Effect of erbium, chromium-doped: yttrium, scandium, gallium, and garnet laser-assisted periodontal therapy using radial firing tip during early healing period: a randomized controlled split-mouth clinical trial.

BACKGROUND: This study aimed to demonstrate the efficacy of erbium, chromium-doped:yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser-assisted nonsurgical periodontal therapy in periodontitis patients during 8 weeks of healing. METHODS: A split-mouth, single-blinded, randomized controlled clinical trial was conducted on 12 patients diagnosed with stage III/IV periodontitis and had a minimum of two teeth with probing pocket depth (PPD) > 5 mm in at least two quadrants. Upon randomization, each quadrant was assigned for conventional scaling and root planing (SRP) procedure or laser-assisted therapy (SRP + laser) using radial firing tip (RFPT 5, Biolase). Clinical measurements and gingival crevicular fluid collection were performed for statistical analysis. RESULTS: In the initial statistical analysis on the whole subject teeth, modified gingival index (MGI) reduction was greater in test group at 1(P = 0.0153), 4 (P = 0.0318), and 8 weeks (P = 0.0047) compared to the control in the same period. PPD reduction at 4 weeks in test group was -1.67 ± 0.59 showing significant difference compared to the control (-1.37 ± 0.63, P = 0.0253). When teeth with mean PPD ≥5 mm were sorted, MGI decrease was significantly greater in test group at 1 (P=0.003) and 8 week (P=0.0102) follow-ups. PPD reduction was also significantly greater in test group at 4 week period (-1.98 ± 0.55 vs -1.58 ± 0.56, test vs control, P=0.0224). CONCLUSIONS: Er,Cr:YSGG-assisted periodontal therapy is beneficial in MGI and PPD reductions during early healing period.

The association between the urinary chromium and blood pressure: a population-based study.

BACKGROUND AND AIM: The impact of trace elements and heavy metals on human health has attracted widespread attention. However, the correlation between urinary chromium concentrations and blood pressure remains unclear and inadequately reported, and the aim of this study was to investigate the relationship between urinary chromium concentrations and blood pressure in adults in the United States (US). METHODS: We utilized data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018 for this study. Multivariate logistic regression and multivariate linear regression were used to explore the association of urinary chromium concentrations with hypertension and blood pressure. Additionally, we also performed subgroup analysis and restricted cubic splines (RCS). RESULTS: A total of 2958 participants were enrolled in this study. The overall mean systolic blood pressure and diastolic blood pressure were 123.98 ± 0.60, 72.66 ± 0.57 mmHg, respectively. The prevalence of hypertension was found in 41.31% of the whole participants. In the fully adjusted model, we did not observe a correlation between urinary chromium concentrations and the risk of hypertension and systolic blood pressure. However, we found a negative association between urinary chromium concentrations and diastolic blood pressure. In subgroup analysis, we observed a positive association between urinary chromium and the risk of hypertension among participants older than 60 years of age and those who were Non-Hispanic Black. The interaction term highlighted the influence of age and race on this positive association. We also found a negative association of urinary chromium with diastolic blood pressure in male, participants who were current smokers, overweight, and other races, as well as those without alcohol use and anti-hypertensive drug use. However, the interaction term only revealed the influence of alcohol consumption on the negative association. CONCLUSION: Our study suggested that urinary chromium concentrations may show a negative association with diastolic blood pressure and this association was significantly dependent on alcohol consumption. Besides, a positive association between urinary chromium and the risk of hypertension was also found among participants older than 60 years of age and those who were Non-Hispanic Black.

Synchronizing positive effect of vitamin C and chromium on hyper lipidemia, hyperglycemia, liver enzymes and BMI of diabetes mellitus type 2 patients.

This study investigates the combined effect of vitamin C and chromium on BMI, lipid profile, LFTs and HbA1c of Diabetes Mellitus type 2 patients. This is randomized controlled trial study. For this study a total of 60 patients (n=28 female, n=32 male) Diabetes Mellitus type 2 patients were selected. They were divided into treatment group (vitamin C (500mg) Chromium (200µg) and control group (placebo) comprising thirty patients per group. Mean age in control group and treatment group is 33± 5.729 and 33±7.017 respectively. Statistical analysis showed significant results of lipid profile; total cholesterol (mg/dl) 198±66.1 P=0.008, High-Density Lipoprotein 38±7.5, P<0.001, Low Density Lipoprotein (LDL) (mg/dl) 105.1±22.4, P=0.002 and Triglycerides 191±64.3, P=0.02 are respectively. Levels of serum ALT (u/l) (34.7±9.1, P<0.001) and AST (u/l) (31.6 ±8.6, P<0.001) were significantly lower as compared to control group. HbA1c percentages were also normalized (5.45±0.2, P<.001) as compared to group 2. BMI values were also improved (P=0.01) after treatment. Combined supplementation of vitamin C and chromium reduce the plasma lipid percentage, blood glucose levels and also improve the ALT and AST functions.

