Evaluation of Serum CA 19-9 as a Diagnostic Marker for Pancreatic Malignancy.

In biliary-pancreatic malignancy, the serum CA 19-9 is considered as a tumor marker. Its high level may indicate the presence of a malignant disorder, but it can also be raised in benign conditions and also in malignancies from other organs. The value may be normal even in malignant condition. This comparative study was conducted in the Department of Surgery of Bangabandhu Sheikh Mujib Medical University (BSMMU), Bangladesh from 1st June 2016 to 31st May 2017 to determine the sensitivity and specificity of CA 19-9 as a tumor marker in pancreatic malignancy in our perspective and to establish a cut-off value of CA 19-9 which might prove as a definitive indication of pancreatic malignancy. We found that when the cut off value of CA 19-9 is 38 U/ml (according to ROC curve), the sensitivity, specificity, PPV and NPV were 77.8%, 77.8%, 77.8%, 77.8% respectively. And if the serum CA 19-9 threshold was raised to 100 and 120 to diagnose pancreatic cancer, sensitivity became 72.2% and 66.7% and NPV 76.2% and 73.9% respectively. However, the specificity increased to 88.9% and 94.4% and the PPV increased to 86.7% and 92.3% respectively.

Ophiorrhiza mungos-Mediated Silver Nanoparticles as Effective and Reusable Adsorbents for the Removal of Methylene Blue from Water.

Green synthesis of silver nanoparticles (AgNPs) using a plant extract has attracted significant attention in recent years. It is found as an alternative for other physicochemical approaches because of its simplicity, low cost, and eco-friendly rapid steps. In the present study, Ophiorrhiza mungos (Om)-mediated AgNPs have been shown to be effective bioadsorbents for methylene blue (MB) dye removal (88.1 ± 1.74%) just after 1 h at room temperature in the dark from an aqueous medium for the first time. Langmuir and Freundlich isotherms fit the experimental results having the correlation coefficient constants R2 = 0.9956 and R2 = 0.9838, respectively. From the Langmuir fittings, the maximum adsorption capacity and adsorption intensity were found to be 80.451 mg/g and 0.041, respectively, indicating the excellent performance and spontaneity of the process. Taking both models under consideration, interestingly, our findings indicated a fairly cooperative multilayer adsorption that might have been governed by chemisorption and physisorption, whereas the adsorption kinetics followed the pseudo-second-order kinetics mechanism. The positive and low values of enthalpy (ΔH0 = 4.91 kJ/mol) confirmed that adsorption is endothermic and physical in nature; however, the negative free energy and positive entropy value (ΔS0 = 53.69 J/mol K) suggested that the adsorption is spontaneous. The biosynthesized adsorbent was successfully reused up to the fifth cycle. A proposed reaction mechanism for the adsorption process of MB dye onto Om-AgNPs is suggested. The present study may offer a novel finding such as an effective and sustainable approach for the removal of MB dye from water using biosynthesized Om-AgNPs as reusable adsorbents at a comparatively faster rate at a low dose for industrial applications.

Evaluation of essential and trace metals/metalloids distribution and probable human health risk implications from branded liquid and powder milks available in Dhaka City, Bangladesh.

