Percentage Of Pb Research Articles

Tolerance pattern against the heavy metals and pesticides in Escherichia coli isolated from water samples.

In this study water samples were investigated for the presence of heavy metals and pesticide resistance in Escherichia coli (E. coli) collected from district Jhal Magsi. Identification of E. coli was carried out via Polymerase Chain Reaction (PCR) assays. Heavy metals and pesticide resistance were conducted by the Kirby-Bauer disk diffusion method. E. coli was confirmed by using uidA (623bp) and usp (515bp) genes primer. A relatively high resistance rate was observed for Cd and DDT (2, 4 D) with 100% at the concentration of 1600µl/mL. Samples showed the resistance pattern for Cr with 55% and sensitivity was 45% at 800µl/mL. Resistance and sensitive percentage of Pb, Co were observed 61, 63, and 39, 37% at 400µl/mL. Cyanazine resistance and the sensitive percentage were 51 and 49% at 800µg/mL. For Chlorpyrifos and Carbofuran, 54 and 65% resistance and sensitivity 46 and 35% were measured at a lower range of 400µl/mL. Excessive use of heavy metals and pesticide pollution in standing water near agriculture fields contributed to accelerating the abundance of multi-pollutant-resistant E. coli in water that could be useful in the bioremediation of pesticides and heavy metals.

ENVIRONMENTAL ASPECTS OF WASTE-DERIVED BOTTOM BLEND CLAY LINERS INCORPORATING ZEOLITE AND BENTONITE

This research investigated the effects of incorporating bentonite and zeolite into bottom blended clay liners (BBCLs) on their engineering properties and adsorption capacity. BBCLs composed of clay, water treatment residue, and calcium carbide in a 40:40:20 ratio by volume were investigated with the addition of 1, 2, and 3 wt.% bentonite or zeolite. The experimental results indicated that bentonite and zeolite had positive effects on the slake durability index and the equilibrium time for the adsorption of lead (Pb) and chromium (Cr) from the leachate, whereas the unconfined compressive strength (UCS) and coefficient of permeability were negatively affected compared to those of the samples without bentonite and zeolite. At 56 days, the UCS of BBCLs with bentonite and zeolite decreased from 3.4 to 2.2MPa, while the coefficient of permeability of all the samples met the regulatory limit of sanitary landfills, which was given at 1×10-7cm/s. The slake durability index of all samples was lower 50% but it remained higher compared to BBCLs without bentonite and zeolite (approximately doubled). Both additives enhanced the equilibrium time and percentage of Pb and Cr adsorption by about 20% and 200%, respectively. SEM-EDS results show the adsorption of Pb and Cr onto the raw materials, calcium silicate hydrate (CSH), zeolite, and bentonite. Therefore, the addition of zeolite can increase the ability to adsorb heavy metals form leachate, which is suitable for use in secured landfills.

Health and Environmental Risk Assessment of Heavy Metals Contamination from Medical Wastes Ash of Baghdad Hospitals

Abstract One of the complex problems that many countries suffer from is how to deal with medical waste because of its harmful and devastating effects on humans and the environment. Hospitals around the world use and consume many different products. These products are composed of various materials, and many of them contain heavy metals in their production and manufacturing, which are ultimately emitted into the environment, posing a major danger and risk to human health. This work focused on assessing the contamination levels of medical waste ash after the incineration process. Ash samples were collected from major hospitals in the capital, Baghdad. The health risks resulting from heavy metal pollution were calculated. Medical waste ash was collected at different times from three major hospitals within the capital, Baghdad, and tested for contamination with heavy metals. To measure the bottom ash samples, X-ray spectroscopy (XRF) technology was used to determine heavy metal concentrations. The results showed the presence of more than twenty elements in the ash of medical waste, including the heavy metals found in Baghdad hospitals. Work was done on eight of these heavy metals due to their high concentrations. These selected elements are considered highly toxic and dangerous if exposed to them, including zinc (Zn), lead (Pb), arsenic (As), cobalt (Co), and copper. (Cu), nickel (Ni), chromium (Cr), and mercury (Hg). To evaluate the health risks of this pollution. All of these elements are a major problem if exposed to them. The amount of contamination was calculated using the contamination factor (CF). The results showed that the percentage of As, Cd, Hg, Zn, Pb, and Cu was very high. Meanwhile, the concentrations of Co and Ni were moderate values in medical waste ash. Adult health risks were calculated using the non-cancer health risk ratio (HL). The calculated values show values higher than the safe level in Imam Ali Central Hospital, indicating a potential high health risk. Meanwhile, other hospitals (Sheikh Zayed and Dhari Al Fayyad) recorded risk values below the safe level, indicating no health risks. The health risk assessment indicated that there are three main routes of human exposure: “ingestion, inhalation, and skin contact.” The cancer risk index (Risk) was also calculated. The values obtained were within the acceptable range. An analysis of the metal pollution index was also conducted, and it was found that heavy metals pose a non-cancerous risk. But the harmful effects of pollution from ash disposal have been particularly serious because they may contain high concentrations of heavy metals.

