Appraisal of contamination, hydrogeochemistry, and Monte Carlo simulation of health risks of groundwater in a lithium-rich ore area.

This study incorporated hydrogeochemical facies, the entropy-weighted water quality index (EWQI), multivariate statistics, and probabilistic human exposure assessment to investigate hydrogeochemistry, analyze groundwater quality, and estimate potential risks to human health in a lithium-rich ore area (Jadar River basin, Serbia). The findings designated the Ca·Mg-HCO3 hydrogeochemical type as the predominant type of groundwater, in which rock weathering and evaporation control the major ion chemistry. Due to the weathering of a lithium-rich mineral (Jadarite), the lithium content in the groundwater was very high, up to 567 mg/L, with a median value of 4.3 mg/L. According to the calculated EWQI, 86.4% of the samples belong to poor and extremely poor quality water for drinking. Geospatial mapping of the studied area uncovered several hotspots of severely contaminated groundwater. The risk assessment results show that groundwater contaminants pose significant non-carcinogenic and carcinogenic human health risks to residents, with most samples exceeding the allowable limits for the hazard index (HI) and the incremental lifetime cancer risk (ILCR). The ingestion exposure pathway has been identified as a critical contaminant route. Monte Carlo risk simulation made apparent that the likelihood of developing cancerous diseases is very high for both age groups. Sensitivity analysis highlighted ingestion rate and human body weight as the two most influential exposure factors on the variability of health risk assessment outcomes.

Arsenic-contaminated groundwater of the Western Banat (Pannonian basin): Hydrogeochemical appraisal, pollution source apportionment, and Monte Carlo simulation of source-specific health risks.

Due to rapid urbanization and industrial growth, groundwater globally is continuously deteriorating, posing significant health risks to humans. This study employed a comprehensive methodology to analyze groundwater in the Western Banat Plain (Serbia). Using Piper and Gibbs plots, hydrogeochemistry was assessed, while the entropy-weighted water quality index (EWQI) was used to evaluate groundwater quality. Pollution sources were identified using positive matrix factorization (PMF) accompanied by Pearson correlation and hierarchical cluster analysis, while Monte Carlo simulation assessed health risks associated with groundwater consumption. Results showed that groundwater, mainly Ca-Mg-HCO3 type, is mostly suitable for drinking. Geogenic pollution, agricultural activities, and sewage were major pollution sources. Consumption of contaminated groundwater poses serious non-carcinogenic and carcinogenic health risks. Additionally, arsenic from geogenic source was found to be the main health risks contributor, considering its worryingly elevated concentration, ranging up to 364 µg/L. These findings will be valuable for decision-makers and researchers in managing groundwater vulnerability. PRACTITIONER POINTS: Groundwater is severely contaminated with As in the northern part of the study area. The predominant hydrochemical type of groundwater in the area is Ca-Mg-HCO3. The PMF method apportioned three groundwater pollution sources. Monte Carlo identified rock dissolution as the primary health risk contributor. Health risks and mortality in the study area are positively correlated.

Dietary Intake of Minerals and Potential Human Exposure to Toxic Elements via Coffee Consumption.

In this study, we investigated the levels of macro, minor, and trace elements in roasted ground and instant coffees (n = 56). We assessed dietary mineral intake and health risks associated with potentially toxic elements (PTEs) using deterministic and probabilistic approaches. The limits of detection (LOD) ranged from 0.13 µg/kg for Be to 3.7 mg/kg for K, with corresponding limits of quantification (LOQ) at 0.43 µg/kg and 12.2 mg/kg. The recovery values (R%) ranged from 89 to 107%. The most abundant element was K, followed by Mg, Ca, and Na. Other elements followed this order: Fe > Mn > B > Cu > Sr > Zn > Al > Ba > Ni > Cr > Co > Se > Sn > Pb > Li > Ag > V > As > Cd > Hg > Be. Instant coffees generally exhibited higher K, Mg, and Na levels than ground-roasted coffees. Notably, Hg, Li, and Se were not detected in 34, 2, and 1 samples, respectively. Coffee samples were generally a good source of dietary elements such as Cu, Mn, Cr, and Se. The PTEs found in coffee products posed negligible risks to human health. The total target hazard quotient (TTHQ) remained below 1, and the incremental lifetime cancer risk (ILCR) did not exceed the threshold of 1 × 10-6. Nevertheless, coffee consumption contributed to Pb and As levels below 15% of the benchmark dose lower confidence limit (BMDL) values, and Sn, Hg, and Cd levels below 0.90% of the provisional tolerable weekly intake (PTWI).

