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In this study, an effective and inexpensive PAA-CG composite was synthesized using polyacrylamide (PAA) and coffee ground (CG) with the help of the in situ polymerization method. The adsorption efficiency of this new composite was investigated in the removal of Pb(II) ions from an aqueous solution. Characterization was done by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive spectroscopy and zero charge point analysis. The maximum adsorption capacity of the PAA-CG composite was calculated as 0.622 mol/kg according to the Langmuir isotherm model. From the obtained data, it was determined that the adsorption mechanism is compatible with pseudo-second-order kinetics and intra-particle diffusion model. The calculated thermodynamic data showed that adsorption is endothermic, spontaneous and entropy increasing. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the relationship between blood lead levels (BLLs) and IVF clinical outcomes in infertile females and to further explore the possible involvement of granulosa cell (GC) endoplasmic reticulum (ER) stress in the process. Methods: One hundred twenty-three infertile women undergoing IVF cycles were included in the current study. All participants were divided into three (low, medium, and high) groups determined by BLL tertiles. Gonadotropin releasing hormone (GnRH) agonist regimen for ovarian stimulation was used for all patients, with follicular fluids being collected on the day of oocyte retrieval. Lactate dehydrogenase (LDH) levels in follicular fluid and the endoplasmic reticulum stress-signaling pathway of granulosa cells (GCs) were examined. Results: The oocyte maturation rate and high-quality embryo rate on cleaved stage decreased significantly as BLL increased. For lead levels from low to high, live birth rate (68.29%, 56.10%, 39.02%; P=0.028) showed negative correlations with BLLs. Also, follicular fluid Pb level and LDH level was significantly higher in the high lead group versus the low group. Binomial regression analysis revealed significant negative correlation between BLLs and live birth rate (adjusted OR, 0.38; 95% CI, 0.15–0.95, P=0.038). Further analysis of the endoplasmic reticulum stress (ER stress) signaling pathway of GCs found that expressions of GRP78, total JNK, phosphorylated JNK, and CHOP increased and BCL-2 decreased with increasing BLLs. Conclusions: BLLs are negatively associated with final clinical outcomes in IVF patients that may be related to increased ER stress response and GC apoptosis. Thus, reducing Pb exposure before IVF procedures may improve final success rates. [ABSTRACT FROM AUTHOR]

One of the most crucial methods for understanding the state of any aquatic ecosystem is the use of test organisms such as fish or invertebrates. The water flea, Daphnia magna, is commonly used as a model species for ecotoxicological studies. In the current examination, D. magna neonates were exposed to concentrations of metals similar to those previously reported to occur in the ecosystem. The 48-h acute toxicity tests of FeCl3, PbCl2, and their mixture at different concentrations were applied to D. magna. The Probit analysis was used to calculate the 48-h median lethal concentration (LC50) for each of Fe, Pb, and their mixture. The results revealed that Fe was more hazardous than Pb, with 48-h LC50 values of 6.47 and 13.14mg/l, respectively. Furthermore, the Fe-Pb mixture had a synergetic impact on Daphnia magna (mixture 48-h LC50 was 3.9mg/l). This study indicated that the realistic levels of Fe and Pb may trigger the lethal impacts of freshwater crustaceans, causing devastating impacts on the ecosystem and food web. These results may be valuable in elaborating water quality criteria and standards to protect the national aquatic systems that are drastically affected by anthropogenic industrial contamination. Because of the unexpected responses of multi-contaminant scenarios, there is a need for more thorough, environmentally appropriate research on the mixture impacts of the pollutants. [ABSTRACT FROM AUTHOR]

A new method for the rapid detection of cadmium (Cd), lead (Pb) and arsenic (As) elements in pig premixed feeds by energy dispersive X-ray fluorescence (EDXRF) spectroscopy was investigated. Samples were added to starch and water, pasted in a water bath at 94 ℃ and scanned by EDXRF spectroscopy, with copper spectral identification for characterisation and standard addition method for quantification. The results showed that the EDXRF spectral peaks of each element were interference-free and the method was well linear (R2 >0.998) in the concentration range examined; the limits of detection were 1.06 mg/kg, 1.68 mg/kg and 1.97 mg/kg for Cd, Pb and As, respectively. The overall recoveries were 93.72%-105.10% and the overall relative standard deviations were 2.30%-9.40%. The method is simple, rapid, accurate and reliable, and can meet the needs of rapid determination of Cd, Pb and As in pig premixed feeds. [ABSTRACT FROM AUTHOR]

Recombinant Saccharomyces cerevisiae expressing metallothionein was used for biosorption of lead (Pb). The Plackett-Burman design (PBD) and Box-Behnken design (BBD) were applied to optimize adsorption conditions of Pb by genetically engineered S. cerevisiae. The PBD and its subsequent statistical analysis indicate that the initial concentration of Pb, pH and concentration of biosorbent were the three critical factors influencing Pb biosorption by genetically engineered S. cerevisiae. The Path of steepest ascent was then used to approximate the optimal levels of the main factors. Then, the response surface method was used to optimize the adsorption conditions further. Considering biosorption quantity of Pb as the response objective, a quadratic model was obtained by BBD for 3 factors. The optimal biosorption conditions were as follows: the initial concentration of Pb (81.12 mg/L), pH 5.05 and the concentration of biosorbent (0.15 g/L). Under optimal conditions, the maximum adsorption quantity of Pb is 129.60 mg/g. Model validation experiments showed good correlation between the predicted values and experimental values. The performance of adsorption of Pb by genetically engineered S. cerevisiae is clearly improved by response surface methodology optimization. Genetically engineered S. cerevisiae show higher adsorption capacity than other reported biosorbents and may therefore be an effective biosorbent for industrial use. [ABSTRACT FROM AUTHOR]

In order to study the effects of oxalic acids on plant growth and Pb accumulation in different parts of the plants of intercropping Arabis alpina and Zea mays, pot experiment was conducted to investigate the changes of oxalic acid contents of the plants and Pb accumulation through exogenous oxalic acid addition (0, 5, 25 and 50 mmol kg−1). The results showed the root biomass of intercropped A. alpina and total biomass of Z. mays increased by 3.22 folds and 2.97 folds with 5 mmol kg−1 oxalic acid treatment. The oxalic acid contents of shoots and root secretions decreased by 86.5% and 44.3%, respectively. The BCF (bio-accumulation factor) and TF (translocation factor) of intercropping A. alpina reduced under 25 − 50 mmol kg−1 oxalic acid treatments. There were relationships between exogenous oxalic acid treatment concentrations and oxalic acid contents of A. alpina shoots, Z. mays root secretions. The Pb contents of shoots of A. alpina and Z. mays were related to exogenous oxalic acid additions and oxalic acid contents of shoots. In general, 5 mmol kg−1 oxalic acid treatment, that can improve plant growth of intercropped A. alpina and Z. mays, which Pb translocation and accumulation of A. alpina were promoted, whereas Pb accumulation of A. alpina was inhibited with 25 − 50 mmol kg−1 concentrations addition. This study will provide a basis for promoting the application of phytoremediation techniques and efficient crop production in heavy metal contaminated areas. Hyperaccumulators intercropped with crops will remediate heavy metal soils or mitigate the damage caused by heavy metals to plants through oxalic acid secretion by the root system. However, the effect of oxalic acid changes on plant growth and Pb accumulation is lacking. Our study investigated the changes in oxalic acid content at different concentrations and sites affected the ability of intercropped plants to grow and accumulate Pb. This work shown that under intercropping conditions, exogenous oxalic acid promotes intercropped plant growth as well as soil pH reduction, Pb content in shoots both Arabis alpina and Zea mays is influenced by exogenous oxalic acid content, while lower Z. mays roots Pb content is determined by a combination of exogenous addition and aboveground oxalic acid content. Low concentrations of oxalic acid promoted Pb enrichment in roots of A. alpina, while reducing the uptake of Pb content in Z. mays. This article gives us a better understanding for the response of intercropping plants to the use of organic acids under heavy metal stress and how to modify their environment so as to favor growth. [ABSTRACT FROM AUTHOR]

Polymetallic exposure causes complex toxicity to microorganisms. In this study, we investigated the responses of Escherichia coli under co-existence of cadmium (Cd) and lead (Pb), primarily based on biochemical analysis and RNA sequencing. Cd completely inhibited bacterial growth at a concentration of 2.41 mmol/L, with its removal rate as low as <10%. In contrast, the Pb removal rate was >95% under equimolar sole Pb stress. In addition, the Raman analysis confirmed the loss of proteins for the bacterial cells. Under the co-existence of Cd and Pb, the Cd toxicity to E. coli was alleviated. Meanwhile, the biosorption of Pb cations was more intense during the competitive sorption with Cd. Transmission electron microscopy images showed that a few cells were elongated during incubation, i.e., the average cellular length increased from 1.535 ± 0.407 to 1.845 ± 0.620 µm. Moreover, NanoSIMS imaging showed that the intracellular distribution of Cd and Pb was coupled with sulfur. Genes regulating sulfate transporter were also upregulated to promote sulfate assimilation. Then, the subsequent production of biogenic sulfide and sulfur-containing amino acids was enhanced. Although this strategy based on S enrichment could resist the polymetallic stress, not all related genes were induced to upregulate under sole Cd stress. Therefore, the S metabolism might remodel the microbial resistance to variable occurrence of heavy metals. Furthermore, the competitive sorption (in contrast to sole Cd stress) could prevent microbial cells from strong Cd toxicity. [ABSTRACT FROM AUTHOR]