Comparison between the Effect of multi-walled carbon nanotubes and single walled carbon nanotubes in removing pb and cd in contaminated bio medical ash

Heavy metal contamination is a highly significant environmental issue. Primarily, this current study is focusing the application of developing Nano technologies which have capacity to remove or reduce toxins from the environment. The extraction and preconcentration abilities of both types of carbon nanotubes, multi-walled (MWCNTs) and single-walled (SWCNTs), were accomplished by using water-acid, acetate, and deghassed water acid EDTA solutions from neuteuche semi-total solid extract from anthropogenic and naturally in origine samples. The results of the study indicated that the adsorption rate was even faster when the solution temperatures were higher in both types of adsorbents. These increases were greater when multi-walled carbon was used. This may be due to the fact that in endothermic nature of adsorption the increase in temperature leads to a faster rate of adsorption. In order to understand the kinetics of Cadmium (II) and Lead(II) adsorption, analysis was executed utilizing the fractional power function model and Lagergren pseudo-first-order and pseudo-second-order methods. A pseudo-second-order model well described the adsorption kinetics of heavy metal ions onto both bioadsorbents. For both biosorbents, the adsorption capacity increased as the solution was heated. The percentage of Pb adsorbed on ultra-sonically assisted MWCNTs was 7.93%, for MWCNTs= 8.33%, 73.50% for swCNTs and 92.46% for amine-MWCNTs (Table 2). Similarly, the percentage of Cd adsorbed on ultra-sonically assisted MWCNTs was 67.92%, 29.30% for MWCNTs, 6.30% for swCNTs and 2.27% for amine-MWCNTs. As far as SWCNTs, they provided some interesting results in terms of adsorption capacity. For example, the adsorption capacity with respect to Pb was about 6.53% with SWCNTs 1, about 7.12% with SWCNTs 2, about 61.33% with SWCNTs 3, and about 79.31% with SWCNTs 4. Similarly, for Cd it was about 61.32% with SWCNTs 1, about 27.13% with SWCNTs 2, about 5.88% with SWCNTs 3, and about 1.53% with SWCNTs 4. The elution tests for single-walled carbon nanotubes and multiwalled carbon nanotubes have been carried out and the results have been shown as binding isotherms and pH effects in Figures 3 and 4. For the study of the adsorption capability of single-walled carbon nanotubes for metal ions, same order of binding to the metal ions has been observed for both the types of the carbon nanotubes-studied, lead (II) < cadmium (II). For multi-walled carbon nanotubes, however, the binding of metal ions was found to depend on the carbon nanotubes type and the binding order, as for carbon nanotubes, were found to be, lead (II) > cadmium (II). Nanotechnologies have facilitated the ability of researchers to address challenges more effectively. This research focuses on the development of Nanotechnologies for the purpose of remediating heavy metals, including cadmium and lead. These metals are considered highly toxic and require urgent attention.

KRAS mutations in patients with AML: clinical characteristics and not reported mutations using NGS

ABSTRACT Background AML is a complex and heterogeneous disease. The KRAS gene is one of the important genes in the pathogenesis of acute myeloid leukemia (AML). Mutant RAS can promote oncogenesis via different mechanisms including oncogenic transcription, cell cycle progression, cellular survival, growth, metabolism, and cell migration. Therefore, it is important to identify the genomic landscape of AML. The aim of the study is to identify KRAS variants in AML and their association with clinic pathological criteria and possible effects on prognosis using NGS. Method Hotspot mutations in the KRAS gene were studied using Ion S5 next-generation sequencing system. Bone marrow samples of newly diagnosed AML patients were collected to identify hotspot mutations in the KRAS gene. DNA amplicons were subjected to sequencing and were analyzed using ion torrent software. Patients were classified according to the FAB classification system. Patients are also classified according to the cytogenetic groups and the ELN risk stratification system. Results KRAS mutations were detected in exon 2, 3, whereas no mutations in KRAS exon 1. Interestingly, Novel mutations were detected in KRAS in AML Egyptian patients. Also, there was no statistically significant association of RAS mutations with different clinical and prognostic parameters. However, KRAS mutant patients tended to have increased PB WBC counts, percentage of PB, and bone marrow blasts. Conclusion NGS is considered a useful tool to identify KRAS variants that could be useful for risk stratification and tailored therapy in AML patients