Entropy-weighted water quality index, hydrogeochemistry, and Monte Carlo simulation of source-specific health risks of groundwater in the Morava River plain (Serbia).

Population growth, urbanization, industry, floods, and agriculture globally degrade groundwater in river plains, necessitating action for its quality assessment and management. Hence, a comprehensive methodology, including hydrogeochemical facies (Piper, Gibbs), irrigation indices (SAR, Wilcox), entropy-weighted water quality index (EWQI), positive matrix factorization (PMF), and Monte Carlo simulation of source-specific health risks was used in this study to analyze groundwater in the Morava river plain (Serbia). The results revealed a prevalent Ca-Mg-HCO3 groundwater type, influenced by water-rock interactions. Although groundwater was found suitable for irrigation, only 66.7 % of the samples were considered drinkable. Agricultural activities, natural processes, and municipal wastewater were identified as primary pollution sources. The incremental lifetime cancer risk (ILCR) and hazard index (HI) threshold exceedance for adults and children ranged from 8.5 % to 39 % of the samples, with arsenic identified as the most risk-contributing contaminant. These findings provide valuable insights for researchers studying groundwater vulnerability in river plains.

Spatial Variability of Rare Earth Elements in Groundwater in the Vicinity of a Coal-Fired Power Plant and Associated Health Risk.

This study investigated the occurrence and distribution of rare earth elements (REEs), including 14 lanthanoids, scandium (Sc), and yttrium (Y), in groundwater around a large coal-fired thermal power plant (TPP). The ICP-MS technique was used to analyze 16 REEs in groundwater samples collected from monitoring wells. REE concentrations ranged from 59.9 to 758 ng/L, with an average of 290 ng/L. The most abundant was Sc, followed by La, accounting for 54.2% and 21.4% of the total REE concentration, respectively. Geospatial analysis revealed the REE enrichment at several hotspots near the TPP. The highest REE concentrations were observed near the TPP and ash landfill, decreasing with the distance from the plant and the landfill. REE fractionation ratios and anomalies suggested the Light REE dominance, comprising over 78% of the total REEs. Correlation and principal component analyses indicated similar behavior and sources for most REEs. Health risk assessment found hazard indices (HI) of 1.36 × 10-3 and 1.98 × 10-3 for adults and children, respectively, which are far below the permissible limit (HI = 1). Likewise, incremental lifetime cancer risks (ILCR) were all below 1 × 10-6. Nevertheless, ongoing ash disposal and potential accumulation in the environment could elevate the REE exposure over time.

Ecological and Health Risks Attributed to Rare Earth Elements in Coal Fly Ash.

The occurrence and distribution of yttrium and rare earth elements (REYs), along with major elements and heavy metal(loid)s (HMs) in coal fly ash (CFA) from five coal-fired power plants (CFPPs), were analyzed, and the REY-associated ecological and health risks were assessed. The individual REYs in CFA were abundant in the following order: Ce > La > Nd > Y > Pr > Gd > Sm > Dy > Er > Yb > Eu > Ho > Tb > Tm > Lu. The total REY content ranged from 135 to 362 mg/kg, averaging 302 mg/kg. The mean light-to-heavy REY ratio was 4.1, indicating prevalent light REY enrichment in CFA. Significantly positive correlations between the REYs suggested that they coexist and share similar origins in CFA. REYs were estimated to pose low to moderate ecological risks, with risk index (RI) values ranging from 66 to 245. The hazard index (HI) and target cancer risk (TCR) of REYs from CFA, estimated to be higher for children (HIc = 0.15, TCRc = 8.4 × 10-16) than for adults (HIa = 0.017, TCRa = 3.6 × 10-16), were well below the safety limits (HI = 1, TCR = 1.0 × 10-6). However, the danger to human health posed by HMs in the same CFA samples (HIc = 5.74, TCRc = 2.6 × 10-4, TCRa = 1.1 × 10-4) exceeded the safe thresholds (excl. HIa = 0.63). The mean RI and HI attributed to REYs in CFA were 14% and 2.6%, respectively, of the total risks that include HMs.

