Trace Metals Research Articles

Assessments of hydrogeochemical characteristics, water quality, and health risk of groundwater of Chapi-Nawabganj District of Bangladesh

ABSTRACT A total of 60 groundwater samples were collected over three seasons, aiming to assess hydrochemical characteristics, water quality, pollution level, and health risk. The concentration of Fe, Mn, and Pb exceeded almost 100% of samples in three seasons. The groundwater was found to be highly contaminated with Cd and Cr in the pre-monsoon and Ni in the monsoon. The order of major ion and trace metal concentrations is as follows: Ca2+ > Na+ > Mg2+ > K+; HCO3− > Cl− > SO42− > NO3− > PO43−, and Fe > Mn > Pb > Cd in three seasons. The groundwater was Ca-Mg-HCO3− type. The study suggests that the contamination sources are mostly geogenic as well as slightly anthropogenic. The water–rock interactions are the dissolution of calcite and dolomite, along with silicate weathering, which controls the hydrochemistry of the groundwater. The indices, including the Water Quality Index (WQI), and the Canadian Council of Ministers of the Environment (CCMEWQI), revealed that the groundwater quality in the area was moderately polluted. The Heavy Metal Pollution Index (HMPI), and human health risk assessment (HRA) illustrated that groundwater is a significant health hazard, indicating it is unsuitable for human consumption and suggesting treatment before drinking.

Influence of Trace Metal in Plastics on Catalyst Activity and Reusability during Polyolefins Upcycling with Polyoxometalates

Influence of Trace Metal in Plastics on Catalyst Activity and Reusability during Polyolefins Upcycling with Polyoxometalates

Soil contamination by trace elements and radioelements and related environmental risks in agricultural soils of the M'Dhilla Basin (southwestern Tunisia).

Agricultural soil contaminated by phosphogypsum pile stocked in plan air remains a major problem in M'Dhilla city southwestern of Tunisia. The present effort aimed to enhance the knowledge of trace elements and radioactivity abundance and to assess the corresponding environment. X-ray fluorescence spectroscopy was used to evaluate the trace elements, radioactive elements, and major element concentrations. Our finding revealed that the mean values of U and Th in all the soil profiles ranged from 0.283 to 2.875mg.kg-1 and from 0.797 to 1.491mg.kg-1 respectively. The statistical analyses indicated that uranium abundance has non-significant correlation with the most of trace metals; it shows a moderate correlated with Sr and inverse correlation with P2O5. Contamination factors indicate that the studied soil ranged from uncontaminated to significantly contaminated. Thus, the pollution load index values classify the sites from background values to high pollution sites. The findings of this study will help improve the environmental conditions of M'Dhilla city by addressing contamination issues through targeted interventions. The study's findings highlight the importance of a periodic environmental monitoring such as soil remediation in the study area. This research fills a critical gap in the current understanding of contamination management in this region.

The Role of Trace Metals in the Development and Progression of Prostate Cancer.

Over the years, prostate cancer (PCa) research has been of great interest, and trace metals have attracted a lot of attention due to their association with prostate cancer development and progression. PCa has a complex etiology, with genetic, environmental, and lifestyle factors being implicated. Trace metals such as zinc (Zn), mercury (Hg), selenium (Se), lead (Pb), cadmium (Cd), manganese (Mn), arsenic (As), and nickel (Ni) have garnered much attention in recent years, suspected of having direct links to the modulation of cancer risk and progression through their impacts on prostate cancer omics (genomics, epigenetics, proteomics, and transcriptomics). This has led to them being the subject of extensive research in this regard. In this review, we explored the influence of trace metals and offered a comprehensive analysis of the current knowledge on how trace metals affect the biology of prostate cancer at a molecular level by integrating findings from the recent literature to help suggest possible directions for future research.