Enhanced biodegradation of phenol under Cr(VI) stress by microbial collaboration and potential application of machine learning for phenol biodegradation.

Cr(VI) and phenol commonly coexist in wastewater, posing a great threat to the environment and human health. However, it is still a challenge for microorganisms to degrade phenol under high Cr(VI) stress. In this study, the phenol-degrading strain Bacillus cereus ZWB3 was co-cultured with the Cr(VI)-reducing strain Bacillus licheniformis MZ-1 to enhance phenol biodegradation under Cr(Ⅵ) stress. Compared with phenol-degrading strain ZWB3, which has weak tolerance to Cr(Ⅵ), and Cr(Ⅵ)-reducing strain MZ-1, which has no phenol-degrading ability, the co-culture of two strains could significantly increase the degraded rate and capacity of phenol. In addition, the co-cultured strains exhibited phenol degradation ability over a wide pH range (7-10). The reduced content of intracellular proteins and polysaccharides produced by the co-cultured strains contributed to the enhancement of phenol degradation and Cr(Ⅵ) tolerance. The determination coefficients R2, RMSE, and MAPE showed that the BP-ANN model could predict the degradation of phenol under various conditions, which saved time and economic cost. The metabolic pathway of microbial degradation of phenol was deduced by metabolic analysis. This study provides a valuable strategy for wastewater treatment containing Cr(Ⅵ) and phenol.

Chromium nanoparticles improve bone turnover regulation in rats fed a high-fat, low-fibre diet.

The aim of the study was to investigate the effect of returning to a balanced diet combined with chromium picolinate (CrPic) or chromium nanoparticles (CrNPs) supplementation at a pharmacologically relevant dose of 0.3 mg/kg body weight on the expression level of selected genes and bone turnover markers in the blood and bones of rats fed an obese diet. The results of the study showed that chronic intake of a high-fat obesogenic diet negatively affects bone turnover by impairing processes of both synthesis and degradation of bones. The switch to a healthy diet proved insufficient to regulate bone metabolism disorders induced by an obesogenic diet, even when it was supplemented with chromium, irrespective of its form. Supplementation with CrPic with no change in diet stimulated bone metabolism only at the molecular level, towards increased osteoclastogenesis (bone resorption). In contrast, CrNPs added to the high-fat diet effectively regulated bone turnover by increasing both osteoblastogenesis and osteoclastogenesis, with these changes directed more towards bone formation. The results of the study suggest that unfavourable changes in bone metabolism induced by chronic intake of a high-fat diet can be mitigated by supplementation with CrNPs, whereas a change in eating habits fails to achieve a similar effect.

Arthrospira platensis enriched with Cr(III), Mg(II), and Mn(II) ions improves insulin sensitivity and reduces systemic inflammation in equine metabolic affected horses.

Equine metabolic syndrome (EMS) is a critical endocrine condition in horses, characterized by hyperinsulinemia, hyperlipidemia, and insulin resistance, posing a significant threat to their health. This study investigates the efficacy of supplementing EMS-affected horses with Arthrospira platensis enriched with Cr(III), Mg(II), and Mn(II) ions using biosorption process in improving insulin sensitivity and glucose tolerance, reducing inflammation, and mitigating obesity-related fat accumulation. Our results demonstrate that Arthrospira supplementation reduces baseline insulin and glucose levels, contributing to decreased adipose tissue inflammation. Furthermore, Arthrospira supplementation results in a decrease in body weight and improvements in overall body condition scores and cresty neck scores. Additionally, administration of Arthrospira leads to reduced levels of triglycerides and aspartate aminotransferase, indicating a decrease in hepatic adiposity and inflammation. These findings suggest that Arthrospira, enriched with essential micro- and macroelements, can be an advanced feed additive to enhance insulin sensitivity, promote weight reduction, and alleviate inflammatory processes, thereby improving the overall condition of horses affected by EMS. The use of Arthrospira as a feed additive has the potential to complement conventional management strategies for EMS.