Spatial distribution and source apportionment of DTPA-extractable metals in soils surrounding the largest Serbian steel production plant.

Despite presenting a practical approach for the characterization of the environmental risk of potentially toxic elements (PTEs) derived from steel production facilities, the analysis of the spatial distribution of bioavailable PTEs concentrations in the soil is frequently overlooked in the management of polluted sites. In this study, the diethylenetriaminepentaacetic acid (DTPA)-extractable forms of PTEs were investigated in soils surrounding the largest Serbian steel production plant. The correlation and geostatistical analysis indicated their pronounced variability suggesting the anthropogenic origin of most investigated elements, apparently from the steel production facility. The detailed visualization of variables and observations derived by self-organizing maps (SOMs) revealed the homologies in PTEs' distribution patterns, implying the common origin of some elements. These observations were confirmed by principal component analysis (PCA) and positive matrix factorization (PMF). The аpplied approach supports a comprehensive assessment of contaminated sites' ecological and health risks and provides a basis for soil remediation.

Removal of Nickel Ions from Aqueous Solutions by 2-Hydroxyethyl Acrylate/Itaconic Acid Hydrogels Optimized with Response Surface Methodology.

The adsorption of Ni2+ ions from water solutions by using hydrogels based on 2-hydroxyethyl acrylate (HEA) and itaconic acid (IA) was studied. Hydrogel synthesis was optimized with response surface methodology (RSM). The hydrogel with the best adsorption capacity towards Ni2+ ions was chosen for further experiments. The hydrogel was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis before and after the adsorption of Ni2+ ions. Batch equilibrium experiments were conducted to investigate the influence of solution pH, hydrogel weight, ionic strength, adsorption time, temperature and initial concentration of nickel ions on the adsorption. Time-dependent adsorption fitted the best to the pseudo-second-order kinetic model. A thermodynamic study revealed that the adsorption was an exothermic and non-spontaneous process. Five isotherm models were studied, and the best fit was obtained with the Redlich-Peterson model. Consecutive adsorption/desorption studies indicated that the HEA/IA hydrogel can be efficiently used as a sorbent for the removal of Ni2+ ions from the water solution. This study develops a potential adsorbent for the effective removal of trace nickel ions.

Spatial distribution, radiological risk assessment and positive matrix factorization of gamma-emitting radionuclides in the sediment of the Boka Kotorska Bay.

Surface sediment from the Boka Kotorska Bay (Adriatic Sea) was analyzed for the content of technogenic cesium (137Cs) and naturally occurring (40K, 226Ra, 232Th, 238U) radionuclides. The activity concentrations of the radionuclides have been correlated with the major elements (Si, Al, Ca, Fe, K, Mg, Ti, P, Mn) content of sediment samples. The spatial interpolation identified primordial radioactivity more pronounced in the inland of the bay. Correlation and hierarchical cluster analyses clearly distinguished 226Ra, 232Th, and 238U from 137Cs. In addition, a strong association between primordial radionuclides and most major elements was found. Positive matrix factorization apportioned technogenic and natural radionuclides sources, while Si and Ca were separated from other elements. Radiological hazard parameters (Raeq, D, AEDE, Hin, Hex, AGDE, AUI) that include the doses and indices, and the excess lifetime cancer risk indicate that the risk in the studied area due to gamma radiation is within the acceptable level.

