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The concentrations of manganese, iron, copper, lead, nickel, cadmium, arsenic, copper and mercury were determined in 10 cultured fish species, which were collected from local markets of Chittagong, Bangladesh, in June 2021. Measurements were performed by atomic absorption spectrophotometry, after acid digestion of the samples. In some cases, the concentration of the investigated elements was more than the maximum limit set by the WHO. Although the concentration of toxic elements in fishes was relatively high in some species, no health risk has been identified in comparison to the estimated daily intake and the maximum limit. Calculated hazard indices were below 1, which indicates the investigated fish would not cause human health risks. Carcinogenic risk indices for Cr, As, and Cu in all species were considered to be significant. [ABSTRACT FROM AUTHOR]

This study investigated the human health risk assessment of polycyclic aromatic hydrocarbons (PAHs) (naphthalene, fluorene, phenanthrene, anthracene, pyrene, benzo(a)anthracene, chrycene, and benzo(a)pyrene) from the consumption of smoked fish (Coral, Telapia, Shrimp, and Rupchanda) and smoked meat (Beef Shikh Kabab, Mutton Shikh Kabab, Kashmiri Kabab, and Chicken Grill) highly consumed by Bangladeshi people quantified by gas chromatography-mass spectrometry (GC-MS) technique. The samples were hydrolyzed in methanolic potassium hydroxide solution and treated with cyclohexane for the extraction of the PAHs from the samples and then subjected to GC-MS technique for the analyses of PAHs. Results showed that the minimum and maximum mean concentrations of the aforesaid PAHs were found to be 19.23 and 294.50 µg/kg in smoked meat, and 4.18 and 4.54 µg/kg in smoked fish samples. Of the carcinogenic PAHs, benzo(a)pyrene (BaP) was the most representative in smoked meat samples ranging from 6.68 to 46.90 µg/kg that exceeded the 5.0 µg/kg maximum level for smoked meat and smoked fish set by the European Commission (EC Regulation No 1881/2006).The present data indicate that all of the smoked meat are unsafe for human consumption. Mathematically calculation representing the carcinogenic risk value of targeted compounds was −4 within the acceptable range of 1.0 × 10−6 to 1.0 × 10−4 (USEPA, 1989). The spike recovery of PAHs was ranging from 70.0 to 90.5% that demonstrated the perfect reliability and accuracy of the methodology employed in this study. [ABSTRACT FROM AUTHOR]

For the first time, using ICP-MS/MS, the 234U, 235U, 236U, and 238U in the sediment samples from coastal region, Bangladesh, were measured as 5.13–5.48, 0.234–0.252, (2.70–4.59) × 10–5, and 4.92–5.31 Bq kg−1, and the 236U/238U atom ratios were (2.87–4.57) × 10–8, indicating the predominate influence of global fallout on 236U. For the rock samples from hilly area, the corresponding concentrations were much higher as 18.7–4023, 0.902–173, 9.58 × 10–5–1.29 × 10–2, and 18.8–2279 Bq kg−1, but the 236U/238U atom ratios were in the same range of (1.52–3.04) × 10–8, indicating the 236U was primarily due to the natural nuclear reactions. [ABSTRACT FROM AUTHOR]

Vanadium pentoxide (V2O5) nanoparticles have gained much attention due to their simple synthesis, a wide range of chemical, industrial, biological, and medicinal applications including anti-inflammation, anti-oxidant, anti-microbial activities. Vanadium complexes of Schiff bases were used as a precursor to synthesis vanadium pentoxide (V2O5) nanoparticles. The precursor Schiff base complexes were obtained by mixing vanadyl acetylacetonate with the prepared Schiff base ligands maintaining a ratio 1:1. After that V2O5 nanoparticles (denoted by C-1, C-2, C-3 and C-4) were synthesized by the direct calcination method based on thermal evaporation-condensation of vanadium complexes at 600 °C for 3 h. Finally, the analytical tools such as FTIR, XRD, EDS and SEM provided evidence in favor of the formation of V2O5 nanoparticles. In addition, microbial study and photocatalytic activity were carried out using a spectrophotometer. An antimicrobial study showed that all the prepared V2O5 nanoparticles have inhibition capacity against the growth of some selected human pathogenic bacteria and few of them against plant pathogenic fungi. Moreover, these V2O5 nanoparticles have photocatalytic activity since these particles degrade organic dye, Eosin yellow. [ABSTRACT FROM AUTHOR]

