Health risks and sources of trace elements and black carbon in PM2.5 from 2019 to 2021 in Beijing

A comprehensive health risk assessment of PM2.5 is meaningful to understand the current status and directions regarding further improving air quality from the perspective of human health. In this study, we evaluated the health risks of PM2.5 as well as highly toxic inorganic components, including heavy metals (HMs) and black carbon (BC) based on long-term observations in Beijing from 2019 to 2021. Our results showed that the relative risks of chronic obstructive pulmonary disease, lung cancer, acute lower respiratory tract infection, ischemic heart disease, and stroke decreased by 4.07%-9.30% in 2020 and 2.12%-6.70% in 2021 compared with 2019. However, they were still at high levels ranging from 1.26 to 1.77, in particular, stroke showed the highest value in 2021. Mn had the highest hazard quotient (HQ, from 2.18 to 2.56) for adults from 2019 to 2021, while Ni, Cr, Pb, As, and BC showed high carcinogenic risks (CR > 1.0×10-6) for adults. The HQ values of Mn and As and the CR values of Pb and As showed constant or slight upwards trends during our observations, which is in contrast to the downward trends of other HMs and PM2.5. Mn, Cr, and BC are crucial toxicants in PM2.5. A significant shrink of southern region sourcesof HMs and BCshrank suggests the increased importance of local sources. Industry, dust, and biomass burning are the major contributors to the non-carcinogenic risks, while traffic emissions and industry are the dominant contributors to the carcinogenic risks in Beijing.

Development of a vortex-assisted switchable-hydrophilicity solvent-based liquid phase microextraction for fast and reliable extraction of Zn (II), Fe (II), Pb (II), and Cd (II) from various baby food products

This manuscript describes the development of a novel liquid phase microextraction (LPME) method for the extraction and determination of Zn (II), Fe (II), Pb (II), and Cd (II) in various infant/baby food and supplements products. The method is based on vortex-assisted extraction combined with a switchable-hydrophilicity solvent (SHS) sample preparation. The SHS, which undergoes reversible phase changes triggered by pH change, enables selective extraction and easy phase separation. A flame atomic absorption spectroscopy was used in the final determination step. Optimization studies revealed, that the optimal pH of the sample solution (after digestion) during analytes extraction is 5.5. A l-proline is added to the sample (375 mM) to ensure the complexation of the target metal cations. After the complexation step, 750 µL of SHS - a N, N-Dimethylcyclohexylamine along with 0.9 mL of 2 M of acetic acid solution is added (hydrophilicity switch-on stage) and mixed manually to obtain a homogeneous solution. In the last stage, 0.45 mL of 10 M NaOH solution (hydrophilicity switch-off stage) is added to the sample solution and a vortex for 100 s is applied to ensure the effective extraction and separation of the complex containing the analytes. At this stage, a cloudy solution is immediately obtained. Finally, the effective phase separation is obtained at the centrifugation step (4000 rpm for 2 mins). The method limit of detection was as 0.03, 0.009, 0.6, and 0.2 ng/L for Zn (II), Fe (II), Cd (II), and Pb (II) respectively with RSD% below 2.0 %. The analysis of certified reference materials and real samples proved the full applicability of the method for routine analysis, contributing to the field of heavy metal analysis and ensuring the safety of baby products. According to the AGREE methodology, this method can be named as green analytical chemistry method with a score of 0.77.

Sulfhydryl-functionalized 3D MXene-AuNPs enabled electrochemical sensors for the selective determination of Pb2+, Cu2+ and Hg2+ in grain

Herein, we made 3D MXene-AuNPs by in situ growth of gold nanoparticles (AuNPs) on the surface of MXene by chemical reduction method, and then introduced three sulfhydryl (-SH) compounds as functionalized modifiers attached to the AuNPs to form a highly selective composite material for the detection of Pb2+, Cu2+, and Hg2+, respectively. The doping of AuNPs changes the microstructure of 2D MXene and generates more active sites. On a sensing platform based on ITO array electrodes, the detection system was optimised with sensitivities up to 1.157, 0.846 and 0.799 μA·μg-1Lcm-2 (Pb2+, Cu2+, and Hg2+). The selectivity of MXene@AuNPs was effectively improved by sulfhydryl group modification. In the range of 1-1300 μg L-1, the detection limits of three ions were 0.07, 0.13 and 0.21 μg L-1. In addition, this method can efficiently and accurately detect heavy metal ions in four cereal samples with consistent results with inductively coupled plasma mass spectrometry.

Migration and transformation of Pb, Cu, and Zn during co-combustion of high-chlorine-alkaline coal and Si/Al dominated coal

Shaerhu (SEH) coal is abundant in Xinjiang, China. The utilization of SEH suffers from severe ash deposition, slagging, and fouling problems due to its high-chlorine-alkaline characteristics. The co-combustion of high-alkaline coal and other type coals containing high Si/Al oxides has been proven to be a simple and effective method that will alleviate ash-related problems, but the risk of heavy metals (HMs) contamination in this process is nonnegligible. Hence, the volatilization rates and chemical speciation of Pb, Cu, and Zn in co-combusting SEH and a high Si/Al oxides coal, i.e., Yuanbaoshan (YBS) coal were investigated in this study. The results showed that the addition of SEH increased the volatilization rates of Pb, Cu, and Zn during the co-combustion at 800°C from 23.70%, 23.97%, and 34.98% to 82.31%, 30.01%, and 44.03%, respectively, and promoted the extractable state of Cu and Zn. In addition, the interaction between SEH and YBS inhibited the formation of the Pb residue state. SEM-EDS mapping results showed that compared to Zn and Cu, the signal intensity of Pb was extremely weak in regions where some of the Si and Al signal distributions overlap. The DFT results indicated that the O atoms of the metakaolin (Al2O3⋅2SiO2) (001) surface were better bound to the Zn and Cu than Pb atoms after adsorption of the chlorinated HMs. These results contribute to a better understanding of the effects of high-alkaline coal blending combustion on Pb, Cu, and Zn migration and transformation.

Development of porous materials via protein/polysaccharides/polyphenols nanoparticles stabilized Pickering high internal phase emulsions for adsorption of Pb2+ and Cu2+ ions

The porous materials (PM) were prepared by the Pickering high internal phase emulsion (PHIPE) template. Firstly, the nanoparticles named as ZHMNPs or MZHMNPs were fabricated based on zein, Hohenbuehelia serotina polysaccharides and Malus baccata (Linn.) Borkh polyphenols without or with Maillard reaction, the average particle sizes and zeta potentials of which were distributed in a range of 718.1-979.4 nm and -21.6-25.2 mV. ZHMNPs possessed the relatively uniform spherical morphology, while MZHMNPs were irregular in shape. With ZHMNPs or MZHMNPs serving as the stabilizers, the PHIPEs were prepared, and exhibited the good viscoelasticity and excellent storage and freeze-thaw stabilities. Based on above PHIPEs template, the constructed PM possessed the large specific surface area and uniform pore structure. Through the investigations of adsorption performances, PM showed the outstanding adsorption capacities on Pb2+ and Cu2+ ions regardless of dissolving in deionized water or simulated gastrointestinal digestive fluid. Furthermore, the results also showed that the pH, temperature and adsorbent dosage had certain impacts on the adsorption performances of PM on Pb2+ and Cu2+ ions.

Simultaneous quantification of tin and lead species in Antarctic krill and fish by interfacing high-performance liquid chromatography with inductively coupled plasma mass spectrometry based on strong cation-exchange and Amphion columns

Tin and lead are a global concern considering their species-dependent toxicity, bioavailability and transformation. Simultaneous speciation analysis of tin and lead is challenging for a large food capacity containing unstable species. Herein, we developed two sensitive methods for rapid quantification of tin and lead species in Antarctic seafood by high-performance liquid chromatography and inductively coupled plasma mass spectrometry based on strong cation-exchange and Amphion columns. Inorganic tin and lead, four organotin and two organolead compounds can be analysed in 16 min on a 10-cm Amphion II column (mobile phase: 4 mM sodium dodecyl benzene sulfonate at pH 2.0) with 0.02-0.24 μg L-1 detection limits. The method was applied to Antarctic krill and fish, demonstrating the presence of any tin and lead species down to μg kg-1 level. Overall, the proposed methods are sensitive, efficient and environment-friendly for routine speciation analysis of tin and lead in food samples.

Simultaneous electrochemical sensing of heavy metal ions (Zn2+, Cd2+, Pb2+, and Hg2+) in food samples using a covalent organic framework/carbon black modified glassy carbon electrode

In this study, for the first time, a selective electrochemical sensor by glassy carbon electrode (GCE) modified with the covalent organic framework (COF) and carbon black (CB) was introduced and applied to simultaneous sensing of Zn2+, Cd2+, Pb2+, and Hg2+ via differential pulse anodic stripping voltammetry (DPASV). The COF is supplied through a condensation reaction between melamine and trimesic acid. The COF and CB, which are used to modify the GCE surface, increase electrochemical activity. The linearity to determine ions was achieved as Zn2+: 0.009-1100 nM, Cd2+: 0.005-1100 nM, Pb2+: 0.003-1100 nM, and Hg2+: 0.001-1100 nM. Besides, the detection limits for Zn2+, Cd2+, Pb2+, and Hg2+ have obtained 0.003, 0.002, 0.001 and 0.0003 nM, respectively. The CB-COF/GCE was applied to simultaneously measure the ions in food samples. For validation, atomic absorption spectrometry (AAS) was applied to measure the amount of target metal ions as a standard method in real samples.