SPECIATION OF HEAVY METALS AND MICROBIAL CONTAMINANTS IN HARMATTAN DUST WITHIN THE FEDERAL POLYTECHNIC KAURA NAMODA MAIN CAMPUS, ZAMFARA STATE

Harmattan dust is a natural phenomenon contributing to air pollution due to the presence of heavy metals and microorganisms. This research aimed to determine the speciation of heavy metal and microbial contaminants in Harmattan dust samples within the polytechnic Kaura Namoda. The composite sample of each month, namely, December 2023, January 2024, and February 2024, was collected with the aid of a sterilized petri dish. Five extraction phases were carried out, in order of mobility of the metals: exchangeable ion > metal bound with carbonate > metal bound to iron and manganese oxide > metals bound to organic matter and sulfide > residual phase. This was achieved using Tessie’s method and AAS for extraction and analysis. The result for the heavy metals shows Cr (13.6%) and Zn (25.5%) are more abundant in the exchangeable phases in December and January. Metals bound to Fe and MnO extraction phases have Zn (25.50%) abundance in December and January. The residual phase of extraction shows the highest percentage of pb (95.3%) and nickel (85.40%) for December and January. The bacteria and fungi identified are Bacillus cereus, Staphylococcus, Aspergillum, and Clodosporium, respectively. There is no significant difference in physicochemical parameters between the Harmattan dust samples collected in December, January, and February. The percentages of heavy metals in the Harmattan dust are high in the immobility phase of extraction, and bacterial and fungal levels are high in December and January. There is a need for preventive and protective measures to mitigate the health effects associated with...

From ID-TIMS U-Pb dating of single monazite grain to APT-nanogeochronology: application to the UHT granulites of Andriamena (North-Central Madagascar)

Monazite and zircon grains from the ultra-high temperature (UHT) granulite of the Andriamena unit in the centre north of Madagascar, previously investigated using micro-drilled single grain isotopic dissolution geochronology and in-situ electron microprobe chemical dating by Paquette et al. (2004), are reinvestigated using high spatial resolution techniques: atom probe tomography (APT), transmission electron microscopy (TEM), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and secondary ion mass spectrometry (SIMS). The dated grains are located in quartz, garnet belonging to the peak UHT metamorphic assemblage and in retrograde coronitic texture composed of biotite, cordierite and orthoamphibole. Monazite grains show complex discordant trends with several radiogenic Pb (Pb*) loss dispersions, that were previously interpreted as recording at least four geologic episodes occurring from the Archean (~2.7 Ga) to the Proterozoic-Cambrian (~0.5 Ga). Multiscale investigations with SIMS, TEM and APT have been carried out on monazite and LA-ICP-MS on zircon. Zircon grains hosted in garnet and those in quartz record concordant ages at 2758 ±28 Ma and 2609 ±51 Ma, respectively. Monazite grains show age dispersion and a Pb*-loss trend correlated with the grain petrographic position. Grains located in garnet and quartz present less Pb*-loss than those located in the coronitic texture. The discordia indicates a crystallisation age at 2555 ±71 Ma and monazite grains hosted in quartz and garnet record a disturbance event at 1053 ±246 Ma. TEM investigations show that monazite located in quartz and garnet contain numerous Pb-bearing nanophases compared to monazite located in coronitic texture. There is an inverse correlation between the number of Pb-bearing nanophases and the percentage of Pb*-loss in monazite grains. 232Th/208Pb ratio obtained with APT in monazite matrix (i.e. excluding Pb-bearing nanophases) located in quartz and garnet indicated a mean age of 1092 ±127 Ma. This date is interpreted as a hitherto undetected geochronological record in Andriamena unit.

