Search Results (199)

The Sustainable Development Goals seek to achieve universal, adequate, and equitable access to drinking water and sanitation by the year 2030. Yet, significant and persistent disparities in water and sanitation access exist, with rural and low-income households in Sub-Saharan Africa exhibiting some of the lowest levels. This paper uses household surveys from rural villages in Zambia’s Western Province to identify, highlight, and examine spatial barriers to improved water and sanitation. Most households included in the study area drink unimproved water, including surface water, and either use unimproved sanitation facilities or practice open defecation. Access to improved water sources and improved sanitation in the study area lags behind the rest of rural Zambia. Beyond the distance to urban areas that makes piped water and sanitation expensive, the location of these villages in the Barotse Floodplain necessitates seasonal migration, which creates barriers to universal access to improved water and sanitation. Full article

Drinking water biofilm ecosystems harbor complex and dynamic prokaryotic and eukaryotic microbial communities. However, little is known about the impact of copper corrosion on microbial community functions in metabolisms and resistance. This study was conducted to evaluate the impact of upstream Cu pipe materials on downstream viable community structures, pathogen populations, and metatranscriptomic responses of the microbial communities in drinking water biofilms. Randomly transcribed cDNA was generated and sequenced from downstream biofilm samples of either unplasticized polyvinylchloride (PVC) or Cu coupons. Diverse viable microbial organisms with enriched pathogen-like organisms and opportunistic pathogens were active in those biofilm samples. Cu-influenced tubing biofilms had a greater upregulation of genes associated with potassium (K) metabolic pathways (i.e., K-homeostasis, K-transporting ATPase, and transcriptional attenuator), and a major component of the cell wall of mycobacteria (mycolic acids) compared to tubing biofilms downstream of PVC. Other upregulated genes on Cu influenced biofilms included those associated with stress responses (various oxidative resistance genes), biofilm formation, and resistance to toxic compounds. Downregulated genes included those associated with membrane proteins responsible for ion interactions with potassium; respiration–electron-donating reactions; RNA metabolism in eukaryotes; nitrogen metabolism; virulence, disease, and defense; and antibiotic resistance genes. When combined with our previous identification of biofilm community differences, our studies reveal how microbial biofilms adapt to Cu plumbing conditions by fine-tuning gene expression, altering metabolic pathways, and optimizing their structural organization. This study offers new insights into how copper pipe materials affect the development and composition of biofilms in premise plumbing. Specifically, it highlights copper’s role in inhibiting the growth of many microbes while also contributing to the resistance of some microbes within the drinking water biofilm community. Full article

Drinking Water Safety Plans (DWSP) in buildings serve to identify health hazards associated with the drinking water system. Sanitation Safety Plans (SSP) fulfill the same purpose for the sewage system. Water Safety Plans (WSP) include DWSPs, SSPs, and water systems like gray water and firefighting water. WSPs are based on a high-quality description of the water systems. This paper presents a new methodology for describing water systems. In contrast to previous approaches, the system description begins at the point where the water is consumed. These points of use are described using ecomaps, which are then supplemented with information about the pipe network. This approach makes it possible to fulfill four relevant premises: (1) the system description includes all essential parts of the drinking water installation, (2) the system description is possible with usual equipment, (3) the system description can be carried out with the least possible additional personnel costs, and (4) the system description is controllable, versionable, changeable, and forgery-proof. The ecomaps created in this way are suitable for the next step within the WSP framework, namely hazard and risk assessment. In addition, the ecomaps can be integrated into a quality, occupational safety, or environmental management system. Aspects of water security can be added to enable the ecomaps to be used as the basis for a total integrated water management system. Full article

