Amounts Of Pb Research Articles

Pharmacognostic Characterization of Primula macrophylla by Light Microscopy, Scanning Electron Microscopy and Analytical Techniques.

Traditional medicinal systems have extensively used Primula macrophylla (Primulaceae) to treat a variety conditions, including bronchitis, asthma, joint pain, fever and so forth. This study determines various pharmacognostic and phytochemical standards helpful to ensure the purity, safety, and efficacy of medicinal plant P. macrophylla. In experimental section the Intact aerial parts, powdered materials, and extracts were examined macro- and microscopically and pharmacognostic standardization parameters were determined in accordance with the guidelines given by the World Health Organization. Parameters including extractive values, ash values, and loss on drying were determined. Preliminary phytochemical tests, fluorescence analysis, and chromatographic profiling were performed for the identification and standardization of P. macrophylla. The results of macroscopic studies revealed that leaves are farinose, alternating, foliage, toothed and flowers are unbranched, hermaphroditic, large, herbaceous, round, non-woody stem, roots are adventitious. Length of leave is 11 cm, flower 3 cm, stem 38 cm and root 18 cm. Odor is clove or Eucalyptus like, irritating smell and has pungent/ bitterness. Qualitative analysis confirmed that carbohydrates are not present and saponins, terpenoid, flavonoid, phenolic, phytosterol and fixed oils are not present. The atomic absorption spectrophotometer (AAS) showed the trace amounts of Pb (1.604 mg/L), As (-12.91 mg/L), Hg (7.102 mg/L), and Cd (0.226 mg/L) present. The internal structure of the plant was examined using light microscopy (LM) and scanning electron microscopy (SEM). The plant cross-sectional scans revealed several useful botanical properties. LM and SEM revealed important diagnostic features including stomata, phloem, xylem, spiral vessels, and trichomes and so forth. We conclude that the data generated from the present study help to authenticate the medicinally important plant P. macrophylla. This study is helpful for establishing the pharmacopeia standards in accordance with WHO guidelines.

Distribution, Accumulation Characteristics, and Risk Assessment of Heavy Metals in Vegetable Soils of Different Planting Years

To ascertain the influence of prolonged planting on the distribution and accumulation of heavy metals in protected vegetable soil, samples from typical vegetable planting areas in Shenyang were gathered to evaluate the distribution features of Cr, Ni, Cu, Zn, Cd, and Pb in such soil. The Hakanson index, heavy metal risk assessment standard, and secondary phase to primary ratio methods were employed to evaluate the ecological hazard of soil in the research area, while the human health risk model was utilized to evaluate the health of inhabitants. The findings indicated that：① The amount of heavy metals Zn, Cr, Cu, Ni, Pb, and Cd in the topsoil （0~20 cm） of protected vegetable land in the study region decreased successively, and the content of heavy metals in the topsoil increased with the extension of planting years, of which Cd, Zn, and Cu increased most obviously, with maximum increases of 219%, 189%, and 134%, respectively. ② Heavy metals Zn, Cr, Cu, Ni, and Pb were mainly in the residual state, whereas Cd was mainly in the weak acidic state, with a maximum proportion of 53%. ③ The potential ecological risk index of Cd in the topsoil of the study area was 95.77, showing a medium ecological risk； however, the comprehensive potential ecological risk of the six heavy metals was not high. ④ The HI values of the six heavy metals in the study area were less than 1 and the risk of non-carcinogenesis was negligible； however, the carcinogenic risk of heavy metals in some sampling sites should not be ignored.

Effective Dopants Pb and Pb‐SiW12 to Enhance Sb2S3‐Based Photodetector Performance

