Search Results (1,364)

Background: The pollution of organophosphate flame retardants (OPFRs) is of global concern, but the site-specific data of OPFR concentrations in drinking water are scarce for many areas of the world outside of Europe and the US. This study aimed to investigate the occurrence and profiles of OPFRs in the tap water treatment and delivery process in Shanghai. Methods: In total, 106 samples were analyzed for 10 OPFRs, which were collected periodically from monitoring points of drinking water treatment plants and piped water between November 2021 and July 2023. The average daily doses of OPFRs through the ingestion of tap water were calculated by multiplying nominal volumes of water ingestion rates with the measured concentrations of OPFRs. Hazard quotients, the hazard index, and the carcinogenic risks of OPFRs via drinking water were used to estimate the health risks. Results: Tributyl phosphate (TBP), tris(2-chloroethyl) phosphate (TCEP), and tris (1-chloro-2-propyl) phosphate (TCIPP) were found in >90% of the tap water samples, whereas triethyl phosphate (TEP) and tris (2,3-dibromopropyl) phosphate (TDBPP) were not found in any samples. The concentrations of Σ₁₀OPFRs were found at part-per-trillion ranges, with average concentrations that ranged from 86.0 ng/L in February 2023 (dry season) to 218 ng/L in July 2022 (wet season). TCIPP was the most abundant compound among the investigated OPFRs. The average daily dose of Σ₁₀OPFRs via the ingestion of tap water was up to 20.4 ng/kg body weight/day. The hazard quotients of OPFRs through drinking water were in the range of 10⁻⁵–10⁻⁴, indicating low risk levels. Moreover, the hazard index of OPFRs indicated that the risk for children (2 × 10⁻⁴) was higher than adults (7 × 10⁻⁵). Conclusion: Tap water intake may be an important source of OPFRs exposure. But the risk of OPFRs for local residents is at a low level through drinking water. Full article

For millennia, springs have provided water for drinking, domestic use, balneological treatment, liminality rites as well as tourist attractions. Amidst these uses, anthropogenic activities, especially urbanization and agriculture, continue to impair the functionality of springs. With the looming decadal climate change, freshwater springs could be a sustainable source of clean water for the realisation of Sustainable Development Goal 6. This paper presents the results of the sanitary inspection and assessment of limnochemical characteristics and quality of water samples (n = 64) from four freshwater springs (coded SPR1, SPR2, SPR3, and SPR4) in Kansanga, a flash flood-prone area in the African Great Lakes region of Uganda. Each sample was analysed for 17 parameters (temperature, pH, electrical conductivity, turbidity, fluorides, sulphates, chlorides, nitrates, orthophosphates, total dissolved solids, dissolved oxygen, total alkalinity, potassium, sodium, total, magnesium and calcium hardness) following the standard methods. Water quality index (WQI) was calculated to establish the quality of the water samples based on the physicochemical parameters measured. Based on the sanitary risk assessment results, the springs had medium- to high-risk scores, but most water parameters were within the WHO guidelines for potable water, except for nitrates (in SPR1 and SPR2), hardness levels (in SPR2), and dissolved oxygen (in all the samples). Sampling season and location had significant effects on the limnochemistry of the freshwater springs (p < 0.05). The water quality indices calculated indicated that the water from the springs was of good quality (WQI = 50–57), but there was a reduction in water quality during the wet season. The best water quality was recorded in samples from SPR4, followed by those for SPR3, SPR1, and SPR2. These results provide insights into the contribution of floods and poor sanitation facilities to the deterioration of spring water quality in Kansanga, and the need to leverage additional conservation strategies to support vulnerable communities in the area. Further studies are required to establish the risk posed by trace metals and microbes that may contaminate freshwater in the studied springs, especially following flood events. Full article

