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This study investigates the pollution characteristics and environmental risks of crushed microplastics (MPs) generated during plastic recycling, emphasizing their adsorption capacity for heavy metals, particularly lead (Pb). SEM-EDS analysis revealed that crushed MPs exhibit significantly higher adsorption capacity than primary MPs due to their larger surface area and more available adsorption sites, including oxygen-containing functional groups. The adsorption behavior of MPs was influenced by key factors such as MP size, MP quantity, pH, salinity, and biofilm formation. Smaller MPs demonstrated higher adsorption efficiency, while elevated pH enhanced Pb adsorption. Conversely, increased salinity reduced adsorption due to competition for adsorption sites. Increasing MP concentrations improved Pb removal efficiency, but higher MP quantities led to a decrease in maximum adsorption capacity, demonstrating a trade-off between removal efficiency and adsorption capacity. Isothermal adsorption experiments revealed that Pb adsorption on MPs follows a multi-layer mechanism, best characterized by the Freundlich model. The adsorption capacity increased nonlinearly with Pb concentration and stabilized as surface sites became saturated. The formation of biofilms on MPs further enhanced their adsorption capacity by providing additional functional groups and facilitating multi-layer adsorption, increasing ecological risks. Adsorption kinetics were best described by pseudo-second-order and intra-particle diffusion models, indicating chemical adsorption and boundary layer diffusion as dominant mechanisms. Magnetic Fe3O4 nanoparticles demonstrated a high recovery efficiency of 99.3% for MPs, highlighting their potential for environmental remediation. However, the presence of adsorbed Pb slightly reduced recovery performance, emphasizing the need to optimize recovery conditions for maximum efficiency. These findings underscore the dual threat posed by crushed MPs: their capacity to adsorb and concentrate harmful substances, increasing ecological toxicity, and the challenges associated with their recovery. This research provides critical insights into mitigating MP pollution and developing effective recovery strategies under realistic environmental conditions. [ABSTRACT FROM AUTHOR]

In this work, we investigate short-packet communications in power beacon (PB)-assisted Internet-of-Things (IoT) networks, where an energy-constrained actuator first harvests energy from a dedicated PB, and then transmits confidential signals to a desired controller in the presence of an eavesdropper. We derive a closed-form lower bound approximation expression for the average achievable effective secrecy rate (AESR) over Nakagami-m fading channels. To gain more insights, we also present the asymptotic average AESR in the high signal-to-noise ratio (SNR) regime. Specifically, analytical results indicate that an average AESR floor appears with the increase of SNR. Moreover, a low complexity one-dimensional search method is employed to maximize the average AESR by optimizing the energy harvesting length. Monte-Carlo simulations are provided to corroborate our analysis. [ABSTRACT FROM AUTHOR]

Agricultural soils that are close to industrial areas are prone to be polluted by lead (Pb) and cadmium (Cd) caused by industrial waste. Soil remediation is a method to clean the soil from pollutant materials. Utilizing fly ash and organic matter is a way to reduce levels of Pb and Cd pollution in the soil. This research was conducted to study the effect of ameliorants on reducing the availability of Pb and Cd in soil. The greenhouse experiment was carried out using a randomized block design with the application of 3 types of ameliorants, namely fly ash, chicken manure, and cow manure. The experimental design was prepared with 2 dose levels, namely C: control; F1: 450g; F2: 600g; A1: 75g; A2: 105g; S1: 105g; S2: 135g; FAS1: 450 g+75 g+105 g; FAS2: 600g+105g+135g. Each treatment was repeated 3 times to obtain 27 experimental units. The experimental results showed that the effect of the treatment of fly ash, chicken manure, and cow manure significantly increased soil pH, KB, C-organic, and exchangeable bases as well as reduced levels of availability of Pb and Cd compared to controls. The use of single fly ash (F1 and F2) reduces the availability of Pb in the soil, while the available Cd decreased in the application of a combination of fly ash with chicken and cow manure (FAS1 and FAS2). The application of fly ash alone was able to reduce the availability of Pb and Cd which was higher than of chicken manure and cow manure alone. However, the provision of fly ash has not been able to increase the growth of kale plants. [ABSTRACT FROM AUTHOR]

In order to address the problem of the low efficiency of lead(Pb) adsorption from wastewater by biochar, this study briefly describes the current adsorption mechanism and influencing factors of Pb adsorption by biochar・ Based on the different loading substances, the modification methods are categorized into organic compounds modification, nmetallic compounds modification, and metal compounds modification. The contributions of these different modification methods to the technological mechanism involved in Pb adsorption from wastewater by biochar are summarized emphatically・ It is clarified that the investigation of the adsorption mechanism is instructive for the selection of modification methods in the process of Pb adsorption from wastewater by biochar・ It is pointed out that researching two or more composite modification methods is the future trend, providing research ideas for the application of modified biochar in wastewater purification. [ABSTRACT FROM AUTHOR]

Abstract Lead (Pb) exposure negatively impacts fertility in both males and females, pregnancy outcomes, and child brain development. We investigated the reproductive and neurological effects of Pb exposure on male and female mice via Pb-contaminated soil for 4 weeks. Breeding was conducted after completion of exposure, in four groups; group 1 consisted of exposed dams and unexposed sires, group 2 consisted of exposed sires and unexposed dams, group 3 consisted of exposed sires and exposed dams and group 4 was the control. Generally, Pb exposure reduced observed conception rates, with a cumulative decrement observed when both males and females are exposed. Gene expression of the testes revealed oxidative stress as the cause of reduced conception rates. Neurological tests: Morris water maze and rotarod were conducted on F1 generation offspring. Maternally and paternally exposed F1 mice performed poorly in the Morris water maze when compared to the control. The severity of the neurological effects was also parent-dependent and sex-dependent. Paternal Pb exposure effects were more pronounced in female offspring. A comparison of gene expression changes of the hippocampus and prefrontal cortex showed paternal Pb-exposure resulted in more prefrontal cortex changes than in the hippocampus, a trend also recorded in the exposed sires. The pronounced effects in female offspring of paternal Pb exposure may suggest that Pb neurological effects may be X-chromosome-linked.

