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Öğe A global meta-analysis of toxic metals in continental surface water bodies(Elsevier Sci Ltd, 2023) Kumar, Amit; Kumar, Vinod; Pandita, Shevita; Singh, Sumit; Bhardwaj, Renu; Varol, Memet; Rodrigo-Comino, JesusThe anthropogenic toxic metal dissemination in surface water resources is a major ecological and public health concern at diverse scales, from the regional to the global scale. However, in the scientific literature, a review dealing with distributions, pollution levels, potential sources and related health risks of toxic metals in surface water resources at the continental, country and global levels are missed. Conducting such a study will shed light on how the most recent investigations reveal that the average concentrations of iron (Fe), lead (Pb), chromium (Cr) and mercury (Hg) in Asia; Fe, Pb, Hg, Cr, cobalt (Co), nickel (Ni), cadmium (Cd), and arsenic (As) in Africa; As, Hg and Cr in Europe, and North, Central and South America are exceeding the drinking water permissible limits set by the World Health Organization (WHO), respectively. To achieve this goal, we analysed datasets belonging to 233 articles published from 2010 to 2022. After conducting a multivariate statistical analysis, our meta-analysis demonstrated both anthropogenic and natural sources were responsible for the high toxic metal concentrations. Moreover, health risk assessment findings showed that the hazard quotient (HQ) values of As and Pb for the ingestion pathway, and HQ value of Pb for the dermal pathway were greater than one (HQ>1) for all continents, thus leading to non-cancer health risks. The novelty of our findings suggests that necessary control measures and robust policies should be implemented urgently to prevent an increasing contamination load in surface water bodies, save natural ecosystem areas and reduce potential human health risks, not only at the regional or national level but also at the global scale.Öğe Accumulation of trace elements in muscle, gill and liver of fish species (Capoeta umbla and Luciobarbus mystaceus) in the Tigris River (Turkey), and health risk assessment(Elsevier, 2020) Varol, Memet; Kaçar, Emel; Karadede Akın, HülyaTwo fish species (Capoeta umbla and Luciobarbus mystaceus) were collected from the Tigris River (Turkey), and tissues (gill, muscle and liver) of fish samples were analyzed for Cd, As, Mn, Cr, Cu, Co and Ni using the inductively coupled plasma-tandem mass spectrometry. Significant differences were present between fish species in regard to trace element (TE) concentrations in muscle for Mn, in liver for Cu, Cd and Mn, and in gill for As, Co, Cu and Cd (p < 0.05). Liver had the highest total TE concentration, followed by gill and muscle. Significant negative correlations were recorded between fish size (length and weight) and TE concentrations in the tissues. Both fish species showed no gender differences in TE accumulation in muscle, gill and liver (p > 0.05). The estimated daily intakes for all TEs were much lower than the tolerable daily intakes. The target hazard quotient (THQ) and total THQ values of all TEs did not exceed 1, which means that non-carcinogenic health effects are not expected for the consumers. Arsenic carcinogenic risk values were within acceptable range. Mean Cd concentrations in muscle tissue of both fish species exceeded the maximum permissible limit set by the European Commission Regulation, while mean concentrations of As, Cr and Cu were below the legislated limits.Öğe Analysis of metal(loid)s and minerals in tissues of fish from a reservoir on the Euphrates River by ICP-MS/MS: health risks, nutritional benefits and correlations with fish size(Pergamon-Elsevier Science Ltd, 2025) Varol, Memet; Kacar, EmelThis study analyzed the concentrations of 14 metal(loid)s and minerals (MMs) in the muscle, liver, and gills of Cyprinus carpio and Carasobarbus luteus collected from the Birecik Reservoir (T & uuml;rkiye), located along the Euphrates River, using ICP-MS/MS. It also examined the influence of fish size (weight and length) on MM accumulation, assessed potential health risks associated with metal(loid) exposure, and evaluated the nutritional value of essential elements. Significant differences in MM concentrations were observed between the two species across all tissues. In both species, the liver exhibited the highest levels of MMs, followed by gills and muscle. No consistent pattern was found between fish size and MM accumulation. Both fish were identified as good dietary sources of essential elements such as Cu, Mg, P, K, Zn, Fe, and Mn. Health risk assessments indicated that consumption of these fish poses no carcinogenic or non-carcinogenic risk to adults. The weekly safe consumption limits were calculated as 840 g for C. carpio and 1680 g for C. luteus. Overall, the findings suggest that the nutritional benefits of consuming these fish species outweigh the potential risks from metal(loid) exposure.