The processed forms of milk, branded liquid, and power milk available in Dhaka city, the capital of Bangladesh, were investigated for essential and trace metal/metalloids regarding nutritional and human health risk aspects. For this, the potential nutritional contribution, estimated daily intake (EDI) and non-carcinogenic risk for six different life stages with male and female categories, as well as the carcinogenic risk for children and adults of both genders, were addressed. In total, 46 branded liquid and powder milk samples were considered for this analysis employing atomic absorption spectroscopy. The concentration of essential elements showed the trends of K > Ca > Na > Mg > Fe > Zn > Mn > Cu and K > Ca > Na > Mg > Fe > Cu > Mn > Zn for liquid and powder milk samples, respectively, but the potentially hazardous one showed the same trends (Cr > Pb > Hg > As > Cd) for both items. Except for Cr, Hg, and Fe, the elemental compositions of both milk categories differed considerably (< 0.05). Compared to the threshold values for milk samples (liquid and powder), Fe (19% and 27%), Mn (100% and 63%), Cu (0% and 23%), Zn (94% and 0%), Pb (25% and 13%), and Cr (0% and 3%) showed above the permissible limits. The nutrient input was the highest for Ca (27.2% and 18.7%), followed by Mg, K, and Na. The EDI of studied elements was within the daily permissible limit in both the milk category (except age group (≤ 3) and the female category). The non-carcinogenic risk assessment showed that the age groups ≤ 3 for liquid milk and ≤ 3 and 3 < X ≤ 14 with female categories for powder milk exceeded the threshold level (> 1) in the case of Cr, Cd, As, Zn, and Mn. The probable carcinogenic risks indicated an unacceptable risk level (< 1.00E-04) for the ingestion of Cr through powder milk samples for children in male and female categories. Finally, it believes that green cow farming practices and green milk processing technology, as well as continuous monitoring of toxic metals, can limit the ultimate risk worldwide.

Elements in cultured fishes in Chittagong, Bangladesh and risk assessment.

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.

Exploration of Toxic and Essential Metals in Popular Rice Grains of Bangladesh and Associated Human Health Risk Implications.

In order to evaluate the benefits as well as the impacts of essential and toxic metals regarding human health, the six common rice grains (katarivhog, bashful, banglamoti, najirshail, branded miniket and loose miniket) were collected from four wholesale markets in Dhaka, the capital of Bangladesh, and were analyzed with different atomic absorption spectroscopy (AAS) techniques. The mean concentrations of the toxic metals Pb, Cd, Cr, and As had 0.299 ± 0.017, 0.157 ± 0.012, 1.33 ± 0.084, and 0.120 ± 0.006 mg/kg, respectively, while those of the essential metals Fe, Cu, Zn, Na, Ca, and Mg had 7.90 ± 0.447, 3.11 ± 0.097, 10.6 ± 0.340, 37.4 ± 0.622, 90.1 ± 7.70, and 115.8 ± 1.61 mg/kg, respectively. Among them, the mean concentrations of toxic metals (Pb, Cd, Cr, and As) exceeded the maximum allowable concentration in rice set by the Codex Alimentarius Commission (CAC). Risk assessment of the heavy metals Pb, Cd, Cr, As, Fe, Cu, and Zn showed that their estimated daily intakes were below the daily reference doses for adults. However, Cd and Cr individually were found to have the target hazard quotient value close to 1 (threshold limit), indicating that they alone are capable of potential health hazards from continuous rice consumption, while the hazard index has surpassed three units signifying greater danger associated with the current trend of consumption. A very high chance of developing cancer in the near future is predicted by incremental lifetime carcinogenic risk (ILCR) analysis for continued intake of Cr (ILCR > 1E-03), and a moderate to high risk is predicted for other carcinogenic substances (Pb, Cd, and As) (ILCR in between 1E-03 and 1E-05) with present rice consumption. The contribution of the essential metals to the RNI revealed that Cu from rice contributes more than 100% in most samples, and the overall contribution is in the following order: Cu > Zn > Fe > Mg > Ca > Na. To ensure the safety of staple foods for human health, it ought to be necessary to design a plan to measure the budget of hazardous metals from all sources with proper surveillance by relevant authorities.

Exploring Users Pointing Performance on Large Displays with Different Curvatures in Virtual Reality.

Large curved displays inside Virtual Reality environments are becoming popular for visualizing high-resolution content during analytical tasks, gaming or entertainment. Prior research showed that such displays provide a wide field of view and offer users a high level of immersion. However, little is known about users' performance (e.g., pointing speed and accuracy) on them. We explore users' pointing performance on large virtual curved displays. We investigate standard pointing factors (e.g., target width and amplitude) in combination with relevant curve-related factors, namely display curvature and both linear and angular measures. Our results show that the less curved the display, the higher the performance, i.e., faster movement time. This result holds for pointing tasks controlled via their visual properties (linear widths and amplitudes) or their motor properties (angular widths and amplitudes). Additionally, display curvatures significantly affect the error rate for both linear and angular conditions. Furthermore, we observe that curved displays perform better or similar to flat displays based on throughput analysis. Finally, we discuss our results and provide suggestions regarding pointing tasks on large curved displays in VR.