Sarath S Nair,1 Jyothi Nagesh,1 Shambhavi C,2 Anshul Singh,1 Shirley Lewis,1 Umesh Velu,1 Deepika Chenna3 1Department of Radiation Oncology, Kasturba Medical College Manipal MAHE, Manipal, Karnataka, India; 2Department of Medical Radiation Physics Program, MCHP Manipal, MAHE, Manipal, Karanataka, India; 3Department of Immunohematology and Blood Transfusion, Kasturba Medical College Manipal MAHE, Manipal, Karnataka, IndiaCorrespondence: Jyothi Nagesh, Email jyothi.nagesh@manipal.eduObjective: To identify a suitable approach for blood irradiation other than the commonly used water medium and to study the impact of different algorithm dose computations.Methods: Water is the commonly used medium for blood irradiation. In this study computed tomography scans were taken with locally made blood irradiation phantoms other than water, by using air, rice powder and thermocole using parallel beam for 25 Gy. Plans were recalculated for different algorithms such as collapsed cone (CC), Monte Carlo (MC) and pencil beam (PB). The dose–volume parameters and measured doses were collected and analyzed for each medium and algorithm.Findings: The monitor unit (MU) for rice powder and water are close (2461± 57 and 2469± 61, respectively), with a maximum dose of 28.0± 1.8 and 28.0± 1.9 Gy. The PB algorithm resulted in lower monitor unit values regardless of the medium used, generating values of 2418, 2406, 2382, and 2362 for water, rice powder, air, and Thermocol, respectively. A significant increase in dose was observed irrespective of the medium used when the MC algorithm was employed, with a maximum of 30.26 Gy in rice powder; a smaller dose was used when the CC algorithm was employed, with 26.3 Gy in water medium. The average maximum doses of all groups were equal using the one-way Anova statistical test. Regarding the impact of field size, rice powder appears to have consistent doses across various field sizes, with slight increases as field size grows, which is similar to water.Novelty/Applications: While water is the conventional medium, this study highlights the potential benefits of rice powder, such as eliminating the risks associated with bubble formation and water spillage, which can lead to equipment malfunction and safety hazards. Although previous studies have explored rice powder as a bolus and tissue-equivalent material, this study uniquely applies this knowledge to blood irradiation, an area where rice powder has not been thoroughly investigated.Keywords: computed tomography, collapsed cone, Monte Carlo, pencil beam, monitor units, MU, treatment planning station.

Abstract In this work, we investigate short-packet communications in power beacon (PB)-assisted Internet-of-Things (IoT) networks, where an energy-constrained actuator first harvests energy from a dedicated PB, and then transmits confidential signals to a desired controller in the presence of an eavesdropper. We derive a closed-form lower bound approximation expression for the average achievable effective secrecy rate (AESR) over Nakagami-m fading channels. To gain more insights, we also present the asymptotic average AESR in the high signal-to-noise ratio (SNR) regime. Specifically, analytical results indicate that an average AESR floor appears with the increase of SNR. Moreover, a low complexity one-dimensional search method is employed to maximize the average AESR by optimizing the energy harvesting length. Monte-Carlo simulations are provided to corroborate our analysis.

Abstract Heavy metal toxicity adversely affects plants by changing physiological, biochemical, and molecular mechanisms. Lead (Pb) is one of the most common heavy metal pollutants. Hence this study investigated changes caused by exogenous methyl jasmonate (MeJA; 20 and 100 µM) and salicylic acid (SA; 2 and 20 mM) elicitors in local Karacadağ rice exposed to Pb stress (0, 100, and 400 ppm). The effects of elicitors on photosynthetic pigment content (chlorophyll a, chlorophyll b, and total carotenoid), proline, malondialdehyde (MDA), total phenolic and flavonoid, Pb, and total protein contents in stressed plants were evaluated. All parameters studied increased and decreased at varying rates in the treatment groups compared to the Pb-free group (control), indicating that rice plants were affected by Pb stress. The elicitors (MeJA, SA, and MeJA + SA) were applied by foliar spraying. The elicitor treatments increased photosynthetic pigment content, total protein, proline, total flavonoid, and phenolic contents depending on the elicitor type and concentration. MDA and Pb contents, increasing with Pb toxicity, decreased with elicitor treatments, and the stress degree was reduced. When the elicitors were compared, SA was more effective than MeJA in total flavonoid content at 400 ppm Pb toxicity. However, MeJA was more effective in photosynthetic pigment contents, MDA, total protein, Pb, total phenolic, and proline contents. The best results for all parameters examined in rice plants exposed to Pb toxicity were obtained from the 400 ppm Pb + 2 mM SA + 20 µM MeJA treatment group. In conclusion, this study showed that the combined application of MeJA + SA alleviated the harmful effects of Pb by reducing MDA and increasing photosynthetic pigments, total protein, proline, and secondary metabolites, especially at high Pb concentrations. Consequently, this study demonstrated that the combined use of MeJA and SA in rice plants eliminated the negative effects of stress quite effectively, even at high Pb concentrations. Therefore, future studies should focus on the synergistic application of different elicitors to better understand the effects of heavy metal toxicity on plant growth and development.

The problem of Pb pollution emission from sludge during its combustion has received a widespread attention. The migration and transformation characteristics of Pb during sludge combustion were analyzed by a combination of experimental studies and simulations with the help of inductively coupled plasma mass spectrometry (ICP-MS), specific surface and porosity analyzer (BET), and X-ray diffraction (XRD), etc. The influences of factors such as the addition of CaO, moisture, and acidic gases on the volatilization of Pb and the solid-phase enrichment were investigated, and the activity strength of the adsorption of PbCl2 molecules on different surfaces were revealed with the combination of the density-functional theory. The experimental results showed that the increase of Pb residue to 61.37% after sludge combustion at 900 °C was mainly influenced by the melting effect. The addition of 4% CaO was unfavorable to the enrichment of Pb in the solid-phase product at combustion temperatures of 700−900 °C, while the residual rate of Pb in the solid-phase product increased by 7.82% at 1 000 °C with the addition of 4% CaO. The Pb residual rate was reduced by 28.43% at 20% sludge moisture content compared to burnt dry sludge. The presence of acidic gases favored Pb immobilization, but the promotion varied inconsistently with concentration. CO2 had an obvious promotion effect on the fixation of Pb, and the larger the concentration, the more favorable to the enrichment of Pb, when the simulated flue gas was fed with 30% CO2, the residual rate of Pb increased by 23.37%. While SO2 had a weak promoting effect on Pb immobilization, and with the increase of SO2 concentration, the residual rate of Pb was firstly increased and then decreased, and in the combustion condition with 0.15% SO2, the residual rate of Pb was increased to the best extent, which was only 4.82%. The residual rate of Pb after the combustion of sludge loaded with 4% CaO at 20% H2O/20O2/80N2, 20CO2/20O2/60N2 and 0.15CO2/20O2/79.85N2 increased by −3.61%, 8.77% and 7.65%, respectively. Simulations showed that after the adsorption of PbCl2 molecules on the clean CaO(001) surface, the Pb atoms of Pb molecules underwent orbital hybridization with Osurf atoms, whereas on the surface of CaO(001) with pre-adsorbed CO2, SO2 and H2O, the Pb atoms of PbCl2 molecules would undergo orbital hybridization with OH, OC, and OS atoms, which led to an increase of adsorption energies of PbCl2 molecules after adsorption on the surface of CaO(001) with pre-adsorbed CO2, SO2, and H2O on the surface of CaO(001) with pre-adsorbed CO2, SO2 and OS atoms, which resulted in the increase of adsorption energy after adsorption by 90.069, −13.458 and −55.836 kJ/mol, respectively, compared with that on the clean surface. In summary, controlling the combustion temperature and adding an appropriate amount of CaO can effectively improve the residual rate of Pb, the presence of moisture inhibits the immobilization of Pb, and the CO2 and SO2 atmospheres are favorable for the enrichment of Pb in the solid-phase products.