AbstractSb2S3 has excellent photovoltaic properties, but the performance of its photovoltaic devices still needs to be improved. The main issues hindering its photovoltaic performance are the poor carrier transport ability and the significant charge recombination. Doping strategies play a key role in addressing these issues. This study investigates the effect of Pb(CH3COO)2 (Pb) and [Pb(DMF)7]2[SiW12O40] 2DMF (Pb‐SiW12) doping on the photovoltaic properties of Sb2S3 thin films. It is found that the intensity of diffraction peaks on the (130) crystal plane of Pb‐doped Sb2S3 and the (221) crystal plane of Pb‐SiW12@Sb2S3 is increased, which enhances the crystallinity of the films. Meanwhile, Pb and Pb‐SiW12 doping narrow the bandgap (1.69 eV) of Sb2S3 to 1.65 eV and 1.62 eV. Electrochemical tests show that the carrier concentration and carrier lifetime are increased. The Pb‐doped Sb2S3 photodetector photocurrent of 14 μA, 7 times higher than the 2 μA pristine Sb2S3 photodetector. It exhibits a responsivity of 13.9 mA/W and detectivity of 1.2×1011 Jones. The Pb‐SiW12@Sb2S3 photodetector photocurrent is 11 μA. Pb‐SiW12 can immobilize Pb while reducing the amount of Pb. The methodology in this work provides a way to improve the performance of Sb2S3 thin‐film photodetectors.

Potential influence mechanism of mineral–organic matter (OM) interactions on the mobility of toxic elements in Pb/Zn smelter contaminated soils

To date, how complex mineral–organic matter (OM) interactions affect the migration and mobility of potentially toxic elements (PTEs) in soils is highly understudied. This work mainly focused on the occurrence characteristics of PTEs and their close association with the composition characterization of mineral elements and dissolved OM (DOM) molecules. The results revealed that quartz (20.20%), albite (15.60%) and biotite (14.37%) were the dominant minerals in soils. CHO molecules were most abundant, accounting for 58.41%. The unsaturated hydrocarbons with both low and high O/C ratios were the dominant organic compounds, accounting for 21.56% and 36.73%, respectively. Sequential extraction results indicated that most Cd was hosted in carbonate minerals, while considerable amounts of As, Cu, Mn, Pb and Zn were bound to Fe/Mn oxyhydroxides. The elemental distribution characteristics displayed the coexistence of As, Cd, Cu, Mn, Pb and Zn with O, S, Al, Si, Ca and Fe. Fe oxyhydroxides might preferentially retain the unsaturated hydrocarbons with low O/C ratio and phenols. Furthermore, Fe oxide–organic composites had more significant impacts on Mn than As, Cd, Cu, Pb and Zn mobility. Overall, these findings would provide important insights into how mineral–OM interactions played the key roles on PTEs mobility in soils.

Body size and survival of urban and rural populations of a common wolf spider are not influenced by lifelong exposure to lead pollution

Abstract Heavy metal pollution is pervasive in urban soils, and it can negatively impact the fitness of arthropods. Arthropod populations can evolve to become more tolerant or resistant to metals, but the mechanisms of these processes are understudied. Here, we tested the hypotheses of fixed adaptation and facultative adaptation in a lead (Pb)-exposure experiment using the progeny of field-collected Pardosa milvina spiders from urban (elevated soil Pb) and rural (background soil Pb) habitats. We predicted that spiders from both populations that were reared in the elevated Pb treatment would exhibit decreased body size in comparison to individuals reared in background Pb soil due to a facultative shift in metabolic investment from growth to Pb resistance, or, alternatively, that urban spiders would exhibit no change in body size across treatments, supporting fixed adaptation as a consequence of a legacy effect of urban Pb pollution. We found no evidence that exposure to elevated Pb soil had an effect on P. milvina’s adult body size or survival, regardless of population origin. Our results indicate that the amount of Pb accumulated by the spiders was not sufficient to induce a measurable change in body size, or that there was a fitness cost that was not measured in the experiment, such as changes in fecundity or body condition. Overall, these findings do not provide support for fixed or facultative adaptation to Pb pollution in P. milvina; as such, future studies should investigate other possible tradeoffs, including changes in egg size, body weight, and foraging effort.

Toxic heavy metals content in different agrochemicals available in markets of Bangladesh and their loads to the agricultural lands.