Öğe Arsenic and trace metal concentrations in different vegetable types and assessment of health risks from their consumption(Elsevier, 2022) Varol, Memet; Gündüz, Kazım; Sünbül, Muhammet Raşit; Aytop, HalilThe levels of 12 trace metal (loid)s (TMs) in 10 vegetable types including leafy vegetables (purslane, purple basil and parsley) and fruiting vegetables (pepper, tomato, eggplant, cucumber, zucchini, green bean and melon) and in maize grown in Malatya province (Turkey) were investigated and non-carcinogenic health risks from consumption of these crops were assessed. The levels of TMs were measured by inductively coupled plasma-optical emission spectrometry. The mean levels of Ni, Cu, Cd, Cr, As and Zn in all crops were below maximum permissible concentrations (MPCs), while those of Pb in pepper (0.109 mg/kg fw), eggplant (0.103 mg/kg fw) and green bean (0.177 mg/kg fw) slightly exceeded MPCs (0.1 mg/kg fw). Leafy vegetables had relatively higher concentrations of Al, As, Ba, Cr, Cu, Fe and Mn compared to fruiting vegetables and maize. The estimated daily intake value of each TM estimated for each crop was found to be below the tolerable daily intake value. The target hazard quotients of all TMs in all crops did not exceed the acceptable non-carcinogenic risk level. However, hazard index (HI) value (1.57) in tomato was found to be above the threshold value of 1, indicating non-carcinogenic risks for consumers due to the intake of combined TMs in tomato. The THQ values of As, Co and Pb contributed 46.4%, 24.5% and 16.4% of the HI value of tomato, respectively. High daily consumption amount of tomato likely resulted in high HI value. The findings obtained in this study reveal that even if the levels of TMs in vegetables are safe, more attention should be paid to non-carcinogenic risks associated with TMs as a result of high vegetable intake.Öğe Arsenic and trace metals in a large reservoir: Seasonal and spatial variations, source identification and risk assessment for both residential and recreational users(Elsevier, 2019) Varol, MemetThe Keban Dam Reservoir in Turkey is an internationally important reservoir, because it is located on the Euphrates River, which is an important transboundary river. Water samples were seasonally collected from 11 sampling sites on the reservoir between autumn 2014 and summer 2015. Spatial and seasonal variations, possible sources and health risks of dissolved trace metals (TMs) were investigated. Among ten TMs, only Cr and Mn showed significant spatial variations, while Cr, Mn and Pb did not show significant seasonal variations. The average concentrations of TMs except As and Cd indicated a decreasing trend from autumn to summer. Also, minimum total metal concentration was recorded in summer due to raised water level of the reservoir. Maximum concentrations of all TMs were lower than the drinking water guideline values set by EC (European Community), WHO and USEPA. Principle component analysis/factor analysis and correlation analysis demonstrated that all TMs originate from natural sources. Non-carcinogenic and carcinogenic risks through ingestion and dermal contact exposure pathways were estimated for both residential and recreational receptors exposed to TMs in reservoir water. Hazard quotient, hazard index (HI) and total HI values were lower than 1. Also, carcinogenic risk (CR) values of As and Cr for each exposure route and total CR values were within the acceptable range of 10(-4) and 10(-6). Thus, the Keban Dam Reservoir is safe for human health in terms of residential and recreational uses. (C) 2019 Elsevier Ltd. All rights reserved.Öğe Assessment of groundwater quality and fluoride health risks using multimetric indices in Balochistan, Pakistan(Elsevier Sci Ltd, 2026) Zaheer, Muhammad; Jadoon, Waqar Azeem; Varol, Memet; Khan, Ibraheem; Islam, Abu Reza Md TowfiqulIn arid regions, groundwater contamination poses a critical threat to public health and agricultural sustainability. This study presents an integrated assessment of groundwater quality, hydrogeochemical processes, and associated health risks in five key districts (Bolan, Kalat, Nasirabad, Pishin, and Qilla Abdullah) of the water-stressed Baluchistan province, Pakistan. A total of 188 groundwater samples were analyzed for 16 physicochemical parameters. The Groundwater Quality Index (GWQI) classified water as Poor to Unsuitable in 60.0%, 59.0%, and 47.8% of samples from Nasirabad, Qilla Abdullah, and Bolan, respectively. Hydrochemical analysis, supported by Piper diagrams and ionic indices, indicated that groundwater in the study area is primarily dominated by Na-Cl, Na-HCO3, and mixed Ca-Mg-Cl facies, reflecting rock-water interactions, silicate and carbonate weathering, and spatially variable cation exchange processes. Irrigation suitability assessment, based on indices like Potential Salinity and Magnesium Hazard, revealed a high risk of salinity and magnesium hazard in most districts, threatening agricultural sustainability. The Health Risk Assessment model showed that fluoride exposure via ingestion poses a significant non-carcinogenic risk to the local population, with children being the most vulnerable group. Hazard Index (HI) values exceeding the safe threshold were observed in 97.1% of the population in Nasirabad and over 82% in Bolan. This comprehensive analysis underscores the urgent need for targeted mitigation strategies and sustainable groundwater management policies in this arid region.