Forests are critical source regions of high-quality drinking water but forest disturbances such as harvesting can alter stream dissolved organic carbon (DOC) concentrations and influence source water treatability. Most stream DOC-centric forest harvesting impact studies report on effects <10 years post-harvest; less is known about the legacy effects of forest harvesting on stream DOC. Here, inter- and intra-catchment variability in stream DOC concentration and export were evaluated in two northern hardwood-dominated headwater catchments (unharvested reference and 24 years post-clearcut). The relationship between stream DOC and the concentration, spatial distribution, and hydrologic connectivity of hillslope solute pool DOC was investigated. Stream DOC concentrations in the legacy clearcut catchment exceeded those in the reference catchment for all flow conditions. Inter-catchment differences in DOC export were inconsistent. Hillslope solute pool DOC concentrations decreased with soil depth but were not significantly different between catchments. Concentration–discharge regression analysis indicated that DOC was primarily transport-limited (flushing) in both catchments. Aqueous potassium silica molar ratio data indicate the influence of groundwater on stream chemistry and streamflow was similar in both catchments. Results suggest that while clearcut harvesting can have detectable decadal-scale effects on stream DOC concentrations in northern hardwood-dominated headwater catchments, the effects are limited and likely do not pose a reasonable threat to downstream drinking water treatment operations. Full article

In recent years, there has been a clear increase in bottled water consumption globally, which has led to significant health and environmental concerns. This cross-sectional study aims to understand the attitude and preferences of university students in Qatar towards the use of bottled and tap drinking water using an online survey questionnaire (September and October 2022). The number of students who responded to the online survey was 14% (n = 688) of the student population, with a mean age of 22.23 ± 5.15 years from the different colleges. Overall, a higher fraction of students preferred plastic bottled water as the main drinking source on campus (n = 468; 68.02%), with a majority of them being females (72.08%). Out of the 468 students who preferred plastic bottled water, safety was the most important factor (43.80%), followed by convenience (16.88%) and taste (15.60%). Cost (15.17%), personal/family habits (5.13%), environmental concerns (2.14%), and mineral content (1.28%) were found to be the least important factors. Among the 45 students (6.54%) who preferred tap water over plastic bottled water, cost (46.67%) was the dominant factor, followed by convenience (20.00%), environmental concerns and safety (13.33% each), taste (4.44%), and personal/family habits (2.22%). Around 72% believed that plastic water bottles were more harmful to the environment, yet the greater majority still resorted to this source. The research study underscores safety as the major factor favoring bottled water over tap water. Further, it suggests that knowledge alone does not fully explain student behavior, implying other influential factors. This study recommends campaigns focus on attitude and behavior change and not solely emphasize knowledge. There is an immediate need to further educate students through environmental and health literacy programs on water consumption and quality. Enabling the population to understand the positive and negative aspects of their choices may be an effective remedy for ensuring a healthy population and healthy environment. Full article

Drinking water temperatures above 25 °C have been measured more often since Dutch drinking water companies are required to take Random Day Time (RDT) samples. The objective of this study was to obtain more information from the required temperature measurements. A total of 34,595 drinking water temperature measurements between 2012 and 2021 were analyzed and compared with the temperature prediction from a soil temperature model (STM), developed by Blokker and Pieterse-Quirijns (2013) and Agudelo-Vera et al. (2015). More than 300 exceedances of the modeled urban soil temperature were found (ca. 1%). While there were only four measurements with temperatures higher than 25 °C. By looking at the locations of the temperature exceedances, drinking water companies can further investigate whether there are other heat sources near these locations. Using the STM calculations as a reference for the measured drinking water temperature has provided more options for locating hotspots. Full article