El río Tumbes es la principal fuente de agua de la ciudad del mismo nombre en el noroeste del Perú. Sin embargo, en las condiciones actuales recibe la influencia de actividades como la minera artesanal en la parte alta de la cuenca, contaminándolo con metales pesados como el plomo, el cual es potencialmente causante de enfermedades. Por otro lado, el sillar (ignimbrita) es un material de construcción extraído en la ciudad de Arequipa que en el momento de ser cortado en bloques causa un material residual que normalmente es desechado. El objetivo de esta investigación es producir y caracterizar materiales adsorbentes basados en sillar para remover directamente Pb del agua del río Tumbes. El sillar se llevó a tamaños de partícula de 150 µm y 250 µm, y fueron activados por pirolisis lenta con y sin presencia de ZnCl2, para luego ser impregnadas con nanopartículas (NPs) de ZnO utilizando la técnica de impregnación in situ. El tratamiento térmico logro modificar la estructura de los materiales, aumentando la fase cristalina de los mismos, sin embargo, aparentemente la concentración de NPs de ZnO impregnada sobre las muestras de sillar pirolizado fue muy reducida para ser detectada por difracción de rayos X. En las pruebas de cinética de adsorción de Pb utilizando directamente de muestras de agua del rio Tumbes, se demostró que los adsorbentes basados en sillar presentaron limitada capacidad de adsorción comparada con otros adsorbentes derivados de rocas, obteniendo valores de adsorción de entre 0,009 – 0,017 mg de Pb/g del adsorbente. Sin embargo, las concentraciones finales luego de los experimentos de adsorción se encentraron por debajo del límite de 0,05 mg/l establecido por la OMS para el caso de agua potable. A pesar de ello es importante el estudio a mayor profundidad con diversos tipos de sillar y otros tipos de modificaciones para corroborar el potencial uso del sillar como adsorbente.

Abstract Introduction Attention-Deficit/Hyperactivity Disorder (ADHD) is a recognized neurodevelopmental disorder with a complex, multifactorial origin. Lead (Pb) and mercury (Hg) are highly toxic substances that can potentially impair brain development and have been implicated in the development of ADHD. This systematic review aims to analyze the epidemiological literature regarding the association between Pb and Hg exposure and the diagnosis of ADHD. Methods From November 1983 to June 2, 2023, a comprehensive search was conducted in multiple databases and search engines, including PubMed, Web of Science, Scopus, and Google Scholar. Observational studies (case-control, cohort, and cross-sectional) measuring Pb and Hg levels in various biological samples (blood, hair, urine, nail, saliva, teeth, and bone) of children with ADHD or their parents and their association with ADHD symptoms were included. Results Out of 2059 studies, 87 met the inclusion criteria and were included in this systematic review. Approximately two-thirds of the 74 studies investigating Pb levels in different biological samples reported associations with at least one subtype of ADHD. However, most studies examining Hg levels in various biological samples found no significant association with any ADHD subtype, although there were variations in exposure periods and diagnostic criteria. Conclusion The evidence gathered from the included studies supports an association between Pb exposure and the diagnosis of ADHD, while no significant association was found with Hg exposure. Importantly, even low levels of Pb were found to elevate the risk of ADHD. Further research is needed to explore the comprehensive range of risk factors for ADHD in children, considering its significance as a neurodevelopmental disorder.

Heavy metal toxicity adversely affects plants by changing physiological, biochemical, and molecular mechanisms. Lead (Pb) is one of the most common heavy metal pollutants. Hence this study investigated changes caused by exogenous methyl jasmonate (MeJA; 20 and 100 µM) and salicylic acid (SA; 2 and 20 mM) elicitors in local Karacadağ rice exposed to Pb stress (0, 100, and 400 ppm). The effects of elicitors on photosynthetic pigment content (chlorophyll a, chlorophyll b, and total carotenoid), proline, malondialdehyde (MDA), total phenolic and flavonoid, Pb, and total protein contents in stressed plants were evaluated. All parameters studied increased and decreased at varying rates in the treatment groups compared to the Pb-free group (control), indicating that rice plants were affected by Pb stress. The elicitors (MeJA, SA, and MeJA + SA) were applied by foliar spraying. The elicitor treatments increased photosynthetic pigment content, total protein, proline, total flavonoid, and phenolic contents depending on the elicitor type and concentration. MDA and Pb contents, increasing with Pb toxicity, decreased with elicitor treatments, and the stress degree was reduced. When the elicitors were compared, SA was more effective than MeJA in total flavonoid content at 400 ppm Pb toxicity. However, MeJA was more effective in photosynthetic pigment contents, MDA, total protein, Pb, total phenolic, and proline contents. The best results for all parameters examined in rice plants exposed to Pb toxicity were obtained from the 400 ppm Pb + 2 mM SA + 20 µM MeJA treatment group. In conclusion, this study showed that the combined application of MeJA + SA alleviated the harmful effects of Pb by reducing MDA and increasing photosynthetic pigments, total protein, proline, and secondary metabolites, especially at high Pb concentrations. Consequently, this study demonstrated that the combined use of MeJA and SA in rice plants eliminated the negative effects of stress quite effectively, even at high Pb concentrations. Therefore, future studies should focus on the synergistic application of different elicitors to better understand the effects of heavy metal toxicity on plant growth and development. [ABSTRACT FROM AUTHOR]