The co-transport of contaminants by soil colloids can generate substantial environmental risk, and this behavior is greatly affected by environmental conditions. In this study, AF4-ICP-MS was used to investigate the size distribution and composition of Cd/Pb-bearing colloids; saturated sand column experiments were used to investigate the impact of soil colloids on the transport of Cd/Pb under different pH and ionic strength conditions. AF4-ICP-MS characterization showed that natural colloids were primarily associated with two sizes ranges: 0.3–35 KDa (F1, fine nanoparticles) and 280 KDa–450 nm (F2, larger nanoparticles), which mainly consisted of organic matter (OM), iron (Fe), and manganese (Mn) (oxy)hydroxides and clay minerals. Fine nanoparticles could strongly adsorb Cd and Pb under all environmental conditions. Mn and Fe (oxy)hydroxides generally formed under neutral to alkaline conditions and exhibited adsorption capabilities for Cd and Pb, respectively. Transport experiments were conducted under different pH and ionic strength conditions. At pH 3.0, soil colloids had little effect on the transport of Cd2+ and Pb2+. At pH 5.0, soil colloids inhibited the transport of Cd2+ by 16.1%, and Pb2+ recovery was still 0.0%. At pH 7.0 and 9.0, soil colloids facilitated the transport of Cd2+ by 15.6% and 29.6%, facilitated Pb2+ by 1.3% and 6.4%. At an ionic strength of 0, 0.005, and 0.01 mol L−1 NaNO3, soil colloids facilitated the transport of Cd2+ by 77.7%, 45.8%, and 15.6%, only facilitated the transport of Pb2+ by 46.2% at an ionic strength of 0 mol L−1 NaNO3. At an ionic strength of 0.05 mol L−1 NaNO3, soil colloids inhibited the transport of Cd2+ and Pb2+ by 33.1% and 21.0%, respectively. The transport of Cd2+ and Pb2+ facilitated by soil colloids was clearly observed under low ionic strength and non-acidic conditions, which can generate a potential environmental risk. [ABSTRACT FROM AUTHOR]

The electrochemical CO2 reduction reaction (CO2RR) presents a promising approach for producing valuable chemicals and fuels, offering a dual benefit in terms of environmental preservation and the efficient utilization of carbon resources. In this work, we proposed a stepwise electrodeposition method to prepare Cu−Pb bimetallic heterojunction catalyst on polyaniline‐modified carbon paper (PANI‐CuPb‐x), where x is the electrodeposition times(min). Among the studied catalysts, the electrode electrodeposited for 2 min (PANI‐CuPb‐2) exhibited a remarkable performance during the electrocatalysis CO2 to multicarbon (C2+) products process, achieving a Faraday efficiency (FE) of 81.46 % and a partial current density of 15.41 mA cm−2 at −1.2 V (vs. RHE) in an H‐type cell. The detailed study demonstrated that introducing Pb could effectively improve the formation of COOH*inhibit hydrogen evolution reaction (HER). Furthermore, the heterojunction structure in the catalysts facilitated C−C coupling of the generated C1 intermediate species, which enhanced the CO2 to C2+ reaction. [ABSTRACT FROM AUTHOR]

Innovatively regulating the crystalline-amorphous (c-a) interface of electrode materials is critical for enhancing supercapacitor and electrochemical water splitting performance. In this research, an oxygen defect-rich Fe 3 O 4 @Fe electrode material with a unique and tunable c-a interface was synthesized using prussian blue (PB) as a template. The resulting interface facilitates electron transport and ion diffusion, increases the charge storage active sites, and enhances energy storage capacity. Density functional theory (DFT) simulations demonstrated that oxygen defects can effectively enhance ionic conductivity and facilitate electrochemical water splitting. The optimal Fe 3 O 4 @Fe electrode exhibits remarkable specific capacitance (1526.766 mF cm−2 at 1 mA cm−2) and exceptional oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performance, with overpotential values of 231 and 359 mV at 10 mA cm−2, respectively. Furthermore, as an overall water splitting electrocatalyst, the optimal Fe 3 O 4 @Fe can reach 10 mA cm−2 at a battery voltage of 1.645 V, demonstrating its tremendous potential as a highly efficient electrocatalyst. The oxygen defect-rich Fe 3 O 4 @Fe electrode materials with unique c-a interface are a kind of highly efficient multifunctional electrode material for supercapacitors and overall water splitting. [Display omitted] • The tunable c-a interface enhances electron transport, ion diffusion, and energy storage capability. • Introduction of oxygen vacancies improves electron transfer kinetics and electrochemically active area. • The unique synergistic interaction between the c-a interface and oxygen vacancies enhances rate performance. [ABSTRACT FROM AUTHOR]

Assisted phytoremediation is extremely promising, but is still in development and needs further study. Therefore, the combination use of Erythrostemon gilliesii and humic acid was studied to aid the efficiency of lead nitrate Pb(NO3)2 phytoextraction. Seedlings were exposed to five simultaneous treatments of Pb(NO3)2 (0, 100, 300, 500, and 700 mg L−1) and humic acid (0 and 300 mg L−1) for three growth months (90 days in summer) and their effects on physiological and morphological traits of plants were recorded. Up to 300 mg L−1, Pb treatments showed apparent positive (stimulative) effects on plant traits, including dry and fresh weight, length, number of leaves, the diameter of collar and root, and root germination. Lead treatments higher than 300 mg L−1 showed negative (repressive) effects on plant growth. A decrease in Pb uptake was observed in simultaneous treatments of humic acid and Pb, which means more Pb remains unabsorbed in the soil. We conclude that E. gilliesii is well-suited to the phytoextraction of Pb in contaminated areas, but humid acid significantly reduces the efficiency of remediation; therefore, the levels of humic acid should be controlled during the remediation process in an area. [ABSTRACT FROM AUTHOR]

The concentrations of heavy metals Cu, Zn, Cd, and Pb in the leaves of Betula pubescens were analyzed at ten sites along the pollution gradient near the Middle Ural copper smelter. The studies were carried out during the period of moderate emissions (2009) and after their reduction to a minimum (2019). Leaf samples were collected in early and late summer. Cu and Cd showed a strong negative correlation with the distance to the smelter. The interannual differences are most pronounced for Pb, the concentration of which significantly decreased in 2019 at the sites closest to the smelter compared to 2009. In both years, the concentrations of metals in the leaves increased towards the end of the growing season. [ABSTRACT FROM AUTHOR]

Fuel cells are one excellent option for converting energy through green technology. Due to its accessibility and high-energy density, glucose can be employed as a fuel in fuel cells. In this study, hydroxyapatite (HAp) was prepared by the precipitation method, and carbon-doped HAp supported PbHfCd (PbHfCd/C-HAp) composite electrocatalysts at varying metal ratios for the glucose electrooxidation were synthesized via NaBH4 reduction method. Inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy (SEM-EDX), X-ray diffraction analysis (XRD), elemental mapping, and transmission electron microscopy (TEM) were used to evaluate the chemical structure, crystallinity, and morphological characteristics of the PbHfCd/C-HAp. Chronoamperometry (CA), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were utilized to scrutinize the electrocatalytic activity and stability of PbHfCd/C-Haps for glucose electrooxidation. The findings demonstrate that HAp enhances the glucose electrooxidation of PbHfCd alloy. With a specific activity of 4.73 mA/cm2, Pb80Hf10Cd10/C-HAp is the most stable and active anode electrocatalyst in this work, outperforming HAp by 4.9 times. [ABSTRACT FROM AUTHOR]

Lead is a toxic metal that produces effects on the overall health of animals, resulting in mortality at high exposures, adverse physiological and behavioral effects at lower concentrations, and population declines in many species. Scavengers and predators are more susceptible to lead toxicity because of behavioral and physiologic factors, and long lifespans increase the risk of exposure cumulatively. Bonelli's eagle (Aquila fasciata) is a long‐living predator that may have reduced breeding success because of lead exposure. We analyzed the blood lead levels of 54 wild and captive Bonelli's eagles admitted to a recovery center in Spain from May 2014 to July 2015 and the lead relationship among physiological, clinical, and environmental variables. We detected blood lead using anodic stripping voltammetry. Lead levels were below the limit of quantification (3.3 μg/dL) in 100% of captive animals (n = 22); in contrast, 21.9% of wild birds (n = 32) had higher lead levels than captive birds (P = 0.020). Among wild animals, the 2 adults tested had detectable lead, the only eagle sampled in autumn had the highest lead levels of the study (14.7 μg/dL), and 16.7% of nestlings had detectable lead levels. There is no evidence that the lead levels differ between sexes. There were no symptoms associated with lead intoxication or any correlation between lead levels and hematological or biochemical values; however, subclinical lead exposure at early ages can be harmful and could influence neurological and body development. Researchers should determine if lead could be causing damage to wildlife from early ages to determine if lead exposure affects the conservation of the threatened population of Bonelli's eagles in Spain and elsewhere. [ABSTRACT FROM AUTHOR]