Öğe Assessment of hydrochemical characteristics, health risks and quality of groundwater for drinking and irrigation purposes in a mountainous region of Pakistan(Springer, 2024) Jadoon, Waqar Azeem; Zaheer, Muhammad; Tariq, Abdul; Sajjad, Raja Umer; Varol, MemetRenowned for its agriculture, livestock, and mining, Zhob district, Pakistan, faces the urgent problem of declining groundwater quality due to natural and human-induced factors. This deterioration poses significant challenges for residents who rely on groundwater for drinking, domestic, and irrigation purposes. Therefore, this novel study aimed to carry out a comprehensive assessment of groundwater quality in Zhob district, considering various aspects such as hydrochemical characteristics, human health risks, and suitability for drinking and irrigation purposes. While previous studies may have focused on one or a few of these aspects, this study integrates multiple analyses to provide a holistic understanding of the groundwater quality situation in the region. Additionally, the study applies a range of common hydrochemical analysis methods (acid–base titration, flame atomic absorption spectrometry, and ion chromatography), drinking water quality index (WQI), irrigation indices, and health risk assessment models, using 19 water quality parameters. This multi-method approach enhances the robustness and accuracy of the assessment, providing valuable insights for decision-makers and stakeholders. The results revealed that means of the majority of water quality parameters, such as pH (7.64), electrical conductivity (830.13 μScm–1), total dissolved solids (562.83 mgL–1), as well as various anions, and cations, were in line with drinking water norms. However, the water quality index (WQI) predominantly indicated poor drinking water quality (range = 51–75) at 50% sites, followed by good quality (range = 26–50) at 37% of the sites, with 10% of the sites exhibiting very poor quality (range = 76–100). For irrigation purposes, indices such as sodium percent (mean = 31.37%), sodium adsorption ratio (mean = 0.98 meqL–1), residual sodium carbonate (– 3.15 meqL–1), Kelley’s index (mean = 0.49), and permeability (mean = 49.11%) indicated suitability without immediate treatment. However, the magnesium hazard (mean = 46.11%) and potential salinity (mean = 3.93) demonstrated that prolonged application of groundwater for irrigation needs soil management to avoid soil compaction and salinity. Water samples exhibit characteristics of medium salinity and low alkalinity (C2S1) as well as high salinity and low alkalinity (C3S1) categories. The Gibbs diagram results revealed that rock weathering, including silicate weathering and cation exchange, is the primary factor governing the hydrochemistry of groundwater. The hydrochemical composition is dominated by mixed Ca–Mg–Cl, followed by Na–Cl and Mg–Cl types. Furthermore, the human health risk assessment highlighted that fluoride (F–) posed a higher risk compared with nitrate (NO3–). Additionally, ingestion was found to pose a higher risk to health compared to dermal contact, with children being particularly vulnerable. The average hazard index (HI) for children was 1.24, surpassing the allowable limit of 1, indicating detrimental health effects on this subpopulation. Conversely, average HI values for adult females (0.59) and adult males (0.44) were within safe levels, suggesting minimal concerns for these demographic groups. Overall, the study’s interdisciplinary approach and depth of analysis make a significant contribution to understanding groundwater quality dynamics and associated risks in Zhob district, potentially informing future management and mitigation strategies. © The Author(s) 2024.Öğe Bioaccumulation of Metals in Various Tissues of Fish Species in Relation to Fish Size and Gender and Health Risk Assessment(Springer Heidelberg, 2023) Varol, Memet; Kacar, EmelPurpose of ReviewThis study was aimed at identifying the differences in the levels of 17 metals and elements (MEs) between fish species (Capoeta tinca and Squalius pursakensis) and fish tissues (muscle, gills, and liver), at identifying the effect of fish gender and fish size (length and weight) on bioaccumulation of MEs in tissues, at assessing both health risks and benefits of MEs in fish muscle, and at defining safe fish consumption quantities for consumers.Recent FindingsThe levels of most MEs in tissues did not differ significantly between both fish species. The gills had higher levels of most MEs than the liver and muscle. Only a few MEs in the tissues of both fish species demonstrated significant associations with fish length or weight. There were no significant differences between male and female fish in terms of the levels of most metals in tissues. The estimated daily intake (EDI) values of metals were below the reference doses. Target hazard quotient (THQ) and hazard index (HI) values were less than 1. Carcinogenic risk (CR) values