A study was conducted to determine the concentration of toxic heavy metals in various agrochemicals available in Bangladesh and to assess the burden of these metals on agricultural soils. An atomic absorption spectrophotometer (AAS) was used to measure the content of 4 toxic metals (Cd, Pb, Cr, and Ni) in the aqueous extract of various agrochemicals. There were significant differences in the amounts of Cd, Pb, Cr, and Ni in different brands of insecticides (mean < 0.01, 3.16, 17.32, and 47.33 µgg-1), fungicides (mean 12.42, 10.19, 9.63, and 243.34 µgg-1), phosphatic fertilizers (mean 25.43, < 0.01, 206.33, and 210.69 µgg-1), micronutrient fertilizers (mean 0.68, < 0.01, 43.43, and 65.79 µgg-1), and plant hormones (mean < 0.01, < 0.01, 9.90, and 43.08 µgg-1). The concentrations of Cd and Ni were on anaverage higher in phosphatic fertilizers, which exceeded the maximum acceptable limit of fertilizers in Bangladesh by 2.5 and 4.2 times, respectively. The study also revealed that the burden of toxic heavy metals from agrochemicals on farm soils was in the following order: phosphatic fertilizers > fungicides > micronutrient fertilizers > plant hormones > insecticides. Among the toxic heavy metals, Ni posed the highest burden on Bangladeshi farm soils due to a single application of different agrochemicals in a year. The average total burden of each metal in the soils of Bangladesh showed a decreasing trend in the order of Ni > Cr > Cd > Pb, resulting in a total metal burden of 22.88gyear-1ha-1. Finally, the study recommended that certification about the content of metals be made mandatory for agrochemical manufacturing firms to ensure that their products entering in Bangladeshi markets are free from toxic metals.

Accumulation of heavy metals in the leaves of different tree species and its association with the levels of atmospheric PM2.5-bond heavy metals in Isfahan

This study aimed to biomonitor air pollution by measuring heavy metals (HMs) accumulation levels in the leaves of common urban trees, Cupressus arizonica Greene, Melia azedarach L., Morus alba L. and Buxus colchica in different regions of Isfahan. Their association with the levels of PM2.5 and PM2.5-bond HMs was also investigated. PM2.5 were collected on a glass-fiber filter and measured by gravimetric method. The HM contents of the PM2.5 and tree leaves were extracted and analyzed by ICP-OES. The average PM2.5 concentrations in ambient air of all areas varied from 52.34 to 103.96 μg/m3. The mean HMs levels in the leaves were in the following orderZn(31.2) > Cu(11.04) > Pb(4.38) > Ni(4.01) > Cr(3.03) > Co(0.61) > Cd(0.04) (μg/g). The highest level of HMs was detected in the leaves of Morus alba L., followed by Buxus colchica, Melia azedarach L. and Cupressus arizonica Greene. There was a significant correlation between the amounts of Pb and Cu in tree leaves and those in ambient PM2.5 (p value ≤ 0.05). In conclusion, tree leaves can be used as a suitable bioindicator in the evaluation of air pollution. Morus alba L. compared to the other species can be confidently used for green space development.

Efficient remediation of cadmium and lead contaminated soil in coal mining areas by MICP application in hydrothermal carbon-based bacterial agents: Nucleation pathways and mineralization mechanisms

The development of industrial mining has resulted in a large amount of Cd and Pb polluting the soil in mining areas, and leads to adverse health effects on the life of both plants and animals. Here, a soft template method was conducted to prepare hydrothermal carbon (HC) with regular morphology, which assisted with Bacillus pasteurii to induce calcite precipitation for decontamination of mining soil. Soil remediation experiments over 30 days of remediation with an HC microbial agent (HCMA) resulted in 89.4% and 87.8% decrease in the amount of leached Cd and Pb, respectively. The content of exchangeable Cd and Pb decreased by 76.1% and 81.0%, respectively. At the same time, soil fertility significantly improved. The electrostatic potential and surface charge distribution of extracellular polymeric substances (EPS) and sodium citrate (NaCit) were analyzed using DFT simulations, their nucleophilic and electrophilic regions were determined, and the nucleation mechanism was determined. The DFT results indicated that the oxygen-containing groups of EPS and NaCit had strong negative electrostatic potential and electronegativity, which could cause Cd2+, Pb2+, and Ca2+ to aggregate on their surfaces. They also combined with CO32− produced by urease during the decomposition of urea, resulting in Cd2+ and Pb2+ being encapsulated by calcium carbonate to form a coprecipitate. X-ray diffraction analyses revealed that the precipitate was mainly calcite calcium carbonate, which is more stable and less prone to secondary leaching of HMs. The gathered data prove the significant role of HCMA in remediation of mining soil contaminated with Cd and Pb.

