Search Results (57)

Access to clean drinking water is one of the main factors influencing public health during humanitarian crises. In the northern districts of the Gaza Strip, long-term warfare and mass migration caused serious damage to the water supply system, cutting off access to drinking water, limiting the availability of fuel and chemicals used for water chlorination, and increasing reliance on intermittent networks and water transportation services. The present study is a descriptive cross-sectional study of water quality and health risks in 11 emergency camps. Water samples were collected from supply points, communal tanks, and household storage containers and analyzed for key physicochemical indicators (pH, turbidity, electrical conductivity/total dissolved solids, residual free chlorine) and microbiological contamination (E. coli and fecal coliforms). Household surveys documented transport and storage practices, perceived service adequacy, and recent gastrointestinal illness. Overall, 35% of samples exceeded WHO microbiological limits; E. coli was detected in 28% of household containers and 24% of distribution tanks. Residual chlorine was <0.5 mg/L in 40% of samples and turbidity exceeded guidance in 18%. Forty-five percent of households reported transferring water using open/uncovered containers, and 42% reported gastrointestinal illness in the previous month, with higher reporting in sites showing microbial contamination. The results suggest that there are significant weaknesses in the source-to-point-of-use system during emergencies. The priority actions we recommend are, restoring residual disinfection; strengthening monitoring at important control points; improving hygienic transport and covered storage; and providing backup fuel and treatment supplies to minimize the risk of waterborne diseases in shelters in North Gaza. Full article

Petroleum exploitation in the Niger Delta has caused widespread contamination of mangrove ecosystems, yet studies that integrate total petroleum hydrocarbons (TPH) and metals in mangrove water are still very limited. This study presents the first dual-pollutant baseline assessment of TPH and five priority metals (Cd, Cr, Pb, Ni, Zn) in Bille mangrove water, a severely oil-impacted system supporting about 50,000 residents. Water samples were collected from six sites along a contamination gradient (flow station, pipeline passage, old bunkering site) and analyzed for TPH (C8–C40) and metals. All concentrations are reported in mg/L for direct comparability with World Health Organization (WHO) drinking-water guidelines and United States Environmental Protection Agency (USEPA) thresholds. TPH concentrations ranged from 0.18 to 57.66 mg/L, with Site 3 (pipeline passage) showing levels about 320-fold higher than reference sites and exceeding the WHO drinking-water guideline (0.05 mg/L) by up to 1153-fold. Cadmium (0.040–0.350 mg/L) and nickel (0.055–0.561 mg/L) exceeded WHO drinking-water guidelines (Cd 0.003 mg/L; Ni 0.07 mg/L) by 13–117- and up to 8-fold, respectively. Health risk assessment, using USEPA Risk Assessment Guidance for Superfund (RAGS) protocols, revealed a total cancer risk of 4.15 × 10⁻³ at Site 3, 41-fold above the USEPA acceptable threshold of 1 × 10⁻⁴, and extreme non-carcinogenic risk (Hazard Index = 20.03–25.51) at petroleum-infrastructure sites; cadmium contributed 86–88% of both carcinogenic and non-carcinogenic effects. Ecological risk indices classified Site 3 as extreme (Potential Ecological Risk Index = 722, against the Håkanson PERI = 600 “very-high-risk” threshold), mainly driven by cadmium (Er = 310–350) and nickel (Er = 140–150). Source apportionment using the Carbon Preference Index, enrichment factors, and strong TPH–metal correlations (r > 0.88, p < 0.01) clearly identified petroleum operations as the dominant contamination source. This work demonstrates the critical importance of integrated multi-pollutant assessments in petroleum-degraded mangrove water for guiding environmental protection and public-health interventions. Full article

Bottom-up approaches to climate resilience are increasingly promoted, yet there remains a gap in understanding how science-society connections can be operationalized in everyday contexts to support adaptive land-use practices, particularly in small towns and peripheral regions. This paper addresses this gap by examining how Living Labs (LLs) can function as process-oriented interfaces between scientific knowledge, local experience, and participatory negotiation, rather than as instruments for producing novel biophysical and social-learning insights. Drawing on selected case studies from the Biodiversity Hub and the Department for Building and Environment at the University for Continuing Education Krems (Austria), the study applies a qualitative, transdisciplinary Living Lab approach combining regular shared site walks, emotional communication, and cross-sectoral ecosystem services assessment matrices (aligned with established classifications and quantitative data collection). Resilience is grounded in the literature as a social–ecological capacity for adaptation and transformation and is operationalized pragmatically as the strengthening of connectedness between people, place, and ecological processes. The key findings show that short, place-based, and experiential interactions—such as shared walks and co-creative ecosystem service assessments—can lower participation barriers, mitigate power asymmetries, and enable rapid integration of scientific perspectives into everyday land-use decision-making. Rather than producing directly replicable outcomes, Living Labs generate transferable process principles, including emotional correspondence, structured negotiation, and the use of simple boundary tools to support collective learning and action. The paper contributes to resilience and land-system research by demonstrating how Living Labs can enhance local adaptive capacity and climate resilience through process design, immediate feedback, and continuous experimentation. It thereby complements conventional, indicator-driven assessments by illustrating how resilience can be enacted through participatory, place-based governance practices, offering practical guidance for municipalities and regions facing climate-related risks such as heat stress, drought, soil degradation, biodiversity loss, and increasing pressures on the secure provision of food, materials, and drinking water. Full article