Key message: Cd induces photosynthetic inhibition and oxidative stress damage in H. citrina, which mobilizes the antioxidant system and regulates the expression of corresponding genes to adapt to Cd and Pb stress. Cd and Pb are heavy metals that cause severe pollution and are highly hazardous to organisms. Physiological measurements and transcriptomic analysis were combined to investigate the effect of 5 mM Cd or Pb on Hemerocallis citrina Baroni. Cd significantly inhibited H. citrina growth, while Pb had a minimal impact. Both Cd and Pb suppressed the expression levels of key chlorophyll synthesis genes, resulting in decreased chlorophyll content. At the same time, Cd accelerated chlorophyll degradation. It reduced the maximum photochemical efficiency of photosystem (PS) II, damaging the oxygen-evolving complex and leading to thylakoid dissociation. In contrast, no such phenomena were observed under Pb stress. Cd also inhibited the Calvin cycle by down-regulating the expression of Rubisco and SBPase genes, ultimately disrupting the photosynthetic process. Cd impacted the light reaction processes by damaging the antenna proteins, PS II and PS I activities, and electron transfer rate, while the impact of Pb was weaker. Cd significantly increased reactive oxygen species and malondialdehyde accumulation, and inhibited the activities of antioxidant enzymes and the expression levels of the corresponding genes. However, H. citrina adapted to Pb stress by the recruitment of antioxidant enzymes and the up-regulation of their corresponding genes. In summary, Cd and Pb inhibited chlorophyll synthesis and hindered the light capture and electron transfer processes, with Cd exerting great toxicity than Pb. These results elucidate the physiological and molecular mechanisms by which H. citrina responds to Cd and Pb stress and provide a solid basis for the potential utilization of H. citrina in the greening of heavy metal-polluted lands. [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 fibrinolytic kinase identified in the nereid worm (Perinereis aibuhitensis Grub) displays exceptional kinase activity, stability, and specificity, suggesting its potential as a promising candidate for the advancement of new thrombolytic drugs. In this study, a process was optimized for the production of fibrinolytic kinase using Escherichia coli, and the effects of factors such as inoculum, pH, OD, temperature, inducer concentration, and time on the protein yield were investigated. The optimum points of key parameters were determined by single-factor experiments, and the initial pH, OD, and time were determined to be significant by PB (Plackett–Burman design) with six factors at two levels of experiments. The response surface experiments highlighted the key roles of initial pH and induced OD values, and the convergence of the model and experimental data confirmed the optimal conditions and reasonable fluctuation intervals, which proved the reliability of the model. [ABSTRACT FROM AUTHOR]

Nano-sized biochar, which is a small structure prepared from biochar by grinding, has surpassed traditional biochar in performance, showing enhanced effects and potential for a wide range of environmental applications. Firstly, this paper visualizes and analyzes the literature in this field by CiteSpace to clarify the development trend of nano-sized biochar. The review intuitively shows the most influential countries, the most productive institutions, and the most concerned hot spots in the field of nano-sized biochar. Secondly, these hotspots in environment management are summarized by keywords and clustering: (1) The application of ball milling is a modification scheme that researchers have paid attention to, and it is also a key method for preparing biochar nanomaterials. It has a more dispersed structure and can support more modified materials. (2) Nano-sized biochar in the comprehensive utilization of water, soil, and plants was discussed and is a small range of application modification methods. (3) The bidirectional effects of nano-sized biochar on plants were analyzed, and the challenges in its application were listed. Finally, the economic management of nano-sized biochar and the relationship between microorganisms are the focus of the next research. [ABSTRACT FROM AUTHOR]

Humans have drastically altered the ecology of heavy metals, which can have negative effects on animal development and neural functioning. Many species have shown the ability to adapt to anthropogenic increases in metal pollution, but such evolutionary responses will depend on the extent of metal variation over space and time. For terrestrial vertebrates, it is unclear how metal exposure has changed over time: some studies suggest metal content peaked with the enactment of policies controlling lead emissions, while other studies suggest metal levels peaked at least a century earlier. We used 162 specimens of four mammal species (a mouse, shrew, bat, and squirrel) to ask how metal content of the fur and skin has changed over a 90-year time period, and impacts on individual performance (body size and cranial capacity). Using ICP-MS, we show that for lead, cadmium, copper, and chromium, there were significant declines in metal content in mammal tissue over the 90-year time period, with lead levels five times lower now than in the early 1900s. Importantly, metal content began to drop well before the pollution regulation of the 1970s. Effects of time greatly outweighed any effects of an individual living near a human population center. Surprisingly, there were no effects of body metal content on body size, and only manganese was negatively related to relative cranial capacity. Taken together, these results suggest that present day populations of mammals are experiencing levels of heavy metal exposure that are less stressful than they were 100 years ago. In addition, temporal decreases in metal loads likely partly reflect global patterns of pollution decline that affect atmospheric metal deposition rather than local point sources of exposure. [ABSTRACT FROM AUTHOR]

Studying efficient and accurate soil heavy-metal detection technology is of great significance to establishing a modern system for monitoring soil pollution, early warning and risk assessment, which contributes to the continuous improvement of soil quality and the assurance of food safety. Laser-induced breakdown spectroscopy (LIBS) is considered to be an emerging and effective tool for heavy-metal detection, compared with traditional detection technologies. Limited by the soil matrix effect, the LIBS signal of target elements for soil heavy-metal detection is prone to interference, thereby compromising the accuracy of quantitative detection. Thus, a series of signal-enhancement methods are investigated. This study aims to explore the effect of conductive materials of NaCl and graphite on the quantitative detection of lead (Pb) in soil using LIBS, seeking to find a reliable signal-enhancement method of LIBS for the determination of soil heavy-metal elements. The impact of the addition amount of NaCl and graphite on spectral intensity and parameters, including the signal-to-background ratio (SBR), signal-to-noise ratio (SNR), and relative standard deviation (RSD), were investigated, and the mechanism of signal enhancement by NaCl and graphite based on the analysis of the three-dimensional profile data of ablation craters and plasma parameters (plasmatemperature and electron density) were explored. Univariate and multivariate quantitative analysis models including partial least-squares regression (PLSR), least-squares support vector machine (LS-SVM), and extreme learning machine (ELM) were developed for the quantitative detection of Pb in soil with the optimal amount of NaCl and graphite, and the performance of the models was further compared. The PLSR model with the optimal amount of graphite obtained the best prediction performance, with an Rp that reached 0.994. In addition, among the three spectral lines of Pb, the univariate model of Pb I 405.78 nm showed the best prediction performance, with an Rp of 0.984 and the lowest LOD of 26.142 mg/kg. The overall results indicated that the LIBS signal-enhancement method based on conductive materials combined with appropriate chemometric methods could be a potential tool for the accurate quantitative detection of Pb in soil and could provide a reference for environmental monitoring. [ABSTRACT FROM AUTHOR]

