Streams and rivers are among the most vulnerable water resources to contamination due to their extensive contact with terrestrial environments. Contaminated streams and rivers pose significant threats to downstream ecosystems. This study examined water quality parameters in lotic or potamic habitats (n = 60) that flow into the Marmara Sea. Samples were collected during the spring season (May 12-26, 2024) and analysed for ten limnological parameters, including dissolved oxygen (DO), electrical conductivity (EC), pH, total dissolved solids (TDS), nitrate nitrogen (NO3-N), nitrite nitrogen (NO2-N), ammonium nitrogen (NH4-N), phosphate phosphorus (PO4-P), turbidity, and salinity. The average values of these parameters were 6.76 mg/L for DO, 4.00 NTU for turbidity, 1.23 mg/L for NO3-N, 0.20 mg/L for NO2-N, 0.91 mg/L for NH4-N, and 0.35 mg/L for PO4-P. Water quality was further examined using statistical and ecotoxicological indicators to assess potential risks to ecosystems and human health, including concerns related to mucilage formation. This study employed a range of statistical models-including principal component analysis (PCA), cluster analysis (CA), water quality index (WQI), nutrient pollution index (NPI), hazard quotient (HQ), hazard index (HI), and geospatial mapping-to deliver a comprehensive toxicological, statistical, and spatial assessment. The results identified the Gemlik and I(center dot)zmit Gulfs as the highest-risk zones for the Marmara Sea. Additionally, high population densities, industrial activities, and inadequate infrastructure in the watersheds of the Gemlik, Gebze, S,erefli, and & Ccedil;anakkale streams were identified as significant stressors for the Marmara Sea ecosystem.

Rivers discharging into the Marmara Sea integrate contaminant inputs from industrial, urban, agricultural, mining, and geogenic sources. Dissolved potentially toxic elements (PTEs) and phosphorus were measured in spring 2024 at 60 freshwater river channels immediately upstream of their discharge into the Marmara Sea. Concentrations showed substantial spatial heterogeneity. The WHO drinking-water guideline values for boron (2400 µg/L) and arsenic (10.00 µg/L) were exceeded at 2/60 and 10/60 stations, respectively. Dilovası Creek in the İzmit Gulf represented the principal industrial-metal hotspot, with the basin-wide maxima for Ni (119.2 µg/L), Al (368.4 µg/L), Cr (19.2 µg/L), Zn (142.3 µg/L), and Co (1.99 µg/L). Çapraz Stream in the Susurluk Basin had the highest B (3522.8 µg/L) and As (36.8 µg/L) concentrations and the poorest index-based water-quality status (WQI = 93.826; HPI = 232.391), whereas Şerefli Creek in the Tekirdağ Region showed the maximum dissolved-P concentration (6656.3 µg/L). Multivariate analysis and positive matrix factorization distinguished industrial-metal, B–As-enriched, and nutrient-related chemical profiles. Arsenic was the principal toxicological concern: Monte Carlo 95th-percentile HI values were 1.28 for adults and 1.60 for children, while corresponding CR values were 5.81E-04 and 7.29E-04. These screening results identify B–As-enriched southwestern sub-basins and industrialized eastern sites as priorities for targeted monitoring and source-specific mitigation.

The Thrace Region of Türkiye hosts diverse lacustrine habitats (LH) that are particularly vulnerable to potentially toxic elements (PTEs). This study investigated 25 PTEs in 33 LH, including 19 irrigation ponds, 12 reservoirs, and 2 natural lakes, across dry and wet seasons. Concentrations varied considerably, with Na and Mg showing the highest levels across all sites and seasons. Seasonal changes were pronounced: several PTEs, including Li, B, Na, and Mg, were strongly diluted during the wet season (up to 99