Background/Objectives: Per- and polyfluoroalkyl substances (PFAS) are environmentally persistent chemicals widely detected in aquatic systems and drinking water. Perfluorononanoic acid (PFNA), a long-chain PFAS, has been reported globally in environmental matrices and fish tissues. Although PFNA has been linked to developmental, metabolic, and neurological toxicity, its effects on lipid-related pathways and neurotoxicity remain poorly characterized. Methods: This study evaluated the developmental and neurotoxic effects of PFNA exposure in zebrafish embryos and larvae following a 7-day exposure to environmentally relevant PFNA concentrations. Results: PFNA exposure did not significantly affect survival or deformity rates at the concentrations tested. Apoptosis was significantly increased in larvae exposed to 1 µg/L PFNA compared to controls, whereas reactive oxygen species levels were unaffected. Two concentrations (0.1 µg/L and 10 µg/L) were further examined for transcriptomic responses, and the transcriptome response was largely different for each concentration. Low-dose PFNA exposure primarily affected lipid transport, cholesterol metabolism, sphingolipid signaling, and neurodegeneration-related pathways, whereas high-dose PFNA altered transcripts related to synaptic signaling, axon guidance, and thyroid hormone synthesis. Hypoactivity was observed in the movement of larval zebrafish based on a Visual Motor Response test. Conclusions: Taken together, PFNA exposure induced molecular changes related to neurotoxicity and lipid metabolism in zebrafish, which may contribute to adverse neurodevelopmental outcomes. Full article

Nanofiltration (NF) is increasingly applied for advanced drinking water treatment, but achieving stable operation at high recovery rates remains challenging for surface waters with high scaling potential. This pilot study investigated the performance and optimization of a three-stage NF270 system (4:2:1 tapered array) for treating coagulated surface water in northern Jiangsu, China, aiming to identify sustainable operating conditions for high-recovery applications. The NF system was operated at recoveries of 80–90% with a feed flux of 20–23 LMH, and the effects of forward flushing frequency, acid dosing location, and concentrate recirculation on fouling behavior were evaluated. The NF270 membrane achieved consistent removal of organic matter (effluent chemical oxygen demand (COD_Mn) < 0.5 mg/L), hardness (40–60% rejection), and alkalinity (~20% rejection), meeting Jiangsu Province drinking water standards. However, operation at 90% recovery resulted in rapid third-stage fouling, with permeate flow declining by >60% within 2.5 h. Osmotic pressure analysis (local concentrate osmotic pressure: 3.8–4.2 bar; net driving pressure: 0.8–2.2 bar) confirmed physical scaling rather than hydraulic limitation as the dominant mechanism. Stage-wise concentration factor calculations (CF₁ = 1.6, CF₂ = 2.9, CF₃ = 4.4) revealed local Langelier Saturation Index (LSI) values of 1.8–2.2 in the third stage, identifying CaCO₃ supersaturation as the primary scaling cause. Reducing recovery to 85% and flux to 20 LMH with 2 h forward flushing extended stable operation. Acid addition effectively mitigated scaling, but dosing location was critical: first-stage addition (pH 8.1 → 7.6) reduced third-stage LSI to 0.7–0.9 and stabilized performance, whereas third-stage addition (pH 8.0 → 7.3) inadvertently promoted Al(OH)₃ precipitation from residual coagulant (feed Al: 0.07–0.11 mg/L). Concentrate recirculation (90% ratio) did not alleviate fouling. These findings demonstrate that for aluminum-rich coagulated surface waters, optimizing recovery, flushing frequency, and acid dosing location is essential for sustainable NF operation, and provide engineering guidance for full-scale applications. Full article