Heavy metal pollution is a critical issue affecting the safety of drinking water sources. However, the impact of human activities on heavy metal risk levels in water-carrying lakes remains unclear. This study aims to explore the risk mechanisms of heavy metals in Luoma Lake, an important water-carrying lake for the South-to-North Water Diversion Project. We explored the spatial and temporal differences in the distribution of heavy metals in Lake Luoma using methods such as the heavy metal pollution index (HPI) and assessed the risk variations using a health assessment model. The results indicated that heavy metal concentrations in water-carrying lakes generally decreased during the dry season, with Mn and Zn levels decreasing by 89.3% and 56.2%, respectively. The comprehensive score of HPI decreased by 13.16% following the retreating polder compared to the control area (Non-retreating polder area). Furthermore, the HPI at the drinking water intake was lower, which is closely associated with the elevated dissolved oxygen (DO) and oxidation–reduction potential (ORP) resulting from water diversion. The annual average health risk across the entire lake was not significant, with higher levels observed in the control area. The annual non-carcinogenic risk levels of Mn, Ni, Cu, Zn, and Pb range from 10⁻¹³ to 10⁻⁹, which are considered negligible risk levels. Notably, the carcinogenic risk posed by arsenic (As) through the drinking pathway reached 10⁻⁵ a⁻¹, exceeding the maximum levels recommended by certain organizations. These findings provide a critical foundation for managing heavy metals in water-carrying drinking water sources. Full article

This study was conducted in Ekpoma, a town dependent on rainwater and river water from nearby areas because of a lack of groundwater sources, and the physicochemical and bacteriological (heterotrophic plate count [HPC], total coliform count [TCC], and fecal coliform count [FCC]) properties of 123 stored river water samples grouped into five collection districts (EK1 to EK5). The results were compared with regulatory standards and previous regional studies to identify water quality trends. While most physicochemical properties met drinking water standards, 74% of samples had pH values > 8.5. Twenty-seven samples were fit for drinking, with EK4 having the highest number of bacterio-logically unsuitable samples. Ten bacterial species were identified, with Gram-negative short-rod species such as Escherichia coli, Klebsiella pneumoniae, and Salmonella typhimurium being predominant. HPC values varied from 367 × 10⁴ to 1320 × 10⁴ CFU/mL, with EK2 (2505 × 10⁴ CFU/mL) and EK5 (1320 × 10⁴ CFU/mL) showing particularly high counts. The TCC values ranged from 1049 × 10⁴ to 4400 × 10⁴ CFU/mL, and the FCC values from 130 × 10⁴ to 800 × 10⁴ CFU/mL, all exceeding WHO limits (1.0 × 10² CFU/mL). Historical data show no improvement in water quality, emphasizing the need for individuals to treat water properly before consumption. The findings provide baseline data for local water authorities and serve as a wake-up call for adequate water treatment, storage interventions, and community education on water security. Additionally, this study offers a practical process for improving the quality of water stored in similar regions. Full article

A significant number of people, either seasonally or permanently, migrate from the Thar Desert in Pakistan each year due to droughts caused by climate change. This study aims to investigate the determinants and consequences of these migration decisions, examine the effectiveness of migration as a climate adaptation strategy, and identify challenges in adapting to these changes. Data were gathered from 400 migrated households in the Mithi sub-district. A mixed-method approach was used, combining qualitative and quantitative methods. The findings revealed that threats to the standard of living, including lack of food and clean drinking water, unemployment, and limited educational and medical opportunities, were the primary reasons for permanent and temporary migration from ancestral locations. Migration significantly impacted the origin and destination regions, with positive or negative effects. Specifically, migrants identified various consequences for both the origin and destination communities, including population decline (63%), changes in age structure, increased demand for housing, economic fluctuations (73%), alterations in healthcare services, and increased psychological stress (77%). The study also revealed that individuals who migrated from the Thar Desert experienced improved conditions compared to their previous location, such as diversification of income sources, increased job stability, access to clean water and food, reduced health risks, and overall improvements in their living conditions. However, the destination communities faced significant challenges due to widespread resource depletion and environmental deterioration. Migrants encountered barriers to developing resilient livelihoods in destination areas, including lack of proper knowledge and information, institutional and government issues, environmental and technological challenges, and social and cultural issues. The study highlights the urgent need for comprehensive policies and sustainable solutions to address the root causes of migration and support the resilience of vulnerable populations. Full article