Spinel magnetite (Fe3O4) nanoparticles (MNPs) were successfully synthesized from the reduction of stoichiometric ratio of aqueous solutions of Fe2+ and Fe3+ with NaOH solution. Then naturally available Ipomoea aquatica leaf aqueous extract (IA extract) was used for the surface modification of MNPs where biomolecules of leaf extract were acted as stabilizer. Gas chromatography‐mass spectrometry (GC‐MS), Fourier transform infrared (FT‐IR), and energy dispersive X‐ray (EDX) analyses evidence the proper incorporation of the biomolecules of leaf extract in MNPs. X‐ray diffraction (XRD) confirms the synthesis of MNPs where the uniform size distribution with spherical shape was approved by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analyses. Thermal analysis was performed using differential scanning caloremetry (DSC) and thermogravimetric analysis (TGA) and a phase transition from Fe3O4 to maghemite (γ‐Fe2O3) was detected at 650 °C. The superparamagnetic nature of the studied materials at room temperature was confirmed by vibrating sample magnetometer (VSM) study and the correlation among saturation magnetization (Ms), crystallite size (D), particle size (d), dislocation density (δ), and microstrain (ϵ) were described. The antibacterial activity of the synthesized MNPs was confirmed by investigating the zones of inhibition which were 19 mm for Gram‐negative bacteria Escherichia coli and 14 mm for Gram‐positive bacteria Bacillus subtilis. [ABSTRACT FROM AUTHOR]

To investigate the interplay between varying anthropogenic activities and sediment dynamics in an urban river (Turag, Bangladesh), this study involved 37-sediment samples from 11 different sections of the river. Neutron activation analysis and atomic absorption spectrometry were utilized to quantify the concentrations of 14 metal(oid)s (Al, Ti, Co, Fe, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Zn). This study revealed significant toxic metal trends, with Principal coordinate analysis explaining 62.91 % of the variance from upstream to downstream. The largest RSDs for Zn(287 %), Mn(120 %), and Cd(323 %) implies an irregular regional distribution throughout the river. The UNMIX-model and PMF-model were utilized to identify potential sources of metal(oid)s in sediments. ∼63.65-66.7 % of metal(oid)s in sediments originated from anthropogenic sources, while remaining attributed to natural sources in both models. Strikingly, all measured metal(oid)s' concentrations surpassed the threshold effect level, with Zn and Ni exceeding probable effect levels when compared to SQGs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Tannery-effluent is one of the top-ranked hazardous waste which is generally discharged into the river. To study the fluvial response toward the tannery-effluents and to trace anthropogenic foot-prints in the fluvial-system, a suite of systematically collected sediment and water samples were analyzed for radioactive ( 226 Ra, 232 Th, and 40 K) and non-radioactive elements (Al, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Sb, Hg, and Pb). Neutron activation analysis and atomic absorption spectroscopy were used for elemental analysis, whereas HPGe-gamma-detector was used for measuring the primordial-radionuclides. Ranges of Cr-abundances in sediment and water were 63-4373 μg.g -1 and 15.6-52.2 μg.L -1 , respectively which were ∼4-14 times higher than the geological background. Radioactivity concentrations of 226 Ra, 232 Th, and 40 K ranged from 17.7-48.5, 36.1-81.6, and 687-1041 Bq.kg -1 , respectively which were significantly depleted in effluent discharge point. Hence, primordial-radionuclides were used as natural tracers for tracing anthropogenic foot-prints which were explained in terms of dilution effect, redox environment and differential geo-environmental events/characteristics. From statistical-approaches and geochemical reasoning, elemental sources and responses in fluvial system were explored. Surprisingly, ecological & radiological risks were reduced while sediment quality guideline-based ecotoxicity & water-mediated health risks were increased by the incorporation of tannery effluents. This study describes the sedimentary response toward the received tannery effluents which is particularly explored by the primordial radionuclides., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

In this work, the aqueous leaf extracts of three Ophiorrhiza genus species, namely Ophiorrhiza mungos ( Om ), Ophiorrhiza harrisiana ( Oh ) and Ophiorrhiza rugosa ( Or ), have been used as the reducing and capping agents to control the size of AgNPs, Om -AgNPs, Oh -AgNPs and Or -AgNPs, respectively and found to be an effective antimicrobial agent against a wide range of bacteria and fungi. The biosynthesized AgNPs were studied by UV-Visible spectrophotometer, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray, transmission electron microscopy (TEM) and Fourier transform infrared spectrometer (FTIR). The average particle sizes of Om -AgNPs, Oh -AgNPs and Or -AgNPs were measured as 17 nm, 22 nm and 26 nm, respectively, and observed to be spherical and face-centered cubic crystals. The antibacterial test of synthesized AgNPs was performed against Staphylococcus aureus , Bacillus cereus , Escherichia coli , and Vibrio cholerae where the maximum antibacterial activity was observed by reducing the nano-size and increasing the silver content of AgNPs. The antifungal effect of these three types of AgNPs on Penicillium notatum and Aspergillus niger was also evaluated and their growth with AgNPs concentrations of 450 μg/mL was inhibited up to 80-90% and 55-70%, respectively. The size-control synthesis of AgNPs using the Ophiorrhiza genus species is presented here for the first time where the synthesized AgNPs showed higher stability and antimicrobial activities. Therefore, this study might lead to synthesize AgNPs with different morphologies using plant extracts of the same genus but from different species and provide strong encouragement for future applications in treating infectious diseases., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (© 2023 The Authors.)