Eutrophication of water bodies and the bloom of toxin-producing cyanoprokaryotes raise health concerns. Various cyanoprokaryotes species, including Microcystis, Raphidiopsis, Nodularia, and Chrysosporum, release toxins into the aquatic environment, which can reach concentrations toxic to humans and animals. Rising temperatures and human activities are primary drivers behind the increasing frequency of toxic cyanobacterial blooms. The Word Health Organization (WHO) has established provisional guideline values for cyanotoxins in drinking water and water used for other purposes in daily human activities, and has published guidance for identifying hazards and managing risks posed by cyanobacteria and their toxins. There are currently no acceptable limit values for cyanotoxins. To address monitoring needs, contemporary strategies now incorporate molecular genetics, immunoassays, biochemical profiling, and emerging machine-learning frameworks. This paper reviews current early detection methods for harmful cyanobacterial blooms, highlighting their practical advantages and drawbacks. Full article

This paper presents a practical and auditable methodology for prioritizing drinking water hazards based on fuzzy preference relations (FPR). The method is based on additive pairwise comparisons of tap water quality parameters, which are aggregated (median) into a complete preference matrix. For each parameter, a Fuzzy Priority Index (FPI) was determined as the average “advantage” over the others. The FPI values were mapped to five fuzzy priority levels (very low–very high) using triangular/trapezoidal membership functions, followed by a defuzzification process using the centroid of singletons (COGS) method. The final step is to map the categories to operational actions, ensuring a clear transition from assessment to decision (from routine monitoring to immediate intervention). The method was demonstrated on nine parameters that are relevant for regulatory (WHO/DWD) and operational purposes: As, Pb, THM, NO₃⁻, Hg, Cr, Mn, Cu, Fe. Thirty-six pairwise assessments were determined, which, after aggregation, formed fuzzy relations. The resulting ranking (FPI) is: As (0.76) > Pb (0.70) > THM (0.64) > NO₃⁻ (0.56) > Hg (0.50) > Cr (0.43) > Mn (0.36) > Cu (0.30) > Fe (0.25). Fuzzy categorization assigned As, Pb, THM to the High level, NO₃⁻, Hg, Cr to Medium, and Mn, Cu, Fe to Low, with the Score reflecting the “proximity” of higher levels. The approach is transparent, replicable, and supports sensitivity analysis. The combination of FPI with fuzzy categorization and a decision map transforms expert knowledge and uncertainty into prioritized, actionable steps for water safety management. Full article

Climate change and increasing water scarcity are driving the need for resilient and fit-for-purpose urban water management. This study presents a case from Lisbon, Portugal, where twenty-one groundwater sources were evaluated as potential alternative supplies for emergency drinking and non-potable uses. Between 2018 and 2022, 127 samples were analyzed for microbiological (Escherichia coli, enterococci, fecal coliforms, heterotrophic plate count, Pseudomonas aeruginosa and Legionella pneumophila, physicochemical and fungal parameters (filamentous and yeast), alongside with microbial source tracking (MST) to determine contamination origins. Most sites showed exceedances of fecal indicators and heterotrophic bacteria, making water unsuitable for direct consumption without treatment, while fungi were ubiquitous and often above proposed guidance levels, highlighting a major regulatory gap. MST results indicated that human-derived contamination was rare and highly localized. Physicochemical parameters generally met legal thresholds, although occasional nitrate or salinity elevations reflected agricultural or coastal influences. Several sources were considered suitable for irrigation (EF, CC, AB, VF, and BS) whilst a subset met the criteria for potable supply with minimal treatment for risk management (CG, MM, CC, QC, EB, GR, PO, and MS). The findings of this study demonstrate that systematic, multiparametric assessment supports adaptive water allocation and emergency planning, aligning with EU regulations and advancing Sustainable Development Goal 6. The study argues for reconsideration of current microbiological standards, to improve public health protection in urban water reuse and emergency supply strategies. Full article

Identification of contamination sources is critical for effective remediation planning in contaminated aquifers. This study presents a simulation–optimisation framework that was developed to reconstruct the release history and identify the potential source location after tetrachloroethene (PCE) concentrations that exceeded regulatory limits were detected in production and monitoring wells at the Hrastje well field. The approach integrates a physically based groundwater flow and solute transport model with an evolutionary algorithm to estimate unknown source parameters. The method was tested under realistic field conditions, accounting for the complexity and uncertainty of the subsurface environment. In the optimisation procedure, parameter values converged towards optimal estimates, and the simulated PCE concentrations in monitored wells showed good agreement with the observed values. The delineated source location and the reconstructed temporal and spatial dynamics of PCE contamination in the aquifer provide essential guidance for decision makers in designing and prioritising remediation strategies. By narrowing the potential source area, more targeted and cost-effective field investigations can be planned. The developed model offers a practical tool for evaluating alternative remediation scenarios, supporting adaptive water resource management and safeguarding the drinking water supply. Full article