Effect of aluminosilicates on the release and form transformation of semi-volatile heavy metals during the combustion of hyperaccumulator plants

With the development of phytoremediation of heavy metals contaminated soils, the harmless disposal of hyperaccumulator plants has been imminent. In this study, the effects of typical aluminosilicates on the heavy metal migration during the combustion of ryegrass were compared. The addition of kaolin, montmorillonite, and γ-Al2O3 were all effective in solidifying Pb and Zn. As the combustion temperature increased, the toxicity of remaining Pb and Zn decreased. Compared to montmorillonite, kaolin was more effective in capturing Pb and Zn at 600–825 °C, and the remaining Pb and Zn were mainly in acid-soluble form. The large amount of alkali/alkaline earth metals will react with the Si/Al components to form various potassium feldspars and calcium silicates, thus inhibiting the solidification of heavy/alkali metals. However, the Si in montmorillonite was more effective in converting Pb and Zn into residual form than kaolin when faced with the competition solidification of alkali/alkaline earth metals, at which time the percentage of Pb and Zn in the residual form increased from 13.27% and 6.00% to 39.21% and 9.84%, respectively. This work provided a research perspective based on the solidification of heavy metals by Si component, which enables a more comprehensive analysis of the differences in heavy metals solidification by Si/Al-based minerals.

Iron-based materials functionalized with carbon and phosphorus recovered from sludge enhanced the formation of stable minerals to passivate lead and chromium in wastewater and soil

The bioaccumulation and toxicity of heavy metals are serious threats to human activities and ecological health. The exploitation of environmentally friendly passivated materials is major importance for the remediation of heavy metal contaminated soil. This research developed a new type of environmental functional material with a core-shell structure, which is an iron-based material functionalized with phosphorus and carbon from sludge for heavy metal pollution remediation. The results indicated that the C/P@Fe exhibits excellent heavy metal removal ability, and the maximum removal rates of the two heavy metals in simulated wastewater could reach 100% under optimum reaction conditions. It also effectively converts the labile Cr/Pb into the stable fraction after 28 days of incubation, which increased the maximum residual fraction percentage of Cr and Pb by 32.43% and 160% in soil. Further analysis found that the carbon layer wrapped around the iron base could improve the electron transport efficiency of reducing iron, phosphorus and ferrum could react with heavy metal ions to form stable minerals, such as FeCr2O4, FeO·Cr2O3, Pb5(PO4)3OH, PbCO3, 2PbCO3·Pb(OH)2 and PbS, after reacting with C/P@Fe. The study demonstrated that the Iron-based materials functionalized with carbon and phosphorus from sludge provided a more efficient way to remove heavy metals.

Wastewater treatment from a typical multisystem hospital using chemically modified banana peels: Taguchi parametric optimization and characterization

The study aims to develop an eco-friendly solution for addressing contaminants in hospital wastewater. To achieve this, banana peel, a cost-effective and easily available agricultural waste, was chemically modified using sulfuric acid and sodium hydroxide. The hospital wastewater was analyzed using an Atomic Absorption Spectrometer to identify the presence of heavy metals. The physicochemical properties were measured and compared against the standards set by the World Health Organization (WHO). Scanning electron microscopy and Fourier-transform infrared spectroscopy were used to characterize the chemically modified banana peel. Batch adsorption was conducted with the wastewater using the prepared adsorbent. The effect of contact time, mixing rate, temperature, and adsorbent dosage was examined to know the removal efficiency of the adsorbent. The experimental design incorporates Taguchi OA design to optimize the process. The total heavy metals discovered in the wastewater were As, Cd, Fe, Cu, Ni, Cr, Pb, Mn and Zn. The percentage of Cd, Fe, Cu, Ni, Cr and Pb removed were 79.5%, 87.9%, 56.9%, 89.0%, 88.5% and 93.5%, respectively, at temperature, adsorbent dosage, mixing rate and contact time of 30 °C, 3 g, 700 rpm and 60 min, respectively. The physicochemical properties remain within the acceptable WHO range except the turbidity. At optimum point, the percentage removal of Cd, Fe, Cu, Ni, Cr, Pb and Zn were 64.3%, 80.5%, 51.4%, 82.3%, 72.4%, 86.6% and 72.1%, respectively; while, the conductivity, pH, TDS, and turbidity value were, respectively, 20.57 mS/cm, 6.8, 10.16 mg/l, and 86.31 NTU. Characterization revealed the existence of active functional groups on the adsorbent surface enhancing the hospital wastewater treatment and change in its morphological structure after the treatment was noticed. In conclusion, the modified banana peel was effective for the treatment of hospital wastewater.