Polyphenols show promising application prospects as a novel natural disinfectant for drinking water. This study employed a simulated pipe network system to investigate the effects of tea polyphenols at an initial concentration of 5 mg/L on the characteristics of biofilm on pipe walls and microbial community succession patterns under different water ages (12–48 h). The results showed that with increasing water age, the tea polyphenol residual concentration gradually decreased, and the biofilm structure significantly evolved: the surface roughness increased from 5.57 nm to 32.8 nm, and the biofilm thickness increased from 40 nm to 150 nm. Microbial community diversity exhibited a trend of first increasing and then decreasing, with the Shannon index reaching its peak (2.847) at a water age of 36 h and remaining significantly higher than the control group (1.336) at all stages. High-throughput sequencing revealed a transition from a single dominant genus of Methylophilus (54.41%) at a water age of 12 h to a multi-genus coexistence pattern at a water age of 48 h, with Methylophilus (24.33%), unclassified_Saprospiraceae (21.70%), and Hydrogenophaga (16.52%) as the main dominant groups. Functional bacterial groups exhibited temporal changes, with biofilm colonization-related genera (Caulobacter, Sphingobium) reaching their peaks at 36 h, while special metabolic genera (Methylophilus, Hydrogenophaga) dominated at 48 h. Potential pathogens in the tea polyphenol treatment groups were effectively controlled at low levels (<0.21%), except for a temporary increase in Legionella (6.50%) at 36 h. Tea polyphenols’ selective inhibition mechanism helps suppress the excessive proliferation of specific genera and reduces the risk of potential pathogen outbreaks. This has important implications for ensuring the microbiological safety of drinking water. Full article

Background: Veterinary students experience high levels of mental health issues. Objectives: To analyze substance use, internet consumption, and mental health factors among students and academic staff of the Faculty of Veterinary Medicine of the University of Las Palmas de Gran Canaria, identifying factors associated with well-being and dissatisfaction. Methods: A total of 226 respondents participated, including 177 students (78.3%) and 49 staff members (21.7%). Data were collected between 30 October 2024 and 14 January 2025 using an adapted EDADES-based survey assessing substance use (alcohol, tobacco, electronic nicotine delivery systems (ENDSs), anxiolytics, and illicit drugs), internet habits, and psychological well-being among participants. Binary logistic regression was applied to identify factors associated with dissatisfaction. Results: Students exhibited higher binge drinking rates, greater ENDS consumption, and more problematic internet use than staff. Significant gender differences were observed, with females reporting greater emotional distress and a higher need for psychological support. Water pipe use (OR = 2.79, 95% CI = 1.45–5.38), anxiolytic consumption (OR = 2.31, 95% CI = 1.08–4.92), and excessive internet use (OR = 4.83, 95% CI = 1.66–14.1) were associated with lower overall satisfaction. Age was inversely associated with dissatisfaction (OR = 0.96, 95% CI = 0.94–0.98), and females were significantly more likely to report dissatisfaction (OR = 2.79, 95% CI = 1.45–5.38). Conclusions: Veterinary students exhibited higher psychological distress than teaching staff. Implementing targeted interventions to address substance use and internet habits is needed in order to enhance psychological well-being. Full article

The risk of human exposure to micro- and nanoplastics (MNPs) has received increasing attention in recent years. Consumption of drinking water is a significant route of exposure to MNPs. While previous studies focus on MNPs in treated wastewater or final effluent, research addressing drinking water networks (DWNs) as potential secondary sources of MNPs remains sparse. However, how DWN, a critical component transporting water from treatment plants to consumers, contributes to secondary contamination remains underexplored in existing studies. We extracted keywords from reviewed literature using bibliometric methods and conducted correlation analyses, revealing four research clusters: baseline detection, health assessments, nanoplastic, and treatment. The abundance of MNPs in DWN ranged from 0.01 to 1.4 items/L. The abundance varied between 679.5 and 4.5 × 10⁷ items/kg when calculated based on sample mass (in scales or debris). Based on the shape and polymer composition of MNPs, the DWN is strongly suspected to contribute to the secondary contamination of MNPs in tap water. We also reviewed the main mechanisms for the formation and release of MNPs in pipelines, including mechanical forces, water hammer effects, and chemical aging. Our review highlighted the current gaps in the research on potential MNP contamination in the DWN. It will contribute to understanding the contribution of the DWN to MNP contamination and provide a framework for future monitoring and research efforts. Full article