Coprecipitation of Fe/Cr Hydroxides at Organic-Water Interfaces: Functional Group Richness and (De)protonation Control Amounts and Compositions of Coprecipitates.

Iron/chromium hydroxide coprecipitation controls the fate and transport of toxic chromium (Cr) in many natural and engineered systems. Organic coatings on soil and engineered surfaces are ubiquitous; however, mechanistic controls of these organic coatings over Fe/Cr hydroxide coprecipitation are poorly understood. Here, Fe/Cr hydroxide coprecipitation was conducted on model organic coatings of humic acid (HA), sodium alginate (SA), and bovine serum albumin (BSA). The organics bonded with SiO2 through ligand exchange with carboxyl (-COOH), and the adsorbed amounts and pKa values of -COOH controlled surface charges of coatings. The adsorbed organic films also had different complexation capacities with Fe/Cr ions and Fe/Cr hydroxide particles, resulting in significant differences in both the amount (on HA > SA(-COOH) ≫ BSA(-NH2)) and composition (Cr/Fe molar ratio: on BSA(-NH2) ≫ HA > SA(-COOH)) of heterogeneous precipitates. Negatively charged -COOH attracted more Fe ions and oligomers of hydrolyzed Fe/Cr species and subsequently promoted heterogeneous precipitation of Fe/Cr hydroxide nanoparticles. Organic coatings containing -NH2 were positively charged at acidic pH because of the high pKa value of the functional group, limiting cation adsorption and formation of coprecipitates. Meanwhile, the higher local pH near the -NH2 coatings promoted the formation of Cr(OH)3. This study advances fundamental understanding of heterogeneous Fe/Cr hydroxide coprecipitation on organics, which is essential for successful Cr remediation and removal in both natural and engineered settings, as well as the synthesis of Cr-doped iron (oxy)hydroxides for material applications.

Preparation of a Novel Oat ß-Glucan-Chromium(III) Complex and Its Hypoglycemic Effect and Mechanism.

This study synthesized a novel oat ß-glucan (OBG)-Cr(III) complex (OBG-Cr(III)) and explored its structure, inhibitory effects on α-amylase and α-glucosidase, and hypoglycemic activities and mechanism in vitro using an insulin-resistant HepG2 (IR-HepG2) cell model. The Cr(III) content in the complex was found to be 10.87%. The molecular weight of OBG-Cr(III) was determined to be 7.736 × 104 Da with chromium ions binding to the hydroxyl groups of OBG. This binding resulted in the increased asymmetry and altered spatial conformation of the complex along with significant changes in morphology and crystallinity. Our findings demonstrated that OBG-Cr(III) exhibited inhibitory effects on α-amylase and α-glucosidase. Furthermore, OBG-Cr(III) enhanced the insulin sensitivity of IR-HepG2 cells, promoting glucose uptake and metabolism more efficiently than OBG alone. The underlying mechanism of its hypoglycemic effect involved the modulation of the c-Cbl/PI3K/AKT/GLUT4 signaling pathway, as revealed by Western blot analysis. This research not only broadened the applications of OBG but also positioned OBG-Cr(III) as a promising Cr(III) supplement with enhanced hypoglycemic benefits.

Biomass hydrothermal carbonization solution-assisted synthesis of intercalation-expanded core-shell structured molybdenum disulfide for efficient adsorption of Cr (VI) in electroplating wastewater treatment.

Cr (VI) is a common heavy metal pollutant in electroplating wastewater. This study introduces the liquid-phase product from the hydrothermal reaction of coffee grounds (CGHCL) into the synthesis process of molybdenum disulfide, assisting in the fabrication of an intercalated, expanded core-shell structured molybdenum disulfide adsorbent (C-MoS2), designed for the adsorption and reduction of Cr (VI) from electroplating wastewater. The addition of CGHCL significantly enhances the adsorption performance of MoS2. Furthermore, C-MoS2 exhibits exceedingly high removal efficiency and excellent regenerative capability for Cr (VI)-containing electroplating wastewater. The core-shell structure effectively minimizes molybdenum leaching to the greatest extent, while the oleophobic interface is unaffected by oily substances in water, and the expanded interlayer structure ensures the long-term stability of C-MoS2 in air (90 days). This study provides a viable pathway for the resource utilization of biomass and the application of molybdenum disulfide-based materials in wastewater treatment.