A facile electrochemical immunosensor based on EDTA-Pb2+ complexation reaction

The sensitivity of electrochemical (EC) sensors has been improved through the development of multiple approaches. However, the majority of EC sensors were limited in their practical application by high costs or tedious procedures. Herein, based on ethylenediaminetetraacetic acid (EDTA)-Pb2+ complexation reaction, a facile and affordable immunosensor was designed. Pb2+-magnesium silicate hydrate was served as the sensing substrate. The immunorecognition process was carried out in the Eppendorf tube, and antibody-functionalized Pb2+-polydopamine was utilized as immunoprobe. In the tube, the quantitative and appropriate excess of EDTA was introduced to complex with Pb2+ on the immunoprobes. The remaining EDTA was added to the sensing substrate surface to coordinate with some Pb2+ in it. This leaded to the reduction of the EC signal of Pb2+, which was related to the antigen concentration. Using prostate-specific antigen as the model analyte, the sensitive detection was realized with a low limit of detection (30.49 fg mL-1). Remarkably, the assay results were available within 24 min, sensibly faster than the most existing EC sensors.

Regulating valence states of CuFe-PBA for the simultaneous electrochemical detection of Cd2+, Pb2+ and Hg2+ in food application

Prussian blue analogues, as prospective electrode materials, play a crucial role in detecting heavy metal ions (HMIs), a process closely related to their electron transfer capacities and active surfaces. Here, etched copper-iron Prussian blue analogues (CuFe-PBA) are synthesized through a combination of flash nanoprecipitation (FNP) and an alkali etching process. Furthermore, this study investigates the impact of ammonia on the electronic structure of CuFe-PBA and its electrochemical detection capabilities for HMIs. The etched CuFe-PBA (e-CuFe-PBA) exhibits excellent detection performance for Cd2+, Pb2+ and Hg2+ with 17.6 μA μM-1, 24.2 μA μM-1 and 26.2 μA μM-1, respectively, due to the fact that the ammonia etching not only modulates the electronic properties of the surface of CuFe-PBA but also reduces the degree of agglomeration and enhances the accessible surface area. Additionally, it demonstrates excellent stability and resistance to interference, having been successfully applied to detect HMIs in food samples such as preserved eggs and apple juice. These results provide a new strategy for the use of Prussian blue analogues as electrochemical sensors for food safety applications.

Lead exposure across the life course and age at death

BACKGROUND

Lead (Pb) exposure has been associated with an increased risk of all-cause mortality, even at low levels. Little is known about how the timing of Pb exposure throughout life may influence these relationships. Quantifying the amount of Pb present in various tissues of the body provides measurements of exposure from different periods of life. These include bone, tooth enamel, which is the hard outer layer of the crown, and tooth cementum, which is the calcified connective tissue covering the tooth root. The purpose of the study was to examine Pb exposure at multiple periods throughout life, including childhood (enamel), adulthood (cementum), and later life (bone), and to estimate their associations with age at death.

METHODS

208 skeleton donors (born 1910-1960) from an ongoing case-control study were included in this study. Pb was measured in tibia (shin), bone using X-Ray Florescence and in teeth using Laser-Ablation Inductively Coupled Plasma Mass Spectroscopy. After excluding unusually high measurements (>2sd), this resulted in a final sample of 111 with all exposure measures. Correlations across measures were determined using partial Spearman correlations. Associations between Pb exposure and age at death were estimated using Multivariable Linear Regression.

RESULTS

Pb measures across exposure periods were all significantly correlated, with the highest correlation between cementum and tibia measures (r = 0.61). Donors were largely female (63.0 %), White (97.3 %), and attended some college (49.5 %). Single exposure models found that higher tooth cementum Pb (-1.27; 95 % CI: -2.48, -0.06) and tibia bone Pb (-0.91; 95 % CI: -1.67, -0.15) were significantly associated with an earlier age at death. When considered simultaneously, only cementum Pb remained significant (-1.51; 95 % CI: -2.92, -0.11). Secondary analyses suggest that the outer cementum Pb may be especially associated with an earlier age at death.

CONCLUSION

Results suggest that higher Pb exposure is associated with an earlier age at death, with adulthood as the life period of most relevance. Additional studies using Pb exposure measures from different life stages should be conducted.

Micro solid phase extraction of lead and cadmium using functionalized nanodiamonds@CuAl2O4@HKUST-1 nanocomposite for FAAS analysis in food and water samples

This study focuses on the development and application of a novel nanocomposite (functionalized nanodiamonds@CuAl2O4@HKUST-1)-based µ-SPE method for the sensitive and selective extraction of Pb and Cd from food and water samples. The technique offers high sensitivity and selectivity, allowing accurate measurement of these metals at trace levels. The detection limit is 0.031 µg kg-1 for Cd and 0.052 µg kg-1 for Pb, with a relative standard deviation of 1.7 % for Cd and 4.8 % for Pb. The method was successfully applied to real samples and efficiently quantified Pb and Cd in food and natural water samples. The highest concentrations were found in red lentils (0.274 µg kg-1 Pb) and fresh mint (0.197 µg kg-1Cd), but still below recommended limits set by FAO/WHO (300 µg kg-1 for Pb and 200 µg kg-1 for Cd). It promises to ensure food safety, monitor environmental contamination, and informs regulatory decisions to protect public health.

Glutathione ligand self-assembly enables luminescence from Au15 nanoclusters for highly sensitive and selective monitoring of blood Pb(II) ions

Lead Pb(II) ions is a cumulative toxicant that impacts several biological systems and poses severe harm to young children. Accurate Pb(II) ions monitoring is thus of paramount importance. Here, we present the synthesis and application of glutathione-capped Au15 nanoclusters (Au15(SG)13) as a luminescence probe for the accurate and selective monitoring of blood Pb(II). The introduction of Pb(II) ions triggers orderly self-assembly of Au15 nanoclusters, resulting in the formation of rigid shell around Au nuclei. This limits the localized vibration of the glutathione ligands and their interaction with water molecules, greatly reducing non-radiative energy loss, and thereby enhancing the photoluminescence signal. Consequently, Au15(SG)13 nanoclusters exhibit high sensitivity for Pb(II) detection. The detection signal displays a linear relationship with Pb(II) over a wide detection range (0-800 μg/L), demonstrating a substantial sensitivity of 35.29 μg/L. Moreover, the developed nanoclusters show superior selectivity for Pb(II) ions, distinguishing them from other prevalent heavy metals. This work pave the way for the development of advanced Pb(II) sensors with high sensitivity and selectivity.

A new thiacalix[4]arene-based metal-organic framework as an efficient electrochemical sensor for trace detection of Cd2+ and Pb2

Heavy metal ions (HMIs) can lead to serious harm to human health and ecological environment. Thus, developing an efficient detection method for HMIs is extremely necessary. Herein, a new thiacalix[4]arene-based metal-organic framework (MOF) [Co2(L1)(TPA)2]·DMA·3CH3OH·H2O (Co-LTPA) (L1 = thiacalix[4]arene-based ligand and H2TPA = terephthalic acid) was successfully synthesized. The electrochemical detection platform (Co-LTPA/GCE) was acquired, and Co-LTPA/GCE featured ultrasensitive detection of HMIs with greatly low limits of detection (LODs) of 0.119 nM for Cd2+ and 0.279 nM for Pb2+ as well as wide linear ranges of 0.08-5.8 μM for Cd2+ and 0.01-6.0 μM for Pb2+. More importantly, the Co-LTPA/GCE sensor was employed to detect foods (milk, honey and orange juice) and water samples (tap water, lake water and drinking water) with satisfactory recoveries, proving the sensor reliability in practical applications. This work provided an example that the functional electrochemical Co-LTPA/GCE sensor was employed for Cd2+ and Pb2+ detection.

Experiments and modeling to develop a Pistia stratiotes based Floating Vegetated System (FVS) for the removal of heavy metals (Pb, Zn, Cr, Cu, Ni)

Floating Vegetated System (FVS) emerged as a green and sustainable technology, presenting a viable solution for treating heavy metals (HMs) contaminated water without disrupting the food web. Pistia stratiotes has been used in the design of FVS due to its abundance of aerenchyma tissues, which contribute to its ability to remain buoyant. FVS exhibited significant HMs removal efficiencies, with Pb top at average 84.4 %, followed by Zn (81.1 %), Cr (78.5 %), Cu (76.5 %) and Ni (73 %). Bio-concentration Factor (BCF) and Translocation Factor (TF) values evaluated the plant's adeptness in metal uptake. For plants treated with Cu, the highest post-treatment chlorophyll content of 9 ± 1 mg.ml-1 was observed while Zn induced plant shows the lowest content of 7.1 ± 0.4 mg.ml-1. Using Box-Behnken Design (BBD), the system achieved 81.48 % Pb removal under optimized conditions such as initial Pb conc. of 9.25 mg. l-1, HRT of 24.49 days and a water depth of 26.52 cm. ANOVA analysis highlighted the significant impact of all the factors such as initial HM conc., HRT and wastewater depth on FVS performance. Kinetic analysis estimated a closer observance to the zero-order model, supported by high determination coefficient (R2) values. In conclusion, the FVS, as one of the most eco-friendly technologies, demonstrates higher potential for treating polluted water bodies, offering a sustainable remedy to global metal pollution challenges. Research on FVS for HMs removal is an area of ongoing interest and there are several potential future studies that could be pursued to further understand and optimize their effectiveness such as optimization of plant species, enhancement of plant-metal interactions, effects of environmental factors, economic feasibility studies, disposal of heavy metals accumulated plant, scale-up and application in real-world settings, etc.