Enne Dam Lake (EDL) is a vital resource for regional water supply and ecosystem stability within the Sakarya River Watershed. Located in Kutahya (39° 28′ 21″ N; 29° 51′ 58″ E), this reservoir covers 0.94 km2, has a storage capacity of 6.85 million cubic meters, and has provided drinking water since 1972. Despite its importance, recent data on its water quality remain insufficient. This study evaluated the spatial distribution of hydrochemical parameters in EDL to identify contemporary environmental pressures. Physicochemical factors, including nitrite (NO₂–N), phosphate (PO₄–P), dissolved oxygen (DO), electrical conductivity (EC), and turbidity, were analysed using samples from 15 stations collected in summer 2025. The highest temperature, EC, TDS, NO₂–N, and PO₄–P values of 26.4°C, 650 µS/cm, 299 mg/L, 0.006 mg/L, and 0.57 mg/L were found upstream of the EDL, respectively. Results showed that the inflow regions, impacted by thermal tourism discharges and domestic wastewater, have higher temperatures, reduced DO, and elevated NO₂–N and PO₄–P levels. Spatial distribution maps were generated using Geographic Information Systems (GIS), while the Pearson correlation matrix (PCM), and cluster analysis (CA) identified pollution hotspots. Nutrient pollution index (NPI) values were lowest near the dam outlet (moderate pollution, 1–3) and the highest in the mid-reservoir zone and inlet (high pollution, > 6). These findings reveal significant spatial heterogeneity and highlight the urgency of integrated watershed management.

Lakes are among the most vulnerable freshwater ecosystems to contamination due to their closed nature and limited water movement. Despite this vulnerability, these lakes play a critical role in regulating water supply to downstream rivers and associated ecosystems. This study assessed the quality and potential risks of Saidgai and Katora lakes in the Hindu Kush region of Pakistan. Water samples (n = 5–10 replicates) were collected from Saidgai Lake (SGL), Lower Katora Lake (LKL), and Upper Katora Lake (UKL). Physicochemical parameters were measured using a multiparameter analyzer (C6030, Belgium), and concentrations of heavy metal(loid)s (HM) by inductively coupled plasma mass spectrometry. Most physicochemical parameters were within World Health Organization (WHO) drinking water guidelines, except for turbidity and Pb. According to the drinking water quality index (WQI), 90

The Himalayan lacustrine ecosystems (HLEs) provide ecological services and regulate water flow in streams and rivers of various South Asian countries. The study examined HLEs for drinking and various associated risk evaluation indices and their spatial distribution. For this purpose, forty-two water samples were picked from five HLEs of Kaghan Valley, Pakistan and analyzed for the physicochemical parameters, including heavy metals. Results revealed that the water parameters studied in HLEs were within the WHO drinking guidelines. Water quality was evaluated for the heavy metals evaluation index (HEI) and chronic risks. Based on HEI values, the HLEs were classified into low to medium levels of contamination. Among heavy metals, iron (Fe) showed the maximum average daily dose values of 11.7 +/- 2.08 mu g/kg-day via Paye Lake (PL) water consumption. This study noted higher hazard quotient (HQ) values of 0.37 +/- 0.06 for cadmium (Cd) in children via Siri Lake (SL) water consumption. Hazard index (HI) values via intake of heavy metals in studied HLEs water were observed as less than the threshold of 1.0. Heavy metals concentrations in water showed positive and negative correlations. Cluster analyses grouped the samples into four classes based on their diverse nature of contribution.

The K & uuml;tahya Silver Mine, located in the Felent Stream Basin, stands as T & uuml;rkiye's silver production site. Additionally, thermal tourism facilities in the upstream region are also degrading water quality of Felent Stream. This study meticulously examined the levels and spatial-temporal variations of 18 potentially toxic elements (PTEs) in the sediments of the Felent Stream Basin and evaluated their ecotoxicological risks during dry and wet seasons. The average sediments contamination levels of PTEs were ranked as follows: Fe > Al > Zn > Mn > Sr > Pb > Ba > Ni > Cu > As > Cr > Li > V > Cd > Co > Sb > Se > Hg. Remarkably, during the wet season, sediment samples revealed an approximate threefold surge in the average concentrations of PTEs. Ecological risk assessment indicators highlighted that the basin experienced low pollution levels in the dry season, escalating to moderate pollution levels during the wet season. Non-carcinogenic risks for studied PTEs and carcinogenic risks for As remained below the threshold values in both seasons. Statistical analyses pinpointed the Yoncal & imath; District, a prominent thermal tourism area, as the primary contributor to the sediment contamination of the Felent Stream Basin. The Enne Dam Lake, the region's main stagnant water body, emerged as the least contaminated component, functioning as a natural filter for the basin and significantly mitigating the levels of PTEs in the sediment.