In situ synthesis of Chitin/ZIF-67 composite hydrogel for efficient recovery of high purity acetonitrile by removal of Zn2+ and Ag+

The improper disposal of waste high purity acetonitrile (HPA) not only causes environmental degradation but also poses significant risks to human health. One of the major challenges in the recycling and reuse of waste HPA is the removal of trace metal ions. In this study, we successfully fabricated a chitin/ZIF-67 composite hydrogel (CZ-n) by one pot in situ synthesis method for the purification and recovery of waste HPA for the first time. ZIF-67 was embedded into chitin through hydrogen bonding and coordination and provided more active adsorption sites, which resulted in CZ-3 with higher adsorption capacity than CZ-0. The maximum adsorption capacities of CZ-3 for Zn2+ and Ag+, as determined by fitting the Langmuir model, were 85.46 mg·g-1 and 91.26 mg·g-1, respectively. CZ-3 was able to effectively decrease the metal ion (Zn2+ and Ag+) concentration to below 10 ppb within 24 h through a monolayer adsorption process using chelation. Furthermore, the adsorption capacity remained satisfactory even in the presence of an equivalent concentration of NaCl, and CZ-3 exhibited remarkable reusability, with a removal rate exceeding 80 % after five cycles. Additionally, it also displayed notable biodegradability, with complete degradation observed within 60 days. These results indicated that CZ-3 could be a potential absorbent in the purification and recovery of waste HPA.

Semi-continuous cultivation of microalgae to treat coal mine effluent in pilot scale: Nutrient removal, biodesalination and fatty acid composition analysis

Coal excavation is associated with discharge of an enormous amount of mine water rich in salt and trace metal ions, which require efficient treatment before use. Considering the potentiality of microalgae for high salt tolerance, salt removal and metallic pollutant removal from aqueous system, present study focuses semi-continuous cultivation of candidate microalgae Chlorella pyrenoidosa (NCIM 2738) in bubble column reactor (BCR) and open raceway pond (ORP) for nutrient supplemented coal mine effluent (NSCME) treatment. In between different hydraulic retention times (HRTs), HRT 6 d provide maximum average biomass productivity of 950 mg L−1 d−1 in BCR and 728.4 mg L−1 d−1 in ORP. HRT 9 d facilitates a maximum lipid content of 1.8 g L ̶ 1 in BCR and 1.4 g L ̶ 1 in ORP. Further, HRT 9 d had the maximum COD removal efficiency (96.5 % in BCR and 94.2 % in ORP) and maximum salinity removal efficiency (93 % in BCR and 92 % in ORP). Fatty acid methyl esters (FAME) characterization highlighted potential biodiesel applicability with cetane number (CN) of 53.94. Energy dispersive X-ray spectroscopy (EDS) revealed an excess amount of salt and metal ions deposition on the surface of harvested microalgae samples. Outdoor large-scale C. pyrenoidosa cultivation can be integrated with coal mine closure plans to meet sustainable development goals (SDGs) 6, 7 and 13.

Effect of long-term application of pig slurry and NPK fertilizers on trace metal content in the soil.

One of the goals of sustainable agricultural production is to avoid soil contamination by elements defined as trace metals (TMs). The aim of this study was to assess the long-term impact of the use of pig slurry (PS) and NPK mineral fertilizers on the soil content of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn). In a 9-year crop rotation, PS was used three times only before root crops. The same four levels of NPK doses (N0P0K0, N1P1K1, N3P2K2, N4P2K2) were applied to both plots with and without PS. Soil samples were collected in early spring from topsoil (0-0.3m) and subsoil (0.3-0.6m). Three forms of TMs were determined in the soil: pseudo-total (Aqua regia); bioavailable (Mehlich 3 method) and readily bioavailable (mobile) forms (1M NH4NO3). The tested factors did not have a significant impact on the Cd, Cu and Pb content, regardless of the form analyzed and the soil depth. PS application significantly increased the content of bioavailable forms of Zn regardless of the year, and the content of pseudo-total Zn only in the sugar beet year, i.e. after manure application. Increasing NPK doses increased the content of mobile Zn in the topsoil, especially in PS plots. A tendency to accumulate mobile forms of Cd and Pb was also observed on NPK-fertilized plots. Thus, long-term application of high NPK doses may increase the risk of contamination of the food chain with these metals. The content of mobile Cd and Zn was positively related to the content of total nitrogen in the soil and negatively related to pH.