CO poisoning of Pt group metal (PGM) catalysts is a chronic problem for hydrogen oxidation reaction (HOR), the anodic reaction of hydroxide exchange membrane fuel cell (HEMFC) for converting H2 to electric energy in sustainable manner. We demonstrate here an ultrathin Ru‐based nanoflower modified with Pb (PbRuCu NF) as an active, stable, and CO‐resistant catalyst for alkaline HOR. Mechanism studies show that the presence of Pb can weaken the adsorption of *H, strengthen *OH adsorption to facilitate CO oxidation, as a result of significantly enhanced HOR activity and improved CO tolerance. Furthermore, in situ electrochemical attenuated total reflection surface‐enhanced infrared absorption spectroscopy (ATR‐SEIRAS) suggests that Pb acts as oxygen‐rich site to regulate the behavior of the linear CO adsorption. The optimized Pb1.04‐Ru92Cu8/C displays a mass activity and specific activity of 1.10 A mgRu−1 and 5.55 mA cm−2, which are ≈10 and ≈31 times higher than those of commercial Pt/C. This work provides a facile strategy for the design of Ru‐based catalyst with high activity and strong CO‐resistance for alkaline HOR, which may promote the fundamental researches on the rational design of functional catalysts. [ABSTRACT FROM AUTHOR]

CO poisoning of Pt group metal (PGM) catalysts is a chronic problem for hydrogen oxidation reaction (HOR), the anodic reaction of hydroxide exchange membrane fuel cell (HEMFC) for converting H2 to electric energy in sustainable manner. We demonstrate here an ultrathin Ru‐based nanoflower modified with Pb (PbRuCu NF) as an active, stable, and CO‐resistant catalyst for alkaline HOR. Mechanism studies show that the presence of Pb can weaken the adsorption of *H, strengthen *OH adsorption to facilitate CO oxidation, as a result of significantly enhanced HOR activity and improved CO tolerance. Furthermore, in situ electrochemical attenuated total reflection surface‐enhanced infrared absorption spectroscopy (ATR‐SEIRAS) suggests that Pb acts as oxygen‐rich site to regulate the behavior of the linear CO adsorption. The optimized Pb1.04‐Ru92Cu8/C displays a mass activity and specific activity of 1.10 A mgRu−1 and 5.55 mA cm−2, which are ≈10 and ≈31 times higher than those of commercial Pt/C. This work provides a facile strategy for the design of Ru‐based catalyst with high activity and strong CO‐resistance for alkaline HOR, which may promote the fundamental researches on the rational design of functional catalysts. [ABSTRACT FROM AUTHOR]

Reconstructing spatiotemporal trends in Pb pollution history is important for understanding global Pb cycling, controlling Pb pollution, and allowing assessment of the extent and timing of human impacts on environments. In this study, the high-resolution heavy-metals (Pb, Zn, Cd, Cu, Co, and Ti) pollution history over the past millennium was reconstructed based on sedimentary records from Lake Chenghai in Southwestern China, and the possible origins of Pb and its relationship with global Pb records were revealed. The marked high Pb concentrations occurred during the Medieval period (1200s–1400s), and enrichment factor analysis suggested that the high pollution degrees during the Medieval period were derived primarily from the anthropogenic sources of mining activity. Furthermore, our compilation records worldwide showed that Pb pollution level in most areas of China during the Medieval period is the same as or even higher than present, while in the other regions such as America and Europe, modern-day Pb pollution level is significantly higher than that in the Medieval period. In the past two centuries, Pb concentration rapidly increased again since the 1980s in China, coinciding with China's reform and opening up that spawned social economic transformation and rapid industrial economic growth, while in America and Europe, it rapidly increased in the 1950s and then declined in the 1980s, coinciding with the impacts of industrial revolution on developed regions. Those records imply Pb could be regards as the regional human activity intensity index during the Anthropocene. This study could provide insight into the onset timing of anthropogenic impacts in different areas and also provide scientific supports for Pb pollution control. [ABSTRACT FROM AUTHOR]

Introduction As a great reservoir of nutrients and pollutants, soil plays an important role in health and socio-ecological sustainability. Soil pollution increases as a result of the entry of heavy metals from operations such as agriculture, urbanization, and industrialization. Unlike organic pollutants, heavy metals cannot be decomposed and remain in the soil for more than 150 years. The continuous increase in the concentration of heavy metals in the soil due to wrong agricultural operations has had a serious effect on human health. Long-term use of wastewater in land irrigation often increases the amount of heavy metals in the soil. The present research aims to investigate the amount of heavy metals and pollution indicators. Materails and Methods The study area is located in agricultural soils irrigated with raw sewage in Barzil village of Meshginshahr city (38° 23′ 34″ N and 47° 1′ 7″ E). To perform this research, a regular griding method with a 250 m dimension was done and 97 surface soil samples (0 to 30 cm) were taken. After transferring to the laboratory, the samples were dried and passed through a 2 mm sieve. The physical and chemical characteristics of the soil including pH, EC, texture, organic carbon, and Calcium Carbonate Equivalent (CCE) are measured. The concentration of heavy metals Copper (Cu), Zinc (Zn), Cadmium (Cd), Nickel (Ni), Chromium (Cr), Lead (Pb), Iron (Fe), and Manganese (Mn) was measured by Aqua Regia digestion method and using Atomic Absorption Spectrometry. The spatial distribution of heavy metals was displayed using the Kriging interpolation method. Pollution indices of Enrichment Factor (EF), Geo-accumulation Index (Igeo), Contamination Factor (CF), and Pollution Load Index (PLI) were calculated. Results and Discussion The maximum values of pH and electrical conductivity of the soil in some places irrigated with wastewater have reached 7.70 and 4.35, respectively, and their average values have reached 6.69 and 1.45, respectively. The organic carbon of the studied soil samples varies from at least 0.59% to 3.50% an average of 2.14%. The relatively high amount of organic carbon can be attributed to the land use type of garden. Four texture classes of sandy loam (65%), loamy sand (23%), loam (10%), and sand (2%) have been observed. The average concentration of the three metals Zn (85.41 mg Kg-1 ), Cd (2.42 mg Kg-1 ), and Pb (17.38 mg Kg-1 ) was higher than the average of their continental reference values (0.7, 0.2 and12.50 mg Kg-1, respectively). The higher values rather than continental reference values indicate human intervention and its effect on increasing the concentration of these element contents. It means that irritating sewage caused increasing heavy metal concentration in the study area. The averages of Cu, Ni, Cr, Fe, and Mn were lower than continental references. Pollution indices indicate the state of accumulation of polluting elements in a place compared to the initial values in the parent materials. The EF index of Cd (75.85) is the highest value among the eight metals and 99% of the the study area is classified as a very high enrichment class. The EF of Pb (8.68), Zn (7.42), and Cu (6.14) are in lower ranks. 56.7 % of study area classified as considerable enrichment by Cu and 46.4 % by Zn. The EF clearly indicates the involvement of human activities in the accumulation of four elements Cd, Pb, Zn, and Cu in the study area. Also, moderate enrichment class is caused by Mn, Cu, Zn, and Cr in 63.9, 42.3, 42.3, and 25.8% of the study area, respectively. The lowest and highest amount of the Igeo index is related to Ni (-6.90) and Zn (3.72), respectively. The average of Igeo varies as IgeoCd> Igeopb> IgeoCU> IgeoZn> IgeoMn> IgeoCr> IgeoFe> IgeoNi that introduces Cd as the most pollutant metal. The negative values of Igeo indicate the absence of heavy metal pollution and so absence of pollution. The entire study area grouped as non-polluted or clean class according to Ni, Cr, Fe, and Mn but 86.6% of the area grouped as clean considering Cu and Zn. Cd placed 38.1% of the area in the medium pollution class and 59.8% of the area in the severe pollution class. 69.1% of the area was found to be clean and only 28.9% of the area was moderately polluted with Pb. According to this index, Cd is in the extremely polluted class in the whole study area. The lowest (0.01) and highest (19.72) value of CF belongs to Ni and Zn, respectively. The average of this index varies from 0.13 for Ni to 12.09 for Cd. Except for Cd, which placed 98% of the area in a very high pollution class, the rest of the metals had low or moderate pollution classes. Meanwhile, the low pollution classes had higher contributions than the medium pollution classes. 100% of the area was grouped in the low pollution class considering Ni, Cr, Fe, and Mn but according to Zn and Cu 71.1 and 60.8% of the area was placed in the low pollution class, respectively. Medium pollution class was observed only by three metals Pb (73.2%), Cu (39.2%), and Zn (24.7%). PLI values less than 1 indicate ideal conditions where no pollution has occurred. The values of the calculated PLI index were less than 1 in the whole study area indicating the absence of pollution. Conclusion Among the four indices, the Igeo index has classified a larger extent of the studied area in extremely polluted classes, while the PLI index does not show any pollution in the study area. Because Igeo, like the other two indices (EF and CF), is an individual index and considers the concentration of each metal separately, the PLI index is a cumulative index and shows the cumulative effects of all metals. In other words, high concentrations of metals disappear among low concentrations and individual effects of metals are not visible. This may mislead decision makers in dealing with the type and origin of pollution and cause negligent actions. Therefore, it is recommended that considering the harmful effects of each of the metals, individual indicators should be taken seriously. [ABSTRACT FROM AUTHOR]