Fluvial responses towards the tannery effluent: Tracing the anthropogenic foot-prints.

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 (226Ra, 232Th, and 40K) 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 226Ra, 232Th, and 40K 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.

Size controlled biosynthesis of silver nanoparticles using Ophiorrhiza mungos, Ophiorrhiza harrisiana and Ophiorrhiza rugosa aqueous leaf extract and their antimicrobial activity.

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.

Pollution Characteristics, Source Identification, and Health Risk of Heavy Metals in the Soil-Vegetable System in Two Districts of Bangladesh.

The consequences of climate change, food security, and self-sufficiency goals are driving excessive human activity onto vegetable farms in Bangladesh, and harmful heavy metal exposure is spreading. So, the study assessed the toxic metals (Pb, Cd, and Cr) exposure, characteristics, and human health risk regarding the soil-vegetable system of two distinct locations in Bangladesh using atomic absorption spectrometry. The average concentration of metals in soil and fertilizer/pesticide samples followed the same order (Cr > Pb > Cd), but for vegetable samples, the order was Pb > Cr > Cd, with some extra Pb compared to the World Health Organization (WHO) allowable limit (0.3 mg/kg). Low levels of pollution with negligible ecological concerns were predicted for both locations by the soil quality indexing. But industrial influence boosted the Pb content in location B, and common sources (fertilizer/pesticide) for both locations might be responsible for a moderate level of Cd. The toxic metals transferred to vegetables followed the trend of Cd > Pb > Cr. However, the human health risks arising from harmful metals exposure at both locations were ineffective (< 1) in evaluating noncarcinogenic risk patterns through the target hazard quotient (THQ), total THQ, and hazard index (HI). Again, considering probable carcinogenic risk patterns, vegetable consumption with studied exposure levels of toxic metals followed within the acceptable range (between 1.0E-04 and 1.0E-06). Overall, location B is slightly more vulnerable than location A by considering metal exposure, pollution distribution, and risk evaluation in the study area (significant at p < 0.05). So, systematic monitoring and protective measures are required to ensure food safety and sustainable vegetable production.

Lead Exposure of Four Biologically Important Common Branded and Non-branded Spices: Relative Analysis and Health Implication.

Technological advances and socioeconomic development of Bangladesh are leading to the best choice between branded and non-branded powdered spices. But toxic metal issues can be another factor to elect them. So lead (Pb) exposure and its consequence on the human body for these two categories of four common spices have been ascertained here. A validated laboratory method using hot plate digestion and flame atomic absorption spectrometry (FAAS) has been used for that. The obtained mean concentration of Pb in branded and non-branded spice powders followed the decreasing order of turmeric > coriander > red chili > cumin powder and turmeric > red chili > cumin > coriander powder, respectively, where, in any analysis mode, the non-branded items are potentially ahead of Pb exposure. The market-based mean concentration between these two categories was not a significant difference (t-test). Approximately 90% of the spice samples have shown within the maximum allowable limit by Bangladesh Standard. The sum of estimated daily intake indicated that most of the city market (67%) for non-branded items and some branded (33%) samples have crossed the maximum tolerable daily intake (> 0.21 mg/kg). So, the human health risk assumption for the inhabitant of studied areas suggests there is no significant level of risk for them due to the consumption of spices regarding non-carcinogenic risk factor (THQ and total THQ) and carcinogenic risk factor (CR). But the development of a quality control process for loose spice powders as well as toxic metal screening from raw materials to finish products urgently needed and continuous monitoring with identifying the source of toxic metal is highly recommended.