Geochemical fractionation of trace elements in ostreid and gastropod shells: A potential proxy for heavy metal pollution in Ghana’s coastal environment

The content of trace elements from Crassostrea tulipa (Ostreidae, Bivalvia) from four localities (Pra Estuary, Densu Estuary, Kpone Beach, and Anyanui Creek) along the coast of Ghana has been used as a bioindicator of environmental pollution. The lowest values of heavy metals correspond to the Crassostrea shells from Densu Estuary and Anyanui Creek, whereas the highest contents are recorded in the shells from Pra Estuary and Kpone Beach. Densu Estuary and Anyanui Creek are located in areas not affected by major industries, and only Densu is located in a densely urbanized setting. Crassostrea shells from Densu Estuary are only enriched in Ni. However, the Total Organic Carbon content of the sediments of the Densu Estuary indicates anthropogenic organic pollution not evidenced by the composition of Crassostrea shells. The Crassostrea shells from the Pra Estuary show enrichment in most of the analysed trace elements (Li, Be, V, Cu, Cr, Zn, Ga, Y, Sn, Pb, U, Th, ∑REE, and As) compared with other studied sites. This enrichment is related to heavy metals influx to the Pra River by the mining activities, extensive forest clearance, and loss of soil minerals. The Crassostrea shells from Kpone Beach present comparatively high content of some trace elements (Be, Ba, Cu, Zn, Nb, Pb, and REE). The metal pollutants are related to the input of the Heavy Industrial Area of Tema (located around 3.5 km west of Kpone Beach) and urban effluences from the Greater Accra Region. The high content of Ba, Cu, Zn, and Pb in Crassostrea is directly related to high phytoplankton productivity (mainly for diatoms) linked to the input of trace metals transferred into the marine food webs. In addition, some analyses of gastropod shells from Kpone Beach indicate that Cerithium and Nerita are more sensitive to accumulating Ni and As than Crassostrea. The values of trace metals from the Crassostrea shells of the Densu Estuary and Anyanui Creek are comparatively low. Considering the role of Crassostrea shells as bioindicators for heavy metals pollution, the less polluted localities are Anyanui Creek and Densu Estuary, whereas Pra Estuary and Kpone Beach are affected by anthropic activities such as mining, urban effluents, and industry.

Pyrite trace metal and sulfur isotopic compositions track metalliferous fluid circulation within the Ordovician/Silurian organic-rich black shales in the eastern Sichuan Basin, southwestern China

Depicting metalliferous fluid flows in sedimentary basins has a remarkable implication for understanding the formation and evolution of organic-rich sediments. The Middle-Upper Yangtze region in South China hosts voluminous gaseous hydrocarbons and MVT-type ZnPb deposits. Natural gases are mainly distributed in the Sichuan Basin, yet ZnPb deposits are found in surrounding regions of the basin. Such a unique distribution pattern implies that the interplay between metalliferous fluids and organic-rich sediments may be extensive in the boundary of these two types of deposits. A typical Ordovician/Silurian (Wufeng/Longmaxi formations) organic-rich black shale outcrop occurs in the eastern boundary of the Sichuan Basin. Pyrites are frequently distributed across this section, providing an ideal opportunity to investigate features of metalliferous fluids and their potential impacts on organic-rich sediments. Pyrites associated with high-angle carbonate veinlets are recognized in the studied area, and this group of pyrites (“Group 2”) commonly display planar-laminated morphologies, moderate δ34S values (0.78 ‰–8.86 ‰), and elevated trace metal contents (Ni, Pb, Mn, Mo, Tl, and REE) than those not associated with carbonate veinlets. These features suggest that this group of pyrites may be precipitated via local metalliferous fluid flows. Besides, pyrites with relatively lower trace metal contents can be further divided into two groups, including a group of euhedral/subhedral pyrites with more depleted δ34S values (−18.06 ‰ – -1.15 ‰; “Group 1”) and a group of planar-laminated/cubic pyrites with enriched δ34S values (10.55 ‰–37.62 ‰; “Group 3”). Pyrites of Group 1 and Group 3 may be formed via bacterial sulfate reduction (BSR) and thermochemical sulfate reduction (TSR), respectively. The discovery of fluid-related, trace-metal-enriched pyrites implies that fluid circulation within organic-rich black shales has the potential to remobilize, transport, and re-deposit trace metals. Besides, metalliferous fluid may also promote organic matter maturation within the Sichuan Basin. The outcomes of this study, combined with previous findings of metalliferous fluid flows in the center of the basin and ZnPb mineralization belts surrounding the basin, imply that a widespread Ediacaran-Palaeozoic fluid circulation system may exist in the Middle-Upper Yangtze region.