Efficient and cost-effective adsorbent brick sand nanoparticles used for removal of heavy metals

ABSTRACT We are introducing cost effective, easily available brick sand nano-particles (BSNP) (44.208 nm) as an adsorbent in batch process for removal of heavy toxic metals such as Pb, Cd, and Cr from aqueous solution. We used two types of adsorbents, one is acid treated BSNP and other one is untreated BSNP, and investigated adsorbent properties with function of contact time, temperature, and pH. The efficiency or performance of adsorbent was characterized by AAS for percentage of removal from solution, EDS for elemental analysis to confirm the metals adsorption. The Langmuir, Freundlich, Temkin, Hill De Boer, Elovich, and Redlich-Peterson adsorption isotherms were studies to find out the quality of the adsorbent. At 5.68 to 7.6 pH, the maximum removal percentages of Pb, Cd, and Cr were 97% from the aqueous solution. The temperatures at 40℃ to 60℃, the Pb, Cd, and Cr experiments were carried out at their highest possible percentages (98%). The reaction process was pseudo-second order model and several thermodynamic factors, including Intraparticle diffusion, Elovich kinetic model, Boyd kinetic model, activation energy, Gibbs free energy, enthalpy change, and entropy change ensured the adsorbent efficiency of brick sand nanoparticles. The results of present research indicated that Brick Sand Nano-Particles (BSNP) may play a vital role as a cost-effective, efficient, and easily available adsorbent for the removal of Pb, Cd, and Cr from wastewater.

Synthesis and characterization of bio-nanocomposite based on chitosan and CaCO3 nanoparticles for heavy metals removal

Water is a vital component of life; therefore, it is critical to have access to pure water for various life-sustaining activities including agriculture and human consumption. An eco-friendly nanocomposite based on chitosan (Cs) and nanomaterials (CaCO3-NPs) were combined to amalgamate the advantages of biopolymers and nanomaterials to overcome the problems of instability, poor mechanical properties, and low removal percentage of biopolymers. The as-prepared samples were characterized and were used for the removal of heavy metal from wastewater. X-ray diffractometer, Fourier transform infrared spectroscopy, and transmission electron microscope were used to distinguish the prepared absorbents. The absorption of the heavy metals by as-prepared samples was examined at different conditions. The kinetic and isotherm models of the adsorption process were also studied. The data showed that the removal percentages of Cd, Cu, Pb, Zn, Cr and Ni by the composite were 98.0, 94.8, 99.0, 97.9, 97.4 and 98.3 %, respectively. The kinetic and isothermal studies showed that the absorption of these metal ions by the samples obeyed a pseudo-second-order mechanism and Langmuir isotherm model, respectively. In addition, the maximum adsorption capacities of Cd, Cu, Pb, Zn, Cr, and Ni ions by as-prepared nanocomposite were 83.33, 47.84, 98.03, 89.28, 62.11, and 63.69 mg/g, respectively.

Evaluation of Elasticity, Dose Reduction, and Image Quality on Sr-Pb Shield for Thoracic CT Examination

The performance of chest CT always involved the scanning of breast since it was positioned within the scan range. It makes this organ always receives an amount of radiation that potentially harms the biological system. Many attempts have been performed to reduce the radiation doses objected to breast, including the utilization of radio-protective shield. This study aims to develop the radio-protector shield silicon rubber (SR) - Lead (Pb) based for the breast. The shield was developed with a thickness of 0.6 mm and SR:Pb ratios of 100:0, 98:2, 96:4, 94:6, and 92:8. After that, the shield was placed over an anthropomorphic phantom. The shield’s reliability was tested in terms of elasticity, radiation dose, and image quality. The elasticity level of a material was indicated by Young's modulus yielded. Our results showed that the Young's modulus decreased as the percentage of Pb increased. Breast surface dose was measured using a Radcal ion chamber on the surface of the breast phantom. The measured dose was reduced as Pb increased, the dose using shielding at the highest percentage of 92:8 wt% is 8.71 mGy. The measured SNR without using shielding is 18.38, while the measured SNR using shielding 100:0, 98:2, 96:4, 94:6 and 92:8 was 18.47; 17.45; 16.65; 15.49, and 14.23, respectively. SR-Pb shielding has a Young’s modulus less than 0.035 GPa and can cover the chest of phantom well. SR-Pb shield was able to reduce the breast dose by 26% while the image quality in all variations of the SR:Pb ratio was above the rose criterion value with an insignificant decrease.