Risk factors, contemporary challenges and psychological well-being of the Rohingya refugees in Bangladesh: Policy implications.

Over the last few years, the number of Rohingya refugees in Bangladesh has increased exponentially. On arrival, they experience poor mental health and psychological well-being. This commentary explores the risk factors and contemporary challenges that deteriorate Rohingyas' psychological well-being in Bangladesh. The onslaught of Covid-19 compounds the pre-existing psychological health conditions of the Rohingyas living in cramped and flimsy camps. The recent relocation to Bhashan Char may likely trigger tensions and eventually exacerbates their existing psychological well-being. The relocation to Bhashan Char has presumably happened against their volition. Meanwhile, the Myanmar military's coup has added additional fear about their bleak future of a safe and dignified return from Bangladesh to Myanmar. All these have contributed to the worsening of their existing psychological well-being. In order to subside their psychological health challenges, this commentary suggests: (a) the immediate execution of 'National Deployment and Vaccination Plan for Covid-19 Vaccines and initiation of vaccine rollout among the refugees; and (b) involving Rohingyas in economic activities and making them a self-reliant and economically empowered community. We suggest that safe and dignified repatriation is the only solution to the challenges they have been going through in Bangladesh and to preserve their psychological well-being.

Rohingya refugees in the pandemic: Crisis and policy responses.

The purpose of this article is to demonstrate how a lack of policy attention has exacerbated the extreme circumstances faced by the Rohingya and how they can contribute to deterioration of their health, livelihood, and education, as well as their repatriation to their homeland. This article is based on data collected from field observations and interviews prior to and during the pandemic. This study confirms that the Rohingya refugee populations endure a higher level of suffering from lack of food security and livelihood, lack of basic amenities and financial resources, and accommodation is overcrowded compared with the pre-pandemic period. The lack of a specific policy for the Rohingya has compounded the current situation in Bangladesh. This research is crucial for countries receiving refugees as well as the countries from which they flee and other actors.

Concentration, source identification, and potential human health risk assessment of heavy metals in chicken meat and egg in Bangladesh.

Chicken meat and hen egg are very popular foodstuffs around the world and highly consumed as curry, fast food, processed food, etc. assuming a promising source of protein. In the present study, the concentrations of Pb, Cd, Cr, As, Hg, Mn, Fe, and Zn in nationally representative samples of chicken meat and hen egg were determined and found in the range of 0.03-2.73, 0.01-0.015, 0.025-0.67, 0.04-0.06, 0.01-0.015, 0.15-0.63, 2.50-38.6, and 1.02-19.4 mg/kg-fw, respectively. The results demonstrated that only Pb exceeded the maximum allowable concentration (MAC) for dietary food. Multivariate statistical analyses depicted that anthropogenic activities were the major source of heavy metals in the investigated foodstuffs. Human health risks associated with the dietary intake of these metals through the consumption of chicken meat and hen egg were evaluated in terms of estimated daily intake (EDI), non-carcinogenic risk of individual heavy metal by target hazard quotient (THQ), total target hazard quotient (TTHQ) for combined metals, and carcinogenic risk (CR) for lifetime exposure. The calculated values of EDI, THQ, TTHQ, and CR were below their respective permissible benchmarks indicating the safe consumption of the investigated foodstuffs with respect to heavy metal contamination.

Accumulation of Trace Metals in Indigenous Fish Species from the Old Brahmaputra River in Bangladesh and Human Health Risk Implications.