Seasonal dynamics in microbial trace metals transporters during phytoplankton blooms in the Southern Ocean.

Trace metals are required as cofactors in metalloproteins that are essential in microbial metabolism and growth. The microbial requirements of diverse metals and the capabilities of prokaryotic taxa to acquire these metals remain poorly understood. We present here results from metagenomic observations over an entire productive season in the region off Kerguelen Island (Indian Sector of the Southern Ocean). We observed seasonal patterns in the abundance of prokaryotic transporters of seven trace elements (zinc [Zn], manganese [Mn], nickel [Ni], molybdenum [Mo], tungsten [W], copper [Cu] and cobalt [Co]) and the consecutive spring and summer phytoplankton blooms were strong drivers of these temporal trends. Taxonomic affiliation of the functional genes revealed that Rhodobacteraceae had a broad repertoire of trace metal transporters (Mn, Zn, Ni, W and Mo) and a more restricted set was observed for other prokaryotic groups, such as Flavobacteriaceae (Zn), Nitrincolaceae (Ni and W) and Thioglobaceae (Mo). The prevalence of trace metal transporters within a prokaryotic group, as determined on the family level, was overall confirmed in representative metagenome-assembled genomes. We discuss the potential involvement of prokaryotic groups in processes related to organic matter utilisation that require these metals and the consequences on carbon and trace metal cycling in surface waters of the Southern Ocean.

Gaseous and aerosol emissions from open burning of tree pruning and hedge trimming residues: Detailed composition and toxicity

Gaseous and PM10 samples were collected during the open burning of pruning residues (olive branches and garden waste) and characterised by distinct analytical techniques to obtain comprehensive chemical emission profiles. Oxidative potential (dithiothreoitol and ascorbic acid assays) and cell viability tests were also performed with the aim of evaluating aerosol toxicity. Emission factors (EFs) were as follows (g kg−1 biofuel, dry basis): 1537–1672 for CO2, 41.9–80 for CO, 2.74–6.6 for CH4, 0.89–3.51 for ethane, 0.79–1.78 for ethylene and 0.56–3.47 for formaldehyde. Emissions of PM10, organic carbon (OC) and elemental carbon (EC) were in the ranges 8–41, 3–18, and 0.4–1.5 g kg−1 biofuel, dry basis, respectively. OC accounted for 35–45% of the total PM10 mass, while EC contributed between around 3% and 5%. WSOC/OC ratios varied from 0.4 to 0.6, revealing that a substantial portion of the carbon emitted was hydrosoluble. Water soluble ions constituted around 8–21% of the PM10 mass, with potassium and chloride as the most abundant ions in all samples. Levoglucosan, widely used a reliable biomass burning tracer, was found in significant amounts in all samples (up to 1.2% of the PM10 mass). Retene, generally pointed out as a biomass combustion biomarker, was the predominant PAH. WSOC and some PAHs showed significant positive correlations with the intrinsic OP measured with the DTT assay, while the OPAA was significantly correlated with some trace metals, such as Fe or Ni. All samples significantly reduced the viability of alveolar epithelial cells.