The interaction of anionic magnetite nanoparticles (MNPs) of size 18 nm with negatively charged giant unilamellar vesicles (GUVs) formed from a mixture of neutral dioleoylphosphatidylcholine (DOPC) and negatively charged dioleoylphosphatidylglycerol (DOPG) lipids has been investigated. It has been obtained that NPs induces the deformation of spherical GUVs. The reaction of other GUVs on NPs consists in the appearance of pores in their membranes. We focused the effect of electrostatics on the interaction of charged membranes with MNPs. To study the influence of the surface charge of GUVs on the processes under consideration, we varied the fraction of DOPG in the vesicles from 0 to 100%. We examined the influence of salt concentration in the range of 50-300 mM NaCl concentration. To describe the degree of deformation, a special parameter compactness was introduced. The pore formation in the membranes of GUVs was investigated by the leakage of sucrose. The compactness increases with time and also NPs concentration. The fraction of deformed GUVs increases with the increase of surface charge density of membranes as well as the decrease of salt concentration in buffer. The value of compactness for neutral membrane is 1.25 times higher than that of charged ones. The fraction of deformed GUVs become constant after 20 min, however it increases with NPs concentration. The time taken for stochastic pore formation is less for charged membrane than neutral one. The physical mechanism explaining the experimental results obtained in these investigations., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Household drinking water security is one of the major issues among coastal communities in Bangladesh. To examine the groundwater quality and social consequences, groundwater samples and household questionnaires were administered across the study area. Instrumental and statistical tools were used to analyze the water quality and social survey data. The average concentrations of electrical conductivity (EC) (7135.67 μS/cm), total dissolved solids (TDS) (3691 mg/L), Na + (1569.51 mg/L), Ca 2+ (289.5 mg/L), Mg 2+ (340.51 mg/L), Cl - (2940.78 mg/L), F - (11.85 mg/L), NO 3 - (54.44 mg/L), NO 2 - (162.95 mg/L), PO 4 represented possible saltwater intrusion along the coastal aquifer. The positive correlations between EC and trace and toxic elements indicated the potential influence of groundwater salinization on the dissolution of more chemical contaminants in the aquifer. These results showed that 100% of samples were unsuitable for drinking purposes. Severe drinking water scarcity is a serious issue, and local people have been affected by water-related diseases owing to the long-term consumption of contaminated water. Salinity problems in drinking water and related health diseases have increased significantly in the past several years. In addition, climate change and its associated hazards, including sea-level rise, cyclonic storm surges, flooding, and resulting inundation problems, have intensified the drinking water scarcity and health problems at the community level. To ensure household water security, environmental exposure, hydrogeology, and anthropogenic interventions must be considered to determine future sustainable water policies.3- (105.19 mg/L), Fe (4.9 mg/L), Mn (1.22 mg/L), As (16.55 μg/L), B (833.28 μg/L), and Pb (34.22 μg/L) were observed in groundwater, and exceeded the drinking water standards from 30% to 100% depending on the sampling location. Thus, the remarkably high contents of EC, TDS, Cl - , and Na + represented possible saltwater intrusion along the coastal aquifer. The positive correlations between EC and trace and toxic elements indicated the potential influence of groundwater salinization on the dissolution of more chemical contaminants in the aquifer. These results showed that 100% of samples were unsuitable for drinking purposes. Severe drinking water scarcity is a serious issue, and local people have been affected by water-related diseases owing to the long-term consumption of contaminated water. Salinity problems in drinking water and related health diseases have increased significantly in the past several years. In addition, climate change and its associated hazards, including sea-level rise, cyclonic storm surges, flooding, and resulting inundation problems, have intensified the drinking water scarcity and health problems at the community level. To ensure household water security, environmental exposure, hydrogeology, and anthropogenic interventions must be considered to determine future sustainable water policies., Competing Interests: Declaration of competing interests The authors declare no competing interests., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

With the development of nanotechnology, silver nanoparticles (Ag-NPs) have become one of the most in-demand nanoparticles owing to their exponential number of uses in various sectors. The increased use of Ag-NPs-enhanced products may result in an increased level of toxicity affecting both the environment and living organisms. Several studies have used different model cell lines to exhibit the cytotoxicity of Ag-NPs, and their underlying molecular mechanisms. This review aimed to elucidate different properties of Ag-NPs that are responsible for the induction of cellular toxicity along with the critical mechanism of action and subsequent defense mechanisms observed in vitro . Our results show that the properties of Ag-NPs largely vary based on the diversified synthesis processes. The physiochemical properties of Ag-NPs (e.g., size, shape, concentration, agglomeration, or aggregation interaction with a biological system) can cause impairment of mitochondrial function prior to their penetration and accumulation in the mitochondrial membrane. Thus, Ag-NPs exhibit properties that play a central role in their use as biocides along with their applicability in environmental cleaning. We herein report a current review of the synthesis, applicability, and toxicity of Ag-NPs in relation to their detailed characteristics.