Colorimetric-SERS dual-mode sensing of Pb(II) ions in traditional Chinese medicine samples based on carbon dots-capped gold nanoparticles as nanozyme

Peroxidase (POD)-mimicking nanozymes have got great progress in the sensing field, but most nanozyme assaying systems are built with a single-signal output mode, which is vulnerable to the effect of different factors. Thus, establishment of a dual-signal output mode is necessary for acquiring dependable and durable performance. This work described an Fe doped noradrenaline-based carbon dots and Prussian blue (Fe,NA-CDs/PB) nanocomposite as a POD-like nanozyme and modified gold nanoparticles (AuNPs) for the colorimetric and surface-enhanced Raman scattering (SERS) dual-mode sensor of Pb(II) in traditional Chinese medicine samples. With 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 3,3',5,5'-tetramethylbenzidine (TMB) as the substrates, it was found that the addition of Pb(II) inhibited the POD-like activity of Fe,NA-CDs/PB and AuNPs, so it was used for colorimetric and SERS dual-mode assays. The POD-like activity was shown to be a "ping-pong" catalytic mechanism, whereas the addition of Pb(II) produced noncompetitive inhibition with modulatory effects on Fe,NA-CDs/PB. The linear response range for colorimetric and SERS sensor detection of Pb(II) was 0.01-1.00 mg/L with the detection limit of 5 μg/L and 8 μg/L, respectively. This dual-mode detection system shows excellent selectivity. More importantly, the Pb(II) in traditional Chinese medicine samples have successfully assayed with good recovery from 90.4 to 108.9 %.

Effects of remediation agents on rice and soil in toxic metal(loid)s contaminated paddy fields: A global meta-analysis

Toxic metal(loid)s contamination of paddy soil is a nonnegligible issue and threatens food safety considering that it is transmitted via the soil-plant system. Applying remediation agents could effectively inhibit the soil available toxic metal(loid)s and reduce their accumulation in rice. To comprehensively quantify how remediation agents impact the accumulation of Cd/Pb/As in rice, rice growth and yield, the accumulation of available Cd/Pb/As in paddy soil, and soil characteristics, 50 peer-reviewed publications were selected for meta-analysis. Overall, the application of remediation agents exhibited significant positive effects on rice plant length (ES = 0.05, CI = 0.01-0.08), yield (ES = 0.20, CI = 0.13-0.27), peroxidase (ES = 0.56, CI = 0.18-0.31), photosynthetic rate (ES = 0.47, CI = 0.34-0.61), and respiration rate (ES = 0.68, CI = 0.47-0.88). Among the different types of remediation agents, biochar was the most effective in controlling the accumulation of Cd/Pb/As in all portions of rice, and was also superior in inhibiting the accumulation of Pb in rice grains (ES = -0.59, 95 % CI = -1.04-0.13). This study offers an essential contribution for the remediation strategies of toxic metal(loid)s contaminated paddy fields.

The association between trace metals in both cancerous and non-cancerous tissues with the risk of liver and gastric cancer progression in northwest China

Liver cancer and gastric cancer have extremely high morbidity and mortality rates worldwide. It is well known that an increase or decrease in trace metals may be associated with the formation and development of a variety of diseases, including cancer. Therefore, this study aimed to evaluate the contents of aluminium (Al), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), selenium (Se), and zinc (Zn) in cancerous liver and gastric tissues, compared to adjacent healthy tissues, and to investigate the relationship between trace metals and cancer progression. During surgery, multiple samples were taken from the cancerous and adjacent healthy tissues of patients with liver and gastric cancer, and trace metal levels within these samples were analysed using inductively coupled plasma mass spectrometry (ICP-MS). We found that concentrations of As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn in tissues from patients with liver cancer were significantly lower than those in healthy controls (P < 0.05). Similarly, patients with gastric cancer also showed lower levels of Cd, Co, Cr, Mn, Ni, and Zn-but higher levels of Cu and Se-compared to the controls (P < 0.05). In addition, patients with liver and gastric cancers who had poorly differentiated tumours and positive lymph node metastases showed lower levels of trace metals (P < 0.05), although no significant changes in their concentrations were observed to correlate with sex, age, or body mass index (BMI). Logistic regression, principal component analysis (PCA), Bayesian kernel regression (BKMR), weighted quantile sum (WQS) regression, and quantile-based g computing (qgcomp) models were used to analyse the relationships between trace metal concentrations in liver and gastric cancer tissues and the progression of these cancers. We found that single or mixed trace metal levels were negatively associated with poor differentiation and lymph node metastasis in both liver and gastric cancer, and the posterior inclusion probability (PIP) of each metal showed that Cd contributed the most to poor differentiation and lymph node metastasis in both liver and gastric cancer (all PIP = 1.000). These data help to clarify the relationship between changes in trace metal levels in cancerous liver and gastric tissues and the progression of these cancers. Further research is warranted, however, to fully elucidate the mechanisms and causations underlying these findings.

Dual detection of Hg2+ and Pb2+ by a coumarin-functionalized Schiff base in environmental and biosystems

Fluorescent chemosensors are often preferred for tracking toxic ions because of their non-destructive measurement and ease of use in environmental real samples and biosystems. Exploring high selectivity, great sensitivity, and biocompatible fluorophores with facile, accessible and dual-responsive features is currently highly demanding. A coumarin-based naphthol hydrazone Schiff base chemosensor, NaChro, is designed and synthesized in a two-step process to detect toxic metal ions with strong emission. Fluorescence spectra analysis demonstrates that the probe binds to Hg2+ and Pb2+ ions with a 1:1 and a 2:1 stoichiometry, respectively, with high sensitivity, short response time and minimal interference from other metal ions. The observed reversible turn-on reaction was attributed to the inhibition of C = N isomerization and excited-state intramolecular proton transfer (ESIPT) processes once the ions were introduced. The practical applications of NaChro are successfully addressed in paper strips, various water samples, HeLa cells and Zebrafish, demonstrating that the probe can detect and track Hg2+ and Pb2+ ions in environmental samples and biosystems.

Size-resolved distribution of trace elements in lysimeter soil solutions under contrasting long-term agricultural management to assess their bioavailability

The chemical species of trace elements (TEs) in agricultural soils is highly variable under diverse conditions, requiring tools with clear resolution and minimal disturbance for exploration. A novel surgical (316L) stainless steel (SS) lysimeter with a 5 μm pore size was developed to collect field soil solutions. The size-resolved distribution of TEs were characterized into total (nitric acid digestion), particulate (0.45-5 μm), dissolved (<0.45 μm), colloidal (1 kDa to 0.45 μm), and mainly ionic (<1 kDa) fractions in the lysimeter soil solutions. Total concentrations of TEs (dry weight basis) in acid digested Gray Luvisolic soils were analyzed. Most TEs in lysimeter soil solutions were present in particulate phases, relevant to their geochemical affinities and occurrences in soil minerals. Among dissolved fractions, As, Ba, Co, Li, Mn, Tl, and V existed as mainly ionic species in the soil solutions. Copper, Pb, Al, Th, and U showed variable associations with dissolved organic matter (DOM) and/or inorganic colloids among agricultural treatments. Inorganic NPKS or NKS fertilizer applications with lower pH (5.25-5.74) enhanced mobility and potential bioavailability of Ba, Co, Li, Mn, and Pb present in mainly ionic species, compared with other locations (pH 5.82-6.37). Manure application exhibited a dual effect, potentially increasing bioavailability for As, Tl, and V due to probably enhanced cation exchange capacity (CEC), while also facilitating specific adsorption of Cu and U on DOM, potentially reducing their bioavailability depending on DOM molecular weight. Colloidal and ionic Al and Th concentrations were higher in forest soils than agricultural soils, with extremely low potential bioavailability of Th attributed to strong precipitation with inorganic colloids and adsorption on DOM. The lysimeter sampling and size fractionation method provided a clear insight into agricultural effects on TE distributions and enhancing understanding of agricultural soil health in terms of TE bioavailability in situ.

Speciation, bioaccumulation, and toxicity of the newly deposited atmospheric heavy metals in soil-earthworm (Eisenia fetida) system near a large copper smelter

The speciation, bioaccumulation, and toxicity of the newly deposited atmospheric heavy metals in the soil-earthworm (Eisenia fetida) system were investigated by a fully factorial atmospheric exposure experiment using soils exposed to 0.8-year and 1.8-year atmospheric depositions. The results shown that the newly deposited metals (Cu, Cd, and Pb) primarily accumulated in the topsoil (0-6 cm) and were present as the highly bioavailable speciation. They can migrate further to increase the concentrations of Cu, Cd, and Pb in soil solution of the deeper layer (at 10 cm) by 12 %-436 %. Earthworms tended to preferentially accumulate the newly deposited metals, which contributed 10 %-61 % of Cu, Cd, and Pb in earthworms. Further, for the unpolluted and moderately polluted soils, the newly deposited metals induced the significant oxidative stress in earthworms, resulting in significant increases in antioxidant enzyme activities (SOD, CAT, and GSH-Px). No significant differences were observed in the levels of heavy metals in soil solutions, bioaccumulation, and enzyme activities in earthworms exposed to 0.8-year and 1.8-year depositions, indicating the bioavailability of atmospheric metals deposited into soils was rapidly decreased with time. This study highlights the high bioaccumulation and toxicity of heavy metals to earthworm from the new atmospheric deposition during the earthworm growing period.

Efficient DNA walker guided by ordered cruciform-shaped DNA track for ultrasensitive and rapid electrochemical detection of lead ion

The rational design of DNA tracks is an effective pathway to guide the autonomous movement and high-efficiency recognition in DNA walkers, showing outstanding advantages for the cascade signal amplification of electrochemical biosensors. However, the uncontrolled distance between two adjacent tracks on the electrode could increase the risk of derailment and interruption of the reaction. Hence, a novel four-way balanced cruciform-shaped DNA track (C-DNT) was designed as a structured pathway to improve the effectiveness and stability of the reaction in DNA walkers. In this work, two kinds of cruciform-shaped DNA were interconnected as a robust structure that could avoid the invalid movement of the designed DNA walker on the electrode. When hairpin H2 was introduced onto the electrode, the strand displacement reaction (SDR) effectively triggered movements of the DNA walker along the cruciform-shaped track while leaving ferrocene (Fc) on the electrode, leading to a significant enhancement of the electrochemical signal. This design enabled the walker to move in an excellent organized and controllable manner, thus enhancing the reaction speed and walking efficiency. Compared to other walkers moving on random tracks, the reaction time of the C-DNT-based DNA walker could be reduced to 20 min. Lead ion (Pb2+) was used as a model target to evaluate the analytical performance of this biosensor, which exhibited a low detection limit of 0.033 pM along with a wide detection ranging from 0.1 pM to 500 nM. This strategy presented a novel concept for designing a high-performance DNA walker-based sensing platform for the detection of contaminants.