In recent years, sudden water pollution accidents have frequently occurred and seriously endangered people’s drinking water safety. Early warnings for water pollution accidents has become the core work for emergency response and sparked substantial research. However, risk assessments for different water receptors still needs to be solved for the early warning of water pollution accidents. This paper proposes a new early warning assessment method based on water quality models for different receptors, divided into the water source area (including drinking water source area and agricultural water use area) and the non-water source area. The constructed method was applied to the Three Gorges Dam area in China to simulate a phosphorus leakage accident caused by a traffic accident. Based on the EFDC model, the migration evolution process and the distribution change characteristics of phosphorus were simulated. Accordingly, the different risk levels of zones between the incident site and the downstream drinking water source area were obtained. The application results show that the risk warning system for sudden water pollution accidents based on the water quality model proposed in this paper can be applied to provide scientific support for the emergency response of sudden water pollution accidents. Full article

The potential of DWDS pipewall biofilms to shelter and propagate opportunistic pathogens is currently poorly understood. Here, we use an annular biofilm reactor approach to quantify the fate of the opportunistic pathogen Pseudomonas aeruginosa when introduced to a simulated DWDS environment. We found that P. aeruginosa was capable of swift attachment to surfaces and able to persist for up to 14 days under shear stress conditions. Further, we demonstrate that P. aeruginosa is capable of detachment/reattachment and mobilisation through the bulk water, potentially acting as a source of inoculum to drinking water. Full article

Exploration of the pollution status of river-based water sources is important to ensure quality and safe drinking water supply for the public. The present study investigated physicochemical parameters of surface water in the upper segment of River Mahaweli, which provides drinking water to the Nuwara Eliya and Kandy districts of Sri Lanka. River surface water from 15 intakes and treated water from 14 Water Treatment Plants (WTPs) were tested for pH, water temperature, turbidity, EC, COD, 6 anions, 21 cations, 3 pesticides, and 30 antibiotics once every 3 months from June 2022 to July 2023. Except for turbidity and iron concentrations, all other parameters were within the permissible range as per the Sri Lanka Standard Specification for Potable Water (SLS 614:2013). The uppermost Kotagala WTP raw water had a high concentration of iron due to runoff from areas with abundant iron-bearing minerals. Turbidity increased as the river flowed downstream, reaching its highest value of 13.43 NTU at the lowermost Haragama. Four intakes had raw surface water suitable for drinking as per the Water Quality Index (WQI). Pollution increased gradually towards downstream mainly due to agricultural runoff, industrial effluents, and urbanization. Poor water quality at the upstream Thalawakale-Nanuoya intake was due to highly contaminated effluent water coming from Lake Gregory in Nuwara Eliya. Cluster analysis categorized WTP locations in the river segment into 3 clusters as low, moderate, and high based on contaminations. Principal component analysis revealed that the significance of the 41.56% variance of the raw water was due to the pH and the presence of heavy metals V, Cr, Ni, Rb, Co, Sr, and As. All treated water from 15 WTPs had very good to excellent quality. In general, heavy metal contamination was low as indicated by the heavy metal pollution index (HPI) and heavy metal evaluation index (HEI). The treatment process could remove up to 94.7% of the turbidity. This is the first attempt to cluster the river catchment of the Mahaweli River based on physicochemical parameters of river water. We present here the land-use pattern-based pollution of the river and efficacy of the water treatment process using the Mahaweli River Basin as a case study. Regular monitoring and treatment adjustments at identified points are recommended to maintain the delivery of safe drinking water. Full article

Fluoride and nitrate contamination in groundwater is a global concern due to their toxicity and associated negative health effects. This study incorporated a comprehensive methodology, including hydrogeochemical analysis, drinking and irrigation water quality assessment, source apportionment, and health risk estimation of groundwater fluoride and nitrate in a lithium ore deposit basin in western Serbia. Groundwater major ion hydrogeochemistry was governed by water–rock interactions, with Ca-Mg-HCO₃ identified as the predominant groundwater type. The entropy-weighted water quality index (EWQI), sodium adsorption ratio (SAR), and sodium percentage (%Na) revealed that 95% of the samples were of excellent to good quality for both drinking and irrigation. Moreover, the results showed that fluorides were of geogenic origin, whereas nitrates originated from agricultural activities. Although the fluoride and nitrate levels in groundwater were relatively low, averaging 1.0 mg/L and 11.1 mg/L, respectively, the results of the health risk assessment revealed that the ingestion of such groundwater can still lead to non-cancerous diseases. The threshold of one for the hazard index was exceeded in 15% and 35% of the samples for adults and children, respectively. Children were more vulnerable to non-carcinogenic risk, with fluorides being the primary contributing factor. The study outcomes can serve as a reference for other lithium-bearing ore areas and guide the management of regional groundwater resources. Full article

