis, providing a finer-scale perspective than otherwise possible. However, wider use of utility or regulator data requires investment in monitoring of small-scale community supply intermittency and utility coverage area data.
{"title":"Household, neighbourhood and service provider risk factors for piped drinking-water intermittency in urban and peri-urban Zambia: A cross-sectional analysis","authors":"Mair L. H. Thomas-Possee, Andrew A. Channon, Robert E. S. Bain, James A. Wright","doi":"10.1371/journal.pwat.0000127","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000127","url":null,"abstract":"Given nearly one third of sub-Saharan Africa’s population lack access to an improved water source that is available when needed, service continuity restricts access to safely managed services. Household surveys, water regulators, and utilities all gather data on service continuity, but few studies have integrated these disparate datasets to quantify continuity-related risk factors and inequalities. This study aimed to assess the added value of utility and regulator data for international monitoring by assessing factors affecting piped water availability in urban and peri-urban Zambia. Household ‘user’ data from the 2018 Demographic and Health Survey (n = 3047) were spatially linked to provider data from an international utility database and regulator reports. Multilevel modelling quantified provider-related and socio-economic risk factors for households reporting water being unavailable for at least one day in the previous fortnight. 47% (95% CI: 45%, 49%) of urban and peri-urban households reported water being unavailable for at least one full day, ranging from 18% (95% CI: 14%, 23%) to 76% (95% CI: 70%, 81%) across providers. Controlling for provider, home ownership (odds ratio (OR) = 1.31; p <0.01), speaking Luvale, Kaonde, Lunda (OR = 2.06; p <0.05) or Tonga (OR = 1.78; p <0.1) as an ethnicity proxy, and dry season interview dates (OR = 1.91; p <0.05) were associated with household-reported interruptions. Households using a neighbour’s tap (OR = 1.33; p <0.1) and in mid-wealth neighbourhoods (OR = 4.31; p <0.1) were more likely to report interruptions. For every $1000 increase in utility-level GDP per capita, the odds of an interruption were 0.51 times less (p<0.01). Substantial inequalities in drinking-water availability were found between provider coverage areas. Spatial integration of user, provider and regulator data enriches analysis, providing a finer-scale perspective than otherwise possible. However, wider use of utility or regulator data requires investment in monitoring of small-scale community supply intermittency and utility coverage area data.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"50 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139864477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-01DOI: 10.1371/journal.pwat.0000209
K. K. Vadde, Sina V. Moghadam, A. Jafarzadeh, A. Matta, Duc C. Phan, Drew Johnson, V. Kapoor
This study investigated the sources of fecal pollution in surface and groundwaters collected from three urban watersheds in Texas during dry and wet weather and identified the impact of precipitation on water quality. Water samples (n = 316 and 107 for dry and wet events, respectively) were collected biweekly from eight sampling sites (6 sites from creeks and ponds, and 2 well sites) during two-year monitoring and analyzed for six physico-chemical parameters and ten qPCR-based assays targeting general (E. coli, Enterococcus, and universal Bacteroidales), human (BacHum and HF183), animal (Rum2Bac, BacCow, BacCan), and avian (Chicken/Duck-Bac and GFD) fecal markers. Elevated concentrations of NO3-N and NO2-N were observed in ponds and creeks sites during wet weather. Fecal markers analysis indicated higher concentrations of Rum2Bac, BacCow, and BacCan markers in most of pond and creek sites under wet weather, suggesting stormwater runoff contributed to non-point sources of fecal contamination by animal sources. Furthermore, sporadically higher concentrations of these markers were detected at groundwater sampling sites, demonstrating the significant human health risk. Multivariate statistical analysis such as cluster analysis (CA) and principal coordinate analysis (PCoA) was performed to identify relationship between sampling sites; while CA majorly classified ponds, creeks, and well sites separately, PCoA identified similarities in water quality characteristics between waters of wells with ponds and creeks. Overall, results indicate ruminant and dog fecal contamination is a major concern during storm events, consequently impacting surface and groundwater quality of the study.