[Analysis and Evaluation of Heavy Metal Pollution in Farmland Soil in China：A Meta-analysis]

In this study, a Meta-analysis was used to investigate the pollution status of eight farmland soil heavy metal elements (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) in China. Meanwhile, their spatiotemporal changes and differences between different types of cultivated land were explored. The research data were chosen from 449 relevant literature data collected by CNKI and Web of Science from 2005 to 2021, and the Meta-analysis used a weighted method based on "sampling numbers", "study area", and "standard deviation". The results showed that the national average values of the eight heavy metal elements in Chinese farmland soil were ω(As)11.00 mg·kg-1, ω(Cd)0.350 2 mg·kg-1, ω(Cr)62.91 mg·kg-1, ω(Cu)28.87 mg·kg-1, ω(Hg)0.135 1 mg·kg-1, ω(Ni)28.91 mg·kg-1, ω(Pb)34.67 mg·kg-1,and ω(Zn)90.24 mg·kg-1. Compared with their background values, all elements except As accumulated to some extent, and Cd and Hg accumulated the most, exceeding their background values by 177.9% and 340.3%, respectively. The research results indicated that Cd and Hg were the main pollution elements in farmland soil in China, and their accumulation was mainly influenced by human activities. In terms of their temporal and spatial changes, the Yunnan-Guizhou Plateau and the eastern coast were the most concentrated areas of pollution cases, and the pollution center shifted from the middle reaches of the Yangtze River to the southwest over time. The accumulation of heavy metals in farmland soil was affected by crop planting types, and the accumulation of heavy metals in vegetable and paddy soil was significantly greater than that in other cultivated land types.

[Bacterial Community Structure of Typical Lake Sediments in Yinchuan City and Its Response to Heavy Metals]

Lake wetlands are extremely important and special ecosystems, which are important for regional water resource storage, environmental protection, and biodiversity maintenance. Sediment bacteria are an important component of lake ecosystems and are a major driver of biogeochemical cycling in lakes. In order to investigate the community structure of bacteria in typical lake sediments in Yinchuan City and their influencing factors, three typical lakes in Yinchuan City (Yuehai Lake, Mingcui Lake, and Xiniu Lake) were selected for the study and surface sediments were collected in January, April, July, and October 2021. The composition of the sediment bacterial community was examined using 16S rDNA high-throughput sequencing technology, and the response relationships between them and heavy metals were explored. The results showed that the ecological hazard coefficient for heavy metals in the sediments of three typical lakes in Yinchuan City was far less than 40, and the ecological hazard index was far less than 150, all of which indicated a minor ecological hazard. There were no significant differences in bacterial community diversity among the three lakes, but there were significant variations in diversity among the lakes in different seasons and significant differences in community composition. The dominant phyla (top three in terms of relative abundance) in Yuehai Lake, Mingcui Lake, and Xiniu Lake were Proteobacteria, Bacteroidetes, and Chloroflexi. The dominant lower orders were Gammaproteobacteria, Alphaproteobacteria, and Deltaproteobacteria. The main divergent species that occurred at the phylum level in typical lakes in Yinchuan were Proteobacteria, Bacteroidetes, Euryarchaeota, Firmicutes, Actinobacteria, and Acidobacteria. The sediment bacterial community structure of Yuehai Lake was significantly correlated with Cu, Fe, Mn, Zn, As, and Pb; the sediment bacterial community structure of Lake Mingcui was significantly correlated with Fe, Pb, and Cr; and the sediment bacterial community structure of Xiniu Lake was not significantly correlated with heavy metals. The types and contents of sediment heavy metals had a significant effect on the bacterial community structure of sediments in Yinchuan Yuehai Lake and Mingcui Lake and were important environmental factors that caused changes in the bacterial community structure of lake sediments.

Effect of biochar, zeolite and bentonite on physiological and biochemical parameters and lead and zinc uptake by maize (Zea mays L.) plants grown in contaminated soil

Heavy metals (HMs) are common contaminants with major concern of severe environmental and health problems. This study evaluated the effects of organo-mineral amendments (mesquite biochar (MB), zeolite (ZL) and bentonite (BN) alone and in combination) applied at different rates to promote the maize (Zea mays L.) growth by providing essential nutrient and improving the soil physio-chemical properties under zinc (Zn) and lead (Pb) contamination. Result revealed that the incorporation of organo-mineral amendments had significantly alleviated Pb and Zn contamination by maize plants and improved the physiological and biochemical attributes of plants. Combined application of organo-mineral amendments including BMA-1, BMA-2 and BMA-3 performed excellently in terms of reducing Pb and Zn concentrations in both leaves (19-60%, 43-75%, respectively) and roots (24-59%, 42-68%, respectively) of maize. The amendments decreased the extractable, reducible, oxidisable and residual fractions of metals in soil and significantly reduced the soil DTPA-extractable Pb and Zn. BMA-1 substantially improved antioxidant enzyme activities in metal-stressed plants. This study indicated that combined use of organo-mineral amendments can effectively reduce the bioavailability and mobility of Pb and Zn in co-contaminated soils. Combined application of organo-mineral amendments could be viable remediation technology for immobilization and metal uptake by plants in polluted soils.

Arsenic, cadmium, lead, antimony bioaccessibility and relative bioavailability in legacy gold mining waste

Bioaccessibility and relative bioavailability of As, Cd, Pb and Sb was investigated in 30 legacy gold mining wastes (calcine sands, grey battery sands, tailings) from Victorian goldfields (Australia). Pseudo-total As concentration in 29 samples was 1.45-148-fold higher than the residential soil guidance value (100 mg/kg) while Cd and Pb concentrations in calcine sands were up to 2.4-fold and 30.1-fold higher than the corresponding guidance value (Cd: 20 mg/kg and Pb: 300 mg/kg). Five calcine sands exhibited elevated Sb (31.9-5983 mg/kg), although an Australian soil guidance value is currently unavailable. Arsenic bioaccessibility (n = 30) and relative bioavailability (RBA; n = 8) ranged from 6.10-77.6% and 10.3-52.9% respectively. Samples containing > 50% arsenopyrite/scorodite showed low As bioaccessibility (<20.0%) and RBA (<15.0%). Co-contaminant RBA was assessed in 4 calcine sands; Pb RBA ranged from 73.7-119% with high Pb RBA associated with organic and mineral sorbed Pb and, lower Pb RBA observed in samples containing plumbojarosite. In contrast, Cd RBA ranged from 55.0-67.0%, while Sb RBA was < 5%. This study highlights the importance of using multiple lines of evidence during exposure assessment and provides valuable baseline data for co-contaminants associated with legacy gold mining activities.

Exposure risks of lead and other metals to humans: A consideration of specific size fraction and methodology

Particle size is a critical influencing factor in assessing human exposure risk as fine particles are generally more hazardous than larger coarse particles. However, how particle composition influences human health risk is only poorly understood as different studies have different utilised different definitions and as a consequence there is no consensus. Here, with a new methodology taking insights of each size fraction load (%GSFload), metal bioaccessibility, we classify which specific particle size can reliably estimate the human exposure risk of lead and other metals. We then validate these by correlating the metals in each size fraction with those in human blood, hair, crop grain and different anthropogenic sources. Although increasing health risks are linked to metal concentration these increase as particle size decrease, the adjusted-risk for each size fraction differs when %GSFload is introduced to the risk assessment program. When using a single size fraction (250-50 µm, 50-5 µm, 5-1 µm, and < 1 µm) for comparison, the risk may be either over- or under-estimated. However, by considering bulk and adjusting the risk, it would be possible to obtain results that are closer to the real scenarios, which have been validated through human responses and evidence from crops. Fine particle size fractions (< 5 µm) bearing the mineral crystalline or aggregates (CaCO3, Fe3O4, Fe2O3, CaHPO4, Pb5(PO4)3Cl) alter the accumulation, chemical speciation, and fate of metals in soil/dust/sediment from the different sources. Loaded lead in the size fraction of < 50 µm has a significantly higher positive association with the risk-receptor biomarkers (BLLs, Hair Pb, Corn Pb, and Crop Pb) than other size fractions (bulk and 50-250 µm). Thus, we conclude that the < 50 µm fraction would be likely to be recommended as a reliable fraction to include in a risk assessment program. This methodology acts as a valuable instrument for future research undertakings, highlighting the importance of choosing suitable size fractions and attaining improved accuracy in risk assessment results that can be effectively compared.

Biochar and nano-hydroxyapatite combined remediation of soil surrounding tailings area: Multi-metal(loid)s fixation and soybean rhizosphere soil microbial improvement

The soil near tailings areas is relatively barren and contaminated by multi-metal(loid)s, seriously threatening the safety of crop production. Here, biochar and nano-hydroxyapatite (nHAP) were combined to improve the sterilized and unsterilized polymetallic contaminated soil, and soil incubation and soybean pot experiments were designed. Results showed that biochar and nHAP not only increased soil C, N, and P but also effectively reduced multi-metal bioavailability, wherein the combined application of the two amendments had the best effect on metal immobilization. The synergistic effect of the two amendments decreased the acid-soluble contents of Co, Cu, Fe, and Pb in rhizosphere soils up to 86.75%, 80.69%, 89.09%, and 96.70%, respectively. The ameliorant reduced the accumulation of metal(loid)s in soybean plants, and rhizosphere microorganisms inhibited the migration of soil metals to plants. Additionally, biochar and nHAP regulated the rhizosphere soil microbial community. The rhizosphere soil of the sterilization group tended to prioritize the restoration of the original dominant bacteria. As, Pb, Fe, Urease, OM, TN, and TP were the critical environmental variables affecting rhizosphere soil bacterial communities. Therefore, combining biochar and nHAP is an environmentally friendly strategy to reduce polymetallic mobility in tailings soil and crops and improve soil microbial community structure.