Contamination with potentially toxic elements (PTEs) frequently occurs in surface water in coal mining areas. This study analyzed 34 surface water samples collected from the Yunnan–Guizhou Plateau for their hydrochemical characteristics, spatial distribution, source apportionment, and human health risks. Our statistical analysis showed that the average concentrations of PTEs in the surface water ranked as follows: Fe > Al > Zn > Mn > Ba > B> Ni > Li > Cd > Mo > Cu > Co > Hg > Se > As > Pb > Sb. The spatial analysis revealed that samples with high concentrations of Fe, Al, and Mn were predominantly distributed in the main stream, Xichong River, and Yangchang River. Positive matrix factorization (PMF) identified four sources of PTEs in the surface water. Hg, As, and Se originated from wastewater discharged by coal preparation plants and coal mines. Mo, Li, and B originated from the dissolution of clay minerals in coal seams. Elevated concentrations of Cu, Fe, Al, Mn, Co, and Ni were attributed to the dissolution of kaolinite, illite, chalcopyrite, pyrite, and minerals associated with Co and Ni in coal seams. Cd, Zn, and Pb were derived from coal melting and traffic release. The deterministic health risks assessment showed that 94.12% of the surface water samples presented non-carcinogenic risks below the health limit of 1. Meanwhile, 73.56% of the surface water samples with elevated As posed level III carcinogenic risk to the local populations. Special attention to drinking water safety for children is warranted due to their lower metabolic capacity for detoxifying PTEs. This study provides insight for PTE management in sustainable water environments. Full article

A novel comprehensive resilience assessment framework for drinking water systems is proposed integrating different resilience perspectives (i.e., robustness, autonomy, flexibility, reliability, preparedness and recovery), oriented by objectives, criteria and metrics, applicable at the tactical level. The resilience assessment framework is applied to a Portuguese real water distribution network, enabling the evaluation of the system’s resilience. The infrastructure dimension is the main contributor to the low resilience results, particularly in terms of infrastructural robustness, as the infrastructure has exceeded the average service life and has low rehabilitation rates. In terms of autonomy, the system highly depends on external water and energy sources. Regarding the service dimension, most of the drinking water available is used for non-potable uses (e.g., irrigation), without alternative sources. The detailed diagnosis identified network area R6 as the priority area. Assets rehabilitation, increasing storage capacity, finding alternative water and energy sources, and minimizing non-potable uses are relevant improvement measures that promote the reinforcement of the system’s resilience. The resilience assessment framework is a very useful tool for the daily and tactical management of drinking water systems. Full article

Identified as a potential reference pathogen by the WHO Guidelines for Drinking-Water Quality, Rotavirus (RV) is among the main enteric viruses that cause waterborne diseases. The aim of this study was to identify and correlate the presence of RV in collective and individual water sources of rural communities in the state of Goiás, within the seasons in which the collections were made (rainy and dry seasons). For this, 86 water samples in the dry period and 160 samples in the rainy period were collected. Concentration of water samples, extraction of viral genetic material and molecular tests were performed. When analyzing the presence of RV in the samples, taking into consideration the period studied, RV was found to be more prevalent in the dry season (54.7%) than in the rainy season (20%), showing a strong statistical association with the dry season (p-value < 0.001). The presence of pathogenic microorganisms in water is a public risk issue, enabling the emergence of outbreaks, endemics and epidemics. In the present research, there was an association between the presence of Rotavirus and the dry period of the year when compared to the rainy period. Full article