Most people in the world now live in urban areas and their shared quest for better cities is embodied in several Sustainable Development Goals of the United Nations. These indicate that successful cities need jobs, adequate housing stock, effective governance, and other support systems. At the most basic level, they need a basket of core public works services like clean water and efficient transit, among others. These must be provided to improve public trust in government by addressing equity and affordability while also improving operational and cost efficiency. These targets are moving as transitions are occurring from stove-piped to integrated services, even while social contracts between government and the private sector are also shifting. Essential tools to improve cities include urban planning and infrastructure development, but applying them effectively faces challenges like climate change, inequality, social disorder, and even armed conflicts. This paper focuses on seven core public works services for drinking water, wastewater, stormwater, trash collection, mass transit, streets and traffic control, and disaster management. It reviews how these have evolved in the US, how they are organized under the federalism system, and how the goal of integrated management is being pursued. Challenges to integrated approaches include increasing responsibilities but lack of funding, political stress, and rule-driven and internally oriented management. Methods for performance assessment are explained under legacy systems based on methods like indicators and benchmarking applied to public works systems. Current methods focus on regulatory targets and the details; information has been shallow and not always timely. This paper projects how the performance assessment of core public works systems can be broadened to address goals like those of the SDGs and assesses why it is difficult to rate major systems. Examples of the activities of NGOs are given and an example of how progress toward SDG6 is included to show why performance management of integrated management applied to linked systems is needed. Performance dashboards with open government are currently the most common pathways, but emerging methods based on data analytics and visualization offer new possibilities. Reviewing the status of public works management shows that it is an important branch of the field of public administration, and it can be presented as a professional field with its own identity. The findings will support educators and researchers as well as provide policy insights into public works and stakeholder engagement. Full article

The water distribution system is a critical infrastructure aiming to deliver safe and clean drinking water, with pipeline materials significantly influencing water quality and efficiency. One critical factor in selecting pipeline materials is the potential for biofilm formation on the inner surfaces of pipes. This study investigates the effects of three iron salts—iron (II) sulfate heptahydrate, iron (III) nitrate nonahydrate, and iron (III) chloride on biofilm formation by Escherichia coli and Enterococcus faecalis in pipeline environments, focusing on water distribution systems. While previous research has examined the effects of iron on various bacterial species, there are limited data on E. coli and E. faecalis biofilm formation in the context of water distribution systems. Results reveal that iron (III) chloride significantly inhibited E. coli biofilm formation by up to 80%, while E. faecalis biofilm growth was promoted by iron (II) sulfate heptahydrate, with an increase of approximately 45%. These findings underscore the critical role of managing iron concentrations to mitigate biofilm-related issues, which influence water quality, infrastructure durability, and microbial resistance. The study highlights the importance of integrating these insights into sustainable water management practices and advancing pipeline material innovations to enhance public health and environmental resilience. Full article

This study examines the impact of water produced by membrane processes on bacterial dynamics within drinking water distribution systems. Employing a closed-loop pilot plant designed to replicate real-world conditions, the research focused on two primary objectives. First, it assessed the effects of different water compositions, which vary in their nutrient concentrations, including tap water, softened water, ultrafiltered water, and low-pressure reverse osmosis (LPRO) water, on bacterial development in pipes over successive 30-day phases. The findings indicated that water produced by LPRO, characterized by low nutrient levels, reduced microbial concentrations and altered the composition of bacterial communities, leading to the lowest overall bacterial counts during stationary phases. Second, the study investigated the behavior of established biofilms in response to changes in water type (tap water/LPRO water), revealing that after a certain duration, aging biofilms maintained their structural integrity and diversity despite variations in water quality. The presence of a robust biofilm could buffer the microbial community against drastic shifts associated with different water types, suggesting that pipe history plays a critical role in microbial dynamics within distribution systems. These results highlight the complex interplay between water quality and biofilm characteristics in the drinking water distribution systems. Full article