Heavy metal pollution has been one of the most significant concerns on the soil environmental quality for the Taicang agricultural sustainability and human health. It is of paramount importance to analyze the spatial variations and influencing factors of regional distribution in the soil heavy metal. Among them, the Manghai River watershed is nestled within a typical ecological zone in the southern Taihang region. Rapid socioeconomic development has also been experienced by the convergence of industries, such as non-ferrous metal smelting, coal coking, and mining. Soil environmental pollution is also coupled with the unique terrain and topographical features, especially heavy metal pollution, notably lead (Pb) and cadmium (Cd). Much attention has been gained to prevent and control the soil heavy metal pollution in this region. This study aims to unveil the spatial variation patterns and influencing mechanisms of soil Pb content at the scale of the Manghai River watershed. The sampling points were employed as a 1 km×1 km grid using high-resolution remote sensing imagery and land use data. A total of 121 topsoil samples (0-20 cm) and 15 environmental auxiliary samples were collected, including 5 surface water samples, 5 dust samples, and 5 sediment samples. The classic statistical methods, geostatistics, and geographic detectors were utilized to probe the spatial variation characteristics of soil Pb content and their influencing factors. Results were as follows: 1) Soil Pb content was relatively high with an average of 110.40 mg/kg, particularly over the regional background values. Notably, the soil Pb content exceeded the threshold to identify the soil pollution risk at some locations in the agricultural land, indicating the sever contamination risks; 2) There was an outstanding variation in the soil Pb content across the study area, with the marked variances in various directions. The spatial patterns were dominated in the variability along the south-north (0°) and northeast-southwest (45°) axes, indicating the influence of structural factors, such as the parent material and terrain; 3) Empirical Bayesian kriging spatial interpolation showed that there was a gradual, belt-like increase in the soil Pb content from the southwest to the northeast, indicating the distinct local features. The northeastern foothill plain and central plain areas emerged as the focal points to monitor and control the soil Pb pollution risks; 4) Geological type and land use were the primary determinants of spatial distribution differences in the soil Pb content. The combined influence significantly heightened the impact of factors, like proximity to the mines and industries. Therefore, a comprehensive investigation can be preferred on the regional heavy metal pollution within the complex environments, including the geological and topographical factors, natural elements, such as atmospheric conditions, and complex interactions with industrial and agricultural activities. There was also the spatial heterogeneity of distribution patterns in the soil heavy metal pollution using watershed units. The spatial distribution and influencing factors of soil Pb pollution can provide precise support to the prevention, control, and remediation of soil heavy metal pollution under the complex environment of the southern Taihang region. [ABSTRACT FROM AUTHOR]

Organic wheat production systems have lower yields compared with intensive conventional production and often do not achieve the grain protein content and quality thresholds set by millers and bakers. In contrast, organic production methods were reported to result in higher concentrations of nutritionally desirable micronutrients and lower concentrations of the toxic metal Cd in wheat grain and wholegrain flour. However, although N-availability and variety characteristics are known to affect both gain yields and bread-making quality, the exact reasons for the yield gap and differences in grain processing and nutritional quality between organic and conventional spring wheat production in the UK are poorly understood. The overall aim of this study was therefore to determine to what extent changes in variety choice and fertilization regimes may reduce the yield gap and improve processing quality without affecting nutritional quality in organic spring wheat production. To achieve this aim, we compared crop health, yield, grain processing, and nutritional quality parameters in spring wheat produced using (i) six contrasting spring wheat varieties grown with a standard fertilization regime and (ii) one variety widely used by organic farmers (Paragon) with nine different fertilization regimes in (iii) three UK sites/farms with contrasting pedoclimatic conditions. Significant differences in foliar disease severity, grain yield, and quality parameters were detected between six contrasting spring wheat varieties when grown under organic management regimes. Specifically, the varieties Paragon and Tybalt were identified as the best-performing varieties with respect to foliar disease resistance and grain yield under organic farming conditions and also produced high processing and nutritional quality across the three UK sites. However, the highest grain yields were obtained by Paragon at the Gilchester site and Tybalt at the Sheepdrove and Courtyard sites, while the highest protein contents were produced by Tybalt at the Gilchester site and Paragon at the Sheepdrove and Courtyard sites, which suggests that there is a need for site-specific wheat variety selection in the UK organic sector. Although organic fertilizer input type and level also affected wheat performance, differences between fertilization regimes were smaller than those observed between the five contrasting varieties, which suggests that improvements in spring wheat breeding/selection have a greater potential for increasing crop yield and quality in the organic sector compared with changes to fertilization practices. Overall, results suggest it is feasible to breed/select spring wheat varieties that combine high protein, vitamin E, and micronutrients with low toxic metal (Cd, Pb) concentrations when produced under organic farming conditions. These findings also support the hypothesis that differences in variety choice by organic and conventional farmers have contributed to the differences in nutritional quality between organic and conventional wheat products reported in previous studies. [ABSTRACT FROM AUTHOR]

The neutron multiplier lead (Pb) containing Li 2 TiO 3 -0.5Li 4 SiO 4 –Pb was prepared, which aimed at the improvement of the tritium release performance of the lithium ceramic without an increase in lithium density. Li 2 TiO 3 -0.5Li 4 SiO 4 –Pb and that without Pb were irradiated at Kyoto University Research Reactor (KUR) with the thermal neutron flux of 5.5 × 1012 n s−1 cm−2 and the fast neutron flux of 1.2 × 1012 n s−1 cm−2. Fast neutrons can trigger the Pb (n , 2 n) reaction. The tritium release experiments were conducted using the tritium thermal desorption spectroscopy (tritium-TDS) system. Compared with Li 2 TiO 3 -0.5Li 4 SiO 4 , the tritium release rate at the lower temperature range was higher than that for Li 2 TiO 3 -0.5Li 4 SiO 4 –Pb. The tritium-TDS spectrum was also shifted to the lower temperature side. The isothermal heating experimental results confirmed that tritium in the form of gas species (HT) was controlled by the diffusion process, while the trapping and de-trapping process contributed to the total tritium release. Further, 3 keV D 2 + implantation with the fluence of 2.0 × 1022 D m−2 and subsequent TDS measurements were performed. It was shown that the D 2 release at the lower temperature side was increased for Li 2 TiO 3 -0.5Li 4 SiO 4 –Pb. Meanwhile, HD and HDO release at higher temperature side was significantly decreased. [ABSTRACT FROM AUTHOR]

Lead (Pb) exposure induces testicular damage and infertility. The aim of this study was to analyze and compare the therapeutic effects of antioxidants or vitamin D and calcium, which have previously been shown to reduce the toxic effects of Pb co-exposure, in rats. Rats were exposed to Pb for 28 days and subsequently treated with antioxidant (melatonin, silymarin), vitamin D and calcium (VitDCa) or a combination (melatonin or silymarin with VitDCa) for 28 days. Control groups included untreated rats (no Pb exposure or therapy), rats exposed only to melatonin or silymarin and rats exposed to Pb without post exposure therapy. Pb exposure induced testicular damage, increased blood lead level (BLL) and reduced serum testosterone level (STL). Rats exposed to Pb and left untreated for 28 days showed persistent pathological testicular alterations. The two treatments that were most effective in reversing pathological testis damage and restoring spermatogenesis were melatonin and silymarin. However, silymarin and melatonin treatment resulted in significantly different serum testosterone levels in rats. Whereas melatonin therapy reduced serum testosterone to levels lower than those in control rats, silymarin increased serum testosterone to levels higher than those in controls. Our pathological analysis of testes revealed that melatonin promoted spermatogenesis and regression of Pb exposure-induced degenerative changes, despite the associated reduction in serum testosterone levels. This result suggests that circulating testosterone may not have an important role in spermatogenesis. Collectively, our results suggest that melatonin and silymarin are effective therapies against the toxic effects Pb exposure in the male reproductive system. [ABSTRACT FROM AUTHOR]

Lead (Pb) is a non-essential, highly toxic, and persistent element widely recognized as one of the most concerning pollutants. It is listed on the Priority List of Hazardous Substances. Widespread environmental contamination from Pb is a serious issue for human health and wildlife. In fish, Pb mainly accumulates in the liver, which is a key component for metal detoxification and excretion processes. In this study, we investigated, for the first time, the morphological and functional injuries induced in zebrafish (Danio rerio) liver by two very low and environmentally relevant concentrations of Pb (2.5 and 5 μg/L) after 48, 96, and 192 h of exposure. We observed significant histological alterations in all the exposed samples, and it was demonstrated that the extent of injuries increased with dose and exposure time. The most common modifications observed were congestion of blood vessels and sinusoids, cytoplasmic vacuolizations, parenchyma dyschromia, and macrophage proliferation. Pb administration also resulted in a significant increase in lipid content and the upregulation of key genes that are involved in metal detoxification (mtf1) and the defensive response against oxidative stress (sod1 and cat). We show that even very low doses of Pb can disrupt liver morphology and function. [ABSTRACT FROM AUTHOR]