In arid and water-stressed regions, groundwater desalination plants are critical for ensuring reliable potable water supplies, making improvements in their operational efficiency and cost effectiveness a priority for utilities. In many such facilities, lime and soda ash softening remain common pretreatment practices, which increase chemical consumption and sludge generation, prompting the need for alternative low-chemical strategies. This study evaluates the technical, operational, and economic implications of transitioning a full-scale brackish groundwater desalination plant, from lime–soda ash softening (old plan) to a low-chemical pretreatment strategy based on antiscalant dosing (new plan) upstream of reverse osmosis (RO). Key parameters, including pH, total hardness, calcium and magnesium hardness, silica, iron, alkalinity, and total dissolved solids (TDS), were measured and compared at multiple locations within the treatment plant under both the old and new plans. Removing lime and soda ash caused higher levels of hardness, alkalinity, and silica in the water before RO treatment, increasing the risk of scaling. Operationally, the feed pressure increased from 11.43 ± 0.16 bar (old plan) to a peak of 25.50 ± 0.10 bar in the new plan, accompanied by a decline in water production. Chemical cleaning effectively restored performance, reducing feed pressure to 13.13 ± 0.05 bar, confirming that fouling and scaling were the primary, reversible causes. Despite these challenges, the plant consistently produced water that complied with Saudi Standards for Unbottled Drinking Water (e.g., pH = 7.18 ± 0.09, TDS = 978.27 ± 9.26 mg/L). Economically, the new strategy reduced operating expenditure by approximately 54% (0.295 → 0.135 $/m³), largely due to substantial reductions in chemical and sludge handling costs, although these savings were partially offset by higher energy consumption and more frequent membrane maintenance. Overall, the findings emphasize the importance of systematic performance evaluation during operational transitions, providing guidance for utilities seeking to optimize pretreatment design while maintaining compliance, long-term membrane protection, and environmental sustainability. Full article

Monitoring nitrate levels in water is critical to protect public health and ensure compliance with regulatory standards. This study provides a comprehensive evaluation of four analytical techniques—test strips, ion-selective electrodes (ISE), colorimetric methods, and titration—to assess nitrate levels in a variety of water sources, including standard solutions, rainwater, bottled water, and groundwater from both shallow and deep wells located in semi-urban regions of Saudi Arabia. Each method was assessed for sensitivity, accuracy, detection limits, reproducibility, and operational practicality. Test strips offer rapid, low-cost screening but consistently underestimate nitrate concentrations, particularly at low levels. The ISE demonstrated broad applicability and reliable performance across a wide concentration range when properly calibrated, making it suitable for both field and laboratory applications. Colorimetric methods provide excellent sensitivity for trace-level detection, whereas titration delivers the highest accuracy for high-nitrate samples despite its time-intensive nature. By calibrating and validating the methods against certified standards, we quantitatively demonstrated their reliability through statistical measures such as precision and accuracy rates. Moreover, the application of Geographic Information System (GIS) techniques in spatial analysis has revealed significant differences in the distribution of nitrates. Notably, shallow wells located in the northern regions surpass the 50 mg/L limit set by the World Health Organization (WHO), thereby indicating the presence of localized contamination hotspots. This study is among the first to systematically compare nitrate detection methods across a wide range of water types in a semi-urban area of Saudi Arabia. Building on a detailed analysis of each method, we underline the crucial need for the strategic selection of nitrate analysis techniques. This selection should be tailored to specific operational contexts, accuracy requirements, and concentration ranges to guide stakeholders towards more informed decision-making. These findings provide actionable guidance for public health officials and water managers to prioritize monitoring, safeguard drinking-water sources, and mitigate nitrate-related health risks in semi-urban communities. Full article