A near-infrared fluorescent ratiometric probe with large Stokes shift for multi-mode sensing of Pb2+ and bioimaging

Pb2+ is a heavy metal ion pollutant that poses a serious threat to human health and ecosystems. The conventional methods for detecting Pb2+ have several limitations. In this study, we introduce a novel fluorescent probe that enables the detection of Pb2+ in the near-infrared region, free from interference from other common ions. A unique characteristic of this probe is its ability to rapidly and accurately identify Pb2+ through ratiometric measurements accompanied by a large Stokes shift of 201 nm. The limit of detection achieved by probe was remarkably low, surpassing the standards set by the World Health Organization, and outperforming previously reported probes. To the best of our knowledge, this is the first organic small-molecule fluorescent probe with both near-infrared emission and ratiometric properties for the detection of Pb2+. We present a triple-mode sensing platform constructed using a probe that allows for the sensitive and selective recognition of Pb2+ in common food items. Furthermore, we successfully conducted high-quality fluorescence imaging of Pb2+ in various samples from common edible plants, HeLa cells, Caenorhabditis elegans, and mice. Importantly, the probe-Pb2+ complex exhibited tumour-targeting capabilities. Overall, this study presents a novel approach for the development of fluorescent probes for Pb2+ detection.

Neurological risks arising from the bioaccumulation of heavy metal contaminants: A focus on mercury

This study investigated the concentrations of heavy metals in the water sources of the upstream region of the Huangpu River, the Yangtze River Estuary, and various areas in Shanghai, as well as the heavy metal concentrations in the blood of Shanghai residents. It aimed to analyze the heavy metal elements absorbed by the human body and the resulting pathological effects. The results revealed that surface water primarily contains five heavy metals: copper (Cu), lead (Pb), zinc (Zn), arsenic (As), and mercury (Hg), while water sediments primarily contain seven heavy metals: Cu, cadmium (Cd), Pb, chromium (Cr), Zn, As, and Hg. The main heavy metals present in the human body are Pb, Hg, As, and Cd. By reviewing previous articles, it was found that heavy metal concentrations in human blood are higher than those in surface water, suggesting uncertainties in the heavy metal content of surface water and its tendency to settle at the bottom. Furthermore, a comparison of heavy metal content in sediments revealed that Hg is the most readily absorbed heavy metal by the human body and is also a toxic environmental pollutant. Within the cell, Hg is highly toxic to mitochondria and may cause oxidative stress and neurodegenerative disease. This study concludes that water sediments serve as the major source of pollution in the human body and pose significant health risks, thereby necessitating the implementation of effective preventive measures.

Lead exposure in Chinese children: Urbanization lowers children's blood lead levels (BLLs)

Lead is a toxic metal that can pose a huge threat to children's health. China has experienced rapid urbanization since the reform in 1978; however, there has been no examination of the potential influence of this urbanization on children's blood lead levels (BLLs). This study is the initial investigation to explore the correlation between urbanization and BLLs in Chinese children. Five windows of time are considered: pre-2000, 2001-2005, 2006-2010, 2011-2015 and 2016-2021. The results show that urbanization affected lead distribution in urban soil and agricultural soil during the above periods, especially in northern China. The higher non-carcinogenic risk of lead for children is consistent with the lead pollution in soil (3 < Igeo ≤ 4). Urban children's BLLs are slightly higher than those of rural children in 2001-2010, but rural children's BLLs in 2011-2021 are higher than those of urban children during China's urbanization. The areas of rural decline and the areas of urban growth increased across all the window periods. However, the BLLs decrease in all rural and urban areas during all window periods, especially in urban areas. Children's BLLs have a significantly negative correlation with urban areas (p < 0.01). Therefore, China's urbanization has a significant effect on the decrease in children's BLLs. The significance of this study is to provide a fresh perspective and innovative strategy for policymaking in order to reduce children's BLLs and prevent lead exposure. This can be achieved by transforming their external living environment from a rural lifestyle to an urban one, while also ensuring access to well education and maintaining a balanced nutrient intake.

A miniaturized sample preparation method for routine elemental determination in whole blood using volumetric absorptive micro-sampling by ICP-QQQ

Volumetric absorptive micro-sampling (VAMS) has emerged as a simple and safe tool for collecting and storing blood samples in clinical and bioanalytical fields. This study presents a novel method for determining essential and non-essential trace elements (As, Be, Cd, Cs, Cu, Fe, Mg, P, Pb, S, Sb, Se, Tl, V, U) in VAMS-collected blood samples using microwave-assisted digestion with diluted acid as sample preparation method and an inductively coupled plasma triple quadrupole mass spectrometry (ICP-QQQ) as determination technique. While certain elements posed challenges due to VAMS tip background issues (Al, Ti, Cr, Mn, Co, Ni, Sn, Mo, Ba), the method demonstrated high precision and accuracy for the targeted analytes. It was demonstrated that 4.5 mol L-1 HNO3 plus 100 µL H2O2 30% (w/w) was suitable for an efficiency of digestion for further elemental determination using micro-analysis (spending less than 300 µL analytical solution) by ICP-QQQ, given that the residual carbon content (RCC) after the digestion procedure was lower than 5%. All the results higher than limit of quantification (LOQ) were in agreement with reference values for all analytes. Accuracy was assessed through reference material analysis and recovery tests using spiked samples. Moreover, suitable agreements (p > 0.05) between this method (VAMS-M) and the comparative method (liquid sampling method) were obtained for all analytes >LOQ. Furthermore, all results >LOQ showed good precision according to precision requirements (Horwitz equation). In this way, with the use of dilute acid, low dilution factor (30-fold), and excellent digestion efficiency (>95%), the proposed method was able to achieve an excellent detection limit, precision, and accuracy for 15 elements: As, Be, Cd, Cs, Cu, Fe, Mg, P, Pb, S, Sb, Se, Tl, V, and U using ICP-MS/MS, without the need for matrix-matched calibration curves. This research showcases an innovative analytical approach using VAMS for blood samples, offering biosafety, practicality, sensitivity, versatility, and robustness. This method contributes to the advancement of trace element analysis in biomedical research and clinical applications.

Shared hairpin structure electrochemiluminescence biosensor based on Au@Ni-Co metal organic frameworks for simultaneous detection of Pb(II) and S.aureus

The excessive content of lead (Pb(II)) and Staphylococcus aureus (S.aureus) seriously harms the quality of aquatic products. In this paper, a highly sensitive electrochemiluminescence (ECL) biosensor was constructed using the synergistic effect of Au NPs@Nickel-Cobalt-Metal-organic frameworks (Au@Ni-Co-MOFs) and double potential resolution function of urchin-like Au@luminol and Cadmium sulfide quantum dots (CdS QDs) for synchronous detection of Pb(II) and S.aureus in aquatic products. Au@Ni-Co-MOFs as the base material, its cube structure can improve the surface active area and sensitivity of the sensor, providing more catalytic active sites for the two functional probes. Urchin-like Au@luminol binding aptamer DNA2 specifically recognizes Pb(II), CdS QDs binding aptamer DNA3 specifically recognizes S.aureus, which collaboratively catalyzed hydrogen peroxide reduction to produce two electrochemiluminescence signals. The shared hairpin structure DNA1 binds stably to Au@Ni-Co-MOFs via the Au-S bond, and the two functional probes are complementary paired with the DNA1 respectively to ensure the specificity of the aptamer. According to the ECL intensity changes of different potentials signal sources, the synchronous detection of Pb(II) and S.aureus with different concentrations is realized. The sensor realizes the detection of two targets in aquatic products and provides a new strategy for the simultaneous detection of multiple targets.

Breastmilk mineral composition among well-educated mothers from Central Poland - Associations with maternal dietary intake, dietary patterns and infant psychomotor development

BACKGROUND

Maternal dietary habits could affect breastmilk mineral composition, which may influence infant development. Mineral dietary intake or supplementation slightly affects its breastmilk concentration. However, the intake of selected food groups or dietary patterns that reflect diet complexity could have a greater impact. Hence, the aim of the study was to assess breastmilk mineral composition at one, three, and six months of lactation among mothers living in urban area of Central Poland, as well as the evaluate maternal dietary determinants and associations with infant anthropometric and psychomotor development.

METHODS

The study was conducted among 43 healthy and exclusively breastfeeding mothers. In the first, third, and sixth months of lactation, we collected breastmilk samples and assessed the concentration of Ca, P, Zn, Fe, Se, Ni, As, Pb, and Cd using the ICP-MS method. Maternal dietary habits were evaluated by a food frequency questionnaire in the first month of lactation, whereas in the third and sixth by the three-day food record. Based on the collected data adherence to the Polish-adapted Mediterranean (Pl-aMED; 1 month) and the DASH diet (Mellen's Index; 3 and 6 months) was assessed. In the third and sixth months of lactation infant anthropometric parameters and the sixth month of lactation psychomotor development were evaluated.

RESULTS

Breastmilk Se, Ni, As, Pb, and Cd levels were under the LOQ in all the breastmilk samples at all study visits. Median breastmilk mineral concentrations of Ca, P, Zn, and Fe in the first, third, and sixth months of lactation varied from 381.9 to 332.7 mg/L, 161.6 to 139.1 mg/L, 2.2 to 0.8 mg/L, and 0.26 to 0.17 mg/L, respectively. Maternal dietary intake and supplementation did not affect breastmilk Ca, P, Zn, and Fe. Pl-aMED scores were associated with breastmilk Ca (β = 0.489, 95% CI 0.180 - 0.799, p = 0.003) and Zn (β = 0.499, 95% CI 0.199 - 0.798, p = 0.002) in the first month of lactation, whereas no association with the DASH diet were observed in the third and sixth month of lactation. Breastmilk Fe in the third month was associated with infant motor development (β = 0.420, 95% CI 0.113 - 0.727, p = 0.009) in the sixth month of life, but no other associations with anthropometric or psychomotor development were observed. Moreover, we estimated that few infants meet their adequate intake (AI) requirements for P, Zn, and Fe.