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Introduction: Attention-Deficit/Hyperactivity Disorder (ADHD) is a recognized neurodevelopmental disorder with a complex, multifactorial origin. Lead (Pb) and mercury (Hg) are highly toxic substances that can potentially impair brain development and have been implicated in the development of ADHD. This systematic review aims to analyze the epidemiological literature regarding the association between Pb and Hg exposure and the diagnosis of ADHD. Methods: From November 1983 to June 2, 2023, a comprehensive search was conducted in multiple databases and search engines, including PubMed, Web of Science, Scopus, and Google Scholar. Observational studies (case-control, cohort, and cross-sectional) measuring Pb and Hg levels in various biological samples (blood, hair, urine, nail, saliva, teeth, and bone) of children with ADHD or their parents and their association with ADHD symptoms were included. Results: Out of 2059 studies, 87 met the inclusion criteria and were included in this systematic review. Approximately two-thirds of the 74 studies investigating Pb levels in different biological samples reported associations with at least one subtype of ADHD. However, most studies examining Hg levels in various biological samples found no significant association with any ADHD subtype, although there were variations in exposure periods and diagnostic criteria. Conclusion: The evidence gathered from the included studies supports an association between Pb exposure and the diagnosis of ADHD, while no significant association was found with Hg exposure. Importantly, even low levels of Pb were found to elevate the risk of ADHD. Further research is needed to explore the comprehensive range of risk factors for ADHD in children, considering its significance as a neurodevelopmental disorder. [ABSTRACT FROM AUTHOR]

Fine particular matter (PM2.5) and lead (Pb) exposure can induce insulin resistance, elevating the likelihood of diabetes onset. Nonetheless, the underlying mechanism remains ambiguous. Consequently, we assessed the association of PM2.5 and Pb exposure with insulin resistance and inflammation biomarkers in children. A total of 235 children aged 3–7 years in a kindergarten in e-waste recycling areas were enrolled before and during the Corona Virus Disease 2019 (COVID-19) lockdown. Daily PM2.5 data was collected and used to calculate the individual PM2.5 daily exposure dose (DED-PM2.5). Concentrations of whole blood Pb, fasting blood glucose, serum insulin, and high mobility group box 1 (HMGB1) in serum were measured. Compared with that before COVID-19, the COVID-19 lockdown group had lower DED-PM2.5 and blood Pb, higher serum HMGB1, and lower blood glucose and homeostasis model assessment of insulin resistance (HOMA-IR) index. Decreased DED-PM2.5 and blood Pb levels were linked to decreased levels of fasting blood glucose and increased serum HMGB1 in all children. Increased serum HMGB1 levels were linked to reduced levels of blood glucose and HOMA-IR. Due to the implementation of COVID-19 prevention and control measures, e-waste dismantling activities and exposure levels of PM2.5 and Pb declined, which probably reduced the association of PM2.5 and Pb on insulin sensitivity and diabetes risk, but a high level of risk of chronic low-grade inflammation remained. Our findings add new evidence for the associations among PM2.5 and Pb exposure, systemic inflammation and insulin resistance, which could be a possible explanation for diabetes related to environmental exposure. [ABSTRACT FROM AUTHOR]

Pb-contaminated soil poses serious hazards to humans and ecosystems and is in urgent need of remediation. However, the extensive use of traditional curing materials such as ordinary Portland cement (OPC) has negatively impacted global ecology and the climate, so there is a need to explore low-carbon and efficient green cementitious materials for the immobilization of Pb-contaminated soils. A red mud/steel slag-based (RM/SS) geopolymer was designed and the potential use of solidifying/stabilizing heavy metal Pb pollution was studied. The Box–Behnken design (BBD) model was used to design the response surface, and the optimal preparation conditions of RM/SS geopolymer (RSGP) were predicted by software of Design-Expert 8.0.6.1. The microstructure and phase composition of RSGP were studied by X-ray diffractometer, Fourier transform infrared spectrometer, scanning electron microscopy and X-ray photoelectron spectroscopy, and the immobilization mechanism of RSGP to Pb was revealed. The results showed that when the liquid–solid ratio is 0.76, the mass fraction of RM is 79.82% and the modulus of alkali activator is 1.21, the maximum unconfined compressive strength (UCS) of the solidified soil sample is 3.42 MPa and the immobilization efficiency of Pb is 71.95%. The main hydration products of RSGP are calcium aluminum silicate hydrate, calcium silicate hydrate and nekoite, which can fill the cracks in the soil, form dense structures and enhance the UCS of the solidified soil. Pb is mainly removed by lattice immobilization, that is, Pb participates in geopolymerization by replacing Na and Ca to form Si-O-Pb or Al-O-Pb. The remaining part of Pb is physically wrapped in geopolymer and forms Pb(OH)2 precipitate in a high-alkali environment. [ABSTRACT FROM AUTHOR]

The goal of this study is to assess how well litmus waste can remove Lead (Pb) from an under various process settings, an aqueous system is examined. litmus stalks were burned to create adsorbents, which were subsequently used to soak up water in a variety of applications. The use of litmus plant It has been investigated as a Pb reducing agent for the removal of Lead from synthetic waste water. Adsorbent properties were determined via the use of ultraviolet (UV), x-ray diffract grams (XRD) and synthetic methods (SEM). 20 milligrams per liter of Pb experiments a study on chromium recovery in batches found that increasing the pH of the aqueous solution enhanced metal recovery. pH = 7, adsorbent dose of 0.03 gr, and 25°C temperature were shown to be optimal for the removal of Pb. Pb may be removed from synthetic model effluent by using litmus stalks, according to the results of this study. The litmus stalks has successfully cleaned synthetic waste water by rapidly removing Pb from aqueous solution. [ABSTRACT FROM AUTHOR]