Subsurface Superoxide Spans the Baltic Sea

AbstractSuperoxide is a reactive oxygen species that is influential in the redox chemistry of a wide range of biological processes and environmental cycles. Using a novel in situ sensor we report the first water column profiles of superoxide in the Baltic Sea, at concentrations higher than previously observed in other oceans. Our data revealed consistent peaks of superoxide (2.0–15.1 nM) in dark waters just below the mixed layer. The oxic waters, low metal concentrations, and lack of sunlight imply that the peak is likely of biological origin. Several profiles displayed a concomitant dip in dissolved oxygen mirroring this superoxide peak, strongly suggesting a link between the two features. The magnitude and distribution of superoxide observed warrants re‐evaluation of the most relevant sources and controls of superoxide in seawater. Locally, these high concentrations of superoxide may create environments conducive to reactions with trace metals and organic matter and present an overlooked sink of oxygen in the Baltic Sea.

Iron Isotopes reveal volcanogenic input during Oceanic Anoxic Event 2 (OAE 2 ∼ 94 Ma)

Anomalously high metal concentrations including iron enrichments are recorded in marine carbonates deposited during Ocean Anoxic Event 2 (OAE 2). These metal enrichments have been attributed to massive submarine eruptions during the formation of one or more large igneous provinces, the proposed trigger for OAE 2 (hydrothermal hypothesis), or to the release of metals from the reoxidation of formerly anoxic marine sediment during a period of temporary cooling during OAE 2 (sediment release hypothesis). Here we use iron stable isotopes to help distinguish between the two hypotheses for a trace metal enriched interval during OAE 2 in the Iona-1 core in the Western Interior Seaway, Texas. Our results show a two-step negative excursion during OAE 2 that is coincident with osmium isotope volcanic proxies measured in the same core, with peak negative values centered on a trace metal-enriched interval. After corrections for detrital and locally supplied iron to the study setting, the δ56Fe value of the remotely supplied iron is –0.28 ± 0.05 ‰, falling in the range of iron δ56Fe values observed in modern hydrothermal plumes (–0.1 to –0.5 ‰), thus supporting the hydrothermal hypothesis as the source of iron and other associated trace metals enriched in the study core during OAE 2. By contrast, the sediment release hypothesis predicts much lower δ56Fe values, between –1.0 ‰ to –3.3 ‰ predicted for benthic supplies of iron from anoxic marine sediment overlying re-oxygenated bottom waters. This study shows that combining iron with other proxies for environmental change, particularly submarine volcanism, can distinguish hydrothermally supplied iron from dust, rivers, and shelf sediment supplies of iron despite iron’s reputation for complicated cycling.

Review to Elucidate the Correlation between Cuproptosis-Related Genes and Immune Infiltration for Enhancing the Detection and Treatment of Cervical Cancer.

Copper is a vital trace element in oxidized and reduced forms. It plays crucial roles in numerous biological events such as redox chemistry, enzymatic reactions, mitochondrial respiration, iron metabolism, autophagy, and immune modulation. Maintaining the balance of copper in the body is essential because its deficiency and excess can be harmful. Abnormal copper metabolism has a two-fold impact on the development of tumors and cancer treatment. Cuproptosis is a form of cell death that occurs when there is excessive copper in the body, leading to proteotoxic stress and the activation of a specific pathway in the mitochondria. Research has been conducted on the advantageous role of copper ionophores and chelators in cancer management. This review presents recent progress in understanding copper metabolism, cuproptosis, and the molecular mechanisms involved in using copper for targeted therapy in cervical cancer. Integrating trace metals and minerals into nanoparticulate systems is a promising approach for controlling invasive tumors. Therefore, we have also included a concise overview of copper nanoformulations targeting cervical cancer cells. This review offers comprehensive insights into the correlation between cuproptosis-related genes and immune infiltration, as well as the prognosis of cervical cancer. These findings can be valuable for developing advanced clinical tools to enhance the detection and treatment of cervical cancer.