CONCLUSION

Our study showed that maternal adherence to Pl-aMED is a significant predictor of breastmilk Ca and Zn in the first month of lactation, which may be especially important considering that more than 75% of infants had inadequate Zn intake. Moreover, we found that breastmilk Fe positively influenced infant motor development, despite the majority of infants having inadequate intake. On the other hand, no infant had deficiency symptoms, which emphasizes the necessity to evaluate of AI norms for infants.

Sustainable management of campus fallen leaves through low-temperature pyrolysis and application in Pb immobilization

Realizing campus sustainability requires the environmental-friendly and economical treatment of tremendous fallen leaves. Producing fallen leaf biochar at a low temperature is a candidate approach. In this study, six common types of fallen leaves on the campus were pyrolyzed at 300 °C. The obtained biochars were characterized and the adsorption mechanisms of lead (Pb) by the fallen leaf biochars were investigated. The adsorption capacity of leaf biochar for Pb was relatively high, up to 209 mg/g (Yulania denudata leaf biochar). Adsorption of Pb onto active sites was the rate-limiting step for most leaf biochars. But for Platanus leaf biochar, intraparticle diffusion of Pb2+ dominated owing to the lowest adsorption capacity. However, the highest exchangeable Pb fraction (27%) indicated its potential for removing aqueous Pb2+. Ginkgo and Prunus cerasifera leaf biochar immobilized Pb by surface complexation and precipitation as lead oxalate. Hence, they were suitable for soil heavy metal remediation. This study shed the light on the sustainable utilization of campus fallen leaves and the application of fallen leaf biochars in heavy metal remediation.

Selective dissolution of zinc and lead from duplex β-phase brasses in low and high conductivity water

This study provides insights regarding the selective metal leaching of brass in various tap water conditions, which benefits water utilities to predict the potential of metal released from brass water meters. The long-term time-dependent selective metal dissolution of brass with various β phase fractions have not previously been investigated. In this study, a 201-d immersion experiment was carried out in low and high conductivity tap water (LCTW and HCTW, respectively). Three commercialized brass samples in different β phase fractions (β = 51%, β = 43%, β = 39%), named brass 51, brass 43, and brass 39, respectively, were used. The results showed that brass 51 had the most negative corrosion potential (-0.17 V) and the lowest polarization resistance (8.5 kΩ) compared to brass 43 and brass 39 (-0.04 V and 10.1-14.7 kΩ, respectively) in LCTW. This trend was verified by the 201-d immersion experiment in which brass 51 exhibited the highest zinc leaching rate (21-30 μg L-1 cm-2 d-1), followed by brass 43 and brass 39 (16-23 μg L-1 cm-2 d-1) in both waters. The leaching amounts of lead and copper were extremely low compared to zinc. In LCTW, the uniform corrosion (UC) mechanism dominated from day 1 to day 120. Afterwards, UC was replaced by the galvanic corrosion (GC) mechanism, with the selective leaching coefficient of Zn over Cu (SZn/Cu) increasing from 10 to 25 to 40-80. In HCTW, however, the SZn/Cu reached 300-1000, and the transition of UC to GC occurred earlier on day 30 due to the rapid formation of the ZnO layer on the brass surface that hindered the ion attack.

CRISPR/Cas12a-derived ratiometric fluorescence sensor for high-sensitive Pb2+ detection based on CDs@ZIF-8 and DNAzyme

Benefiting from specific target recognition and trans-cleavage capabilities, the CRISPR/Cas12a system has great application prospects in the design of highly sensitive and rapid fluorescence biosensors. The CRISPR/Cas12a-based fluorophore-quencher molecular beacons exhibit single-color emission and are easily exposed to interference from environmental factors. Herein, we design a CRISPR/Cas12a-derived ratiometric fluorescence sensor for Pb2+ detection based on embedded carbon dots@zeolitic imidazolate framework-8 (CDs@ZIF-8) composites and DNAzyme. The functions of ZIF-8 about encapsulating red emissive CDs in the inner cavity and adsorbing DNA on the outer surface are integrated to establish dual fluorescence signals, thereby reducing the possibility of interference and improving sensing accuracy. The presence of Pb2+ is converted into the change of activator by the GR5 DNAzyme to activate the CRISPR/Cas12a system, which provides signal amplification through multiple turnovers of side branch cutting, achieving highly sensitive detection of Pb2+ with a low detection limit of 18 pM. This method has the advantages of simplicity, universality, and excellent quantitative ability, and has broad prospects in sensing applications.

On the electrokinetic remediation of Pb-contaminated soil: A coupled electro-transport-reaction modelling study based on chemical reaction kinetics

The accumulation of lead (Pb) in soil resulted from industrialization and urbanization poses a threat to human health and the ecosystem. This study proposes a mathematical model for Pb migration and transformation in soil porous media, aiming to guide the design of electrokinetic remediation schemes for Pb-contaminated soils. To improve the validity of the model, the chemical reactions considered in the model are all based on chemical reaction kinetics, which were usually overlooked for model simplification. The model quantitatively describes various physical and chemical processes of Pb at the soil-pore fluid interface and in the pore fluid, including diffusion, electromigration, electroosmosis, electrolytic water reaction, precipitation, adsorption/desorption, protonation/deprotonation reaction, and water self-ionization reaction. The numerical results show that the pH value is a key factor affecting the distribution of Pb in the soil and determining the removal efficiency of Pb. The effects of different enhancement methods on Pb concentration distribution and removal efficiency were evaluated with this model. It was found that placing a cation exchange membrane at the cathode boundary while using 0.01 M nitric acid as anode electrolyte can effectively improve Pb removal efficiency from 3.9% to 93.6%. The developed model can be used to guide the design of the enhanced electrokinetic remediation schemes.

Temporal changes in metal and arsenic concentrations in blood and feathers of tropical seabirds after one of the largest environmental disasters associated with mining

Monitoring of contaminant levels in wildlife over time is a tool for assessing the presence and persistence of environmental impacts at ecosystem, community and population levels. Tropical seabirds breeding in the Abrolhos Archipelago, 70 km off the Brazilian coast, forage in areas under the influence of the Doce River discharge. In 2015, the Fundão Dam collapsed and released ca 60 million tons of iron ore tailings into the ocean. In the present study, red-billed tropicbirds Phaethon aethereus and brown boobies Sula leucogaster breeding in Abrolhos were monitored over four years (2019-2022) for metal (Fe, Mn, Zn, Cu, Cr, Hg, Pb, Cd) and metalloid (As) concentrations in blood and feathers. Over six sampling events, metal (loid) concentrations showed strong temporal variation in both tissues. Overall, feathers showed greater element concentrations than blood, with stronger correlations between elements, especially Mn and the nonessential As, Cd, Hg and Pb. Mn is one of the major chemical markers of the Fundão Dam tailings. Metal (loid) concentrations in the tropical seabirds evaluated were above suggested threshold levels for most nonessential elements (As, Cd and Pb), especially in February 2021, when metal (loid) concentrations peaked in feathers. In this case, values were orders of magnitude higher than those observed in other sampling events. This occurred one year after a major rainy season in the Doce River basin, which increased river discharge of contaminated mud into the ocean, where contaminants are further remobilized by winds and currents, resulting in transference through the marine food web. This finding is consistent to what has been observed for other ecosystem compartments monitored in the region under the influence of the Doce River. Our findings highlight the utility of using tropical seabirds as sentinels of marine pollution, revealing strong temporal patterns in metal (loid) concentrations associated to bottom-up climatic processes.

Recovery of biochar particles laden with lead in saturated porous media by DC electric field

The co-transport behavior of environmental pollutants with biochar particles has aroused great interests from researchers due to the concerns about pollutant diffusion and environmental exposure after biochar is applied to soil. In this work, the recovery and co-transport behavior of biochar micron-/nano-particles (BCMP and BCNP) and lead (Pb2+) in saturated porous media were investigated under different ionic strength conditions (IS = 1, 5 and 10 mM) under a direct current electric field. The results showed that the electric field could significantly enhance the mobility of Pb adsorbed biochar particles, particularly BCNP. The recovery of Pb laden biochar particles was improved by 1.8 folds, reaching 78.8% at maximum under favorable condition at +0.5 V cm-1. According to the CDE (Convection-Dispersion-Equation) model and DLVO (Derjaguin-Landau-Verwey-Overbeek) theory analysis, the electric field facilitated the transport of Pb carried biochar mainly by increasing the negative charges on biochar surface and improving the repulsive force between biochar and porous media. High IS was favorable for biochar transport under the electric field, but inhibited desorbing Pb2+ from biochar (18% by maximum at IS = 10 mM). By switching the electric field power, a two-stage strategy was established to maximize the recovery of both biochar particles and Pb, where BCNP and Pb recovery were higher than electric field free case by 90% and 35%, respectively. The findings of this study can help build a biochar recovery approach to prevent potential risks from biochar application in heavy metal contaminated soil remediation.

Investigation of elemental composition in red teff grains using inductively coupled plasma optical emission spectroscopy (ICP OES), Sire District, Arsi zone, Ethiopia

BACKGROUND

Minerals are important not only for better plant growth and development but also for human and animal nutrition. It is known that east and west Gojam in the Amhara region and east and west Shoa areas in the Oromia region Ethiopia's most teff growing areas. However, there is no information on the mineral content and nutritional worth of Teff Sire district, Arsi zone, Ethiopia. Since ICP OES is a powerful technique to examine elemental compositions even in lower concentration, it is used in this work to investigate the elemental composition of red teff samples.