{"title":"Precipitation impacts the physicochemical water quality and abundance of microbial source tracking markers in urban Texas watersheds","authors":"K. K. Vadde, Sina V. Moghadam, A. Jafarzadeh, A. Matta, Duc C. Phan, Drew Johnson, V. Kapoor","doi":"10.1371/journal.pwat.0000209","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000209","url":null,"abstract":"This study investigated the sources of fecal pollution in surface and groundwaters collected from three urban watersheds in Texas during dry and wet weather and identified the impact of precipitation on water quality. Water samples (n = 316 and 107 for dry and wet events, respectively) were collected biweekly from eight sampling sites (6 sites from creeks and ponds, and 2 well sites) during two-year monitoring and analyzed for six physico-chemical parameters and ten qPCR-based assays targeting general (E. coli, Enterococcus, and universal Bacteroidales), human (BacHum and HF183), animal (Rum2Bac, BacCow, BacCan), and avian (Chicken/Duck-Bac and GFD) fecal markers. Elevated concentrations of NO3-N and NO2-N were observed in ponds and creeks sites during wet weather. Fecal markers analysis indicated higher concentrations of Rum2Bac, BacCow, and BacCan markers in most of pond and creek sites under wet weather, suggesting stormwater runoff contributed to non-point sources of fecal contamination by animal sources. Furthermore, sporadically higher concentrations of these markers were detected at groundwater sampling sites, demonstrating the significant human health risk. Multivariate statistical analysis such as cluster analysis (CA) and principal coordinate analysis (PCoA) was performed to identify relationship between sampling sites; while CA majorly classified ponds, creeks, and well sites separately, PCoA identified similarities in water quality characteristics between waters of wells with ponds and creeks. Overall, results indicate ruminant and dog fecal contamination is a major concern during storm events, consequently impacting surface and groundwater quality of the study.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"127 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139832510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-01DOI: 10.1371/journal.pwat.0000213
Juliana Marçal, Junjie Shen, Blanca Antizar-Ladislao, David Butler, Jan Hofman
Water security, which is key for sustainable development, has been broadly investigated through different spatial scales, time frames and perspectives, as a multi-dimensional concept. Fast growth and the diversity of the urban environment add to the challenges of reaching good levels of water security in cities. Yet, few studies have focused on evaluating the heterogeneous distribution of water security in urban areas, which is a key step to highlight where inequalities in large cities are present and how to best guide interventions. The objective of this research is to investigate the spatial heterogeneity of urban water security as well as quantifying inequalities using the new assessment presented in this paper. A holistic indicator-based evaluation framework to intra-urban sectors of the city of Campinas in Brazil is applied, followed by an inequality analysis to describe the distribution of water security aspects. A spatial correlation analysis is then carried out to identify patterns for high inequality indicators. Results show that even though Campinas has established good overall water security conditions, spatial heterogeneity is still noticeable in the urban area. Quantification of inequality by the Theil index highlighted aspects, such as vegetation cover, social green areas, and wastewater collection, that are inequitably distributed in the urban area. The subsequent analysis of spatial patterns exposed areas on the outskirts of the city where infrastructure challenges and social vulnerability coincide. This novel approach has been therefore successfully validated in a city in Brazil, and it has been demonstrated that our water security assessment framework identifies what are the main water security challenges and where they are in the city. For the first time we show that associating spatial and inequality analysis with conventional evaluation of urban water security has the potential to help target areas in need and tackle specific water security issues in the urban area. This is crucial to inform urban planning and policy making for a sustainable and inclusive urban water management strategy.