(1) Background: Synthetic cannabinoids (SCs) are emerging drugs of abuse sold as 'K2', 'K9' or 'Spice'. Evidence shows that using SCs products leads to greater health risks than cannabis. They have been associated with greater toxicity and higher addiction potential unrelated to the primary psychoactive component of marijuana, Δ9-tetrahydrocannabinol (Δ9-THC). Moreover, early cases of intoxication and death related to SCs highlight the inherent danger that may accompany the use of these substances. However, there is limited knowledge of the toxicology of Spice ingredients. This systematic review intends to analyze the toxicity of SCs compounds in Spice/K2 drugs. (2) Methods: Studies analyzing synthetic cannabinoid toxicity and dependence were included in the present review. We searched the PubMed database of the US National Library of Medicine, Google Scholar, CompTox Chemicals, and Web of Science up to May 2022. (3) Results: Sixty-four articles reporting the effects of synthetic cannabinoids in humans were included in our review. Ten original papers and fifty-four case studies were also included. Fourteen studies reported death associated with synthetic cannabinoid use, with AB-CHMINACA and MDMB-CHMICA being the main reported SCs. Tachycardia and seizures were the most common toxicity symptoms. The prevalence of neuropsychiatric symptoms was higher in third-generation SCs. (4) Conclusion: SCs may exhibit higher toxicity than THC and longer-lasting effects. Their use may be harmful, especially in people with epilepsy and schizophrenia, because of the increased risk of the precipitation of psychiatric and neurologic disorders. Compared to other drugs, SCs have a higher potential to trigger a convulsive crisis, a decline in consciousness, and hemodynamic changes. Therefore, it is crucial to clarify their potential harms and increase the availability of toxicology data in both clinical and research settings. [ABSTRACT FROM AUTHOR]

Background: This study was conducted to investigate the effects of salicylic acid and rice husk ash on Pb and Cd concentration in pinto bean plants grown in soil that was contaminated with both diesel oil and heavy metals. Methods: The treatments in this study included the application of rice husk ash to soil at concentrations of 0 %, 4 %, and 8 % (W/W) as well as the foliar application of salicylic acid to pinto bean plants grown in soil contaminated with diesel oil, Cd, and Pb at concentrations of 0 %, 4 % and 8 % (W/W). After a growth period of 90 days, the pinto bean plant was harvested and the concentration of Pb and Cd in the plants was measured using Atomic absorption spectroscopy. In addition, the extent of diesel oil bio-degradation in the soil was determined. Results: The results indicate a significant reduction in the concentration of Cd and Pb in pinto bean plants (by 11.7 and 15.4 %, respectively) due to the application of rice husk ash (8 % (W/W)) in the soil. Furthermore, the bio-degradation of diesel oil in the soil was found to be significantly enhanced, while the activity of plant enzymes APX and POX was observed to be decreased. Conclusion: The interaction between rice husk ash and salicylic acid the reduction in Pb and Cd concentration was significantly influenced by, while the bio-degradation of diesel oil in the soil increased. [ABSTRACT FROM AUTHOR]

In order to rapidly adsorb trace coexisting Pb and As ions in wastewater by modified kenaf core, the effects of acid -base modification, concentration of sodium carbonate and modification time on the adsorption performance were investigated ・ The results showed that compared w让h hydrochloric acid, citric acid and sodium hydroxide, sodium carbonate modified kenaf core had better adsorption both of Pb and As. The optimum modification conditions were: the solid-liquid ratio of kenaf core to 0. 1 mol/L sodium carbonate solution was 1: 80 g/mL, and the reaction was stirred at 400 i/min at room temperature (about 25 °C) for 30 min. The removal rate could reach 77. 7% and 21 ・ 5% respectively when 50 mL, 0. 1 mg/L Pb and As wastewater was treated by 0. 5 g sodium carbonate modified kenaf core, oscillating in the 25 °C constant temperature water bath at 200 r/min for 30 min. The adsorption process can be described by the pseudsecond order model, which indicates that it is chemical adsorption. [ABSTRACT FROM AUTHOR]

Background: There is increasing evidence that the reliance on synthetic chemical pesticides and mineral fertilizers in agriculture has significant negative environmental and/or health impacts and poses a risk for future food security. Systematic reviews/meta-analyses showed that organic production systems, which omit the use of agrochemicals, produce crops with lower yields, but superior nutritional composition. However, the agronomic parameters responsible for differences in crop yields and nutritional quality are poorly understood. Methods: Here we report results for four field vegetable crops from the Nafferton Factorial Systems Comparison (NFSC) trial. This long-term factorial field experiment was designed to (i) identify effects of growing season/climatic variation, and contrasting rotational designs, crop protection protocols and fertilization regimes used in organic and conventional systems on crop health, yield and nutritional parameters and (ii) estimate the relative importance of climatic and agronomic drivers for crop health, yield and nutritionally relevant quality parameters. Quality parameters monitored in harvested products, included phenolic, glucosinolate, vitamin C, vitamin B9, carotenoid, cadmium (Cd), nickel (Ni), lead (Pb) and glycoalkaloid concentrations. Results: Climatic conditions during the growing season were found to have a larger impact on crop yield and quality than the agronomic factors (pre-crop, crop protection, fertilization) studied. However, the (i) interactions between growing season with contrasting climatic conditions and agronomic factors identified by ANOVA for crop health, yield and quality parameters and (ii) the associations between the three climatic drivers (precipitation, temperature, radiation) and crop yield and quality parameters differed substantially between the four crop plant species. Among the agronomic factors, fertilization had a substantially larger impact compared with both pre-crop and crop protection. Specifically, crop yields were found to be significantly increased by the use of (i) conventional fertilization and crop protection methods in potato, (ii) conventional fertilization, but organic crop protection methods in cabbage, and (iii) conventional fertilization regimes in lettuce, while none of the agronomic factors had a significant effect on onion yields. When important crop pest and diseases were assessed, (i) conventional crop protection resulted in significantly lower late blight severity in potato, while (ii) organic crop protection resulted in lower bird damage and cabbage root fly (CRF) incidence in cabbages, and Sclerotinia incidence in lettuce and (iii) organic fertilization resulted in lower CRF and Sclerotinia incidence in cabbage and lettuce respectively. When concentrations of nutritionally relevant phytochemicals were compared, organic fertilization resulted in significantly higher phenolic concentrations in potato, cabbage and lettuce, higher glucosinolate and carotenoid concentrations in cabbage, higher vitamin C concentrations in potato and cabbage and higher vitamin B9 concentrations in potato and lettuce—but lower concentrations of toxic glycoalkaloids in potato. Significant effects of crop protection protocols on phytochemical concentrations were only detected in cabbage with conventional crop protection resulting in higher glucosinolate and vitamin B9 concentrations. When toxic metal concentrations were compared, organic fertilization resulted in significantly lower Cd concentrations in all four crops and lower Ni concentrations in potato, cabbage and onion. Significant effects of crop protection were only detected in cabbage, where organic crop protection resulted in lower Ni concentrations. Pb concentrations were not affected by any of the agronomic factors. The potential implications of results for improving (i) strategies to reduce the use of non-renewable resources and environmental impacts of vegetable production and (ii) the productivity of organic and other low-input vegetable production systems without compromising food quality are discussed. Conclusions: The study confirms that organic vegetable production protocols result in higher concentrations of phenolics and other nutritionally desirable phytochemicals, but lower concentrations of the toxic metals Cd and Ni in harvested products. It also demonstrates, for the first time, that this is primarily due to differences in fertilization regimes. The finding that in three of the four crops (cabbage, lettuce and onion) the application of synthetic chemical crop protection products had no measurable positive impact on crop health and yield should be considered in the context of the growing concern about health impacts of pesticide use in field vegetable crops. [ABSTRACT FROM AUTHOR]

In this paper, gangue Coal biochar GCC was developed to absorb heavy metals from an aqueous solution. There is currently insufficient information on the identification of the best biochar modifiers for the purpose of removing heavy metals as well as changes in physicochemical and morphological compositions after modification. For this purpose, after physical treatment GCC ware modified with 5 different offending chemical methods (GCCacidic), (GCCalkaline), (GCCoxidic), (GCCMnOx), and (GCCFeOx). using (XRF), (FT-IR), (XRD), (SEM-EDX), and (BET) assortment. Adsorption tests of 3 heavy metals (Cu, Pb, and Cd) ions under different conditions, ion concentration, pH, Adsorbent dosage, and contact time were investigated in batch experiments. Improved post-modification GCC properties, especially (GCCalkaline) and (GCCMnOx) Significant changes in its surface area as well as functional groups (hydroxyl group, and Manganese oxide group). To will know adsorption capacity of every modified GCC, experimental data were placed in Langmuir and Freundlich's isotherms models. The GCC process follows pseudo-second-order and pseudo-first-order kinetic curves with linear regression. GCC modified with Manganese oxide shows it has the best adsorbent for adsorption of Pb and GCC modified with alkaline is the best adsorbent for adsorption of Cd and Cu metals. For adsorption of mixed metals solution (Pb, Cd, and Cu) GCCMnOx was more suitable than other GCC and modified GCCs biochars. The results show that GCC modified with an acidic component is the worst attraction for removing heavy metals from an aqueous solution. [ABSTRACT FROM AUTHOR]

The co-pyrolytic biochar was prepared by co-pyrolysis of peanut shell biochar and phosphate rock powder with different weight ratios. The influences of solution PH value, biochar dosage, initial concentration of heavy metal ions and adsorption time on the adsorption of Pb2+ by co-pyrolytic biochar were investigated through batch experiments. Langmuir and Freundlich isothermal adsorption models as well as quasi-first-order and quasi-second-order adsorption kinetic models were used for fitting analysis. The results showed that the optimum pH value of co-pyrolysis biochar for Pb2+ adsorption was 5. Under the conditions of biochar dosage of 2 g/L and adsorption time of 120 min, Pb2+ reached adsorption equilibrium, the maximum adsorption capacity was 62.438 mg/g, and the adsorption process was in accordance with Freundlich isothermal adsorption model and quasi-second-order adsorption kinetics model. The results showed that the adsorption capacity of co-pyrolysis of peanut shell and phosphate rock powder to Pb2+ was obviously better than that of peanut shell biochar, which had broad research prospects. [ABSTRACT FROM AUTHOR]