A chemometric approach using I-optimal design for optimising Pb(II) removal using bentonite-chitosan composites and beads

This paper reports adsorption studies of Pb(II) ions onto Bentonite-Chitosan (Bt-Ch) composites or beads when using an I-optimal design experiment approach. Three adsorption factors (pH, adsorbent dosage, and initial concentration) were optimised whilst simultaneously investigating multiple adsorbents. The Bt-Ch composites and beads (type A and B) adsorbents were made using weight ratios 90%/10% and differed characteristically due to their preparation methods of solution blending and precipitation, respectively. A batch procedure was used for adsorption experiments, and the amounts of Pb(II) ions (adsorbed onto Bt-Ch composites/beads) were analysed using inductively coupled plasma optical emission spectrometry (ICP-OES). Adsorption experimental parameters were analysed and optimised by using a response surface method (I-optimal design) generated from Design-Expert® 13.0 software. The main achievements of this study were to intensify the understanding and application of I-optimal experimental designs, which allow simultaneous determination of adsorption capacities and efficiencies across multiple adsorbents in an economical manner. A reduced quadratic model provided the best fit for the experimental data and exhibited minimal deviation between predicted and experimental values. This was evidenced by the very small covariance (CV) values of 1.81% and 1.33% observed for adsorption capacity and adsorption efficiency, respectively, also suggesting high reproducibility. It was observed that the adsorption factors studied (pH, adsorbent dose, and initial concentration) have a more pronounced effect on the adsorption capacity (F-value = 714.37) compared to adsorption efficiency (F-value = 140.62). Adsorbent dosage was found to have the greatest effect on adsorption capacity, while the initial pH of Pb(II) solution had the greatest effect on adsorption efficiency. Under optimal conditions, the adsorption capacities of beads-A (73.2 mg/g) and beads-B (77.6 mg/g) were found to be higher than that of the corresponding composite (51.7 mg/g). Whilst the optimum adsorption efficiency values for all three adsorbents were ∼100% (with ranges of pH 2–5, initial concentrations 50–200 mg/L, and adsorbent dosage 0.05–0.5 mg). The desirability indexes for the optimised conditions for these respective responses (and each adsorbent) were found to be within the ranges of 0.892–0.974 and 0.945–0.967 for adsorption capacity and adsorption efficiency, respectively. These high desirability index values for both responses indicate that the optimised conditions lead to very good performance for both measures. The information obtained in this study provides detailed understanding of the adsorption phenomena of the adsorbents studied. It gives confidence in the use of I-optimal designs to be applied as a chemometric tool for the specific adsorbents studied herein and others.

Multifunctional Acetaminophen Interlayer for High Efficiency and Durability Lead-Lean Perovskite Solar Cells.

Due to the easy oxidation of Sn2+, which leads to form tin vacancy defects and poor perovskite film quality, caused by the rapid crystallization rate in tin-based perovskite solar cells (PSCs), their efficiency lags far behind that of lead-based PSCs. To improve the photovoltaic (PV) performance and stability of FA0.9PEA0.1SnI3-based PSCs (T-PSCs), a small amount of Pb(SCN)2 is introduced into a perovskite precursor as an antioxidant, and acetaminophen (ACE) with various functional groups is used to modify a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/perovskite interface. The results show that the Pb(SCN)2 additive and ACE interfacial modification can not only optimize energy level alignment in T-PSCs but also inhibit Sn2+ oxidation to reduce the trap-state density, resulting in promoted carrier transport. The synergetic effect of the Pb(SCN)2 antioxidant and ACE interfacial modification significantly reduces nonradiative recombination and improves the PV performance and stability of T-PSCs. Consequently, the unsealed T-PSCs with the Pb(SCN)2 additive and ACE modification achieve a champion efficiency of 12.04% and maintain 99% of their initial PCE after being stored in N2 for more than 2100 h, while reference T-PSCs demonstrate a champion PCE of 6.20% and retain only 72% of its initial PCE. Moreover, the modified T-PSCs without encapsulation demonstrate much better stability in humid air.