Himalayan rivers were observed to be more vulnerable having irregular water flows, flooding, and contamination due to various stresses, including climate change, urbanization, and industrial development. This study investigated the occurrence, sources, ecological, and health-based ramifications for heavy metal(loid)s (HM), i.e., As, Cu, Zn, Co, Pb, Sb, Cr, Cd, Mn, and Ni in the Astore river basin (ARB), Himalayas, Pakistan. Results of HM contamination index (HCI) estimations suggested that 2.43 %, 12.2 %, and 24.4 % of water samples from the Astore and Rupal valleys may pose strong, moderate, and low toxicity risks, respectively. Pb, Cu, and Cd contribute more to the aquatic toxicity than any other HM included in the ecological risk index (ERI) estimations. Children are the most vulnerable age group to health ailments caused by HM. Statistical analyses revealed that geogenic sources mainly contribute to HM, except for Ni and Cr, which are mainly derived from anthropic sources in ARB.

Lakes are more vulnerable to water contamination due to their stagnant and close nature. This study investigated spatiotemporal distributions of organic stressors in the Uluabat Lake Basin (ULB) water. The ULB include Uluabat Lake (UL) and Emet (ES), Orhaneli (OS), and Mustafakemalpas,a streams (MS). A total of 20 locations (17 fluvial and three lacustrine habitats) were defined, and water samples were collected in the wet and dry seasons of 2023-24 and measured for 14 limnological parameters. The DO values decreased approximately by 1.5 times and turbidity ten times, while COD and NH4-N values increased by approximately 1.5 times, SO4 2.5 times, and temperature, NO2-N, and PO4-P 3.5 times in the dry season. The ULB was evaluated for water quality index (WQI), organic pollution index (OPI), eutrophication index (EI), nutrient pollution index (NPI), hazard quotient (HQ), hazard index (HI), Pearson's correlation index (PCI), principal component analysis (PCA), cluster analysis (CA) and Geographic Information System (GIS) to show the comprehensive holistic quality characteristics for ecotoxicological, statistical and visual perspectives. Results revealed the contamination of the investigated habitats as follows: OS > UL > MS > ES. The health risk assessment was under the acceptable level (HI < 1) for the studied habitats. The PCA noted two influential factors ("agriculture factor" and "sewage factor"), and CA established three groups such as "relatively less contaminated zone", "relatively moderate contaminated zone" and "relatively more contaminated zone".

This study comprehensively assessed the groundwater quality for drinking and irrigation, its hydrochemical characteristics, and potential health risks associated with nitrate (NO3) concentration via the oral pathway. The studied parameters were within the acceptable limits, except for TDS, turbidity, Na, K, SO4, and Cl, which exceeded the limits in 11

The safe and sustainable use of global groundwater resources demands regular monitoring, conservation strategies, and public awareness to ensure and maintain water quality standards. However, this job is more challenging for developing nations, primarily due to the capital costs of environmental conservation and inadequate data availability. This study aimed to investigate the groundwater in Kotli district, risk assessment indices, source apportionment, and their spatial distribution pattern in the Azad Jammu and Kashmir, Pakistan. Groundwater (n = 40) was sampled from two major towns in Kotli District and examined for physicochemical parameters. Results revealed that most parameters were under the drinking water thresholds set by WHO. Water suitability was evaluated through the drinking water quality index (WQI), health risks assessment, and irrigation indices. The drinking WQI categorized the water as excellent, and hazard quotient values remained below the threshold of 1. Irrigation indices classified water into good to excellent categories. These findings highlight that although groundwater in the Kotli district is mainly suitable for drinking and irrigation, continued monitoring and comprehensive risk assessment are pivotal to safeguard public health and ensure long-term water sustainability in the region.