STUDI IN VIVO SHIELDING SILICON RUBBER DAN TIMBAL (SR-PB) PADA PEMERIKSAAN COMPUTED TOMOGRAPHY (CT) OBJEK AYAM

Computed Tomography (CT) produces excellent images when diagnosing patient abnormalities. However, the dose received by some radiation-sensitive organs is a significant concern. This study aims to evaluate the reduction in Hounsfield Unit (HU) values and the resulting image quality of a composite-based shielding consisting of silicon rubber (SR) and lead (Pb), comparing it to whole-body chicken images without shielding during CT examination of the abdomen. Exposure factor by type of abdominal protocols with a voltage of 70 kV, 19 mAs, CTDIvol 0.35 mGy, and DLP 18.8 mGy.cm.The synthetic SR-Pb shield had Pb percentages ranging from 0 to 5 wt% and a thickness of 0.6 cm. Scanning on the chicken's abdomen was performed with and without the SR-Pb shield placed directly on the abdomen surface. The HU values were analyzed using MicroDicom software. Image quality was assessed based on the consistency of HU values in the object's anterior, posterior, and lateral areas. A detailed evaluation of image quality was conducted using image subtraction techniques. The study found that the HU values for specific organs did not tend to increase significantly with an increase in the Pb percentage in the SR-Pb shield. The use of the SR-Pb shield had a minor impact on the resulting images, and image quality was well-maintained for every anatomical part. Application of SR in CT examination with precise image results and HU value of each white matter 79-93 HU, liver 86-111 HU, ribs 1032-1189 HU, wing bones 391-531 HU, upper femur 1512 – 1746 HU. In conclusion, the study demonstrates that the resulting images are high quality without artifacts in chicken images, even at higher Pb percentages. Keywords: shielding, silicon rubber, CT Examination.

Polyacrylonitrile (PAN)/Freeze-dried Chitosan (FCS)-NaY zeolite triple layer nanostructure fibrous adsorptive membrane (PAN/FCS-NaY TNAM) for Cu(II) and Pb(II) ions removal from aqueous solutions

In this study, an innovative PAN/FCS-NaY TNAM was fabricated using an electrospinning technique for Cu(II) and Pb(II) removal from contaminated water. Top and bottom fibrous layers (M1) were fabricated using a combination of FCS and PAN blends. Middle layer (M2) was electrospun from pure PAN solution and loaded with NaY zeolite particles. The physicochemical properties of the material and fibrous samples were investigated through SEM, FTIR-ATR, DSC, AFM, DMTA analysis, and contact angle measurement. The effective parameters, including initial ions concentration, time, reusability, and pH on the dynamic adsorption performance of the prepared membrane and its stability in the aqueous medium for Cu(II) and Pb(II) ions removal were investigated at a pressure of 0.006 bar. Dynamic metal ions adsorption was modeled using dynamic filtration prediction models such as Thomas and Yoon-Nelson. The fabricated nanostructure fibrous membranes with the removal percentage of Cu(II) and Pb(II) ions (94.6% and 98.7%, respectively) under the optimal operating conditions (initial concentration: 50 ppm, time: 10 min, and pH: 4.6), high compatibility in modeling dynamic filtration (R2 > 0.99), high pure water flux (298 LMH), suitable reusability (four-cycle without significant reduction in adsorption) as well as long-term stability, can be as potential filters in water treatment applications.

Assessment of heavy metal contamination in street dust: concentrations, bioaccessibility, and human health risks in coal mine and thermal power plant complex.

Coal mining has also been associated with adverse environmental and health impacts including cancer and respiratory disorders, with the presence of thermal power plants exacerbating the problem of heavy metal pollution. Minimal studies have been conducted on the environmental impacts, health risks, and bioaccessibility of heavy metals in coal mine areas. Consequently, samples of street dust were collected from different locations in the Singrauli mine complex and analysed. Heavy metals (Cu, Ni, Zn, Cr, Co, As, and Mo) were found to be higher than the background concentration, with the maximum concentration was found in areas close to the Thermal Power Plants, like Near Vindyachal TPP, Near Shakti Nagar TPP, and Anpara. The highest geo-accumulation index value was found for Co, Mo, Zn, and As, indicating moderate to strong pollution levels. Health risk assessment (for both adults and children) revealed that Cr and Fe posed significantly higher Hazard Quotient and Hazard Index (HI) values, indicating significant non-carcinogenic threats. Moreover, Carcinogenic Risk (CR) values for Cd, Cr, and Ni indicated a risk of carcinogenicity to the public exposed to road dust. The study also examined the bioaccessibility of the metals, which showed that the gastric phase accumulated a higher percentage of Ni (42.52%), Pb (34.79%), Co (22.22%), As (20%) and Cu (15%) than the intestinal phase. Strong positive correlation was observed between metal concentration (Cu, Pb, Cr, Fe, Zn, and Mn), HI, and CR of adult and child, while bioaccessibility of intestinal phase was positively correlated with gastric phase of metals (Cu, Ni, Co, As, and Mn).