Spring water discharge and metal enrichment in urban soils

Abstract Urban centers have inherited a unique mix of persistent contamination that impacts interactions among urban soil and groundwater systems. In particular, the potential for urban groundwater to transport contaminants from surface sources through the subsurface environment and ultimately to soils is not well understood. Studies have focused on specific ‘natural’ mechanisms driving distribution of metals in urban soils. However, very few studies have examined the accumulation of contamination in soils at groundwater discharge locations (springs) and the potential for groundwater to redistribute urban legacy contaminants far from the source. Soil transects straddling four groundwater springs in Pittsburgh, Pennsylvania were sampled to evaluate patterns resulting from contaminated groundwater discharge on urban soils. Metal concentrations were measured in pore water and compared with concentrations observed in total digestions and exchangeable extractions (acetic acid) of the soil. Across the springs Co, Cr, Ni, and V (metals often used in steel alloys) were elevated downslope, suggesting contaminated groundwater discharge enriches trace metals in these locations. These processes create unexpected biogeochemical patterns on the landscape and have the potential to create hotspots of soil metal contamination at predictable points across the urban landscape.

Cost‐Effective Approach for Fabrication of High‐Quality Expanded Vermiculite for Alizarin Red S Removal From Aqueous Media

AbstractVermiculite is extensively utilized for several applications, including as a hydroponic substrate, for soil conditioning, oil cleansing, and addressing trace metal pollution. In this study, the expansion of natural vermiculite was easily achieved by utilizing hydrogen peroxide (H2O2) with the aid of microwave technology. The characterization of expanded vermiculite involved the use of X‐ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), nitrogen adsorption isotherm (BET), and energy dissipation X‐rays (EDX). The vermiculite has been enlarged to have a structure resembling flakes, and its surface area measures 73.9 m2/g. The adsorption of Alizarin Red S onto expanded vermiculite was investigated under varying conditions, such as pH, starting concentration, adsorbent content, and duration of exposure. The enlarged vermiculite achieved a maximum adsorption capacity of 182.5 mg/g for Alizarin Red S. Out of the three adsorption isotherm models, both the Freundlich and Temkin models accurately describe the adsorption of Alizarin Red S onto expanded vermiculite. When studying adsorption kinetics, the second‐order adsorption kinetic model is more appropriate than the first‐order adsorption kinetic model, as indicated by an R2 value of 0.8964.

Vortex-Assisted Magnetic Solid-Phase Extraction of Heavy Metals in Water and Food Samples Using Iron Oxide Nanoparticle-Impregnated Carboxymethyl-β-Cyclodextrin.

The excessive accumulation of heavy metals has adverse effects on the human body. Here, magnetic iron oxide-impregnated carboxymethyl-β-cyclodextrin was synthesized. The synthesized material was employed as a magnetic solid-phase extracting adsorbent for specific heavy metals like lead (Pb), nickel (Ni), copper (Cu), and cobalt (Co). Characterization was performed by X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller, and Fourier-transform infrared spectroscopy. The analytical merits, like detection limits (Pb: 1.38ng/mL, Ni: 0.5ng/mL, Co: 0.14ng/mL, and Cu: 0.55ng/mL) andquantification limits (Pb: 4.14ng/mL, Ni: 1.62ng/mL, Co: 1.85ng/mL, and Cu: 1.82ng/mL) were calculated. Similarly, the preconcentration and enhancement factors (15) and relative standard deviation (Pb: 3.5, Ni: 0.92, Co: 2.7, and Cu: 1.5) were also calculated. The interfering study shows that the method is highly selective. For validation, it was applied to certified reference materials such as the Institute of Nuclear Chemistry and Technology ornamental Basma tobacco leaves and trace metal double addition 63.4 environmental water with good percent recovery values (92%-99%). Real water and food samples were also used with satisfactory (90%-99%) recovery results.