Assessment of heavy metals and proximate composition in jellyfish (Lobonemoides robustus Stiasny, 1920) collected from Cox's Bazar coast: Human health risk assessment

Jellyfish are known for experiencing periodic blooms in population, which occur when their density increases suddenly. The present study assessed the level of heavy metals and proximate composition in the jellyfish Lobonemoides robustus collected from Cox's Bazar coast of Bangladesh. This is the first study conducted in Bangladesh. Most of the studied metals were not possible to detect in L. robustus samples because concentrations were below the detection limit. Ca, Na, Se, and Mg were found to have safe levels in the L. robustus while the amount of Pb was recorded 0.39 ppm. The findings of Target Hazard Quotient, and Carcinogenic Risk indicate that the L. robustus is safe for human consumption (both for children and adults). Hence, it is suitable for consumption and can be exported. This study emphasizes the need for regular marine environment monitoring to ensure that the seafood harvested from these waters is safe for consumption.

Interaction of Pb(II) with microplastic-sediment complexes: Critical effect of surfactant

In this study, the impact of surfactants on the adsorption behavior of Pb(II) onto microplastics-sediment (MPs-S) complexes was investigated. Firstly, virgin polyamide (VPA) and polyethylene (VPE) were placed in Xiangjiang River sediment for six months to conduct in-situ aging. The results indicated that the biofilm-developed polyamide (BPA) and polyethylene (BPE) formed new oxygen-containing functional groups and different biofilm species. Furthermore, the adsorption capacity of Pb(II) in sediment (S) and MPs-S complexes was in the following order: S > BPA-S > VPE-S > VPA-S > BPE-S. The addition of sodium dodecyl benzenesulfonate (SDBS) promoted the adsorption of Pb(II), and the adsorption amount of Pb(II) increased with the higher concentration of SDBS, while adding cetyltrimethylammonium bromide (CTAB) showed the opposite result. The adsorption process of MPs-S complexes to Pb(II) was dominated by chemical adsorption, and the interaction between MPs-S complexes and Pb(II) was multilayer adsorption involving physical and chemical adsorption when the surfactants were added. Besides, the pH exerts a significant effect on Pb(II) adsorption in different MPs-S complexes, and the highest adsorption amount occurred at pH 6. Noteworthy, CTAB promoted the adsorption ability of Pb(II) when the exogenous FA was added. The binding characteristic of sediment endogenous DOM components and Pb(II) was influenced by the addition of MPs and surfactants. Finally, it confirmed that adsorption mechanisms mainly involve electrostatic and hydrophobic interaction. This study provides a new perspective to explore the environmental behaviors of Pb(II) by MPs and sediments with the addition of surfactants, which was conducive to evaluating the ecological risks of MPs and heavy metals in aquatic environments.

Femtosecond laser-induced surface nanostructures for enhanced trace metal element detection in water.

As societal concern for environmental and public health issues intensifies, precisely monitoring harmful heavy metal concentrations in aquatic systems has become a critical scientific endeavor. Although laser-induced breakdown spectroscopy (LIBS) allows for the simultaneous detection of multiple elements, its sensitivity for tracing metal in water remains inadequate. This work investigates the enhancement of LIBS signals for chromium (Cr) and lead (Pb) detection of micro/nanostructures on aluminum surfaces, generated by femtosecond laser irradiation. These structures effectively reduce the coffee-ring effect, increasing plasma temperature and electron density. At a concentration of 100 µg/L, the spectral intensities of Cr and Pb increased by 378% and 307%, respectively. Consequently, this reduced the detection limits to 6.33 µg/L for Cr and 2.53 µg/L for Pb. Additionally, a partial least squares regression (PLSR) model was employed to quantitatively analyze the concentrations of Cr and Pb in water, achieving correlation coefficients (R2) of 0.997, 0.981 for Cr, and 0.995, 0.977 for Pb, in the training and prediction sets, respectively. This work demonstrates that integrating micro/nanostructures induced by femtosecond lasers on aluminum surfaces with the PLSR model substantially improves the detection sensitivity for trace amounts of Cr and Pb in water, offering new avenues for environmental monitoring and research.