Influence of Proteins and Building Direction on the Corrosion and Tribocorrosion of CoCrMo Fabricated by Laser Powder Bed Fusion.

Cobalt-chromium-molybdenum (CoCrMo) alloys are common wear-exposed biomedical alloys and are manufactured in multiple ways, increasingly using additive manufacturing processes such as laser powder bed fusion (LPBF). Here, we investigate the effect of proteins and the manufacturing process (wrought vs LPBF) and building orientation (LPBF-XY and XZ) on the corrosion, metal release, tribocorrosion, and surface oxide composition by means of electrochemical, mechanical, microscopic, diffractive, and spectroscopic methods. The study was conducted at pH 7.3 in 5 g/L NaCl and 5 mM 2-(N-morpholino) ethanesulfonic acid (MES) buffer, which was found to be necessary to avoid metal phosphate and metal-protein aggregate precipitation. The effect of 10 g/L bovine serum albumin (BSA) and 2.5 g/L fibrinogen (Fbn) was studied. BSA and Fbn strongly enhanced the release of Co, Cr, and Mo and slightly enhanced the corrosion (still in the passive domain) for all CoCrMo alloys and most for LPBF-XZ, followed by LPBF-XY and the wrought CoCrMo. BSA and Fbn, most pronounced when combined, significantly decreased the coefficient of friction due to lubrication, the wear track width and severity of the wear mechanism, and the tribocorrosion for all alloys, with no clear effect of the manufacturing type. The wear track area was significantly more oxidized than the area outside of the wear track. In the reference solution without proteins, a strong Mo oxidation in the wear track surface oxide was indicative of a pH decrease and cell separation of the anodic and cathodic areas. This effect was absent in the presence of the proteins.

Machine learning-assisted chromium speciation using a single-well ratiometric fluorescent nanoprobe.

Chromium is widely recognized as a significant pollutant discharged into the environment by various industrial activities. The toxicity of this element is dependent on its oxidation state, making speciation analysis crucial for monitoring the quality of environmental water and assessing the potential risks associated with industrial waste. This study introduces a single-well fluorometric sensor that utilizes orange emissive thioglycolic acid stabilized CdTe quantum dots (TGA-QDs) and blue emissive carbon dots (CDs) to detect and differentiate between various chromium species, such as Cr (III) and Cr (VI) (i.e., CrO42- and Cr2O72-). The variations of fluorescence spectra of the proposed probe upon chromium species addition were analyzed using machine learning techniques such as linear discriminant analysis and partial least squares regression as a classification and multivariate calibration technique, respectively. Linear discriminant analysis (LDA) demonstrated exceptional accuracy in differentiating single-component and bicomponent samples. Additionally, the findings from the partial least squares regression (PLSR) showed that the sensor created has strong linearity within the 1.0-100.0, 1.0-100.0, and 0.1-15 µM range for Cr2O72-, CrO42-, and Cr3+, respectively. Furthermore, appropriate detection limits were successfully achieved, which were 2.6, 2.9, and 0.7 µM for Cr2O72-, CrO42-, and Cr3+, respectively. Ultimately, the successful capability of the sensing platform in the identification and quantification of chromium species in environmental water samples provides innovative insights into general speciation analytics.

Metal organic framework anchored onto biowaste mediated carbon material (rGO) for remediation of chromium (VI) by the photocatalytic process.

Groundwater contaminated with hexavalent chromium Cr(VI) causes serious health concerns for the ecosystem. In this study, a hybrid amino functionalized MOF@rGO nanocatalyst was produced by utilization of a biowaste mediated carbon material (reduced graphene oxide; rGO) and its surface was modified by in situ synthesis of a nanocrystalline, mixed ligand octahedral MOF containing iron metal and NH2 functional groups and the prepared composite was investigated for Cr (VI) removal. The photocatalytic degradation of Cr(VI) in aqueous solutions was carried out under UV irradiation. Using a batch mode system, the effect of numerous control variables was examined, and the process design and optimization were carried out by response surface methodology (RSM). The photocatalyst, NH2-MIL(53)-Fe@rGO, was intended to be a stable and highly effective nanocatalyst throughout the recycling tests. XRD, SEM, EDS, FTIR examinations were exploited to discover more about surface carbon embedded with MOF. 2 g/L of NH2-MIL-53(Fe)/rGO was utilized in degrading 200 mg/L of Cr(VI) in just 100 min, implying the selective efficacy of such a MOF-rGO nanocatalyst. Moreover, the Eg determinations well agreed with the predicted range of 2.7 eV, confirming its possibility to be exploited underneath visible light, via the Tauc plot. Thus, MOF anchored onto biowaste derived rGO photo-catalyst was successfully implemented in chromium degradation.