were within or below the acceptable range. Also, maximum safe fish consumption quantities (MSCQs) were established for consumers.Because both fish species were collected from the same water body and had the same habitat preferences, the levels of most MEs did not differ significantly in the tissues of both fish species. Because the gills and liver are metabolically active organs, they had higher levels of MEs than the muscle. The relationships between the levels of MEs in the tissues and fish size were both unclear and inconsistent. The results indicated that ME accumulation in tissues of individuals within the same species was not significantly influenced by gender. The THQ, HI, CR, and EDI values indicated that no adverse health consequences are expected for consumers. It was established that daily consumption of less than 50 g of C. tinca or 80 g of S. pursakensis would not be harmful to consumers' health. Nutritional evaluation results indicated that both fish species are good sources of essential MEs. Therefore, consumption of the fish species would bring tremendous health benefits.Öğe Boron contamination and related health risk assessment in the soils collected from olive groves in İzmir province, Türkiye(Elsevier Ltd, 2023) Varol, Memet; Deliboran, Aişe; Aytop, Halil; Ateş, ÖzgürAlthough boron (B) is an essential element for plants, high levels are also toxic. In this respect, pollution of soils by B may pose a serious problem for ecosystem and human health. On the other hand, studies evaluating the ecological and human health risks that may arise due to B contamination in agricultural soils are limited. In this study, it was aimed to determine the B pollution degree of the soils taken from the olive groves of İzmir province, which is approximately 180 km away from the B deposits in the Bigadiç district. In addition, the factors affecting boron adsorption and availability were discussed and the ecological and health risks of boron were evaluated. For this, soil samples were collected at depths of 0–30 cm from 118 olive groves and their B, Al, Fe, pH and organic matter contents were determined. The mean B content (47.08 mg/kg) of the study area was comparable to world-soil average B concentration (42 mg/kg). Also, B had a “low potential ecological risk” in the study area according to the ecological risk index results. On the other hand, based on the results of contamination factor (Cf) and enrichment factor (EF), “moderate contamination” and “significant enrichment” were found in the study area for B. These findings indicated that the B content in the study area is mainly related to the soil parent material, but irrigation water also contributes slightly to B content. Correlation analysis results suggested that Al and Fe contents of the soils in the study area may have an effect on B adsorption. The results of health risk assessment indicated non-carcinogenic effects are not expected for adults and children exposed to soil B content by ingestion, dermal contact and inhalation. © 2023 Elsevier LtdÖğe Characteristics of effluents from trout farms and their impact on water quality and benthic algal assemblages of the receiving stream(Elsevier, 2020) Varol, Memet; Balcı, MustafaIn this study, characteristics of effluents from three flow-through rainbow trout farms in Turkey and their impact on water quality and epilithic algal communities of the receiving stream were investigated. Water samples were taken monthly from both inlets and outlets of three fish farms, while both water and epilithic algae samples were collected from two stations (upstream and downstream) in the stream. A significant increase from inlets to outlets was observed for chemical oxygen demand (COD), soluble reactive phosphorus (SRP), total suspended solids (TSS), NH4–N and total phosphorus (TP) (p < 0.05) due to no effluent treatment processes and high FCR at the fish farms. The daily average total nitrogen (TN) and TP fluxes of the fish farms predicted with the nutritional method were found close to those measured with the hydrological method. Although there were significant increases in COD, TSS, NH4–N, TN, NO3–N, NO2–N, TP and SRP concentrations at the downstream station compared to the upstream station of the receiving stream (p < 0.05), water quality of the downstream station remained in Class I in terms of examined parameters. Trophic Diatomic Index and Biological Diatom Index values indicated that the upstream station had a better water quality than the downstream station. Also, filamentous algae such as Cladophora glomerata, Ulothrix zonata and Stigeoclonium lubricum were observed at the downstream station. In view of the above findings, several suggestions were put forward to protect the water quality of the receiving stream.