Heavy Metal Bioremediation Potential of Autochthonous Lactic Acid Bacteria for Use in Edible Leafy Vegetables

Heavy metals are well-known as destructive environmental pollutants that cause serious health problems. The use of bacterial biological biosorption has been proposed as a practical and environmentally friendly solution for the removal of heavy metals. The current study was conducted in in vitro and in situ conditions. Initially, seven strains of lactic acid bacteria with probiotic properties (Lacticaseibacillus casei, Lacticaseibacillus rhamnosus, Lactiplantibacillus plantarum, Limosilactobacillus fermentum, Enterococcus faecium, Lactobacillus helveticus, and Lactobacillus acidophilus) were screened for their ability to bind cadmium, lead, and nickel in an aqueous solution. Three of the potent probiotic strains that showed the highest biosorption efficiency at this stage were selected for further analysis. The effect of these bacteria mixed at a ratio of 1 : 1 : 1 on the removal of toxic metals in fresh leaves of edible vegetables including coriander, leek, and parsley was evaluated within 15 and 30 minutes. During in vitro analysis, the sorption percentage of Pb and Cd appeared higher than 99% during 15 minutes of initial contact, while increasing contact time (30 minutes) had no significant effect on the removal of these metals. While during in situ analysis, Ni sorption by the selected lactic acid bacteria (LAB) isolates was significantly enhanced with increasing contact time, such that the highest biosorption rate was recorded in coriander leaves at 30 minutes (91.15%). Overall, E. faecium showed the highest sorption of Pb, Cd, and Ni (79.75 ± 0.11, 75.28 ± 0.05, and 83.99 ± 0.10%), respectively. The combination of three bacterial strains had a synergistic effect on the toxic metal binding capacity compared to the single state of these bacteria, and the biosorption level increased to 99.94 ± 0.02, 99.91 ± 0.01, and 93.75 ± 0.04%, respectively. Scanning electron microscopic (SEM) observations and energy dispersive X-ray (EDX) analysis confirmed that the majority of Pb, Cd, and Ni were bound to the surface of the bacterial cell.

Prolonged maturation reduces cleavage and blastocyst rates after ICSI

Most equine assisted reproduction laboratories use overnight room-temperature holding of immature oocytes, followed by in vitro maturation (IVM) for ∼30 hours. The period of maturation may vary according to laboratory workload and shipment schedules. Prolonged IVM (36 h) has been reported to increase blastocyst rates, and in vivo-matured oocytes are typically cultured until 40 to 46 h after gonadotrophin administration before ICSI is performed. There is no information on whether prolonged IVM (48 h) of immature oocytes supports acceptable blastocyst production. We compared maturation, cleavage and blastocyst rates for oocytes held overnight before being cultured for 30 or 48 h before ICSI. We noted that after IVM, some oocytes appeared mature (intact plasmalemma, heterogenous cytoplasm) but lacked a visible polar body, and we assessed whether these oocytes could produce blastocysts. Oocytes from slaughterhouse-derived ovaries were held at room temperature overnight (17 to 20 h) then randomly divided into two groups (n = 115 each): T30, 30 hours IVM culture; and T48, 48 hours IVM culture. After IVM, oocytes were divided into those with a visible polar body (MII) and those that appeared mature but without a polar body (PB-). Frozen-thawed semen from a single stallion was used for ICSI.The injected oocytes were cultured in vitro using a sequential mix of human embryo culture medium, DMEM/F-12, and FBS. Differences between groups were analyzed by Fisher's exact test. There was no difference (P > 0.1) between T30 and T48 in percentage of MII oocytes (37.4% and 32.3%, respectively), percentage of PB- oocytes (8.7% and 15.7%, respectively) or total percentage of oocytes with intact cytoplasm (MII+PB-; 46.1% and 47.8%, respectively). Within maturation duration, there were no significant differences in cleavage or blastocyst rate between MII and PB- oocytes (e.g. for T30, 27.9% and 20% blastocysts, respectively), so data for MII and PB- were combined. The cleavage rate was significantly higher for T30 than T48 (69.8% vs. 41.8%, p = 0.004). Similarly, the blastocyst rate per injected oocyte (26.4% vs. 5.5%, p = 0.003) and the blastocyst rate per cleaved oocyte (38% vs. 13%; p = 0.045) were significantly higher for T30 than T48. We conclude that increasing the duration of IVM to 48 hours does not increase the number of mature oocytes obtained, and indeed significantly decreases oocyte developmental competence. However, we were able to obtain blastocysts after 48 hours IVM, which has not been reported previously. After 30 h IVM, oocytes with a mature morphology but without a visible polar body may be used effectively for ICSI.