In situ carbothermal synthesis of carbonized bacterial cellulose embedded with nano zero-valent iron for removal of Cr(VI).

Carbonized bacterial cellulose embedded with highly dispersed nano zero-valent iron (nZVI), denoted as nZVI@CBC, was prepared through one-step in situ carbothermal treatment of bacterial cellulose adsorbing iron(III) nitrate. The structure characteristics of nZVI@CBC and its performance in removing hexavalent chromium Cr(VI) were investigated. Results showed the formation of nZVI@CBC with a surface area of 409.61 m2/g at 800 °C, with nZVI particles of mean size 28.2 nm well distributed within the fibrous network of CBC. The stability of nZVI was enhanced by its carbon coating, despite some inevitable oxidation of exposed nZVI. Batch experiments demonstrated that nZVI@CBC exhibited superior removal efficiency compared to bare nZVI and CBC. Under optimal conditions, nZVI@CBC exhibited a high Cr(VI) adsorption capacity of up to 372.42 mg/g. Therefore, nZVI@CBC shows promise as an effective adsorbent for remediating Cr(VI) pollution in water.

Elevated cobalt levels in metal-on-polyethylene knee megaprostheses: a prospective 1-year cohort study of 56 patients with hip and knee megaprostheses.

BACKGROUND AND PURPOSE: Concerns have emerged regarding elevated levels of cobalt and chromium in patients with metal-on-metal megaprostheses. This prospective study aims to identify systemic cobalt and chromium levels in metal-on-polyethylene knee and hip megaprostheses and their associations with other factors. METHODS: 56 patients underwent knee or hip megaprosthesis surgery at 2 sarcoma centers. Serum cobalt and chromium levels were measured preoperatively and thrice within the first year using inductively coupled plasma mass spectrometry. RESULTS: A statistically significant difference in serum cobalt levels (1.4 ppb; 95% confidence interval [CI] 0.0-3.3) was observed 1 year after knee megaprosthesis surgery compared with preoperative levels. In contrast no difference in chromium levels was observed after 1 year compared with preoperative levels (0.05 ppb; CI 0.0-0.8). An association between younger age, higher eGFR, and increased cobalt levels was observed. No significant correlations were found between ion levels and resection length or the number of modular connections. CONCLUSION: We found elevated serum ion levels in metal-on-polyethylene knee megaprostheses in contrast to metal-on-polyethylene hip megaprostheses. Furthermore, a positive correlation between cobalt and chromium levels, and between cobalt and eGFR was identified, along with a negative correlation between cobalt and age. This study highlights the importance of monitoring systemic cobalt and chromium levels in patients with megaprostheses.

Impact of organic matter molecular weight on hexavalent chromium enrichment in green microalgae.

In lightly polluted water containing heavy metals, organic matter, and green microalgae, the molecular weight of organic matter may influence both the growth of green microalgae and the concentration of heavy metals. This study elucidates the effects and mechanisms by which different molecular weight fractions of fulvic acid (FA), a model dissolved organic matter component, facilitate the bioaccumulation of hexavalent chromium (Cr(VI)) in a typical green alga, Chlorella vulgaris. Findings show that the addition of FA fractions with molecular weights greater than 10 kDa significantly enhances the enrichment of total chromium and Cr(VI) in algal cells, reaching 21.58%-31.09 % and 16.17 %-22.63 %, respectively. Conversely, the efficiency of chromium enrichment in algal cells was found to decrease with decreasing molecular weight of FA. FA molecular weight within the range of 0.22 µm-30 kDa facilitated chromium enrichment primarily through the algal organic matter (AOM) pathway, with minor contributions from the algal cell proliferation and extracellular polymeric substances (EPS) pathways. However, with decreasing FA molecular weight, the AOM and EPS pathways become less prominent, whereas the algal cell proliferation pathway becomes dominant. These findings provide new insights into the mechanism of chromium enrichment in green algae enhanced by medium molecular weight FA.