Bioaccumulation of heavy metals in water and mollusks in the Karnafully estuary: Potential human health risk and environmental contamination

This study investigates the bioaccumulation of heavy metals lead (Pb), cadmium (Cd), copper (Cu), and chromium (Cr) in water and mollusks across the Karnafully River estuaryof Bangladesh. Samples were collected from six different sites encompassing diverse ecological conditions over three seasons: monsoon, post-monsoon, and winter. Six mollusk species were analyzed using atomic absorption spectrophotometry to quantify metal concentrations in both tissues and shells. These species are Neritina violocea, Neritina sulculosa, Telescopium telescopium, Cerithida ecingulata, Corbicula fluminea, and Bellamya bengalesis. The Chaktai canal site had the highest concentration of Cu (13.99±0.92 mg/kg) from the mussel species B. Bengalesis during monsoon season, which was higher than the tolerable limit for human. The the lowest concentration of Cu (1.13±0.76 mg/kg) from the composite mussel species N. sulculosa were fround from the 15 No. Jetty site in winter.. The highest concentration of Cr was found at the Marine Academy site (0.54±0.24 mg/kg) during the post-monsoon period from the mussel species N. violocea, while the lowest concentration was found near the Karnafully Bridge (0.05±0.02 mg/kg) during the monsoon from the mussel species Cerithidea cingulata. The highest concentration of Cd was observed in the Chaktai canal site (0.77±0.04 mg/kg) during the winter from the B. bengalesis, and the lowest concentration was recorded in the Karnafully Bridge (0.33±0.06 mg/kg) site during the winter season from the Cerithidae cingulata species. The highest amount of Pb was found in Chaktai canal site (0.32±0.06 mg/kg) during the monsoon season in B. bengalesis fuana. The lowest amount was found in Karnafully Bridge (0.09±0.02 mg/kg) in the Cerithidae cingulate species at the same time. The results suggested that the possibility of the occurrence of acute toxicities of Cu, Cr, Cd and Pb was unlikely except for the mussel of T. telescopium in the Marine Academy that indicates heavy metals presence at the Marine Academy site. The study revealed that the average concentrations of the heavy metals were in the order of Cu>Cd>Cr>Pb in the monsoon, postmonsoon, and winter seasons. The principal Component Analysis (PCA) highlighted distinct seasonal patterns in metal accumulation, underscoring the need for seasonal-specific monitoring and management strategies in estuarine ecosystems.

The Effect of Component Defects on the Performance of Perovskite Devices and the Low-Cost Preparation of High-Purity PbI2.

The efficiency and reproducibility of perovskite solar cells (PSCs) are significantly influenced by the purity of lead iodide (PbI2) in the raw materials used. Pb(OH)I has been identified as the primary impurity generated from PbI2 in water-based synthesis. Consequently, a comprehensive investigation into the impact of Pb(OH)I impurities on film and device performance is essential. In this study, PbI2, with varying stoichiometries, was synthesized to examine the effects of different Pb(OH)I levels on perovskite device performance. The characterization results revealed that even trace amounts of Pb(OH)I impede the formation of precursor prenucleation clusters. These impurities also increase the energy barrier of the α-phase and facilitate the transition of the intermediate phase to the δ-phase. These effects result in poor perovskite film morphology and sub-optimal photovoltaic device performance. To address these issues, a cost-effective method for preparing high-stoichiometry PbI2 was developed. The formation of Pb(OH)I was effectively inhibited through several strategies: adjusting solution pH and temperature, modifying material addition order, simplifying the precipitation-recrystallization process, and introducing H3PO2 as an additive. These modifications enabled the one-step synthesis of high-purity PbI2. PSCs prepared using this newly synthesized high-stoichiometry PbI2 demonstrated photovoltaic performance comparable to those fabricated with commercial PbI2 (purity ≥ 99.999%). Our novel method offers a cost-effective alternative for synthesizing high-stoichiometry PbI2, thereby providing a viable option for the production of high-performance PSCs.