Aim of the study Although groundwater is a primary source of accessible freshwater, it is also particularly susceptible to contamination. Recognizing its importance is crucial for ensuring clean and sustainable drinking water on a global scale. The Thrace Region, renowned for its fertile agricultural lands, faces environmental pressures as agricultural and livestock activities pose a potential risk to local freshwater quality. This study aimed to assess the seasonal variation in drinking water quality in the Lalapa & scedil;a district of the Edirne province, within the Thrace Region, by analysing a range of physicochemical parameters. Material and methods A total of 28 drinking water samples were collected from various villages in Lalapa & scedil;a during the summer, autumn, and winter seasons of 2020-2021. Each sample was analysed for the following twelve parameters: dissolved oxygen (DO), oxygen saturation (O2%), pH, electrical conductivity (EC), total dissolved solids (TDS), suspended solids (SS), salinity, turbidity, nitrate (NO3-), nitrite (NO2-), phosphate (PO43-), and sulfate (SO42-). The results were evaluated against national and international drinking water quality standards. Furthermore, ecological assessment was conducted using the water quality index (WQI), and statistical analyses were carried out using factor analysis (FA) and the pearson correlation index (PCI). Results and conclusions FA revealed three major factors-'salinity factor,' 'agricultural factor,' and 'oxygen factor' - which together explained 74% of the total variance. Despite elevated concentrations of nitrogen and phosphorus in some samples, WQI values at all stations remained within acceptable limits. These findings highlight the essential role of sustainable polyculture agricultural practices in protecting the region's groundwater resources.

Aim of the study The Meriç Plain, a critical agricultural region known as the "Rice Land" in Türkiye, hosts the country's largest rice cultivation area. This study examines the environmental sustainability awareness of rice farmers in the region. Material and methods Data were collected from 103 farmers using a convenience sampling method and statistically analysed using SPSS 27 software. Results and conclusions The findings revealed that environmental sustainability awareness is not significantly influenced by demographic factors such as age or income, while the level of education has a significant positive impact. Farmers with only primary education exhibited significantly lower awareness compared to those with higher education levels. No significant difference was observed among those with high school, associate, and bachelor's degrees, indicating that awareness stabilizes after a certain educational threshold.

Surface water pollution through uncontrolled industrial discharge is a global concern. In this study, 50 water samples from Dhaleshwari River (Bangladesh) were collected and analyzed for 27 water quality parameters (temperature, DO, BOD, pH, EC, TDS, alkalinity, hardness, Pb, Cd, Cr, As, Hg, Ag, Mn, Co, Fe, Ni, Zn, Cu, Mg, F-, Cl-, NO2-, Br-, NO3-, and SO42-) in wet and dry seasons. The aim of this study was to delineate seasonal river water quality, trace pollutants source, and evaluate public health risks through exposure, for environmental sustainability. Water physicochemical properties were measured using a Multimeter. Toxic metals were determined using an atomic absorption spectrophotometer while anions were estimated using the ion chromatography. Spatial and seasonal variation of the parameters were evaluated through GIS and statistically. Several indices were used for water quality and health risk evaluations. Investigation revealed Cr, Mn, Fe, Ni, and Hg were the most prevalent pollutants in this river in both wet and dry seasons, while temperature, DO, BOD, EC, TDS, Cl-, and NO3- were the most concerning parameters in the dry season. One-way ANOVA indicates significant (p < 0.05) variations in concentration for most of the parameters over the studied region in both seasons. Water quality indices indicate severe heavy metal pollution in the river water. Discharged pollutants have changed the water physicochemical parameters significantly. Principal component analysis revealed significant anthropogenic elemental (Cr, Pb, Cd, As, Hg, Ag, Mn, Co, Ni, Zn, and Cu) contributions to the river water. Health risk assessment suggests that Mn, Cr, Co, Hg, and As in the river water could cause adverse effects on human health. Therefore, effective legislative and administrative measures should be implemented for the regulated discharge of industrial effluents in the area to ensure a safe and sustainable environment for aquatic organisms and human beings.

Lakes are among the most susceptible freshwater ecosystems to heavy metal (HM) contamination. Sediment acts as a sink and a source of HM contamination in an aquatic environment. This study investigated HM contamination in the six Hindu Kush Lacustrine (HKL) sediments. HM contaminations in sediments were examined using atomic absorption spectrophotometry. Mn showed the highest average contamination of 984 ± 71.8 mg/kg in the Sosot Lake (SL), while Cd displayed the lowest of 0.58 ± 0.20 mg/kg. The SL showed elevated levels of Mn, Cr, Ni, and Zn, while Cu, Pb, Co, and Cd were dominant in Lower Katora Lake (LKL). The contamination factor (Cf) of Cd reached a maximum level of 6.01 ± 0.63 in Saidgai Lake (SGL) and a minimum of 0.70 ± 0.10 in SL. Results of pollution load index (PLI) values were reported as less than 1 for the studied HKL ecosytem, showing no HM pollution in sediments. Ecological risk index (E_r^i ) and risk index (RI) values identified the SGL sediments as the most affected, mainly due to Cd enrichment. Statistical analyses revealed that geogenic and mixed anthropic factors governed HM contamination in these HKL. The findings provide baseline information on sediment quality in the HKL, supporting future monitoring and conservation efforts in this ecologically important region under a climate change scenario.