Equilibrium and kinetic modeling of Cr(VI) removal by novel tolerant bacteria species along with zero-valent iron nanoparticles.

This work describes the study of the removal of a refractory contaminant, i.e., Hexavalent chromium (Cr(VI)) from aqueous systems by a novel adsorbent comprising Cr(VI) tolerant bacteria and zero valent iron nanoparticle (nZVI). A gram-positive, rod-shaped bacteria used in the study were isolated from wastewater (WW) received from the effluent of leather industries. The adsorbents were prepared with bacteria, nZVI alone, and a combination of both. The adsorbent comprising both elements was found to remove Cr(VI) with a higher percentage (93%) and higher capacities (0.58 mg/g) as compared to adsorbent with bacteria (Cr(VI) removal = 63%, qe = 0.163 mg/g) or nanoparticles (Cr(VI) removal = 80%, qe = 0.45 mg/g) alone. The adsorbent worked best at neutral pH, and the removal became saturated after 90 min of incubation. Equilibrium studies with isotherm modeling suggested that the adsorption process follows sips isotherm (R2 = 0.9955), which is expected to bean intra-particle diffusion process before the actual adsorption. Process kinetics was modeled with pseudo-first order, pseudo-second order, and Vermeulen model. The diffusion coefficient determined by fitting the kinetic data to Vermeulen model was found to be 0.0000314 cm2/s. The adsorbent can be tested further for continuous flow processes to find more insights about the usage on a large scale.

A promising approach for the removal of hexavalent and trivalent chromium from aqueous solution using low-cost biomaterial.

Heavy metal pollution is an enduring environmental challenge that calls for sustainable and eco-friendly solutions. One promising approach is to harness discarded plant biomass as a highly efficient environmental friendly adsorbents. In this context, a noteworthy study has spotlighted the employment of Euryale ferox Salisbury seed coat (E.feroxSC) for the exclusion of trivalent and hexavalent chromium ions. This study aims to transform discarded plant residue into a novel, environmentally friendly, and cost-effective alternative adsorbent, offering a compelling alternative to more expensive adsorption methods. By repurposing natural materials, we can contribute to mitigating heavy-metal pollution while promoting sustainable and economically viable solutions in environmental remediation. The effect of different parameters, i.e., chromium ions' initial concentration (5-25 mg L-1), solution pH (2-7), adsorbent dosage (0.2-2.4 g L-1), contact time (20-240 min), and temperature (298-313 K), were investigated. E.feroxSC proved highly effective, achieving 96.5% removal of Cr(III) ions at pH 6 and 97.7% removal of Cr(VI) ions at pH 2, with a maximum biosorption capacity of 18.33 mg/g for Cr(III) and 13.64 mg/g for Cr(VI), making it a promising, eco-friendly adsorbent for tackling heavy-metal pollution. The adsorption process followed the pseudo-second-order kinetic model, aligning well with the Langmuir isotherm, exhibited favorable thermodynamics, and was characterized as feasible, spontaneous, and endothermic with physisorption mechanisms. The investigation revealed that E.feroxSC effectively adsorbed Cr(VI) which could be rejuvenated in a basic solution with minimal depletion in its adsorption capacity. Conversely, E.feroxSC's adsorption of Cr(III) demanded rejuvenation in an acidic milieu, exhibiting comparatively less efficient restoration.

Toxicological profile and potential health concerns through metals and trace elements exposure in brick kiln workers from Lahore, Pakistan.