Production performance and biochemical profile of sea lettuce (Ulva lactuca): Influence of site-specific ecological factors and cultivation strategies

Production performance and biochemical characteristics of seaweed under varying cultivation strategies and ecological conditions provide crucial insights for improving sustainable farming practices. Therefore, this study aims to investigate the production performance and biochemical profile of sea lettuce (Ulva lactuca) under three farming systems, namely floating long-line (FLL), off-bottom long-line (OBLL), and off-bottom net (OBN), and three site-specific (Khurushkul, Nuniachora, and Sonapara) ecological conditions for a period of nine months (October 2022 to June 2023). Depending on the site suitability for different cultivation systems, 15 plots (5 FLL, 5 OBLL, and 5 OBN) were established in Nuniachora, 10 plots (5 FLL, 5 OBLL) were established in Sonapara, and 5 plots (FLL) were established in Khurushkul of the Cox's Bazar district, Bangladesh. Depending on the cultivation months, we partially harvested U. lactuca every 15–30 days once it reached 25–35 cm in length. Results showed that the gross weight biomass (GWB) of U. lactuca cultured in the FLL (F = 200.43, p < 0.001) cultivation system was 45.38% and 39.85% higher compared to OBN and OBLL, respectively. The average daily growth rate (DGR) was found to be 11%–13% higher in the FLL method (F = 236.11, p < 0.001). Location-based comparisons indicated a significantly higher (p < 0.05) U. lactuca production in Khurushkul, followed by the Nuniarchora, and the lowest was observed in Sonapara. Seasonality influenced the production performances of U. lactuca, with significantly higher (p < 0.05) growth observed from December to March due to favourable physio-chemical parameters. Multivariate analysis revealed that high salinity, pH, and nutrient concentrations positively influenced growth performances, while high temperature, turbidity, and total suspended solids (TSS) had negative effects. U. lactuca harvested from the FLL and OBN systems contained 14.3% and 9.44% higher amounts of protein (F = 36.77, p < 0.001) than the OBN system. The fatty acid analysis showed that U. lactuca from the FLL and OBN systems contained a significantly lower amount of saturated fatty acids but a higher amount of monounsaturated and n-6 polyunsaturated fatty acids compared to the OBLL system. Among the heavy metals and minerals analyzed, U. lactuca harvested from the FLL system contained significantly (p < 0.05) higher amounts of Na and K and lower amounts of Pb, Cr, Co, and Fe. The findings of the present study underscore the superiority of the floating long-line cultivation system for U. lactuca, highlighting its potential for sustainable farming practices to address global food security and utilization in various industrial applications.

Effect of Polystyrene Microplastics on Pb(II) Adsorption onto a Loessial Soil (Sierozem) and Its Mechanism.

Microplastics (MPs) have received significant attention recently. However, their influence on soil heavy metal adsorption remains unclear. The effect of polystyrene (PS) MPs on the adsorption of Pb(II) onto a loessial soil (sierozem) was studied by batch experiments in single soil (S), soil with 1 mm PS (S-PS1), and soil with 100 μm PS (S-PS100) systems. The mechanisms of Pb(II) adsorption reduction were investigated. The adsorption of Pb(II) reached equilibrium within 12 h, and the pseudo-second-order model fitted the adsorption processes best. The Langmuir adsorption model provided a better fit to the isotherms, compared to the Freundlich one. The presence of PS decreased the level of adsorption of Pb(II). Larger PS particle size, dose, and fulvic acid (FA) concentration inhibited Pb(II) adsorption onto the soil. The solution pH value showed a positive correlation with the adsorption amount. The adsorption amounts (q e) of Pb(II) in binary metal systems (Cu-Pb and Cd-Pb) were lower than those in single Pb systems, indicating the competitive adsorption among the ions. The adsorption amount presented a trend of S > S-PS100 > S-PS1. The primary mechanism on which PS reduced the adsorption of Pb(II) was the "dilution effect" of MPs. Conclusively, the presence of MPs might elevate the availability of heavy metals by reducing the soil's adsorption capacity for them and then amplifying the risk of heavy metal contamination and migration.