{"title":"Assessing inequalities in urban water security through geospatial analysis","authors":"Juliana Marçal, Junjie Shen, Blanca Antizar-Ladislao, David Butler, Jan Hofman","doi":"10.1371/journal.pwat.0000213","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000213","url":null,"abstract":"Water security, which is key for sustainable development, has been broadly investigated through different spatial scales, time frames and perspectives, as a multi-dimensional concept. Fast growth and the diversity of the urban environment add to the challenges of reaching good levels of water security in cities. Yet, few studies have focused on evaluating the heterogeneous distribution of water security in urban areas, which is a key step to highlight where inequalities in large cities are present and how to best guide interventions. The objective of this research is to investigate the spatial heterogeneity of urban water security as well as quantifying inequalities using the new assessment presented in this paper. A holistic indicator-based evaluation framework to intra-urban sectors of the city of Campinas in Brazil is applied, followed by an inequality analysis to describe the distribution of water security aspects. A spatial correlation analysis is then carried out to identify patterns for high inequality indicators. Results show that even though Campinas has established good overall water security conditions, spatial heterogeneity is still noticeable in the urban area. Quantification of inequality by the Theil index highlighted aspects, such as vegetation cover, social green areas, and wastewater collection, that are inequitably distributed in the urban area. The subsequent analysis of spatial patterns exposed areas on the outskirts of the city where infrastructure challenges and social vulnerability coincide. This novel approach has been therefore successfully validated in a city in Brazil, and it has been demonstrated that our water security assessment framework identifies what are the main water security challenges and where they are in the city. For the first time we show that associating spatial and inequality analysis with conventional evaluation of urban water security has the potential to help target areas in need and tackle specific water security issues in the urban area. This is crucial to inform urban planning and policy making for a sustainable and inclusive urban water management strategy.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"49 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139880260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-01DOI: 10.1371/journal.pwat.0000213
Juliana Marçal, Junjie Shen, Blanca Antizar-Ladislao, David Butler, Jan Hofman
Water security, which is key for sustainable development, has been broadly investigated through different spatial scales, time frames and perspectives, as a multi-dimensional concept. Fast growth and the diversity of the urban environment add to the challenges of reaching good levels of water security in cities. Yet, few studies have focused on evaluating the heterogeneous distribution of water security in urban areas, which is a key step to highlight where inequalities in large cities are present and how to best guide interventions. The objective of this research is to investigate the spatial heterogeneity of urban water security as well as quantifying inequalities using the new assessment presented in this paper. A holistic indicator-based evaluation framework to intra-urban sectors of the city of Campinas in Brazil is applied, followed by an inequality analysis to describe the distribution of water security aspects. A spatial correlation analysis is then carried out to identify patterns for high inequality indicators. Results show that even though Campinas has established good overall water security conditions, spatial heterogeneity is still noticeable in the urban area. Quantification of inequality by the Theil index highlighted aspects, such as vegetation cover, social green areas, and wastewater collection, that are inequitably distributed in the urban area. The subsequent analysis of spatial patterns exposed areas on the outskirts of the city where infrastructure challenges and social vulnerability coincide. This novel approach has been therefore successfully validated in a city in Brazil, and it has been demonstrated that our water security assessment framework identifies what are the main water security challenges and where they are in the city. For the first time we show that associating spatial and inequality analysis with conventional evaluation of urban water security has the potential to help target areas in need and tackle specific water security issues in the urban area. This is crucial to inform urban planning and policy making for a sustainable and inclusive urban water management strategy.
{"title":"Assessing inequalities in urban water security through geospatial analysis","authors":"Juliana Marçal, Junjie Shen, Blanca Antizar-Ladislao, David Butler, Jan Hofman","doi":"10.1371/journal.pwat.0000213","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000213","url":null,"abstract":"Water security, which is key for sustainable development, has been broadly investigated through different spatial scales, time frames and perspectives, as a multi-dimensional concept. Fast growth and the diversity of the urban environment add to the challenges of reaching good levels of water security in cities. Yet, few studies have focused on evaluating the heterogeneous distribution of water security in urban areas, which is a key step to highlight where inequalities in large cities are present and how to best guide interventions. The objective of this research is to investigate the spatial heterogeneity