This study examined levels of lead (Pb), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), and arsenic (As) in blood, hair, and nails of 18 brick kiln workers from three brick kiln units located around a metropolitan city, Lahore, Pakistan. All the trace elements except Hg and As were detected in the studied matrices of Brick kiln workers. In general, brick kiln workers reflect the highest concentration of Pb, followed by Cd, Cr, and Cu. Of the pollutants analyzed, Pb has the highest mean (min-max) concentrations at 0.35 (0.09-0.65) in blood (µg/mL), 0.34 (0.14-0.71) in hairs (µg/g), and 0.44 (0.32-0.59) in nails (µg/g) of brick kiln workers. Following Pb, the trend was Cd 0.17 (0.10-0.24), Cu 0.11(0.03-0.27), and Cr 0.07 (0.04-0.08) in blood (µg/mL), followed by Cr 0.11(0.05-0.20), Cd 0.09 (0.03-0.13), and Cu 0.08 (0.04-0.16) in hairs (µg/g) and Cu 0.16 (0.05-0.36), Cd 0.13 (0.11-0.17), and Cr 0.10 (0.05-0.14) in nails (µg/g) respectively. Relatively higher concentrations of metals and other trace elements in blood depicts recent dietary exposure. The difference of trace elements except Pb was non-significant (P > 0.05) among studied matrices of workers as well as between Zigzag and traditional exhaust-based brick kilns. The concentrations of Pb, Cd and Cr in blood of brick kilns workers are higher than the values reported to cause health problems in human populations. It is concluded that chronic exposure to metals and other trace elements may pose some serious health risks to brick kiln workers which needs to be addressed immediately to avoid future worst-case scenarios.

Leachability of hexavalent chromium from fly ash-marl mixtures in Sarigiol basin, Western Macedonia, Greece: environmental hazard and potential human health risk.

Hexavalent chromium (Cr (VI)) is an environmental contaminant brining high concerns due to its higher toxicity and mobility in comparison with trivalent chromium Cr(III). Cr (VI) has been linked with several adverse health effects, including respiratory diseases, lung cancer, and skin irritation. The primary sources of it in the environment are industrial activities.Most of the time, fly ash made of lignite can release Cr(VI) when it comes into contact with water in an aquatic environment. The objective of this study is the investigation of Cr (VI) concentration in leachates of fly ash and marl mixtures and the determination of its solubility under different pH conditions. Samples of fly ash were collected from the Power Plant of Agios Dimitrios. Additionally, samples of marl were collected from the mine of South Field, and both samples were mixed and prepared in in different proportions (% w.t.). The leaching experiments were carried out according to the EN-12457/1-4 (2003) standard under different pH conditions and chemical analysis of the leachates were performed by spectrophotometry with diphenylcarbazide (DPC). The environmental footprint of Cr (VI) in the study area was significant, especially in mixtures containing higher concentrations of fly ash. A critical pH range between 6 to 12 is observed. At acidic pH values, a high release of Cr (VI) was observed, while at the mentioned critical values (pH 10-12), a gradual decrease in its leachability was noticed. The high concentrations of Cr (VI) in the industrial area studied require immediate actions in terms of managing and limiting the potential hazardous impacts on the environment and by extension on the public health by developing appropriate prevention strategies.

Evaluation Health Risks and Sorption of Hexavalent Chromium (Cr(VI) by Biochar and Iron Doped Zinc Oxide Modified Biochar (Fe-ZnO@BC) Using Trifolium: A Green Synthesis Technique.

Contamination of aquatic and terrestrial environment with hexavalent chromium Cr(VI) is one of the major hazards worldwide due its carcinogenicity, persistency and immobility. Different research techniques have been adopted for Cr(VI) remediation present in terrestrial and aquatic media, while adsorption being the most advance, low cost, environmentally friendly and common method. The present study discussed the mechanisms of Parthenium hysterophorus derived biochar, iron-doped zinc oxide nanoparticles (nFe-ZnO) and Fe-ZnO modified biochar (Fe-ZnO@BC) involved in Cr(VI) mobility and bioavailability. Pot experiments were conducted to study the effect of Parthenium hysterophorus derived biochar, nFe-ZnO and Fe-ZnO@BC application rates (2%, 2 mg/kg, 10 mg/kg, respectively). The results indicated that the addition of soil amendments reduced Cr(VI) mobility. The findings revealed that the reduction in chromium mobility was observed by P. hysterophorus BC, and Fe-ZnO@BC but nFe-ZnO application significantly (p = 0.05) reduced Cr(VI) and CrT uptake as compared to the control treatments. The results of SEM coupled with EDS showed a high micropores and channel, smooth surface which helped in adsorption, and may enhance soil conditions. The concentration index (CI) by different amendments in trifolium plant was followed the descending order as: nFe-ZnO > Fe-ZnO@BC > P. hysterophorus BC after 30, 60 and 90 days of harvesting, respectively. In addition, human health risk index was found less than one (H1 < 1.0) in amended soils as compared to control treatments.