Heavy metals (HMs) stress, particularly lead (Pb) stress, is one of the most hazardous environmental stresses that can negatively affect plants' growth, yield, and quality. Therefore, the effects of zinc oxide nanoparticles (ZnO-NPs; 50 mg L−1), nano-hydroxyapatite (HP-NPs; 50 mg kg−1), and their combination on growth, physiological, and yield traits of maize grown in soil contaminated with Pb (i.e., 100 mg kg−1) were investigated. The results showed that Pb stress significantly reduced plant leaf area by 50.9% at 40 days after sowing (DAS), 55.5% at 70 DAS, and 54.2% at 100 DAS in comparison to the unstressed plants (control). However, the combined application of ZnO-NPs (50 mg L−1) + HP-NPs (50 mg kg−1) reduced the adverse effects of Pb on plant growth in terms of increasing leaf area by 117.6% in plants grown in Pb-contaminated soil (100 mg kg−1). Similarly, the combined application of ZnO-NPs + HP-NPs resulted in increments in the total chlorophyll content by 47.1%, photosynthesis rate by 255.1%, and stomatal conductance by 380% in comparison to that obtained from maize stressed with Pb. On the other hand, antioxidants such as sodium dismutase (SOD; 87.1%), peroxidase (POX; 90.8%), and catalase (CAT; 146%), and proline content (116%) were significantly increased as a result of Pb stress compared to unstressed plants. Moreover, N, P, K, and Zn contents in the whole plant grown under Pb stress were decreased by 38.7%, 69.9%, 46.8%, and 82.1%, respectively, compared to those obtained from the control. Whereas the combined treatment of ZnO-NPs (50 mg L−1) + HP-NPs (50 mg kg−1) resulted in increased uptake of plant nutrients and, consequently, the highest values of ear weight, grain yield, and harvest index were obtained. Furthermore, the combined application of HP-NPs + ZnO-NPs in contaminated soil reduced Pb uptake in plant biomass by 77.6% and grains by 90.21% in plants exposed to Pb stress. In conclusion, the combined application of ZnO-NPs and HP-NPs significantly improved growth, physiological traits, antioxidants, and yield as well as elemental uptake of maize grown under Pb stress. [ABSTRACT FROM AUTHOR]

Environmental pollution is a global threat and represents a strong risk factor for human health. It is estimated that pollution causes about 9 million premature deaths every year. Pollutants that can cross the blood–brain barrier and reach the central nervous system are of special concern, because of their potential to cause neurological and development disorders. Arsenic, lead and mercury are usually ranked as the top three in priority lists of regulatory agencies. Against xenobiotics, astrocytes are recognised as the first line of defence in the CNS, being involved in virtually all brain functions, contributing to homeostasis maintenance. Here, we discuss the current knowledge on the astroglial involvement in the neurotoxicity induced by these pollutants. Beginning by the main toxicokinetic characteristics, this review also highlights the several astrocytic mechanisms affected by these pollutants, involving redox system, neurotransmitter and glucose metabolism, and cytokine production/release, among others. Understanding how these alterations lead to neurological disturbances (including impaired memory, deficits in executive functions, and motor and visual disfunctions), by revisiting the current knowledge is essential for future research and development of therapies and prevention strategies. [ABSTRACT FROM AUTHOR]

Material fluxes at the land--ocean interface impact seawater composition and global cycling of elements. However, most attention has been focused on the fluvial dissolved fluxes. For elements like lead (Pb), whose fluvial particulate flux into the ocean is two orders of magnitude higher than the dissolved counterpart, the role of particulates in elemental cycling is potentially important but currently less appreciated. Using both chemical analyses on samples collected from around equatorial Southeast Asia and model simulations, we show that particulate-dissolved exchange is an important mechanism controlling the concentration and isotopic composition of dissolved Pb in the ocean. Our model indicates that Pb contributed from particulate-dissolved exchange at ocean boundaries is larger than, or at least comparable to, other major Pb sources to the seawater before the Anthropocene, when the anthropogenic Pb was absent. Our work highlights the importance of boundary exchange in understanding marine element cycling and weathering-climate feedback. [ABSTRACT FROM AUTHOR]

Isothermal kinetic methods were used to investigate reduction process in the Zn and Pb during the vacuum carbothermal reduction of electric arc furnace dust (EAFD). During the experiments, the volatilization ratios of Zn and Pb in EAFD increased with the increase of temperature and holding time, which was 96.29 % and 83.91 % for Zn and Pb respectively at a temperature of 1000 °C and holding time of 60 min. The main phase changes of Zn and Pb in the reduction process were ZnFe 2 O 4 → ZnO → Zn and PbSO 4 → PbO → Pb, and the generated Zn and Pb gases escaped and were collected via condensation. In the kinetic study, the volatilization of Zn was controlled by three-dimensional diffusion (Jander) with an apparent activation energy of 19.97 kJ/mol, whereas the volatilization of Pb was controlled by the interfacial chemical reaction with an apparent activation energy of 85.68 kJ/mol. The results show that higher purity of valuable metals Zn and Pb could be obtained, laying a theoretical foundation for the treatment of EAFD pollution. [ABSTRACT FROM AUTHOR]

China is the major producer of chestnut, with 1.84 million tons of chestnut production, resulting in an enormous waste of chestnut shells. In the current study, shell biochar (SBC) was produced using the inside shell covering fruit, and the outside shell with thorns was used to produce thorn biochar (TBC). Both types of biochar were characterised through Brunauer–Emmett–Teller (BET) analysis, scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR). These analytical results showed a more obvious smooth surface and micro-pore structure in SBC. The vibration of C=O/C=C and C–O (phenolic) showed a significant difference between the two types of biochar. Sorption experiments indicated that the adsorption capacity of the different types of biochar for cadmium (Cd) did not differ significantly, whereas the adsorption capacity of TBC for lead was better than that of SBC. In the pakchoi cultivation experiment (28 days), the application of TBC (1.5%) promoted plant shoot weight, root weight, shoot length and root length by 465%, 143%, 109% and 97% respectively. The application of biochar effectively increased soil pH and reduced the bioavailability and migration of heavy metals. Besides, membrane integrity and chlorophyll content were enhanced because of the alleviation of oxidative stress. Noticeably, application of TBC (0.1% and 1.5%) reduced the Cd concentration in the root by 40–60%, and enhanced accumulation of Pb by 75–191%. Overall, our study demonstrated that 1.5% TBC has promising potential for remediating Cd-contaminated soil. Our study has demonstrated the remediation potential of chestnut and provided a clue for sustainable management of chestnut shell waste for further development of chestnut resources. China is a major producer of chestnut, with 1.84 million tons of chestnuts produced worldwide, resulting in a massive amount of waste of chestnut shells. In this study, biochar from two types of chestnut shell was produced, characterised and used for remediation of cadmium- and lead-contaminated soil. This research demonstrated that chestnut biochar has potential to repair Cd-contaminated soil and also demonstrated that combining phytoremediation of Pb-contaminated soils with biochar is promising. [ABSTRACT FROM AUTHOR]

Biochar has received significant attention for its potential in bioremediation of polluted soils. However, the impact of biochar particle size is yet to be investigated. We evaluated the role of various particle sizes (<3, 3–6 and 6–9 mm) of commercially available hardwood Acacia arabica biochar applied at the rate of 10 g kg−1 soil in the immobilisation of heavy metals 12 months after application. Heavy metals cadmium (Cd), nickel (Ni) and lead (Pb) were spiked in designated pots from their respective sources CdSO4, Ni(NO3)2 and PbNO3 according to their permissible limits (0.2–2, 8.1 and 10–15 mg kg−1, respectively). Biochar particles of sizes <3, 3–6 and 6–9 mm significantly mitigated contamination of Cd by 35%, 10% and 9%; Pb by 61%, 60% and 35%; and Ni by 64%, 45% and 3.2%. Relative to the control, application of biochar particles of sizes <3, 3–6 and 6–9 mm significantly increased soil porosity by 10.3%, 4.2% and 3%; saturation percentage by 100%, 42% and 27%; pH by 0.53%, 2.6% and 4%; and organic matter by 33.6%, 19.7% and 16.8%. Soil bulk density decreased by 12%, 5% and 2.3%; and electrical conductivity by 19%, 20% and 24%. The contamination factor for Cd was >1 (in the moderate contamination category), whereas Pb and Ni had contamination factors <1 (in the low contamination category), under biochar application. The heavy metal spiking effect was also significant and ranked as Pb > Cd > Ni for soil pH, electrical conductivity and porosity; Cd > Ni > Pb for organic matter; and Ni > Cd > Pb for bulk density and saturation percentage. Smallest sized biochar (<3 mm) maximally stabilised heavy metals in the soil and improved soil physicochemical properties. Therefore, heavy metal polluted soils should be treated with fine (<3 mm) biochar for maximum immobilisation for heavy metals and improvement in soil physicochemical properties. Use of inorganic material is the main cause of soil pollution globally, hindering efforts toward sustainable and safe agriculture. In this regard, heavy metals pollute the soil and endanger food quality, but biochars with very high surface area are effective in absorbing toxic heavy metals. In this study, various sizes of biochar were tested for phyto-stabilisation of heavy metals, and the finest biochar (<3 mm) proved most effective. [ABSTRACT FROM AUTHOR]