of urban water security as well as quantifying inequalities using the new assessment presented in this paper. A holistic indicator-based evaluation framework to intra-urban sectors of the city of Campinas in Brazil is applied, followed by an inequality analysis to describe the distribution of water security aspects. A spatial correlation analysis is then carried out to identify patterns for high inequality indicators. Results show that even though Campinas has established good overall water security conditions, spatial heterogeneity is still noticeable in the urban area. Quantification of inequality by the Theil index highlighted aspects, such as vegetation cover, social green areas, and wastewater collection, that are inequitably distributed in the urban area. The subsequent analysis of spatial patterns exposed areas on the outskirts of the city where infrastructure challenges and social vulnerability coincide. This novel approach has been therefore successfully validated in a city in Brazil, and it has been demonstrated that our water security assessment framework identifies what are the main water security challenges and where they are in the city. For the first time we show that associating spatial and inequality analysis with conventional evaluation of urban water security has the potential to help target areas in need and tackle specific water security issues in the urban area. This is crucial to inform urban planning and policy making for a sustainable and inclusive urban water management strategy.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"1005 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139820451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-01DOI: 10.1371/journal.pwat.0000209
K. K. Vadde, Sina V. Moghadam, A. Jafarzadeh, A. Matta, Duc C. Phan, Drew Johnson, V. Kapoor
This study investigated the sources of fecal pollution in surface and groundwaters collected from three urban watersheds in Texas during dry and wet weather and identified the impact of precipitation on water quality. Water samples (n = 316 and 107 for dry and wet events, respectively) were collected biweekly from eight sampling sites (6 sites from creeks and ponds, and 2 well sites) during two-year monitoring and analyzed for six physico-chemical parameters and ten qPCR-based assays targeting general (E. coli, Enterococcus, and universal Bacteroidales), human (BacHum and HF183), animal (Rum2Bac, BacCow, BacCan), and avian (Chicken/Duck-Bac and GFD) fecal markers. Elevated concentrations of NO3-N and NO2-N were observed in ponds and creeks sites during wet weather. Fecal markers analysis indicated higher concentrations of Rum2Bac, BacCow, and BacCan markers in most of pond and creek sites under wet weather, suggesting stormwater runoff contributed to non-point sources of fecal contamination by animal sources. Furthermore, sporadically higher concentrations of these markers were detected at groundwater sampling sites, demonstrating the significant human health risk. Multivariate statistical analysis such as cluster analysis (CA) and principal coordinate analysis (PCoA) was performed to identify relationship between sampling sites; while CA majorly classified ponds, creeks, and well sites separately, PCoA identified similarities in water quality characteristics between waters of wells with ponds and creeks. Overall, results indicate ruminant and dog fecal contamination is a major concern during storm events, consequently impacting surface and groundwater quality of the study.
{"title":"Precipitation impacts the physicochemical water quality and abundance of microbial source tracking markers in urban Texas watersheds","authors":"K. K. Vadde, Sina V. Moghadam, A. Jafarzadeh, A. Matta, Duc C. Phan, Drew Johnson, V. Kapoor","doi":"10.1371/journal.pwat.0000209","DOIUrl":"https://doi.org/10.1371/journal.pwat.0000209","url":null,"abstract":"This study investigated the sources of fecal pollution in surface and groundwaters collected from three urban watersheds in Texas during dry and wet weather and identified the impact of precipitation on water quality. Water samples (n = 316 and 107 for dry and wet events, respectively) were collected biweekly from eight sampling sites (6 sites from creeks and ponds, and 2 well sites) during two-year monitoring and analyzed for six physico-chemical parameters and ten qPCR-based assays targeting general (E. coli, Enterococcus, and universal Bacteroidales), human (BacHum and HF183), animal (Rum2Bac, BacCow, BacCan), and avian (Chicken/Duck-Bac and GFD) fecal markers. Elevated concentrations of NO3-N and NO2-N were observed in ponds and creeks sites during wet weather. Fecal markers analysis indicated higher concentrations of Rum2Bac, BacCow, and BacCan markers in most of pond and creek sites under wet weather, suggesting stormwater runoff contributed to non-point sources of fecal contamination by animal sources. Furthermore, sporadically higher concentrations of these markers were detected at groundwater sampling sites, demonstrating the significant human health risk. Multivariate statistical analysis such as cluster analysis (CA) and principal coordinate analysis (PCoA) was performed to identify relationship between sampling sites; while CA majorly classified ponds, creeks, and well sites separately, PCoA identified similarities in water quality characteristics between waters of wells with ponds and creeks. Overall, results indicate ruminant and dog fecal contamination is a major concern during storm events, consequently impacting surface and groundwater quality of the study.","PeriodicalId":93672,"journal":{"name":"PLOS water","volume":"41 1-2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139892783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：