Aerobic and anaerobic burning alter trace metal availability in peat soils: evidence from laboratory experiments

AbstractAs global warming becomes more pronounced, climate change and human activities are leading to frequent peat fire incidents. Fire plays an important role in the environmental distribution of trace metals in peat soils. In the current study, we collected peat soils from six peatlands of the Great Khingan Mountains in Northeast China, where wildfires have often occurred in recent decades. To investigate the transformation of trace metals in peat soils by fire, burning experiments at 250°C (light) or 600°C (severe) and under aerobic (AE, flaming) and anaerobic (AN, smouldering) conditions (AE250, AE600, AN250, AN600) were carried out in the laboratory to investigate the effect of different burning intensities on the distribution of Cu, As, Pb, and Cd in peat soils. The European Community Bureau of Reference (BCR) sequential extraction method for metal fractions was applied for partitioning four fractions (exchangeable, reducible, oxidizable, and residual). The results showed that AE600 significantly decreased the percentages of oxidizable Cu, As, Cd and Pb (Cuoxi, Asoxi Cdoxi and Pboxi) compared with those of the original samples, e.g., Cuoxi decreased from 68.84% ± 12.76% to 15.82% ± 8.02% in peat under moss, which might result from organic matter decrease. Under AN250 conditions, the exchangeable As (Asexc) and Pb (Pbexc) significantly increased by more than twice. Different burning intensities significantly changed the various fractions of Cu, e.g., more than 20% Cuoxi transferred to exchangeable and reducible fractions as the temperature increased. Most of the available fractions of As transformed to residual As after burning. Our study suggests that the AE600 treatment increased the ecotoxicity and bioavailability of Cu, Pb and Cd in peat soils, while AN250 burning decreased the potential ecotoxicity of Cu, As, and Pb. Compared with lower temperature flaming burning (AE250), the ecotoxicity and bioavailability of Cu and Pb were greater in high temperature (AE600) conditions. Smouldering fires at both temperatures (AN250 and AN600) maintained a high potential ecotoxicity and bioavailability of Cu and Pb in peat soils.

Bioremediation system consisted with Leclercia adecarboxylata and nZVI@Carbon/Phosphate for lead immobilization: The passivation mechanisms of chemical reaction and biological metabolism in soil

Bioremediation is one of the most promising strategies for heavy metal immobilization. A new remediation system was demonstrated in this research, which combined phosphate solubilizing bacteria (PSB) with nZVI@Carbon/Phosphate (nZVI@C/P) composite to remediate lead contaminated soil. Experimental results indicated that the new system (nZVI@C/P + PSB) could effectively convert the labile Pb into the stable fraction after 30 days of incubation, which increased the maximum residual fraction percentage of Pb by 70.58%. The characterization results showed that lead may exist in the forms of Pb5(PO4)3Cl, PbSO4 and 3PbCO3·2Pb(OH)2·H2O in the soil treated with nZVI@C/P + PSB. Meanwhile, soil enzyme activities and Leclercia abundance were enhanced in the treated soil compared with CK during the incubation time. In addition, the specialized functions (e.g. ABC transporters, siderophore metabolism, sulfur metabolism and phosphorus metabolism) in PSB and nZVI@C/P + PSB group were also enhanced. These phenomena proved that the key soil metabolic functions may be maintained and enhanced through the synergistic effect of incubated PSB and nZVI@C/P. The study demonstrated that this new bioremediation system provided feasible way to improve the efficacy for lead contaminated soil remediation.