The direct or indirect discharge of industrial wastewater leads to the high degree of pollution of heavy metals in Chinese natural water resources. The removal of heavy metals sewage is a problem that is exigent to be solved. However, existing heavy metal removal methods are generally found to be too complicated or expensive. Because the waste concrete particles contain cement hydration products and unhydrated cement particles, which have a certain activity and a high specific surface area. This paper tries to use the waste concrete particles as the adsorption material of water polluted by heavy metals. Through the heavy metals leaching test, it is found that the heavy metal leaching capacity is related to the particle size of the waste concrete. The larger the particle size is, the smaller the heavy metal leaching capacity is. Based on the test data and the discharge threshold requirements of the National Comprehensive Sewage Discharge Standard, the optimal selected particle size of the waste concrete particle material is finally determined. Then, by the static adsorption test, the effect of the adsorption time, the adsorbent dosage and the initial mass concentration of heavy metal on the adsorption of heavy metals copper and lead in waste concrete are mainly investigated. The result shows that the adsorption time, waste concrete dosage and initial concentration of heavy metal copper and lead will affect the adsorption properties of waste concrete. With the increase of adsorption time, the adsorption of two heavy metals copper and lead shows a trend of increasing first and then stabilizing. In the first 100 min, the adsorption of copper and lead quickly reached the equilibrium. With the increase of the initial mass concentration of copper and lead, the removal rate of the two heavy metal gradually decreases, and the adsorption capacity gradually increases and then stabilizes. When the initial mass concentration is less than 150 mg/L, the adsorption capacity for heavy metal copper is positively correlated, while heavy metal lead is positively correlated at the initial mass concentration of 200 mg/L. However, with the increase of waste concrete dosage, the removal rate of the two heavy metals copper and lead increases first and then stabilized. The adsorption of heavy metals copper and lead on waste concrete conforms to the Langmiur isothermal adsorption model, and the maximum adsorption capacity obtains 40.75 and 86.73 mg/g respectively; the pseudo-second-order kinetic model is more suitable for describing the adsorption process of heavy metals copper and lead on waste concrete, which indicating that the adsorption rate is controlled by chemisorption. Compared with other common adsorbent materials, the maximum adsorption capacity of heavy metals lead and copper on the waste concrete is much higher than natural zeolite and palygorskite, while the maximum adsorption capacity of heavy metal copper is lower than activated carbon. However, based on the price, the recycling price of waste concrete is still far lower than the market price of activated carbon even if the processing cost caused by crushing. This also reflects that the waste concrete has good adsorption capacity for the heavy metals copper and lead, which can be used as an adsorption material to treat the wastewater containing heavy metals copper and lead. [ABSTRACT FROM AUTHOR]

With the increase in municipal solid waste incineration, fly ash, its heavy metal content, and its disposal methods have attracted wide attention. This work investigates if the alkali-activated mineral slag gel solidification of heavy metals in fly ash has positive significance in promoting the harmless treatment of fly ash. This study obtained the optimal solidification conditions of fly ash from a grate incinerator, which are mineral slag content of 40%, activator content of 4%, and water content of 27.5%. Furthermore, the stability of synthesized calcium chloroaluminate is systematically investigated. The solidification effect of calcium chloroaluminate on Pb at pH = 10–13 was conducted at ambient temperatures from 15 °C to 35 °C to simulate the solidification environment of fly ash. The results show that the adsorption capacity of calcium chloroaluminate to Pb in a strongly alkaline environment is 0.1–3.5 mg/g. Pb is mainly solidified as lead-acid calcium chloroaluminate. This work provides a novel treatment strategy for fly ash. [ABSTRACT FROM AUTHOR]

• The effect of Fe 2 O 3 on the leaching behavior of Pb in fly ash was investigated. • The mechanism of Pb leaching behavior was revealed based on phase transformation. • The PbFe 12 O 19 effectively inhibit the leaching of Pb in thermal treated fly ash. This study investigated the leaching behavior of Pb in hazardous waste incineration fly ash (HWIFA) after adding Fe 2 O 3 thermal treatment and revealed the leaching mechanism of Pb from the perspective of phase transformation. The static leaching results showed that at 600 °C-1300 °C, with the addition of Fe 2 O 3 increased, the Pb leaching toxicity continued to decrease. The dynamic results indicated that as the thermal treatment temperature was higher than 1100 °C, the addition of Fe 2 O 3 can effectively inhibit the dynamic leaching of Pb in HWIFA. Meanwhile, the inhibition effect was not very closely related to the amount of Fe 2 O 3. The addition of Fe 2 O 3 can react with PbO to form PbFe 12 O 19 , which has a better stability. The appearance of PbFe 12 O 19 was the main reason for adding Fe 2 O 3 to enhanced the immobilization of Pb. However, the amount of Fe 2 O 3 should be carefully controlled to avoid an excessive reducible fraction of Pb in the thermal treated HWIFA, which will affect the long-term stability of Pb. [ABSTRACT FROM AUTHOR]

• Lead increased levels of osmoprotectants and phenol compounds in the metallicolous Matthiola flavida. • Reduced root-to-shoot translocation and enhanced Pb accumulation in the root, under drought stress, is responsible for reduced toxic effects of Pb in the shoot of the metallicolous species. • Lead stimulates drought resistance in the metallicolous species by the accumulation of reducing sugars, phenolic compounds and antioxidant enzymes. Plants growing on quarry tailings at the Irankouh Pb/Zn mine encounter both drought stress and high levels of Pb. To better understand the role of drought and Pb in plant adaptation to Pb/Zn quarry tailings, we compared effects of drought stress (simulated by polyethylene glycol - PEG) and Pb, individually and in concert, to determine how these stressors affected two plant species: the metallicolous species Matthiola flavida (M) and the non-metallicolous congener, M. incana (NM). Plants were exposed to Pb (Pb(NO 3) 2) and three levels of PEG-6000 (0, -0.25, and -0.75 MPa) in a complete factorial design. Pb had non-significant effects on growth and oxidative stress but enhanced levels of osmoprotectants and phenol compounds in the M species M. flavida , whereas in M. incana the effect of Pb was non-significant on the same variables (except for anthocyanins and the osmoprotectants, proline and glycine betaine). Compared to M. incana , the M species M. flavida was tolerant of Pb, showing strongly reduced root-to-shoot translocation and enhanced Pb accumulation in the root (especially when under drought stress), which reduced toxic effects of Pb in the shoot. Tolerance of Pb by the M species M. flavida was aided by the accumulation of reducing sugars and phenolic compounds, as well as by greater catalase activity. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the effect of contaminated soil with lead and chromium using three species of trees Platanus orientalis, Eucalyptus camaldulensis, and Populus nigra as a remediation tool which considers as a priority restoring method to keep healthy soil which support life system for all organisms. The experiment was conducted with three concentrations of Pb (200,400, and 600 mg.kg-1 ) and three levels of Cr (100, 200, and 300 mg.kg-1 ) along with control. The results reveals that root dry weight for orientale plane and poplar tree were reduced meanwhile, eucalyptus showed significant increase at 200 and 400 mg.kg-1 of lead. Shoot dry weight of poplar revealed a stimulatory effect (187.26, and 193.5 g) at 200 and 400 mg.kg-1 of lead respectively. Chlorophyl content decreased significantly linearly with the increasing the concentration of Pb and Cr. At the same time, proline content showed the highest values ((76.53, 35.325, and 45.020 µmoles. g-1 ) at 300 mg.kg-1 of chromium in oriental plane, eucalyptus, and poplar respectively. Generally, the root system accumulates more Pb and Cr than leaves in which the bioaccumulation factor was < 1 for all species similarly the translocation factor except in eucalyptus (1.135, 1.013, and 1.018) at control, 200, and 400 mg.kg-1 of lead respectively as well as their leaves content of lead was morethan root. In conclusion the species showed differ responses to Pb and Cr. [ABSTRACT FROM AUTHOR]

As a ubiquitous toxic heavy metal, lead (Pb) exposure is known to be implicated in the onset and development of neurodegenerative diseases which may cause more serious health hazards with age and the accumulation of Pb in the body. Autophagy is the main degradation route for abnormal aggregated proteins and damaged cell organelles. Here, we aimed to study the effects of adolescent Pb exposure on autophagy at different life nodes. In this study, we developed a time-series model of Pb exposure in mice and randomly divided 4-week-old male C57BL/6 mice into six groups (4 C, 13 C, 16 C, 4Pb, 13Pb and 16Pb). Mice in Pb groups was consumed deionized water containing 0.2 % Pb(Ac) 2 for 3 months and then reared to anticipated life nodes, while the control group consumed deionized water. Western blot and Real-time qPCR were used to assess the effects of developmental Pb exposure on individual components of the autophagy machinery and modulation of microtubule-associated protein 1 light chain 3 (LC3) at each age stage. Our results showed that Pb exposure during adolescence reduced the p-mTOR/mTOR ratios with enhanced expression of Beclin-1, Atg12 and Atg7in both the hippocampus (HPC) and prefrontal cortex (PFC) of senescent mice while upregulation of LC3II/LC3I ratios and p62 suggested that autophagy mediates degradation was interrupted. Overall, we confirm that Pb exposure during adolescence promotes autophagic processes in the aged mice brain and that autophagic degradation is hindered, ultimately leading to a failure of autophagic degradation. • Prepubertal lead (Pb) exposure lead to failed autophagy in the aging mice. • Age-varying profiles of autophagic processes were manipulate by Pb exposure. • Pb exposure decreased the p-mTOR/mTOR ratio and upregulated the LC3II/LC3I ratio. [ABSTRACT FROM AUTHOR]