Cadmium retention and distribution in contaminated soil: effects and interactions of soil properties, contamination level, aging time and in situ immobilization agents.

As soil cadmium (Cd) contamination becomes a serious concern and one of the significant environmental pollution issues all over the world, knowledge of the basic chemistry, origin, inputs, sources, quantity, chemical forms, reactions, as well as the fate and transport of Cd in different types of soil is crucial for better understanding Cd bioavailability, health risks and remedial options. This study aimed to increase the current knowledge on the complex interdependence between the factors affecting behavior, transport and fate of Cd in the soil and to test and compare the performance of the stabilization agents in different soil types. Soils demonstrated various sorption affinity and capacity for Cd accumulation, which proved to be positively correlated with soil pH and the cation exchange capacity (CEC). With increasing levels of contamination, sequential extraction analysis showed the highest increase of relative Cd amounts in the exchangeable fraction regardless of the soil properties, suggesting that added Cd is principally associated with the easily accessible and mobile fraction. For different initial Cd concentrations and soil types, Cd sorption reached the quasi-equilibrium within 24 h of contact. Prolonged aging (two months) influenced the natural stabilization of Cd in all types of soil, but only at low contamination level. The application of both, conventional (slaked lime Ca(OH)2) and alternative phosphate-rich (annealed bovine bones B400) amendments, resulted in Cd relocation and reduction of exchangeable Cd content. Although the effect was smaller when apatite amendment was utilized, observed re-distribution of Cd to more stable soil fractions is preferable for achieving long-term stabilization. Cd concentrations extracted in exchangeable and acid soluble fractions after the treatments of contaminated soil samples suggest that the practical applicability of in situ immobilization depends on the soil properties and the level of contamination, as well as that effect, should be monitored for the possible re-mobilization of Cd.

Estimation of Cadmium uptake by tobacco plants from laboratory leaching tests.

The objective of the present study was to determine the impact of cadmium (Cd) concentration in the soil on its uptake by tobacco plants, and to compare the ability of diverse extraction procedures for determining Cd bioavailability and predicting soil-to-plant transfer and Cd plant concentrations. The pseudo-total digestion procedure, modified Tessier sequential extraction and six standard single-extraction tests for estimation of metal mobility and bioavailability were used for the leaching of Cd from a native soil, as well as samples artificially contaminated over a wide range of Cd concentrations. The results of various leaching tests were compared between each other, as well as with the amounts of Cd taken up by tobacco plants in pot experiments. In the native soil sample, most of the Cd was found in fractions not readily available under natural conditions, but with increasing pollution level, Cd amounts in readily available forms increased. With increasing concentrations of Cd in the soil, the quantity of pollutant taken up in tobacco also increased, while the transfer factor (TF) decreased. Linear and non-linear empirical models were developed for predicting the uptake of Cd by tobacco plants based on the results of selected leaching tests. The non-linear equations for ISO 14870 (diethylenetriaminepentaacetic acid extraction - DTPA), ISO/TS 21268-2 (CaCl2 leaching procedure), US EPA 1311 (toxicity characteristic leaching procedure - TCLP) single step extractions, and the sum of the first two fractions of the sequential extraction, exhibited the best correlation with the experimentally determined concentrations of Cd in plants over the entire range of pollutant concentrations. This approach can improve and facilitate the assessment of human exposure to Cd by tobacco smoking, but may also have wider applicability in predicting soil-to-plant transfer.

Natural radionuclides in cigarette tobacco from Serbian market and effective dose estimate from smoke inhalation.

The activity concentrations of natural radionuclides ((40)K, (210)Pb, (210)Po, (226)Ra and (228)Ra) in 17 most frequently used cigarette brands in Serbia and corresponding effective doses due to smoke inhalation are presented. The mean annual effective doses for (210)Pb and (210)Po were estimated to be 47.3 and 724 µSv y(-1) for (210)Pb and (210)Po, respectively. Serbia currently has the highest smoking rate in the world. The results of this study indicate the high contribution of the annual effective dose due to smoke inhalation to the total inhalation dose from natural radionuclides. The more effective implementation of actions for reducing smoking prevalence in Serbia is highly needed.