Biochar and nanoparticles (NPs) are potential strategies for increasing plant yield and minimizing the negative effects of toxic metals on sweet basil (Ocimum basilicum L). The current study aims to reduce the access of toxic elements to the oil extracted from basil plants growing in polluted soils by biochar and NPS of silicon (Si) and boron (B). Sweet basil plants were grown in contaminated soil that contained cadmium (Cd) and lead (Pb) at concentrations of 58 and 800 mg kg−1, respectively. The experiment included two doses of biochar (0 and 1%, w/w) and four foliar combinations of Si and B nanoparticles at the dose of 100 mg L−1 of Si and/or B. Cd and Pb availability were reduced by 44 and 48%, respectively, compared to the control. The soil pH raised significantly (p < 0.05) as a result of biochar addition. Furthermore, biochar addition at the dose of 1%, (w/w) caused a 14% increase in the soil organic matter. The highest growth parameters of basil plants were obtained from the biochar treatment with Si + B NPs foliar application. The treatment that was amended with biochar and sprayed with Si + B showed the greatest significant values of nitrogen (N), phosphorus (P), potassium (K), and calcium (Ca) content in basil plants. The chlorophyll content of basil leaves rose along with the synthesis of proline and soluble carbohydrates after the addition of biochar to the polluted soil and Si + B spraying. Biochar minimized Cd in the leaf and oil by 48 and 49%, respectively, compared to the control, while Pb concentrations were reduced by 29 and 49%, respectively. The oil extracted from the basil plants grown in the soil amended with biochar contained 50–52 and 23–26 μg kg−1 of Cd and Pb, respectively. Adding biochar to the contaminated soil increases the oil yield of sweet basil and reduces its content of toxic elements, while spraying the basil plant with silicon and boron nanoparticles increases the plant's resistance to metal toxicity. [ABSTRACT FROM AUTHOR]

Fish meat is recommended for consumption as a source of protein, essential unsaturated fatty acids, and fat-soluble vitamins, unfortunately it can also be a source of dangerous contaminants. The aim of the study was to assessment the level of Zn, Cu and Pb in water and bottom sediments collected in summer and autumn from the Koronowo Reservoir and the Wierzchucińskie Duże Lake and in the tissues of perch (Perca fluviatilis L.) and rudd (Scardinius erythrophtalmus L.) for health risk assessment of potential consumers. Metals accumulated in the tissues in the following order: meat, liver and gills: Zn > Cu > Pb. Of the four factors taken into account, such as: type of tissue, fish species, catching season and place of catching, the first one determined the degree of metal accumulation to the greatest extent. The high level of Pb in muscle tissue was determined by the content of this metal in tissue collected from rudd from Wierzchucińskie Duże Lake in the summer (0.383 mg kg−1 ww). The bioconcentration factor (BCF) of Pb, Zn and Cu in all tissues of analysed fish was much higher from water than from sediments. The highest value of metal pollution index (MPI) in the meat (1.42), liver (12.97), and gills (8.49) was calculated for summer-caught fish. The research indicated that consumption of 100 g of fish meat could meet daily requirement for Zn up to 26.3 % and for Cu in 16.4 %. The potential risk of Pb consumption according to RDA is as much as 2.4 %.

Wild boars, being a common game species, inhabit regions across Eurasia, the southern regions of Asia and certain Indonesian islands. Being omnivorous and due to their relatively long lifespan, wide distribution and a relatively high number of shot animals per annual legal hunting season, they are suitable to be biological indicators of occurrence of heavy metals. Concentrations of cadmium, lead, arsenic and mercury were analyzed by atomic absorption spectrometry and cold vapor atomic absorption spectrometry in the livers of free-living wild boars (n = 58) from two locations in the Republic of North Macedonia. In all four examined heavy metals, no statistically significant difference between the locations was found (p > 0.05). The mean levels of heavy metals were Cd 0.391 mg/kg and 0.339 mg/kg; Pb 0.213 mg/kg and 0.204 mg/kg; Hg 0.034 mg/kg and 0.037 mg/kg; As 0.035 mg/kg and 0.029 mg/kg in the livers of boars from Bitola and Gevgelija hunting sites, respectively. Although some samples (two samples of Hg, ten samples of Cd and two samples of Pb) exceeded the legal limits, the average values for all heavy metals were far below the maximum permitted values. These findings are promising since they suggest that the ecosystem in the Republic of North Macedonia is stable concerning heavy metal pollution.

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]

B2O3 was used as a fluxing agent can reduce the melting temperature of municipal solid waste incineration (MSWI) fly ash which related to the formation of the minerals Ca3(BO3)2, Ca2B2O5 and CaB2O4 during vitrification process. However, the relationship between immobilization of heavy metals and borates transformation during melting process remains unclear. In this study, the immobilization of heavy metal Pb inside Ca3(BO3)2, Ca2B2O5 and CaB2O4 based on density functional theory (DFT) were comparatively studied in this paper. The results showed that the defect formation energies for substitutional doping model are higher than interstitial model which is the more favorable the immobilization model for Pb. Pb cause a volume expansion in all borates. In the substitution doping model, Pb can replace Ca to balance the electronegativity of O atom and form chemical bonds with the surrounding O atoms, and the covalency of Pb–O is stronger than that of Ca–O. In addition, the order of covalency between Pb and surrounding O atoms is as follows: Ca3(BO3)2 > Ca2B2O5 > CaB2O4. In the interstitial doping model, bonds of O–Pb and B-Pb exhibited negative population values, revealing that filling of electrons into the antibonding states was the major orbital contribution. In addition, B 2s and 2p orbital and Pb 6p orbital form hybridization near the Fermi level in the CaB2O4 (I) doping model. [ABSTRACT FROM AUTHOR]