In this study, accumulation of the top six most toxic trace metals (Arsenic (As), Cadmium (Cd), Chromium (Cr), Mercury (Hg), Nickel (Ni) and Lead (Pb)) were assessed in six indigenous fish species (Barilius barila, Salmostoma acinaces, Gudusia chapra, Labeo bata, Corica soborna, and Sperata aor) collected from the Old Brahmaputra River in Bangladesh. Human health risk associated with these fish consumption was also evaluated. Metals were analyzed in whole body of fish by an atomic absorption spectrometer (AAS). Mean concentrations of metals (µg/g, wet weight) were in the range of As (< 0.02-0.278), Cd (< 0.002-0.005), Cr (0.239-0.761), Hg (0.008-0.057), Ni (< 0.02-0.044), and Pb (< 0.01-0.038). The metal contents varied significantly among the fishes regarding their feeding habits and living habitats. Concentrations of As, Cr, Hg, and Pb were significantly higher in omnivorous species, whereas the benthopelagic species showed significantly higher accumulation of As (p < 0.05). The target hazard quotient (THQ) for noncarcinogenic risk and target cancer risk (TR) for carcinogenic risk were calculated to estimate the probabilities of experiencing these adverse health effects for the fish consumers. Metal-specific THQ values were all below 1 indicating no potential human health risk. Nonetheless, the hazard index (HI) values to estimate the effects from exposure to all metals collectively elucidated chronic noncarcinogenic health risk particularly from G. chapra consumption. The TR values revealed that there was carcinogenic risk from exposure to As through consumption of the fish. This study finally suggests a systematic and continuous monitoring of trace metal contamination in fishes from the river to ensure the fitness of this food item regarding the safety for human health.

Green Synthesized Silver Nanoparticles-Mediated Cytotoxic Effect in Colorectal Cancer Cells: NF-κB Signal Induced Apoptosis Through Autophagy.

Green synthesized silver nanoparticles (Ag-NPs) have demonstrated promising effects, including cytotoxicity and anticancer potential, in different cell lines. Therefore, in our previous study, Ag-NPs were synthesized from the reduction of AgNO3 using Brassica rapa var. japonica (Bj) leaf extract as a reducing and stabilizing agent. The synthesized Ag-NPs were spherical in shape, with a size range of 15-30 nm. They had phase-centered cubic structure with strong growth inhibition potential against some bacteria. In continuation with our previous study, in the present study, we aimed to investigate the autophagy-regulated cytotoxic effect of Ag-NPs against human epithelial colorectal adenocarcinoma cells (Caco-2 cells). We found that the Bj leaf aqueous extract facilitated Brassica silver nanoparticles (Brassica Ag-NPs)-induced NF-κB mediated autophagy in Caco-2 cells. Results showed that Ag-NPs reduced cell viability of Caco-2 cells by inducing oxidative stress and DNA damage. Therefore, to understand the mechanism underlying the death-promoting activity of Ag-NPs in Caco-2 cells, western blotting was performed. Western blot analysis showed decreased expression of NFκB and increased expression of IκB, which is a sign of autophagy initiation. In addition, autophagosome formation was accelerated by the activity of p53 and light chain 3 (LC3) II. In addition, inhibition of Akt and mTOR also played a pivotal role in autophagy formation. Finally, excessive expansion of autophagy promoted apoptosis, which subsequently resulted in necrosis. These findings support a novel cell death-promoting function of autophagy by Ag-NPs in Caco-2 cells.

Deformation and poration of giant unilamellar vesicles induced by anionic nanoparticles.

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.

SLC26A7 protein is a chloride/bicarbonate exchanger and its abundance is osmolarity- and pH-dependent in renal epithelial cells.