METHODS

The elemental compositions of red Teff grain samples were determined using ICP-OES from three sites: S1, S2, and S3 of Sire district, Arsi zone, Ethiopia. Wet digestion of the teff samples was carried out by weighing 0.5 g red teff sample and digested with 8 ml HNO3 and 2 ml H2O2 (30%) for 3:00 h at a temperature of 100℃ on hot plate. The investigations of method validation, limit of detection and limit of quantification were also carried out.

RESULTS

The average amount of elements in red teff sample obtained as 172-280 mg/kg Fe, 13-76 mg/kg Mn, 8.2-8.5 mg/kg Cu, 24-26 mg/kg Zn, and toxic trace elements 0.12-0.29 mg/kg Pb and 0.15-0.22 mg/kg Cd. The limit of detection found in ranges from 0.21 mg Kg-1 to 10.44 mg Kg-1 whereas quantification limit resulted in 0.7 mg Kg-1 to 34.8 mg Kg-1 for the metals under consideration. The method was validated by its linear range in the concentration range of 0.028-1.4 ppm or 0.056-2.8 ppm and excellent recovery result was achieved in the range of 90-120%.

CONCLUSION

This study aimed to investigate the mineral content in red teff cultivated in Ethiopia specifically Arsi zone by using ICP OES. From the obtained results, Iron was the first abundant essential element in red teff compared to Mn, Cu and Zn. The level of trace elements: Cd and Pb in the samples slightly above the acceptable limit, possibly due to agricultural practices like usage of fertilizers, pesticides, and other industrial products. Overall, this red teff elemental composition information contributes to the nutrition database and food safety in Ethiopia and beyond.

Removal of lead ions from aqueous solutions by modified cellulose

The new adsorbent was prepared by mixing cellulose with dicyclohexyl-18- crown-6 via microwave irradiation method and it was used to remove lead ions from aqueous solution. In contrast to the traditional way (in which grafted polymers are produced by using chemical-free radical producers), this method is rapid, reproducible, and gives a high-quality product. Different physicochemical techniques such as FTIR, SEM, and XRD and TGA were used for the characterization of the produced adsorbent. Based on the ANOVA statistical value, the adsorption of Pb2+ ion onto grafted cellulose has been found to be significant, with very low probability (p) values (<0.001). The pH and initial concentration were observed to be the most significant factors that affected the Pb2+ ion removal from the analysis of variance. Pseudo-second-order and Langmuir equations were applied to the adsorption of Pb2+ ion and under the optimized conditions, the maximum absorption capacity in modified cellulose of Pb2+ was 58.3 mg/g. Various factors which affect metal ion adsorption, including temperature, power of hydrogen, shaking time, adsorbent quantity, and metal ions concentration were studied. More importantly, the adsorbent could be reused by using 0.1 M nitric acid.

Removal of toxic metals from sewage sludge by EDTA and hydrodynamic cavitation and use of the sludge as fertilizer

Sewage sludge (SS) is rich in plant nutrients, including P, N, and organic C, but often contains toxic metals (TMs), which hinders its potential use in agriculture. The efficiency of removal of TMs by washing with ethylenediamine tetraacetate (EDTA), in combination with hydrodynamic cavitation (HC) and the usability of washed sewage sludge as fertilizer were investigated. The environmental risk was assessed. During 8 wash batches an average 35, 68, 47 and 45 % of Pb, Zn, Cd and Cu, respectively, as well as 22 and 5 % Mn and Fe were removed from the SS. The process solutions and EDTA were recycled at a pH gradient of 12.5-2, which was achieved by adding quicklime (CaO) and then acidification by H2SO4, so that no wastewater was produced, only solid waste (ReSoil® method). The quality of the recycled process solutions (they remained unsaturated with salts) and the efficiency of the washing process were maintained across all batches. On average, 46 % of the EDTA was lost during the process and was replenished. The initial leachability of EDTA-mobilized Pb, Zn, Cu, Cr and Fe remaining in the washed SS increased 6-, 17-, 3-, 11- and 11-fold, respectively, but not to hazardous levels except for Zn. After washing, P and K remained in the SS, plant-available P increased 3.3-fold, while total N and C were reduced by 20.28 and 2.44 %, respectively. Washed SS was used as fertilizer in the pot experiment. The yield of Brassica juncea did not improve, the uptake of TMs by the plants and the leaching of TMs from the soil were minimal. Our study highlighted the drawbacks and potential feasibility of the new SS washing method.

Association between blood metals mixture and chronic kidney disease in adults: NHANES 2013-2016

BACKGROUND

The association between single metal exposure and chronic kidney disease (CKD) has been established. However, there is limited research on the effects of multi-metal mixtures and their potential age-specific associations with kidney injury. This study aimed to examine the relationship between metal mixtures and kidney function in adults, while also exploring the modifying effects of age.

METHODS

We included a subset (n = 4250) of a nationally representative adult population in the National Health and Nutrition Examination Survey (NHANES) 2013-2016. Kidney function was assessed using the glomerular filtration rate (eGFR) and creatinine albumin ratio (ACR). The individual and combined effects of lead (Pb), cadmium (Cd), mercury, and manganese on kidney injury and the risk of CKD were evaluated.

RESULTS

Pb and Cd were found to be positively associated with decreased kidney function. For a one Ln-unit increase in lead and cadmium, the adjusted ORs of CKD were 1.60 (95% CI: 1.35, 1.90) and 1.41 (95% CI:1.12, 1.77), respectively. We also observed an interaction between lead and cadmium for ACR. We also observed the joint effect between Pb and Cd on eGFR, ACR and CKD. Stratified analysis found a higher risk of decreased kidney function among older individuals. The quantile-g calculation model further showed that metal mixture was associated with decreased kidney function and the risk of CKD (OR = 1.53, 95% CI: 1.22, 1.90). And lead and cadmium were the main contributors. And Pb and Cd were the major components that increased the risk of CKD.

CONCLUSION

Co-exposure to metal mixture were associated with reduced kidney function in adults, especially in older. Our findings support co-exposure to lead and cadmium as risk factors of CKD in adults.

Microwave-induced combustion for further determination of potentially toxic elements in honey by ICP-MS

Microwave-induced combustion (MIC) was proposed in this study for honey decomposition aiming for As, Cd, Hg, and Pb determination by inductively coupled plasma mass spectrometry (ICP-MS). Sample mass (up to 1.0 g), absorbing solution (0.5 to 14.4 mol L-1 HNO3, and H2O), heating program, and combustion aids were evaluated. The Eurachem guidelines were used for method validation. The proposed method enabled combustion of a high sample mass (0.8 g of honey, with 0.4 g of microcrystalline cellulose and 100 µL of 6 mol L-1 NH4NO3) using 6 mL of an absorbing solution consisting of 1 mol L-1 HNO3, which resulted in low residual carbon in solution (< 25 mg L-1). Honey samples from different geographical origins were analyzed. Results showed no significant difference in comparison to other two microwave decomposition methods, based on microwave-assisted wet digestion with single reaction chamber (MAWD-SRC) and microwave-assisted wet digestion (MAWD). Standard addition experiments resulted in recoveries higher than 98%. The limits of detection ranged from 1.10 (As) to 4.60 ng g-1 (Pb). In addition to using only diluted reagents and resulting in digests virtually free of interferences, the proposed method was faster (< 30 min) than most of those presented in the literature.

Intelligent monitoring of the available lead (Pb) and cadmium (Cd) in soil samples based on half adder and half subtractor molecular logic gates

The available heavy metals in soil samples can cause the direct toxicity on ecosystems, plants, and human health. Traditional chemical extraction and recombinant bacterial methods for the available heavy metals assay often suffer from inaccuracy and poor specificity. In this work, we construct half adder and half subtractor molecular logic gates with molecular-level biocomputation capabilities for the intelligent sensing of the available lead (Pb) and cadmium (Cd). The available Pb and Cd can cleave DNAzyme sequences to release the trigger DNA, which can activate the hairpin probe assembly in the logic system. This multifunctional logic system can not only achieve the intelligent recognition of the available Pb and Cd according to the truth tables, but also can realize the simultaneous quantification with high sensitivity, with the detection limits of 2.8 pM and 25.6 pM, respectively. The logic biosensor is robust and has been applied to determination of the available Pb and Cd in soil samples with good accuracy and reliability. The relative error (Re) between the logic biosensor and the DTPA + ICP-MS method was from -8.1 % to 7.9 %. With the advantages of programmability, scalability, and multicomputing capacity, the molecular logic system can provide a simple, rapid, and smart method for intelligent monitoring of the available Pb and Cd in environmental samples.

Do we underestimate risk of cardiovascular mortality due to lead exposure?

BACKGROUND

Studies using data from the National Health and Nutrition Examination Survey-III (NHANES-III) have demonstrated significant prospective associations between blood lead levels and increased mortality. Bone lead represents cumulative lead burden and thus is a better biomarker for assessing chronic impacts, but its in vivo assessment requires special K-x-ray fluorescence (KXRF) instrumentation. Our team recently developed an algorithm predicting bone lead levels from a combination of blood lead levels, age and other socioeconomic and behavioral variables. We examined the associations of our algorithm-estimated bone lead levels and mortality in NHANES-III.

METHODS

We included 11,628 adults followed up to December 31, 2019. Estimated tibia lead and patella lead levels were calculated using our prediction algorithms. We used survey-weighted Cox proportional hazards models to compute hazard ratios (HRs) and 95 % confidence intervals (CIs).