Öğe CO2 emissions from hydroelectric reservoirs in the Tigris River basin, a semi-arid region of southeastern Turkey(Elsevier, 2019) Varol, MemetThree hydroelectric reservoirs (Kralkizi, Dicle and Batman) in the Tigris River basin (Turkey) were sampled monthly during one year in order to reveal spatial and seasonal changes in aqueous partial pressure of CO2 (pCO(2)) and to estimate diffusive fluxes of CO2 from the reservoirs' surface water. pCO(2) concentrations did not show significant spatial differences, while they showed significant seasonal variations. Temperature, precipitation and biological CO2 uptake through photosynthesis controlled pCO(2) seasonality in the reservoirs, with maximal concentrations in the winter (ranging from 516.9 mu atm in Kralkizi to 1299.2 mu atm in Dicle) and minimal concentrations in the spring (ranging from 47.7 mu atm in Batman to 140.7 mu atm in Kralkizi). Most studies reported that reservoirs worldwide are net sources of CO2 to the atmosphere. However, the reservoirs in this study were sinks for atmospheric CO2 during the spring, summer and autumn seasons, while they were CO2 sources to the atmosphere during the winter. Air-water CO2 fluxes in Kralkizi, Dicle and Batman dam reservoirs were 2.39, 32.88 and 8.12 mmol/m(2)/day in the winter, respectively. On an annual basis, all three reservoirs acted as a sink for atmospheric CO2. These estimated CO2 fluxes were in the lower range for temperate reservoirs, despite the potential for winter conditions that shifted the reservoirs from sink to net source for atmospheric CO2.Öğe A comparison of trace element concentrations in surface and deep water of the Keban Dam Lake (Turkey) and associated health risk assessment(Elsevier, 2020) Canpolat, Özgür; Varol, Memet; Öztekin Okan, Özlem; Eriş, Kürşad Kadir; Çağlar, MetinKeban Dam Lake (KDL) is the second largest dam lake in Turkey. There have been some reports on the trace element (TE) levels in surface water of the KDL, but its deep water has been never studied. We measured 17 TEs (Pb, Hg, Cd, As, Cr, Ni, Co, Mn, Cu, Fe, Al, Sr, U, V, Zn, Zr and Ba) in surface and deep water samples and assessed their health risks for residential and recreational receptors. Copper, Zn, Ba, Ni, Mn and Pb levels in deep water were higher than those in surface water. Total TE level in deep water was higher in wet season, whereas that in surface water was higher in dry season. TE levels in both surface and deep water were much lower than the guideline values for drinking water and the protection of freshwater aquatic life, indicating that TEs in the KDL originate from natural sources. All HQ (hazard quotient) and HI (hazard index) values were below the risk threshold of unity. HI values for child were higher than those for adult, indicating that the health of children is at dramatically higher risk than adults. Arsenic and U for water ingestion were the primary contributors to total risk (HI), while V and Cr for dermal pathway. The presence of U and V, among the TEs which are major contributors to total health risk, reveals the necessity of monitoring of such less-studied elements in the surface water bodies. Carcinogenic risk values of As and Cr in surface and deep water were below the target risk of 1 × 10?4. These findings indicated that TEs in surface and deep water of the KDL do not pose health risks to residential and recreational users. Thus this study may serve as a model for similar studies assessing health risks of multi-elements in freshwater bodies in future.Öğe Comprehensive analysis and risk assessment of fine road dust in Abbottabad city (Pakistan) with heavy traffic for potentially toxic elements(Elsevier, 2025) Jadoon, Waqar Azeem; Khan, Yousaf Ali; Varol, Memet; Onjia, Antonije; Mohany, MohamedHuman activities have far-reaching impact on natural ecosystems, causing increasing disturbances and disruptions to the delicate balance of the environment. Poor land use planning, urbanization, infrastructure development, and unplanned tourism exacerbate contamination and degradation in tourist destinations, yet the pollution of potentially toxic elements (PTEs) in these environments remains inadequately explored. To address this issue, we investigated the concentrations of acid-digested PTEs in road dust in Abbottabad city (Pakistan) with heavy traffic. The current study also evaluated PTE associated pollution, ecological and health risks, and potential sources of these elements. The average concentrations (in mg kg-1) of PTEs in road dust were highest for Fe (15540), followed by Mn (304), Zn (139), Cu (50.0), Pb (21.5), Cr (13.0), Ni (10.3), Co (6.66), and Cd (0.236). The levels of Co, Cr, Mn, Ni, and Fe were below the upper continental crust (UCC) averages, while Cd, Cu, Pb, and Zn exceeded them. Spatially, Cd, Cu, Pb, and Zn were found at higher levels near traffic hotspots, bus stands and automobile workshops. Road dust in Abbottabad exhibited unpolluted to moderate pollution levels (geo accumulation index), with Cd, Cu, Zn, and Pb at 23 % of the sites. The enrichment factor results indicated a significant anthropogenic influence, with Cd being significantly enriched and Zn, Cu, and Pb moderately enriched. The contamination factor results revealed moderate contamination by (Cd: 2.62, Zn: 2.08, Cu: 1.79, Pb: 1.27). Single metal risk index showed that 61 % of the sites posed considerable to very high ecological risks due to Cd, which was highlighted as a significant concern. The absolute principal