Cylindrospermopsin (CYN) is a potent cyanotoxin that poses a significant risk to human and animal health. Due to its occurrence in drinking water and food, as well as its ability to bioaccumulate in aquatic organisms and plants irrigated with contaminated water, the oral route is an important exposure pathway. However, data gaps in the current toxicological data for CYN jeopardize the establishment of health guidance values. In this context, mechanistic data and a deeper knowledge of CYN’s mode of action and its adverse outcome pathways are priorities for risk assessment. In recent years, omics techniques have enabled important advances in the comprehensive characterization of the molecular toxicity of CYN. In vitro studies have mainly focused on liver and kidney models, while in vivo studies have mostly used aquatic organisms. These studies have shown effects at both the transcriptional and protein levels on various signaling pathways related to detoxification, DNA damage, apoptosis, cell survival, and lipid metabolism, among others. However, studies using lipidomic, metabolomic, or microbiomic techniques are limited to date. Nevertheless, a recent study suggests that CYN may also induce gut dysbiosis, which would further extend its toxicological profile. This review emphasizes the need to further expand the use of omics approaches to accurately assess the risks associated with the consumption of CYN-contaminated foods. Full article

Rapid sand filtration is a critical step in the water treatment process, as its effectiveness directly impacts the supply of safe drinking water. However, optimising filtration processes in water treatment plants (WTPs) presents a significant challenge due to the varying operational parameters and conditions. This study applies explainable machine learning to enhance insights into predicting direct filtration operations at the Ålesund WTP in Norway. Three baseline models (Multiple Linear Regression, Support Vector Regression, and K-Nearest Neighbour (KNN)) and three ensemble models (Random Forest (RF), Extra Trees (ET), and XGBoost) were optimised using the GridSearchCV algorithm and implemented on seven filter units to predict their filtered water turbidity. The results indicate that ML models can reliably predict filtered water turbidity in WTPs, with Extra Trees models achieving the highest predictive performance (R² = 0.92). ET, RF, and KNN ranked as the three top-performing models using Alternative Technique for Order of Preference by Similarity to Ideal Solution (A-TOPSIS) ranking for the suite of algorithms used. The feature importance analysis ranked the filter runtime, flow rate, and bed level. SHAP interpretation of the best model provided actionable insights, revealing how operational adjustments during the ripening stage can help mitigate filter breakthroughs. These findings offer valuable guidance for plant operators and highlight the benefits of explainable machine learning in water quality management. Full article

Background/Objective: Chronic constipation is a common gastrointestinal disorder that can be caused by a variety of factors, such as demographic, lifestyle, and medical disorders like hypothyroidism. Its prevalence varies worldwide, affecting quality of life and leading to specialized management strategies. To explore hypothyroidism patients’ knowledge and practice regarding constipation and evaluate the perceived effectiveness of pharmacological and non-pharmacological management approaches. Methods: A descriptive, cross-sectional design was used to collect the data from a private hospital in the eastern region of Saudi Arabia from January to May 2025. A convenient sample of 300 individuals with hypothyroidism completed the Bowel Habits Questionnaire. Results: Most participants knew that hypothyroidism could cause constipation, but they reported that they did not have more knowledge about it. Both pharmacological and non-pharmacological interventions, especially increase water intake, fiber intake, and exercise, were commonly used by the participants, and they perceived these approaches to be effective. There were strong correlations between constipation frequency and age, disease duration, and the use of constipation management methods. A strong association was found between constipation management strategies and treatment effectiveness. Conclusion: Age, disease duration, and constipation management strategies significantly affect constipation in hypothyroidism patients. Drinking plenty of water and eating more fiber are two very effective non-pharmacological strategies. It is recommended that nurses who integrate routine bowel health education and lifestyle guidance into care plans consider the gap in patient knowledge regarding the relationship between hypothyroidism and constipation, to enhance patients’ self-management and contribute to better health outcomes. Full article

Relatively little data exist regarding the presence of unregulated contaminants in drinking waters. We sampled source and finished drinking water from 98 community water supply systems throughout Minnesota (U.S.). Facilities were grouped into four networks based on water source and influences from anthropogenic activities. Measured contaminants were dependent on network and included some combination of pesticides, pharmaceuticals, per- and poly-fluoroalkyl substances (PFAS), benzotriazoles, hormones, wastewater indicators, and illicit drugs. Overall, the number of contaminants detected in samples ranged from 0 to 35 and concentrations ranged from 0.38 ng/L (progesterone) to 47,500 ng/L (bromoform). Fewer contaminants and lower concentrations were detected in finished water samples, compared to source waters. Significantly (p < 0.05) more PFAS and pesticides and higher sample total concentrations were observed in wells designated as vulnerable to contamination. To estimate potential human-health risk from exposure in drinking water, concentrations were compared against bioactivity information from the U.S. Environmental Protection Agency’s ToxCast database and state-based guidance values, when available. Although comparisons could be made for relatively few contaminants, concentrations in finished waters were at least an order of magnitude lower than screening thresholds. Results from this study were used to inform enhancement of the Minnesota Department of Health’s drinking water protection program. Full article