This study assessed the status of water, sanitation, and hygiene (WASH) services at (49) selected primary schools in uMfolozi Local Municipality, which is situated in the province of Kwa-Zulu Natal in South Africa. Data were collected using an observational checklist tool and by conducting a walk-through survey to inspect the conditions of sanitary facilities, observe the hand-washing practices of the school learners, and analyse the accessibility to safe drinking water in school premises. The data were analysed with the Statistical Package for Social Science Version 29. This study revealed that there is easy access to safe drinking water in all but one school. The dependability of the water supply seemed to be one of the most urgent problems in every school, even though all of them have some kind of drinking water infrastructure on their grounds. Municipal water (n = 25, 36%) and rainwater (n = 25, 36%) were the most common type of water used in schools compared to borehole (n = 15, 22%) and tanker truck water (n = 4, 6%). Schools must have a reserved water supply because of the inconsistent supply of municipal water, and because rainwater is a seasonal harvest while borehole water may be affected by factors like load-shedding. The UNICEF-described ratio of one tap or disperser per fifty learners suggests that the water taps in the schoolyard were insufficient in some schools (n = 25, 36%). Rainwater is collected through a gutter system in the school building roofs and stored in 5000–10,000 Jojo tanks. Borehole water is pumped into Jojo tanks at an elevated position where it is stored, and learners receive the water through taps connected to the borehole tanks. During an emergency when there is no water supply from other sources, tanker trucks are hired to fill tanks that are also used to store rainwater. The borehole and rainwater quality appeared to be clear, but water treatment had not been performed, and the microbial quality was unknown. This shows that the Sustainable Development Goal (SGD) 6, clean water and sanitation, is still far from being met. According to national norms and standards for domestic water and sanitation services, people who do not use water treatment or purification techniques fall in the ‘no service’ category and contribute to the water backlog. Pit latrines (n = 46, 94%) and flush toilet (n = 3, 6%) were found to be the only convenient toilet systems used. The number of toilets is not sufficient according to the guidelines. There are (n = 46, 94%) of the schools in the study area using pit latrine due to insufficient or no water supply. In 89.8% of primary schools, sanitation facilities are in working condition in terms of repair and hygiene, while 10.2% are not usable in terms of hygiene, and these are mostly boy’s toilets. All schools (n = 46, 94%) that have flush toilets is because they received sponsorship from non-government stakeholders that funded them in achieving piped water systems that permit the functionality of flush toilets. For the purposes of this study, hygiene was evaluate based on the items found in toilets and handwashing practices. The hygiene aspects of toilets included tissues, cleanness, and toilet seat. For handwashing practices we looked the number of washing basins, the colour of water, and having soaps to use. In the schools that did provide handwashing facilities, some of the toilets were broken, there was no water, or there was no drainage system in place to allow them to function. However, according to the school act, the handwash basins should be inside the facilities. A total of (n = 7, 14%) of handwash basins were inside the toilets. Only (n = 2, 4%) of schools had handwashing facilities which were Jojo tanks with taps near toilets, which were outside of the toilet, with no soap provided. Additionally, (n = 40, 82%) of learners used drinking points for handwashing, which can possibly transmit microbes among them. The findings revealed that, in general, (n = 32, 64%) of school toilets were clean, while, in general, the girls’ toilets were cleaner than the boys’ toilets. In all the schools, the cleaning services were from the people who were involved in school nutrition. In conclusion, there were water sources available for access to water inside schools; however, the situation can be improved by increasing the number of water source points. Pit latrines were the main used toilets, which were in a majority of the schools, and did not have the necessary terms for hygiene such as handwashing basin, tissues, and others. The lack of the main aspect, i.e., access to water and sanitation items, results in an impact on hygiene to learners as they will fail to practice proper hygiene. However, improvement can still be made by keeping the boys’ toilets clean while increasing the number of handwashing basins inside the toilets, so that they do not use taps outside the toilets. Schools should work towards meeting the required number of handwashing basins to increase access to handwashing facilities. Full article

For communities without access to uninterrupted, piped water, household water storage (HWS) practices can lead to adverse public health outcomes caused by water degradation and mosquito proliferation. With over 700,000 deaths caused by vector-borne diseases annually, the objective of this study was to determine whether water disinfectants, at concentrations deemed safe for human consumption and beneficial for water treatment, are effective in reducing the emergence of adult mosquitoes that transmit disease. Laboratory bioassays, designed to resemble the context of treating HWS containers, were conducted to assess the larvicidal effects of chemicals at concentrations below regulatory limits for drinking water: silver (20, 40, 80 μg/L Ag), copper (300, 600, 1200 μg/L Cu), and chlorine (500, 1000, 2000 ug/L free chlorine). The water disinfectants demonstrated the ability to significantly reduce the population of juvenile Ae. aegypti. Sodium hypochlorite was found to be the most effective in decreasing the survival rate of late first instar larvae, while silver nitrate exhibited the highest effectiveness in inhibiting the emergence of late third instar larvae. Ultimately, this study highlights the potential of an integrated approach to Water, Sanitation, and Health (WASH) solutions with vector control management. Full article