component scores-multiple linear regression model identified three factors contributing to PTE pollution: lithogenic (Co, Fe, Mn, Ni), traffic-related (Cd, Cu, Pb, Zn), and mixed sources (Cr), with contributions of 52.8 %, 35.8 %, and 11.4 %, respectively. The PTE hazard quotient and total hazard index values for children and adults were below the safe risk level of 1, indicating no non-carcinogenic health risks. The cumulative carcinogenic risk values to the residents were also within acceptable limits. However, children's susceptibility to non-carcinogenic risks is higher due to their behavior and lower body weight. This study highlights the accumulation of PTEs in Abbottabad's environment, which poses challenges to long-term sustainability, particularly amid unplanned tourism. Therefore, urgent measures are necessary to mitigate PTE pollution and preserve tourist spots and public health.Öğe Comprehensive analysis of microplastics in water, sediment and fish from a large recreational lake(Academic Press Inc Elsevier Science, 2025) Varol, Memet; Karakaya, Gokhan; Arisoy, Guelden; Celik, BurcuWhile global attention has primarily focused on microplastics (MPs) in marine ecosystems, the issue of MP pollution in recreational lakes has received relatively little attention. In this study, the occurrence, spatial and seasonal distribution and characteristics of microplastics (MPs) were investigated for the first time in Lake Hazar (T & uuml;rkiye), an important recreational lake. Water, sediment and fish (Capoeta umbla) were sampled from the lake in the winter and summer of 2020. Thereafter, the MPs were extracted from the samples using the density separation method. Their abundance, shape, color, and size were determined microscopically, while the polymer types were analyzed using ATR-FTIR. The MPs were detected in all surface water and sediment samples, while they were detected in the gastrointestinal tracts of 28 (35 %) out of 80 fish samples. The abundance of MPs was 74-1091 items/m(3) for the surface water, 88-213 items/kg (ww) for sediments and 0-5 items/fish for C. umbla, respectively. The MP concentrations in water samples from the shore sites were found to be significantly higher than those in limnetic sites (p < 0.05). The most common MP shapes, sizes and colors were fragments, <0.5 mm and white/transparent, respectively. Polyethylene and polypropylene were the most common polymer types, indicating that recreational activities and fishing activities may be the main sources of MPs in the lake. The Pollution Load Index results indicated that MP pollution in the lake's water and sediments was at a moderate level.Öğe Comprehensive Assessment of Heavy Metal(loid) Pollution in Agricultural and Urban Soils near an Oil Refining Facility: Distribution Patterns, Source Apportionment, Ecological Impact, and Probabilistic Health Risk Analysis(Mdpi, 2025) Miletic, Andrijana; Veskovic, Jelena; Lucic, Milica; Varol, Memet; Crnkovic, Dragan; Potkonjak, Nebojsa; Onjia, AntonijeThis study investigated the spatial distribution of HMs in agricultural and urban soils near the largest oil refining complex in Serbia, identified pollution sources, and assessed ecological and human health risks. A large fraction of soil samples showed elevated Hg (40% of samples), Pb (53%), Cd (90%), and As (93%) concentrations compared to the background levels. Hotspots for Pb, As, Hg, Cd, and Zn were observed in the industrial area, indicating significant anthropogenic input. Multivariate analysis, including PMF, revealed four contamination sources: emissions from the oil refining industry, agricultural activities, traffic emissions, and natural background. The pollution indices mostly fell into the moderate pollution range, with As, Hg, and Cd showing the highest enrichment. The potential ecological risk index (RI) indicated that about one-third of the samples had moderate ecological risk and determined a major RI hotspot near the refinery. The health risk assessment identified As and Cr as the largest contributors to non-carcinogenic risk, although the average HI was below one. Monte Carlo simulation confirmed that adults and children had negligible health risks at the 95th percentile and highlighted exposure frequency and body weight as the most influential exposure parameters. Based on source-specific risk, the oil refining industry emissions had the highest impact on HI and TCR values.