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Purpose: This study aims to assess the feasibility and efficiency of electrokinetic (EK) remediation of soil contaminated with As, Cd, Cu, and Pb using the biodegradable chelator N, N-bis(carboxymethyl)-tetrasodium salt (GLDA) at the pilot scale. Materials and methods: The experiments were performed under a constant voltage (40 V) in an EK reactor (100 cm (length) × 50 cm (width) × 25 cm (height)) for over 100 days using various enhancement strategies. The current, electroosmotic flow (EOF), microstructure, mineral composition of the soil samples (before and after EK remediation), removal efficiencies, chemical forms, and ecotoxicity risks of As, Cd, Cu, and Pb were determined. Results and discussion: The results showed gradual decreases in the electrical current and EOF over time. The spatial distribution of As, Cd, Cu, and Pb in the soil solution and electrolyte revealed that the removed metals primarily accumulated in anolytes. The soil As, Cd, and Cu contents, especially near the anode, showed gradual reductions. The total removal efficiencies of As, Cd, Cu, and Pb were 49.4%, 44.0%, 53.6%, and 36.6%, respectively. Overall, the ecotoxicity risks of the remaining As, Cd, Cu, and Pb were below the initial values. A soil microstructure and mineral composition analysis indicated that the GLDA-enhanced EK technology effectively removed As, Cd, Cu, and Pb by dissolving soil minerals and breaking chemical bonds. The unit energy consumption ranged from 1.25 to 1.83 kW·h/t/%, indicating lower or comparable values to the data in the literature. Conclusions: The biodegradable chelator, GLDA, has been shown to remove different types of potentially toxic elements using enhancement strategies on a pilot scale with low unit energy consumption. Arsenic migrated to the anode in the anionic form, and the complexes formed by Cd, Cu, and Pb with GLDA were negatively charged and moved toward the cathode. After the EK treatment, the ecotoxicity risks of As, Cd, Cu, and Pb decreased with a reduction in the contents and the chemical form changes of As, Cd, Cu, and Pb. [ABSTRACT FROM AUTHOR]

Environmental factors, such as trace elements and blood lead, have been implicated in the heterogeneity of children with attention deficit hyperactivity disorder (ADHD). This research aimed to investigate the relationship between blood trace elements and cognitive function as well as behavioral problems in children aged 4–12 years diagnosed with ADHD. In this study, we recruited 146 children with ADHD and 91 neurotypical controls matched for age and gender. We used atomic absorption spectrometry to measure the concentrations of Cu, Zn, Ca, Mg, Fe, and Pb in the whole blood. The Conners Parent Rating Scale (CPRS) and Wechsler intelligence tests were employed to evaluate cognitive function and behavioral problems. Compared with controls, children with ADHD exhibited higher levels of Pb. Pb levels indicated a negative correlation with the verbal comprehension index and the full intelligence scale. Cu levels indicated a negative correlation with the verbal comprehension index but positively correlated with conduct, learning, and impulsive-hyperactivity problems. In addition, Fe levels indicated a positive correlation with psychosomatic symptoms. Wechsler intelligence results indicated substantially higher scores in children with normal Zn levels than those outside the reference range. These results indicate a correlation between the present of Pb, Cu, Fe, and Zn in the blood of Chinese children with ADHD and cognitive function and behavioral problems. [ABSTRACT FROM AUTHOR]

To eliminate the negative effect of soil contamination with heavy metals on plant growth and crop yield, different methods and techniques are the subject of discussion and study. In this study, we aimed to evaluate the effect of secondary pulp and paper-mill sludge application to soil on the response of the main physiological processes such as the growth, photosynthesis, and respiration of lettuce (Lactuca sativa L.) plants to soil contamination with Pb. For the pot experiment, Pb was added to sandy loam soil at concentrations of 0, 50, and 250 mg Pb(NO3)2 per kg of the soil, and secondary sludge was added to a 0, 20, or 40% sludge solution during each plant watering. The Pb-mediated change in plant biomass allocation, decrease in the photosynthetic rate, increase in leaf respiration rate, and the degree of light inhibition of respiration were closely associated with increases in both root and shoot Pb content. For the Pb-free soil condition, secondary sludge application contributed to the allocation of plant biomass towards a greater accumulation in the shoots than in the roots. Although stomatal opening was not affected by either Pb or sludge, sludge application increased photosynthetic CO2 assimilation regardless of soil Pb content, which was associated with an increase in the electron-transport rate and carboxylase activity of Rubisco. Soil contamination with Pb significantly increased the ratio of respiration to photosynthesis, reflecting a shift in the carbon balance toward carbon losses in the leaves, but sludge application modified the coupling between the processes with a decrease in the proportion of respiratory carbon losses. The sludge-mediated recovery of the physiological processes of L. sativa reflected an increase in plant tolerance to soil contamination with heavy metals, the formation of which is associated with plant and soil adjustments initiated by secondary sludge application. [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]

The coast of Tanjung Mas, Semarang City, is an industrial area used by the community to cultivate milkfish using stick-net pens. Furthermore, heavy metal contamination such as Cr, Cd, Cu, and Pb potentially disrupts milkfish meat's growth, quality, and safety. This study aims to determine heavy metals concentration in the waters and milkfish meat in stick-net pens cultivation in Tanjung Mas, Semarang City. The study was conducted using exploration, with five observation sites representing household waste disposal flow, industrial discharge, open sea, and intermediate areas. The observation sites were selected based on the milkfish cultivation activity. The sample and data, including water, milkfish, and environmental factors (temperature, pH, salinity, water current, and dissolved oxygen), were collected three times every two weeks. The heavy metals were detected using Atomic Absorption Spectrometry (AAS). The highest heavy metal concentration is Cr, which ranges from 1.70 ± 0.32 ppm to 2.36 ± 0.63 ppm in milkfish and 2.77 ± 0.65 ppm to 3.05 ± 0.58 ppm in the environment. The heavy metals contamination in Semarang City's water areas is still relatively low and has no impact on milkfish growth. Industrial waste, mainly heavy metals, potentially threatens the stick-net pens cultivation model developed by the community in Semarang City. This study can be used as an input for mitigation and adaptive action in anticipating future environmental changes and maintaining their business sustainability. [ABSTRACT FROM AUTHOR]