Interpretative optimization and artificial neural network modeling of the gas chromatographic separation of polycyclic aromatic hydrocarbons.

An interpretative strategy (factorial design experimentation+total resolution analysis+chromatogram simulation) was employed to optimize the separation of 16 polycyclic aromatic hydrocarbons (PAHs) (naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene, benzo(a)anthracene, benzo(k)fluoranthene, benzo(b)fluoranthene, benzo(a)pyrene, indeno(1,2,3-c,d)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene) in temperature-programmed gas chromatography (GC). Also, the retention behavior of PAHs in the same GC system was studied by a feed-forward artificial neural network (ANN). GC separation was investigated as a function of one (linear temperature ramp) or two (linear temperature ramp+the final hold temperature) variables. The applied interpretative approach resulted in rather good agreement between the measured and the predicted retention times for PAHs in both one and two variable modeling. The ANN model, strongly affected by the number of input experiments, was shown to be less effective for one variable used, but quite successful when two input variables were used. All PAHs, including difficult to separate peak pairs (benzo(k)fluoranthene/benzo(b)fluoranthene and indeno(1,2,3-c,d)pyrene/dibenzo(a,h)anthracene), were separated in a standard (5% phenyl-95% dimethylpolysiloxane) capillary column at an optimum temperature ramp of 8.0 degrees C/min and final hold temperature in the range of 260-320 degrees C.

Determination of glass temperature of polymers by inverse gas chromatography.

Inverse gas chromatography (IGC) is an attractive technique for polymer characterization due to possible simultaneous determination of various physicochemical properties of polymer systems merely from retention times of selected sorbates. The technique is especially advantageous to polymers that cannot be characterized by conventional methods. In this review, the utilization of the method for glass transition determination of homopolymers, copolymers and polymer blends is described. Advantages and drawbacks of the IGC method over traditionally used methods for glass transition temperature determination is discussed, along with the most important parameters that influence the precision and accuracy of the glass transition temperature (T(g)) measurements.

Flow-injection chemiluminescence determination of formaldehyde in water.

A modification of the Trautz-Schorigin reaction into a flow-injection analysis configuration is described. Different approaches were used at the optimization of chemiluminescence determination of formaldehyde in water based on the reaction of formaldehyde, gallic acid and hydrogen peroxide in an alkaline solution. Detection system with a 218microl chemiluminescence cell was optimized by both a one-variable-at-a-time method, and a modified simplex method. A calibration graph is linear in the concentration range 4x10(-8) to 1x10(-5)M HCHO. The detection limit of formaldehyde for a signal-to-noise ratio of 3 is 4x10(-8)M. The relative standard deviations for 15 repeated measurements of 1x10(-6) and 5x10(-6)mol l(-1) HCHO are 4.32 and 3.33%, respectively. The analysis time is 1.5min. The method was applied to the determination of formaldehyde in urban rainwater. A comparison of results found by proposed method with those obtained by fluorimetric reference method provided a good agreement.

An inverse gas chromatography study of the adsorption of organics on nickel- and copper-hexacyanoferrates at zero surface coverage.

The surface properties of Ni and Cu hexacyanoferrates were investigated by the inverse gas chromatography method. Retentions of 10 organic compounds were measured at zero surface coverage in the temperature range 80 to 95 degrees C. The gas/solid partition coefficients and the related thermodynamic data of adsorption (standard free energy change, standard state enthalpies, and entropy changes) also at zero surface coverage were determined. The dispersive component of free surface energy of both hexacyanoferrates, at investigated temperatures, was calculated. The surface acid/base properties were also evaluated using polar adsorbates and the results obtained indicate that nickel hexacyanoferrate is more acidic than copper hexacyanoferrate.