Öğe Comprehensive Assessment of Water Quality of a Transboundary River in Nepal Using Hydro-Chemical, Chemometric, Health Risk and Index-Based Approaches(Springer Int Publ Ag, 2025) Pant, Ramesh Raj; Varol, Memet; Awasthi, Mahesh Prasad; Bohara, Rupesh; Paudel, Sudip; Nepal, Jharana; Chakrabortty, RabinIn this study, advanced hydro-chemical analysis, chemometric techniques, health risk assessment and various indices were used to comprehensively assess the water quality of Mahakali River, which is an essential water resource for Nepal and India. Most parameters measured in the water samples collected from 25 sites in the basin during the pre- and post-monsoon periods were found to be compliance with drinking water standards, except NH4+ and Fe. The Water Quality Index values classified both the main river and its tributary (Chameliya River) as unsuitable for drinking. Nutrient pollution was found to be more severe in the tributary, which is much more affected by anthropogenic activities than the main river. Hydro-chemical analysis showed that the dominant water type in the basin is Ca-HCO3, which is mainly controlled by rock weathering. Apart from the magnesium hazard index, other irrigation indices confirmed that the surface water of the study area is suitable for agriculture. Chemometric methods provided deeper insights into the water chemistry of the basin by revealing pollution sources and relationships between parameters. Health risk assessment revealed minimal adverse health effects for children and adults exposed to NO3-N, Fe and F-. This pioneering study not only provides a holistic evaluation of water quality in a Himalayan glacier-fed river system but also establishes an innovative framework for sustainable water management in climate-sensitive regions worldwide.Öğe Determination of potentially toxic elements in soil, river water and spinach samples from the Lesser Himalaya (Pakistan) by ICP-OES: Implications for food security and public health(Academic Press Inc Elsevier Science, 2025) Jadoon, Waqar Azeem; Gul, Iram; Sajjad, Raja Umer; Varol, Memet; Saqib, Abdul; Mohany, Mohamed; Milosevic, MarijaPotentially toxic element (PTE) contamination of soils, irrigation water and vegetables poses food insecurity and human health concerns. This study investigated PTE contamination in water, soil, and spinach from two agricultural areas, Baffa and Ichrian, in the Mansehra District of Pakistan. The cadmium (Cd), chromium (Cr) and lead (Pb) contents of the samples were determined using inductively coupled plasma-optical emission spectrometry (ICP-OES) to evaluate their contamination status and ecological risks, plant bioaccumulation factor (PBAF) and potential human health risks. The results showed that Baffa's water had higher Cd (0.77-2.93 mu g L-1) and Pb (0.10-10.98 mu g L-1) levels than Ichrian's water, but was safe for drinking and irrigation according to guideline values. Soil concentrations of Cd, Cr, and Pb were higher in Baffa, with Cd levels surpassing global upper continental crust values in all samples and exceeding the recommended levels set by the Food and Agriculture Organization/World Health Organization (FAO/WHO) in 33 % of samples. Furthermore, the average Cd concentration in Baffa soils exceeded the European soil average. However, spinach PTE levels did not exceed guideline values. Contamination and ecological risk indices indicated moderate pollution in Baffa and low pollution in Ichrian, presenting moderate and low potential ecological risks, respectively. Based on plant bioconcentration factor analysis, minimal (<0.2) metal accumulation was recorded in spinach. The estimated daily intake (EDI) values revealed a metal ranking of Cr > Pb > Cd, with all values falling below the tolerable daily intake (TDI) levels, indicating no potential health risks. Target hazard quotient (THQ) and hazard index (HI) were below threshold level (<1), indicating no non-carcinogenic risk to the population. Although PTE levels in spinach were within safe limits, our findings emphasize the need for ongoing monitoring of PTE concentrations in soils and a broader range of vegetables, as cumulative exposure through consumption of multiple types of vegetables could exceed threshold limits, posing potential health risks.Öğe Dissolved metal contamination, source identification and health risk evaluation in the Tohma River (Turkiye): A spatial-seasonal study(Elsevier Sci Ltd, 2025) Varol, Memet; Tunc, AbdulkadirThe Tohma River, an important water source in the Euphrates Basin of T & uuml;rkiye, faces potential metal pollution from human activities including industrial discharges, agricultural runoff, mining operations and emissions from a coal-fired thermal power plant. Consequently, the water quality of the Tohma River could impact the ecological integrity of the transboundary Euphrates River. In this study, spatial and seasonal changes, pollution levels, ecological and health risks, and sources of ten dissolved metals (As, Zn, Cd, Pb, Co, Ni, Cr, Mn, Cu, Fe) in the river were comprehensively assessed. Water samples were gathered seasonally from 13 sites between 2023 and 2024 and analyzed using ICP-MS. The average metal levels (mu g/L) were ranked as follows: Fe (80.37) > Zn (27.15) > Cu (11.9) > Mn (7.3) > Ni (5.06) > As (1.72) > Pb (0.61) > Cr (0.129) > Co (0.028) > Cd (0.026). These levels were below the international safety thresholds, which are suitable for aquatic life, drinking, and irrigation. However, spatial analysis detected higher levels of Fe, Zn, and Cu at sites (T9, T13) near industrial discharge points and increased levels of Co, Ni, Cr, and Mn at sites (T1-T3) impacted by the Kangal Thermal Power Plant. Pollution indices (HPI, CD, NPI) and ecological risk index (ERI) confirmed low overall pollution, with Ni and As being identified as the primary metals contributing to pollution. The health risk assessments showed no significant carcinogenic or non-carcinogenic risks for both children and adults, although children were noted to be more vulnerable. Multivariate statistical methods (PCA/FA, cluster analysis) traced the origins of the metals: Co, Cr, Mn, and Ni from anthropogenic sources, Fe, Zn, Cu, Pb and Cd from mixed sources and As from natural sources. These findings highlight the need for targeted pollution control measures to protect the ecosystem and water quality of the Tohma River, ensuring sustainable management of water resources in the region.