Hypertension (HT) is a medical condition arising due to increase in blood pressure (BP) prevalent worldwide. The balanced dietary intakes of macro-elements and micro-elements including Na, K, Ca, Mg, Zn, and Cu have been described to maintain BP in humans by regulating the osmolarity of blood, cells/tissues, prevention of generation of oxidative and nitrosative stress (OANS), and endothelial damage through their functioning as important components of renin-angiotensin-aldosterone system (RAAS), antioxidant enzyme defense system, and maintenance of blood vascular-endothelial and vascular smooth muscle cell (VSMC) functions. However, inadequate/excess dietary intakes of Na/K, Ca/Mg, and Zn/Cu along with higher Pb and As exposures recognized to induce HT through common mechanisms including the followings: endothelial dysfunctions due to impairment of vasodilatation, increased vasoconstriction and arterial stiffness, blood clotting, inflammation, modification of sympathetic activity and higher catecholamine release, increased peripheral vascular resistance, and cardiac output; increased OANS due to reduced and elevated activities of extracellular superoxide dismutase and NAD(P)H oxidase, less nitric oxide bioavailability, decrease in cGMP and guanylate cyclase activity, increase in intracellular Ca2+ ions in VSMCs, and higher pro-inflammatory cytokines; higher parathyroid and calcitriol hormones; activation/suppression of RAAS resulting imbalance in blood Na+, K+, and water regulated by renin, angiotensin II, and aldosterone through affecting natriuresis/kaliuresis/diuresis; elevation in serum cholesterol and LDL cholesterol, decrease in HDL cholesterol due to defect in lipoprotein metabolism. The present study recommends the need to review simple dietary mineral intervention studies/supplementation trials before keeping their individual dietary excess intakes/exposures in consideration because their interactions lead to elevation and fall of their concentrations in body affecting onset of HT. [ABSTRACT FROM AUTHOR]

Sydney estuary catchment supports the largest city in Australia and provides essential eco-social and environmental services; however, the region has been influenced by extensive anthropogenic modification. Soil metal concentrations in the catchment had been studied previously; however, the current investigation was designed to determine the risk posed by these contaminants to human health. Soil metal concentrations were higher than observed in most global capitals and increased substantially in the south and south-east of the catchment and close to the central business district. Road-side soils and road dust contained the highest concentration of metals in the catchment. Lead in catchment soils was closely related to traffic density and sourced from the historic use of Pb in petrol. A human health assessment indicated that soil Cd, Ni and Zn posed no non-carcinogenic risk (NCR), or carcinogenic risk (CR) for children, or adults in Sydney estuary catchment and that Cu and Cr may pose minor NCR for children. Vehicle-related Pb raised the greatest human health risk in catchment soils and may pose NCR at 32% and 4.3% of sites for children and adults, respectively. Inconsistent analytical techniques used in CR and NCR evaluations produce incomparable assessments and a consistent` methodology is suggested to improve interpretation. Human health risk may well be higher than commonly calculated due to pollutants present in urban soil not being included in assessments. [ABSTRACT FROM AUTHOR]

Abstract As evidence regarding the toxicity of lead (Pb) amassed, the heavy metal became banned from several products, such as automotive gasoline and paint. However, Pb bullets are still used for hunting big game animals in most of the world. Although regulatory bans of Pb bullets may appear optimal solutions, stakeholders have reasons to oppose them, favor them, or lie somewhere in between. As the problem has transformed from biophysical to socioecological, we employed a wicked problem lens to dissect the discourse and help inspire targeted solutions. Herein, we identified and critically analyzed 4 relevant traits of a wicked problem: multiple stakeholders are involved, disagreement on a definition, unique nature, and being a symptom of a larger problem. To minimize the impact of these traits, our analysis suggests that voluntary Pb free ammunition programs are more likely to soothe conflict among stakeholders, enable collaborative action upon agreeing on common values, and promote programs tailored to the local landscape of sociopolitical power and values.

The association between metal mixtures and kidney function has been reported. However, reports on the mechanism of metal toxicity were limited. Oxidative stress was reported as a possible cause. This study aimed to determine the association between of kidney function and metals, such as arsenic (As), cadmium (Cd), cobalt (Co), copper (Cu), lead (Pb), selenium (Se), and zinc (Zn), and to explore the possible mediating role of tumor necrosis factor alpha (TNF-α) between metal toxicity and kidney function. In this study, we recruited 421 adults from a health examination. The concentration of blood metals was analyzed using inductively coupled plasma mass spectrometry. We used linear regression models to assess the association between metals and TNF-α. Then, mediation analysis was applied to investigate the relationship between metal exposure, TNF-α, and kidney function. In univariate linear regression, blood As, Cd, Co, Cu, Pb, and Zn levels significantly increased TNF-α and decreased kidney function. Higher blood As and Pb levels significantly increased TNF-α in multivariable linear regressions after adjusting for covariates. We found that blood levels of As (coefficients = −0.021, p = 0.011), Pb (coefficients = −0.060, p < 0.001), and Zn (coefficients = −0.230, p < 0.001) showed a significant negative association with eGFR in the multiple-metal model. Furthermore, mediation analysis showed that TNF-α mediated 41.7 %, 38.8 %, and 20.8 % of blood Cd, As and Pb, respectively. Among the essential elements, TNF-α mediated 24.5 %, 21.5 % and 19.9 % in the effects of blood Co, Cu, and Zn on kidney function, respectively. TNF-α, acting as a mediator, accounted for 20.1 % of the contribution between the WQS score of metal mixtures and the eGFR (p

Millions of adults and children are exposed to high levels of lead, a neurotoxicant, each year. Recent evidence suggests that lead exposure may precipitate neurodegeneration, particularly if the exposure occurs early or late in life, with unique alterations to the structure or function of specific subfields of the hippocampus, a region involved in memory and Alzheimer’s disease. It has been proposed that specific hippocampal subfields may thus be useful biomarkers for lead-associated neurological disease. We turned to a population-representative New Zealand birth cohort where the extent of lead exposure was not confounded by social class (the Dunedin Study; born 1972–1973 and followed to age 45) to test the hypothesis that early life lead exposure (blood-lead level at age 11 years) is associated with smaller MRI-assessed gray matter volumes of specific subfields of the hippocampus at age 45 years. Among the 508 Dunedin Study members with childhood lead data and adult MRI data passing quality control (93.9 % of those with lead data who attended the age-45 assessment wave, 240[47.2 %] female), childhood blood-lead levels ranged from 4 to 31 µg/dL (M[SD]=10.9[4.6]). Total hippocampal volumes were lower among adults with higher childhood blood-lead levels (b=-102.6 mm3 per 5 ug/dL-unit greater blood-lead level, 95 %CI: −175.4 to −29.7, p=.006, β=-.11), as were all volumes of the 24 hemisphere-specific subfields of the hippocampus. Of these 24 subfields, 20 demonstrated negative lead-associations greater than β=-.05 in size, 14 were statistically significant after adjustment for multiple comparisons (pFDR

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]

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]