Tire and road wear particles in infiltration pond sediments: Occurrence, spatial distribution, size fractionation and correlation with metals

Stormwater systems, such as infiltration ponds or basins, play a critical role in managing runoff water and reducing particulate pollution loads in downstream environments through decantation. Road runoff carries several pollutants, including trace metals and tire and road wear particles (TRWP). To improve our understanding of infiltration ponds as regards TRWP and their capacity to reduce TRWP loads, we have studied the occurrence, spatial distribution and size distribution of TRWP, as well as their relationship with metals, in considering the input of metals as tire additives, in the sediments of an infiltration pond located along the Nantes urban ring road (Western France), which happens to be a high-traffic roadway site. The sediment was analyzed using pyrolysis coupled with gas chromatography–mass spectrometry to determine the polymeric content of tires, specifically in quantifying the styrene-butadiene rubber (SBR) and butadiene rubber (BR) pyrolytic markers. By applying an SBR + BR-to-TRWP conversion factor, the results showed significant TRWP contamination, up to 65 mg/g, with a spatial enrichment from the entrance to the overflow section of the pond. Size fractionation revealed a bimodal distribution, indicating two distinct types of TRWP. The first type is characterized by small diameters (63–160 μm), suggesting the presence of TRWP less integrated with mineral and organic particles. The second type, characterized by larger diameters (200–500 μm), suggests a more pronounced integration with these same mineral and organic particles. A significant positive correlation between TRWP and metals (As, Cd, Cr, Cu, Li, Mo, Ni, Sb, V, Zn) was found (r > 0.739, p < 0.05). This correlation implies that TRWP and/or their associated phases may act as an indicator of metal contamination in the pond sediments. Lastly, a mass balance between TRWP inputs and the amount retained in the sediments underscores the role of infiltration ponds as “sinks” for TRWP.

Terrestrial response to the Early Cretaceous Weissert Event: Insights from carbon isotope records of organic matter and leaf wax n-alkanes in an inland East Asian lake

The Weissert Event (WE), a significant Early Cretaceous environmental disruption, is recognized globally in marine carbonate records for its positive carbon isotope excursion (CIE), organic matter (OM) enrichment, and widespread anoxia. However, records of its terrestrial impact are sparse. This study examines carbon isotope compositions (δ13C) from the lacustrine facies of North China's Dabeigou Formation (Yushuxia section, Luanping Basin). The synchronous positive CIEs of total organic carbon (TOC) and C27–C31n-alkanes within Members 2 to 3 of the Dabeigou Formation corroborate the Weissert Event, marking its first terrestrial observation in North China. Ratios of the isoprenoids pristane and phytane (Pr/Ph), Corg/P ratios and enrichment factors (EFs) of redox-sensitive trace metals (Mo and U) indicate transient anoxic conditions within a mainly oxic-suboxic setting from the late Valanginian to early Hauterivian, which were unfavorable for OM preservation. This highlights that although a global positive CIE occurred during the Weissert Event, anoxia and/or high TOC deposition in inland lakes were not inherent features.

Determination of soil environmental criteria for high-risk trace metals in urban park soils using improved CLEA model

The trace metals (TMs) accumulated in urban park soils can pose potential threats to human health, making the management of soil quality based on health risks critically important. Based on the human health risk assessment (HHRA) model coupled with Monte Carlo Simulation, this study improved the contaminated land exposure assessment (CLEA) model. Combined with local parameters, the Soil Environmental Criteria (SEC) for high-risk trace metals (TMs) in urban park soils were calculated. Results indicated that all the mean TCR (Total carcinogenic risk) values of seven TMs exceeded the risk threshold of 1E-06, suggesting a higher likelihood of carcinogenic risks for all populations. As and Cr presented the highest potential carcinogenic risks, and were identified as high-risk TMs in the study area. The traditional CLEA model was enhanced by incorporating region-specific data, optimizing exposure parameter calculations, and addressing parameter sensitivity and uncertainty. Using the improved CLEA model, the SEC values for high-risk TMs were calculated, revealing that the SEC values gradually increased from ages 1 to 18, while significantly decreased for individuals over 80 years old. This study effectively addresses issues of parameter uncertainty and sensitivity in the CLEA model, offering new insights for the development of soil environmental quality standards.