Öğe Ecological and health risk assessment and quantitative source apportionment of dissolved metals in ponds used for drinking and irrigation purposes(Springer Heidelberg, 2023) Tokatli, Cem; Varol, Memet; Ustaoglu, FikretIn this study, dissolved metal levels of 10 different ponds used as irrigation and drinking water sources in the north of Saros Bay (Turkiye) were evaluated using multivariate statistical methods, contamination and ecological risk indices, and absolute principal component score-multiple linear regression (APCS-MLR). The mean levels of metals in the ponds ranged from 0.045 mu g/L (Cd) to 127 mu g/L (Mn). Pond 7 used for drinking water source had the lowest total metal level. Only Mn levels in two ponds (P1 and P2) slightly exceeded the critical value set by EU Drinking Water Directive. However, the levels of all metals in all ponds were lower than the critical values set for irrigation water and aquatic life. According to the heavy metal pollution index (HPI), five ponds showed low metal pollution in terms of drinking water quality, four ponds showed moderate metal pollution, and one pond (P1) showed moderate to heavy pollution. According to the Nemerow pollution index (NPI) values (0.26-1.82), ponds P1 and P2 showed slight metal pollution, while other ponds showed insignificant metal pollution. Contamination degree (CD) values of ponds varied between 0.95 and 3.33, indicating that all ponds showed low pollution. In terms of irrigation water quality, all ponds showed low or insignificant metal pollution according to the HPI, NPI, and CD values. According to the ecological risk index (ERI) values, metals in all ponds posed low ecological risks for both drinking and irrigation purposes. Factor analysis identified two potential sources: mixed sources and natural sources. The APCS-MLR model results revealed that mixed sources and natural sources contributed 78.99% and 21.01% to dissolved metals in the ponds, respectively. Health risk assessment results indicated that both individual and combined metals in the ponds would not cause non-carcinogenic risks to both adults and children. Similarly, it was found that Cr and As would not cause carcinogenic risks to the residents of the region.Öğe Ecological Risk Assessment of Metals in Sediments from Three Stagnant Water Bodies in Northern Turkey(Springer Heidelberg, 2022) Varol, Memet; Ustaoglu, Fikret; Tokatli, CemPurpose of Review In recent years, anthropogenic activities have caused metal pollution in the sediments of stagnant water bodies, and thus threatening aquatic ecosystems and human health. Therefore, determining the potential ecological risks, contamination degree, and possible sources of metals in sediment of stagnant water bodies is essential for effective management of metal pollution. In this study, we used contamination and risk assessment indices together with multivariate statistics to determine ecological risks and contamination degree of 14 metals in sediments of three important stagnant water bodies (Ladik Lake and Yedikir and Degirmendere dam lakes) in northern Turkey. In addition, the effects of organic matter (OM) and pH on metal accumulation in the sediments were also investigated. Recent Findings The mean contents of Al, V, Mn, Fe, Cu, Zn, and Pb did not differ significantly among the water bodies studied (p > 0.05). The Ladik Lake sediments had significantly lower pH level and higher OM content (p < 0.05). Contamination indices indicated that there was no significant metal contamination in the sediments of all water bodies. Similarly, ecological risk indices indicated that metals posed low ecological risks in the water bodies. According to the sediment quality guidelines, metals would not cause harm to benthic organisms. The accumulation of most metals in the Yedikir Dam Lake was controlled by OM, while the distribution of some metals was affected by both OM and pH in the Degirmendere Dam Lake. According to the factor analysis, all metals in the sediments of the water bodies studied mainly originated from natural sources. The results of this study revealed that sediment contamination indices, ecological risk assessment methods, sediment quality guidelines, and multivariate statistics can be used as effective approaches in determining the environmental and ecological risks and pollution sources of metals in the sediments of stagnant water bodies. Thus, this study can provide important information for the ecological risk assessment and management of metals in the sediments of stagnant water bodies.