This study investigated inorganic contamination and associated ecotoxicological, irrigational and health risks in eight fluvial habitats discharging into the Çanakkale Strait (ÇS), analysing twelve potentially toxic (PTEs) and essential (EEs) elements in seasonal surface water samples (2021–2022). Comprehensive water quality (WQI, HPI, NPI, CD, ERI), irrigational suitability (SAR, Na

This study investigates the water quality of the Abdal River System in Türkiye, an important water supply for the metropolitan area, using chemometric applications, including Positive Matrix Factorization (PMF) for source apportionment and Monte Carlo Simulation (MCS) for health risk assessment. Surface water samples were analyzed for 14 potentially toxic elements (PTEs), including nutrients and other elements. Their concentrations, in ascending order, were: Cd (0.13) < Cr (1.34) < Pb (1.50) < Mn (1.89) < Hg (1.98) < Cu (2.96) < Ni (5.32) < As (7.17) < Fe (31.16) < Zn (151.48) < Al (320.86) < K (3631) < Mg (15607) < Na (18870) < Ca (72842) μg/L. The water quality was evaluated utilizing indices including Heavy Metal Pollution Index (HPI), Water Quality Index (WQI), and Contamination Degree (CD), with results indicating generally good water quality and minimal pollution levels. PMF analysis identified three primary sources of contamination: natural/geogenic processes, agricultural runoff, and urban activities including domestic runoff. Health risk assessments highlighted arsenic as the most significant contributor to non-carcinogenic and carcinogenic risks. For children, the hazard index (HI) for arsenic was 7.35E-01 (ingestion: 7.26E-01; dermal: 9.00E-03), remaining below the safety threshold of 1, indicating no significant non-carcinogenic risk. Similarly, the carcinogenic risk (CR) for arsenic was 2.92E-04, within the acceptable range (1E-06 to 1E-04). The Monte Carlo Simulation quantified variability and uncertainty in health risks, highlighting arsenic as the main contributor, with 16.15 % of scenarios for children exceeded the acceptable non-carcinogenic risk threshold. This study is the first to integrate PMF with MCS for a comprehensive evaluation of pollution sources and health risks in the Abdal River System, offering a novel approach to environmental management in semi-urban watersheds. The findings confirm the water quality is safe under current conditions but highlight the need for ongoing monitoring and targeted mitigation to ensure sustainable management of the Abdal River System.

This study evaluates the nutritional value and health risks of fish from Miliç Wetland, Türkiye, focusing on potentially toxic elements (PTEs) in Esox lucius, Squalius cephalus, and Carassius gibelio. Using ICP-MS, mean PTE concentrations were determined, including Zn (4979 μg/kg), Fe (4241 μg/kg), and As (125 μg/kg). Macro elements like K, P, and Ca were also assessed for nutritional profiling. A Monte Carlo-based risk assessment confirmed that PTE levels were below safety limits, indicating safe consumption. Chemometric techniques (PCA, PCC, HCA) helped trace contamination sources, identifying residential, agricultural, and lithogenic inputs. Esox lucius showed the highest essential nutrient levels. This research highlights the importance of combining chemometric analysis with regular monitoring for food safety and public health protection.

This study aims to assess the spatial variation, water quality status, and human health risks of heavy metal(oid)s in the urban water of the Shyamasundari canal, northern Bangladesh. The results showed that Fe, Mn, and Pb concentrations in the canal water were found to be in the range of 0.4-2.3, 0.9-1.8, and 0.001-0.3 mg/L, surpassing the standard water quality values. About 79.56% of the samples were deemed as non-suitable to poor water quality for drinking. The contamination factor (CF), the degree of contamination (CD) and the pollution index (PLI) showed that urban water is highly contaminated in the studied canal. The health risk results showed that the hazard index exceeded the admissible limit (>1) for all age groups, indicating adverse non-carcinogenic risk, in particular for sites S5 and S9. Overall, the results suggest that exposure to surface water may negatively impact the health of individuals living nearby, emphasizing the need for strict regulation and efficient management to monitor and assess Fe, Mn, and Pb at these sites.