RESULTS

During the median follow-up of 26.8 years, 4900 participants died (mortality rate = 1398 per 100,000 adults/year). Geometric means (95 % CIs) of blood lead, predicted tibia lead, and predicted patella lead were 2.69 μg/dL (2.54, 2.84), 6.73 μg/g (6.22, 7.25), and 16.3 μg/g (15.9, 16.8), respectively. The associations for all-cause mortality were similar between blood lead and bone lead. However, the associations for cardiovascular mortality were much greater with predicted bone lead markers compared to blood lead: for comparing participants at the 90th vs. 10th percentiles of exposure, HR = 3.32 (95 % CI: 1.93-5.73) for tibia lead, 2.42 (1.56-3.76) for patella lead, 1.63 (1.25-2.14) for blood lead. The population attributable fractions for cardiovascular disease mortality if everyone's lead concentrations were declined to the 10th percentiles were 45.8 % (95 % CI: 28.1-59.4) for tibia lead, 33.1 % (18.1-45.8) for patella lead, and 22.8 % (10.4-33.8) for blood lead.

CONCLUSIONS

These findings suggest that risk assessment for cardiovascular mortality based on blood lead levels may underestimate the true mortality risk of lead exposure.

Association of exposure to multiple heavy metals during pregnancy with the risk of gestational diabetes mellitus and insulin secretion phase after glucose stimulation

BACKGROUND

Epidemiological evidence for the association between heavy metals exposure during pregnancy and gestational diabetes mellitus (GDM) is still inconsistent. Additionally, that is poorly understood about the potential cause behind the association, for instance, whether heavy metal exposure is related to the change of insulin secretion phase is unknown.

OBJECTIVES

We aimed to explore the relationships of blood levels of arsenic (As), lead (Pb), thallium (Tl), nickel (Ni), cadmium (Cd), cobalt (Co), barium (Ba), chromium (Cr), mercury (Hg) and copper (Cu) during early pregnancy with the odds of GDM, either as an individual or a mixture, as well as the association of the metals with insulin secretion phase after glucose stimulation.

METHODS

We performed a nested case-control study consisting of 302 pregnant women with GDM and 302 controls at the First Affiliated Hospital of Anhui Medical University in Hefei, China. Around the 12th week of pregnancy, blood samples of pregnant women were collected and levels of As, Pb, Tl, Ni, Cd, Co, Ba, Cr, Hg and Cu in blood were measured. An oral glucose tolerance test (OGTT) was done in each pregnant woman during the 24-28th week of pregnancy to diagnose GDM and C-peptide (CP) levels during OGTT were measured simultaneously. The four metals (As, Pb, Tl and Ni) with the highest effect on odds of GDM were selected for the subsequent analyses via the random forest model. Conditional logistic regression models were performed to analyze the relationships of blood As, Pb, Tl and Ni levels with the odds of GDM. The weighted quantile sum (WQS) regression and bayesian kernel machine regression (BKMR) were used to assess the joint effects of levels of As, Pb, Tl and Ni on the odds of GDM as well as to evaluate which metal level contributed most to the association. Latent profile analysis (LPA) was conducted to identify profiles of glycemic and C-peptide levels at different time points. Multiple linear regression models were employed to explore the relationships of metals with glycaemia-related indices (fasting blood glucose (FBG), 1-hour blood glucose (1h BG), 2-hour blood glucose (2h BG), fasting C-peptide (FCP), 1-hour C-peptide (1h CP), 2-hour C-peptide (2h CP), FCP/FBG, 1h CP/1h BG, 2h CP/2h BG, area under the curve of C-peptide (AUCP), area under the curve of glucose (AUCG), AUCP/AUCG and profiles of BGs and CPs, respectively. Mixed-effects models with repeated measures data were used to explore the relationship between As (the ultimately selected metal) level and glucose-stimulated insulin secretion phase. The mediation effects of AUCP and AUCG on the association of As exposure with odds of GDM were investigated using mediation models.

RESULTS

The odds of GDM in pregnant women increased with every ln unit increase in blood As concentration (odds ratio (OR) = 1.46, 95% confidence interval (CI) = 1.04-2.05). The joint effects of As, Pb, Tl and Ni levels on the odds of GDM was statistically significant when blood levels of four metals were exceeded their 50th percentile, with As level being a major contributor. Blood As level was positively associated with AUCG and the category of glucose latent profile, the values of AUCG were much higher in GDM group than those in non-GDM group, which suggested that As exposure associated with the odds of GDM may be due to that As exposure was related to the impairment of glucose tolerance among pregnant women. The significant and positive relationships of As level with AUCP, CP latent profile category, 2h CP and 2h CP/2h BG were observed, respectively; and the values of 1h CP/1h BG and AUCP/AUCG were much lower in GDM group than those in non-GDM group, which suggested that As exposure may not relate to the impairment of insulin secretion (pancreatic β-cell function) among pregnant women. The relationships between As level and 2h CP as well as 2h CP/2h BG were positive and significant; additionally, the values of 2h CP/2h BG in GDM group were comparable with those in non-GDM group; the peak value of CP occurred at 2h in GDM group, as well as the values of 2h CP/2h BG in high As exposure group were much higher than those in low As exposure group, which suggested that As exposure associated with the increased odds of GDM may be due to that As exposure was related to the change of insulin secretion phase (delayment of the peak of insulin secretion) among pregnant women. In addition, AUCP mediated 11% (p < 0.05) and AUCG mediated 43% (p < 0.05) of the association between As exposure and the odds of GDM.

CONCLUSION

Our results suggested that joint exposure to As, Pb, Tl and Ni during early pregnancy was positively associated with the odds of GDM, As was a major contributor; and the association of environmental As exposure with the increased odds of GDM may be due to that As exposure was related to the impairment of glucose tolerance and change of insulin secretion phase after glucose stimulation (delayment of the peak of insulin secretion) among pregnant women.

Combined exposure to lead and microplastics increased risk of glucose metabolism in mice via the Nrf2/NF-κB pathway

The purpose of this study was to explore the effects of combined lead (Pb) and two types of microplastic (MP) (polyvinyl chloride [PVC] and polyethylene [PE]) exposure on glucose metabolism and investigate the role of the nuclear factor erythroid 2-related factor 2 (Nrf2)/nuclear factor-kappa B (NF-κB) signaling pathway in mediating these effects in mice. Adult C57BL/6J mice were randomly divided into four groups: control, Pb (100 mg/L), MPs (containing 10 mg/L PE and PVC), and Pb + MPs, each of which was treated with drinking water. Treatments were conducted for 6 weeks. Co-exposure to Pb + MPs exhibited increase glycosylated serum protein levels, insulin resistance, and damaged glucose tolerance compared with the control mice. Additionally, treatment with Pb + MPs caused more severe damage to hepatocytes than when exposed to them alone concomitantly, exposed to Pb + MPs exhibited improved the levels of interleukin-6, tumor necrosis factor-alpha, and malondialdehyde, but reduced superoxide dismutase, glutathione peroxidase, and catalase assay in livers. Furthermore, they increase the Kelch-like ECH-associated protein 1 (Keap1) and phosphorylated p-NF-κB protein levels but reduced the protein levels of heme oxygenase-1 and Nrf2, as well as increased Keap1 mRNA and Nrf2 mRNA. Co-exposure to Pb + MP impacts glucose metabolism via the Nrf2 /NF-κB pathway.

Reference intervals of 24 trace elements in blood, plasma and erythrocytes for the Slovenian adult population

OBJECTIVES

The aim of the present study was to establish the population- and laboratory-specific reference intervals (RIs) for the Slovenian adult population for 24 trace elements (TEs) in blood, plasma and erythrocytes and to evaluate the impact of gender, age, seafood consumption, smoking habits and amalgam fillings on TEs levels.

METHODS

TEs (Mn, Co, Cu, Zn, Se and Mo, Li, Be, V, Cr, Ni, Ga, As, Rb, Sr, Ag, Cd, Sn, Cs, Au, Hg, Tl, Pb and U) were determined in 192 a priori selected blood donors (107 women and 85 men, aged 18-65 years), using inductively coupled plasma mass spectrometry (ICP-MS) with the Octopole Reaction System. Participants filled out a questionnaire, and RIs were established according to the Clinical and Laboratory Standards Institute (CLSI) guidelines for TEs.

RESULTS

Uniform RIs for non-essential and gender-specific for essential TEs in blood, plasma and erythrocytes were established. In our population, higher blood and plasma Cu, and erythrocyte Mn levels in women were found. In men, blood Zn, plasma Zn, Mn and Se, and erythrocyte Cu levels were higher. Zn levels were higher in 30-39 years age group. Pb and Sr increased with age. Smoking positively affected Cd, Pb, Cs and Rb; seafood consumption increased As, Hg and Zn; and amalgam increased Hg, Ag and Cu levels.

CONCLUSIONS

Essential TEs were inside recommended levels, and the non-essential ones were far below critical levels. Established RIs will provide an important foundation for clinical diagnostics, safety erythrocyte transfusions assessment, toxicology and epidemiological studies.

The Impact of Inoculation of Two Strains of Rhizobacteria on Radionuclide Transfer in Sesbania Grandiflora

Transfer factors of some naturally-occurring and artificial radionuclides from an agricultural soil to rhizobacteria-treated Sesbania grandiflora, a small leguminous tree, were studied. Two plant growth promoting rhizobacteria (PGPR) strains (SCR17 and PCE2) were used to carry out an agricultural experiment in pots in semi-arid region (Syria). The results showed the bacterial strain (SCR17) increased the transfer and accumulation of 238U and 40K in Sesbania grandiflora, while both bacterial strains showed no effect on the accumulation of 234Th, 226Ra, 210Po and 210Pb in the treated plants. The transfer factor of 137Cs from soil to rhizobacteria-treated Sesbania grandiflora was negligible. The values of the transfer factors of 234Th, 226Ra, 210Po and 40K were found to be within the global values, while the values of the transfer factors of 238U and 210Pb were found to be relatively higher. This study highlights the importance of using Phytoremediation by PGPR strains for radionuclides-contaminated soils. Therefore, this method is a promising technique for the restoration and rehabilitation of contaminated sites with radionuclides, as it is low cost, easy to apply, and environmentally friendly.