Summary: CO2 reduction to produce value‐added chemicals/fuels is generally considered as an effective way to solve the energy crisis and global warming. However, the greatest challenge to the technology is the lack of high‐performance catalysts as this process is quite sluggish under mild conditions. Herein, we have carefully prepared a series of bimetallic PbxCdy nanoparticles (NPs) as well as their monometallic counterparts via a facile chemical reduction. Electrocatalytic performances of obtained catalysts were evaluated with respect to chemical composition, electrolytic potential, and so on. All of them exhibit high performance and achieve high faradaic efficiency for HCOOH production (FEHCOOH) over a voltage window of −1.16 to −1.26 V vs the reversible hydrogen electrode (VRHE). Among them, Pb3Cd1 achieved a maximum FEHCOOH of 96% at −1.16 VRHE and a desirable stability over 12 hours of continuous electrolysis. The excellent performance of Pb3Cd1 can be attributed to the huge specific area of NPs and the synergistic effect of the components. This study shows that efficient bimetallic PbxCdy electrocatalysts have a large application potential for highly selective HCOOH production from CO2. Highlights: Bimetallic PbCd nanoparticles were synthesized by facile chemical reduction for electrocatalytic CO2 reduction.PbCd nanocatalysts performed well in highly active, selective, and stable HCOOH electrosynthesis from aqueous CO2.Pb3Cd1 achieved maximum HCOOH faradaic efficiency of 96% at −1.16 VRHE, a record as far as we know.A stable current density (>7 mA cm−2) can be kept after a 12‐hours continuous electrolysis. [ABSTRACT FROM AUTHOR]

Silicate glasses KI and KU consist of 2 types of cells, differing in size from 0.5 to 1.5 nm. After irradiation, weak reflections of nanocrystalline phases responsible for UV absorption appear in them. The fact that the absorbed radiation energy is spent on the crystallization of SiO2 determines their high radiation-optical resistance. [ABSTRACT FROM AUTHOR]

Recent restoration work on Pisa Cathedral provided the opportunity for a multidisciplinary analysis of the monument that identified interesting aspects of its history, preservation, and structural safety. In particular, the study of the matroneum provided clues about the role of the structures in the well-known fire that occurred in 1595. Alteration patterns and damage forms on the stone masonry walls were analysed to better understand their relationship with this catastrophic event. The investigation of the stone specimens enabled textural and mineralogical features typical of fire damage to be identified on the surface. The evidence of fire also provided a terminus ante quem to correctly interpret and diachronically date a damage pattern consisting of cracks in the eastern arch supporting the dome. The cracks were likely to have been induced by a soil consolidation phenomenon related to the renowned leaning of the Pisa tower, centuries before the fire. [ABSTRACT FROM AUTHOR]

The Wenjiaping granite, as one of the few Late Jurassic granites in the Songpan–Garzê fold belt (SGFB), can provide an important clue for comprehensively recognizing the tectonic evolution and mineralization of this belt. In this contribution, we present new age and geochemical data for this pluton to better constrain its petrogenesis and discuss the tectonic and metallogenic implications. LA‐ICP‐MS zircon U–Pb dating shows that the Wenjiaping pluton was emplaced at ~159 Ma. The granite contains minor amphibole, and exhibits slightly peraluminous characteristics (A/CNK = 1.03–1.10) and lower initial Sr–Pb isotope ratios than those of the Liwu Group, which excludes the possibility that the Wenjiaping granite was derived from partial melting of the metasedimentary rock‐dominated Liwu Group as previously suggested. Significantly, high Sr/Y (40.93–54.30), LaN/YbN (39.64–56.64), and K2O/NaO (0.77–1.11) ratios, low MgO (0.47%–0.86%) and Cr (25.1–41.3 ppm) contents, and relatively enriched Sr–Nd–Pb–Hf isotope compositions of the Wenjiaping granite are comparable to those of the Late Triassic adakitic rocks in the SGFB, indicating that they probably share a similar source. Combined with previous researches, we propose that large‐scale detachment of the Jianglang dome caused by post‐collisional lithospheric extension in the SGFB‐induced decompressional partial melting of the Precambrian basement rocks can account for the generation of the Late Jurassic Wenjiaping pluton. In addition, our results also suggest that the Wenjiaping pluton probably cannot supply abundant metal elements for the Liwu‐type Cu‐polymetallic deposits in the Jianglang dome, SGFB. [ABSTRACT FROM AUTHOR]

The addition of small but effective amounts of free-machining elements to Al–Si casting alloys significantly improves the machinability of these alloys. These added elements, which are softer and have a lower melting point than the matrix alloy, form as small globules dispersed in the microstructure of the aluminum casting. In this form, the dispersed phase of low-melting elements promotes chip-breaking and helps to lubricate the cutting tool. The Al-11%Si-Cu-Mg alloys studied were mechanically tested in order to acquire an understanding of the effects of additives on the tensile properties under the same alloy conditions used for preparing the machinability test blocks. Drilling operations were carried out using a high-speed machining center under fixed cutting conditions. The machinability characteristics of these alloys were evaluated by examining the drilling forces and moments, tool life, and chip shape in each case. Results show that the addition of 0.15wt% Sn has a beneficial effect on the tool life of carbide drills, which may be ascribed to the precipitation of small and uniformly distributed β-Sn particles having a low melting point. Lead is not a suitable choice as an additive because of environmental concerns. Bismuth also has several detrimental effects associated with its presence in the Al–Si alloys, including the formation of the high melting point Bi2Mg3 phase, and the interaction of Bi with Sr, which is mainly added/required for Si modification. Thus, of the free-machining elements tested, Sn is the most promising in the context of improving the alloy machinability and mechanical properties. [ABSTRACT FROM AUTHOR]

To investigate the mechanism of Silent information regulator 1 (SIRT1) regulation of DNA methylation and thus the expression of synaptic plasticity-related genes induced by lead (Pb) exposure, the early-life Sprague-Dawley rats and PC12 cells were used to establish Pb exposure models and treated with SIRT1 agonists (resveratrol and SRT1720). In vivo results demonstrated that Pb exposure increased the expression of DNMTs, MeCP2, PP1 and cleaved caspase3, decreased the expression of SIRT1, BDNF and RELIN and altered DNA methylation levels of synaptic plasticity genes. Moreover, we observed marked pathological damage in the hippocampal CA1 region of the 0.2 % Pb-exposure group. After treatment with resveratrol, the effects of Pb exposure on the expression of the above molecules and pathological features were significantly ameliorated in the hippocampus of rats. In vitro results showed that after the treatment with SRT1720, the expression of SIRT1 was activated and thus reversed the effect on DNMTs, MeCP2, apoptosis and synaptic plasticity-related genes and their DNA methylation levels induced by Pb exposure. In conclusion, we validated the important protective role of SIRT1 in neurotoxicity induced by Pb exposure through in vivo and in vitro experiments, providing potential therapeutic targets for the treatment and prevention of brain damage. [Display omitted] [ABSTRACT FROM AUTHOR]

The anomalous increases or deficits in the human body can be detected by the development of accurate and sensitive methods for metal quantification in low-level concentrations. Two digestion procedures have been tested on whole blood samples for use in inductively coupled plasma optical emission spectrometry trace metal analysis (ICP-OES). The two procedures are, (microwave digestion with nitric acid and hydrogen peroxide), and (simple dilution digestion with nitric acid, N-butanol, and Triton X-100). According to the findings, the overall recoveries of all determining metals for the microwave digestion were in the range of (96%) of the expected levels, whereas for simple dilution digestion they were in the range of (85–88%) of the expected levels. The results showed a significant difference in the recovery ratios in favor of lead (Pd) and cadmium (Cd) between simple dilution and microwave digestion procedures. The findings also show that the content of these metals may be reliably measured using simple dilution and microwave digestion procedures. Abbreviations: ICP-OES: Induction coupled optical emission spectroscopy; LOD: Limit of detection; LOQ: Limit quantification; AAPCC: American Association of Poison Control Centers; NAUSS: Naif Arab University for Security Sciences; %RSD: Relative standard deviation). [ABSTRACT FROM AUTHOR]

The River Nile, Egypt's main source of water, is polluted by agricultural, industrial and municipal wastewater discharges. The paper reports a study of biological pollution of river water through bacterial and parasitological analysis, besides chemical pollution by cadmium and lead. The researchers collected water samples seasonally from 12 sites in Greater Cairo along a year (from July 2019 to June 2020). Some sites were contaminated with total coliforms, Acanthamoeba sp., and Cryptosporidium oocysts, whereas Naegleria sp. was recorded at all sites. Although the recorded Cd concentrations were below the permissible levels in all sites, the concentration of Pb exceeded the permissible limit in some sites. In conclusion, Nile River water in Greater Cairo region is contaminated, especially with total coliforms and free living amoebae. This health threat needs to be controlled and diminished by law. [ABSTRACT FROM AUTHOR]