Acid-secreting intercalated cells of the collecting duct express the chloride/bicarbonate kidney anion exchanger 1 (kAE1) as well as SLC26A7, two proteins that colocalize in the basolateral membrane. The latter protein has been reported to function either as a chloride/bicarbonate exchanger or a chloride channel. Both kAE1 and SLC26A7 are detected in the renal medulla, an environment hyper-osmotic to plasma. Individuals with mutations in the SLC4A1 gene encoding kAE1 and mice lacking Slc26a7 develop distal renal tubular acidosis (dRTA). Here, we aimed to (i) confirm that SLC26A7 can function as chloride/bicarbonate exchanger in Madin-Darby canine kidney (MDCK) cells, and (ii) examine the behavior of SLC26A7 relative to kAE1 wild type or carrying the dRTA mutation R901X in iso- or hyper-osmotic conditions mimicking the renal medulla. Although we found that SLC26A7 abundance increases in hyper-osmotic growth medium, it is reduced in low pH growth conditions mimicking acidosis when expressed at high levels in MDCK cells. In these cells, SLC26A7 exchange activity was independent from extracellular osmolarity. When SLC26A7 protein was co-expressed with kAE1 WT or the R901X dRTA mutant, the cellular chloride/bicarbonate exchange rate was not additive compared to when proteins are expressed individually, possibly reflecting a decreased overall protein expression. Furthermore, the cellular chloride/bicarbonate exchange rate was osmolarity-independent. Together, these results show that (i) in MDCK cells, SLC26A7 is a chloride/bicarbonate exchanger whose abundance is up-regulated by high osmolarity growth medium and (ii) acidic extracellular pH decreases the abundance of SLC26A7 protein.

Groundwater salinization and associated co-contamination risk increase severe drinking water vulnerabilities in the southwestern coast of Bangladesh.

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), Ca2+ (289.5 mg/L), Mg2+ (340.51 mg/L), Cl- (2940.78 mg/L), F- (11.85 mg/L), NO3- (54.44 mg/L), NO2- (162.95 mg/L), PO43- (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.

In vitro cytotoxicity and antibiotic application of green route surface modified ferromagnetic TiO2 nanoparticles.

The enormous numbers of applications of TiO2 nanoparticles (NPs) cause concern about their risk to the environment and human health. Consequently, motivated by the necessity of searching for new sources of TiO2 NPs of low cytotoxicity with antibacterial activity, we synthesized TiO2 NPs by a green route using a solution of titanium(iv) isopropoxide as a precursor and an aqueous extract of Artocarpus heterophyllus leaf as a reducing and surface modifying agent. We investigated their structure, shape, size, and magnetic properties, and evaluated their antibiotic application and cytotoxicity. The synthesized TiO2 NPs were applied against two Gram-negative bacteria (E. coli and S. typhimurium) and two Gram-positive bacteria (S. aureus and B. subtilis) to observe their antibacterial activity; and eventually clear zones of inhibition formed by the TiO2 NPs were obtained. Moreover, after exposing the synthesized TiO2 NPs to HeLa cells (carcinoma cells) and Vero cells (normal cells), no toxic effect was found up to a dose of 1000 mg L-1, indicating the safe use of the samples up to at least 1000 mg L-1. However, toxic effects on HeLa cells and Vero cells were observed at doses of 2000 mg L-1 and 3000 mg L-1, respectively. These results indicate the safe use of Artocarpus heterophyllus leaf extract mediated synthesized TiO2 NPs in their potential applications.

Evaluation of Possible Human Health Risk of Heavy Metals from the Consumption of Two Marine Fish Species Tenualosa ilisha and Dorosoma cepedianum.

In order to study the effects of contaminants on human health, fish is considered as a powerful model among all available species for risk-benefit assessments. Tenualosa ilisha and Dorosoma cepedianum are two fish species of great economic importance as they are found in undeveloped, developing and developed countries. Concentrations of heavy metals lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As) and mercury (Hg) were determined using validated and accredited test methods in order to assess the potential human health risk from the dietary intake of these two selected fish species. The estimated daily intake (EDI) of all the five heavy metals was measured from the consumption of the two species considering the mean fish consumption of 61 g person-1 day-1 defined for European population. The EDI indicates that no risk to people's health with respect to the EDI of Pb, Cd, Cr, As and Hg through the consumption of the two fish species. The estimation of target hazard quotient (THQ) demonstrating the non-carcinogenic risk indicates that intake of Pb, Cd, Cr and Hg through the consumption of two fish species is safe for human health, whereas, consumption of As suggests potential risk to consumers. The estimation of carcinogenic risk of Cd, Cr and As due to the consumption of two selected fish species indicates that consumers remain at risk of cancer. Thus, these fish species should not be considered safe for human consumption.