In this study, a novel Cu-bearing 304 stainless steel doped with 4.0 wt.% Cu (304-Cu SS) was developed, and the effects of nitrogen microalloying (304N-Cu SS) and heat treatment on mechanical, antibacterial, and corrosion properties were investigated. It was found that when aging at 700 °C, the Vickers hardness and strength of the 304N-Cu SS first significantly increased with increasing aging time up to 4 h and then slowly decreased with further increase in aging time. The best combination of strength and ductility, namely, a yield strength of 319 MPa, ultimate tensile strength of 657 MPa, and elongation to fracture of 47.0%, was achieved in the 304N-Cu SS after aging at 700 °C for 6 h. Moreover, the antibacterial and corrosion rates of the newly developed 304N-Cu SS reached 99.67% and 0.0032 g·m⁻²h⁻¹, surpassing those of 304-Cu SS by 0.38% and 9.4%, respectively. These enhancements in the mechanical, antibacterial, and corrosion properties were attributed to the precipitation of high-density nanoscale Cu-rich precipitates during aging. Our results demonstrate that nitrogen microalloying is an effective metallurgical method for the future development of new antibacterial austenitic stainless steels with simultaneously enhanced mechanical, antibacterial, and corrosion properties for direct drinking water distribution systems. Full article

Rotavirus group A (RVA) is a major cause of pediatric acute gastroenteritis (AGE). Vaccination is an effective public health strategy and Angola implemented it in 2014. This hospital-based study aimed to estimate the prevalence of RVA infection and the severity of AGE in children under five years of age treated at six hospitals in Luanda Province. Between April 2021 and May 2022, 1251 fecal samples were screened by an immunochromatographic rapid test (SD Bioline). Data on socio-demographic profile, nutritional status, and clinical assessment were obtained. The association of RVA infection and AGE severity with possible risk factors was evaluated with a binary logistic regression model. Overall, the detection rate was 57.8% and girls tend to be more often infected than boys (55.2%). Infection was more common in the youngest group (1 to 6 months, 60.3%). Important sources of RVA infection were drinking water kept in tanks (57.9%) and private sanitary facilities with piped water (61%). Surprisingly, according to the Vesikari Scale score, the most severe symptoms were observed in children vaccinated with two doses (80.7%). RVA prevalence remains high despite vaccination, and further studies should address the association between infection sources and disease severity, as well as the causes underlying vaccine (un)effectiveness. Full article

Background/Objectives: Pathogen inactivation and harmful gene destruction from water just before drinking is the last line of defense to protect people from waterborne diseases. However, commonly used disinfection methods, such as chlorination, ultraviolet irradiation, and membrane filtration, experience several challenges such as continuous chemical dosing, the spread of antibiotic resistance genes (ARGs), and intensive energy consumption. Methods: Here, we perform a simultaneous elimination of pathogens and ARGs in drinking water using local electric fields and in-situ generated trace copper ions (LEF-Cu) without external chemical dosing. A 100-μm thin copper wire placed in the center of a household water pipe can generate local electric fields and trace copper ions near its surface after an external low voltage is applied. Results: The local electric field rapidly damages the outer structure of microorganisms through electroporation, and the trace copper ions can effectively permeate the electroporated microorganisms, successfully damaging their nucleic acids. The LEF-Cu disinfection system achieved complete inactivation (>6 log removal) of Escherichia coli O157:H7, Pseudomonas aeruginosa PAO1, and bacteriophage MS2 in drinking water at 2 V for 2 min, with low energy consumption (10⁻² kWh/m³). Meanwhile, the system effectively damages both intracellular (0.54~0.64 log) and extracellular (0.5~1.09 log) ARGs and blocks horizontal gene transfer. Conclusions: LEF-Cu disinfection holds promise for preventing horizontal gene transfer and providing safe drinking water for household applications. Full article

Water distribution systems (WDSs) are crucial for providing clean drinking water, requiring an efficient design to minimize costs and energy usage. This study introduces an enhanced life cycle energy analysis (LCEA) model for an optimal WDS design, incorporating novel criteria for pipe maintenance and a new resilience index based on nodal pressure. The improved LCEA model features a revised unit energy formula and sets standards for pipe rehabilitation and replacement based on regional regulations. Applied to South Korea’s Goyang network, the model reduces energy expenditure by approximately 35% compared to the cost-based design. Unlike the cost-based design, the energy-based design achieves results that can relatively reduce energy when designing water distribution networks by considering recovered energy. This allows designers to propose designs that consume relatively less energy. Analysis using the new resilience index shows that the energy-based design outperforms the cost-based design in terms of pressure and service under most pipe failure scenarios. The implementation of the improved LCEA in real-world pipe networks, including Goyang, promises a practical life cycle-based optimal design. Full article