Application of soil magnetometry and geochemical methods to investigate soil contamination with antimony

The aim of the study was an assessment of the pollution level and identification of the antimony sources in soils in areas subjected to industrial anthropopressure from: transport, metallurgy and electrical waste recycling. The combination of soil magnetometry, chemical analyzes using atomic spectrometry (ICP-OES and ICP-MS), Sb fractionation analysis, statistical analysis (Pearson’s correlation matrix, factor analysis) as well as Geoaccumulation Index, Pollution Load Index, and Sb/As factor allowed not only the assessment of soil contamination degree, but also comprehensive identification of different Sb sources. The results indicate that the soil in the vicinity of the studied objects was characterized by high values of magnetic susceptibility and thus, high contents of potentially toxic elements. The most polluted area was in the vicinity of electrical waste processing plants. Research has shown that the impact of road traffic and wearing off brake blocks, i.e. traffic anthropopression in general, has little effect on the surrounding soil in terms of antimony content. Large amounts of Pb, Zn, As and Cd were found in the soil collected in the vicinity of the heap after the processing of zinc–lead ores, the average antimony (11.31 mg kg−1) content was lower in the vicinity of the heap than in the area around the electrical and electronic waste processing plant, but still very high. Antimony in the studied soils was demobilized and associated mainly with the residual fraction.

Possible Metal Burden of Potentially Toxic Elements in Rainbow Trout (Oncorhynchus mykiss) on Aquaculture Farm

Aquaculture products are important parts of human nutrition due to their healthy components; however, they may contain elements that are potentially toxic to consumers. The aim of the study was to detect the concentration of As, Cd, Hg, and Pb by inductively coupled plasma optical emission spectroscopy in rainbow trout (Oncorhynchus mykiss) originated from an aquaculture farm in Italy. The amount of As was 1.65 ± 0.49 mg/kg; however, the total As cannot be evaluated due to the absence of official regulation. The calculated EDI and THQ for the inorganic As content were below the reference values. The level of Cd was higher than the regulated limit in 30% of the samples; however, its EDI and THQ were below the recommended limit. The concentration of Hg was below the regulated maximum limit in all the samples. The detected amount of Pb was above the maximum limit in 10% of the samples; however, EDI and THQ were below the reference dose and recommended value. Despite higher concentrations of Cd and Pb than the official regulated limit, HI was below 1 for adults; thus, the consumption of the investigated rainbow trout is safe, but it was above the official regulated limit for children, resulting in a slight risk, particularly during long-term intake.

Potentially toxic metals in road dust: An assessment of ecological and health risks at Woldia and Kobo towns in North Wollo, Ethiopia

ABSTRACT The accumulation of heavy metals (HMs) in the environment threatens the ecosystem and human well-being. This study investigated the amounts of Mn, Fe, Ni, Co, Cu, Zn, Cd, Hg, Pb, As, and Cr, as well as the associated health and ecological risks. Thirty samples of roadside dust were collected in the northern Ethiopian towns of Woldia and Kobo. The collected samples were digested using acid digestion method and the levels of heavy metals were analysed using inductively coupled plasma optical emission spectroscopy. The results showed that the average concentrations of HMs were 0.103 (As)-7.6 (Cd) and 0.083 (Cd)-3.80 (Fe) mg/kg in Woldia and Kobo, respectively. All the HM concentrations investigated in this study were lower than the average global concentration, except for Hg in both towns and Cd in Woldia town. Analysis of variance (ANOVA) for the heavy metal concentration showed a significant difference across each sampling site, while Ni and Hg did not show a significant difference. The hazard quotient (HQ) and hazard index (HI) values of all HMs for adults and children through the three exposure routes were lower than 1, which means that they had a low likelihood of noncarcinogenic risks. The pollution index, geoaccumulation index, ecological risk index, integrated pollution index and risk index parameters were used to estimate the ecological risk. The results demonstrated that the pollution level mainly varied between low and moderate levels, except in Woldia, which is highly polluted by Cd metal that further detailed research is highly recommended to find out the sources of this metal.