Toxic Metals Research Articles

Mycoremediation of heavy metals by Curvularia lunata from Buckingham Canal, Neelankarai, Chennai.

The spread and mobilization of toxic heavy metals in the environment have increased to a harmful level in recent years as a result of the fast industrialization occurring all over the world to meet the demands of a rising population. This research aims to analyze and evaluate the mycoremediation abilities of fungal strains that exhibit tolerance to heavy metals, gathered from water samples at Buckingham Canal, Neelankarai, Chennai. Water samples were examined for heavy metal analysis, and the highest toxic heavy metals, Zn, Pb, Mn, Cu, and Cr, were recorded. Three fungal strains were isolated and named EBPL1000, EBPL1001, and EBPL1002 were selected by primary screening (100ppm) for further studies. Out of three fungal isolates, EBPL1000 grew in all five heavy metal concentrations and showed 2100ppm as the highest Maximum Tolerance Concentration toward Lead, 2000ppm tolerance in Zinc and Manganese, 1700ppm in Chromium, and 1500ppm in copper, respectively. The fungal isolate EBPL1000 was identified as Curvularia lunata with 100% percentage identity and query coverage. The Biosorption result reveals that lead is the highest biosorbed heavy metal with 79.99% at 100ppm concentration while copper is the lowest biosorbed with 24.11% heavy metal at 500ppm concentration. The uptake of Manganese by Curvularia lunata biomass was the highest (5.64mg/g) of all heavy metal's uptake at 100ppm concentration. The lowest uptake of heavy metals was copper (0.43mg/g) at 500ppm concentration, and the growth profile study under heavy metals stress conditions shows the order of Pb > Mn > Zn > Cr > Cu at 60h of time intervals at 100ppm concentration. In addition to the research, FTIR analysis and Molecular Docking studies provide credence to the idea that Curvularia lunata has high biosorption potential and uptake or removal of toxic heavy metals at low cost and in an eco-friendly way from the contaminated environment.

Assessment of total mercury content in fish muscle tissue from the middle basin of the Pastaza River, Ecuador.

One of the most toxic metals is mercury, which exhibits high toxicity during short exposure periods. This study aimed to determine the concentration of total mercury (THg) in fish muscle tissue from various species captured from two locations in the middle basin of the Pastaza River in Ecuador, which the locals use in their weekly diet. The individuals captured belong to the following families: Loricariidae, Cetopsidae, Heptapteridae, Cichlidae, Parodontidae, Characidae, Prochilodontidae, Curimatida, Siluriformes, Cichliformes, Characiformes, Erythrinidae and Curimatidae. Carnivorous species Charax sp. and Cetopsis plumbea, had THg concentrations were 0.241± 0.018 and 0.116 ± 0.045 mg kg-1, respectively. Herbivorous species Hypostomus sp. had a lower of THg. Carnivorous species Hoplias malabaricus exhibited THg concentration of 0.160±0.033 and 0.020±0.007 mg kg-1 for the omnivorous species Creagrutus sp. Carnivorous species accumulated higher levels of Hg compared to non-carnivorous species. Concentration of total mercury in the collected fish did not exceed the maximum permissible limits set by legislative standards (Ecuadorian Institute of Standardization (INEN as per the acronym in Spanish), FAO/WHO and European Commission); and the objective hazard quotient was less than 1, indicating that the consumption of this fish may pose no risk to human health. Considering the mean concentrations of methylmercury, for all the fish species analysed, the results for daily consumption rate were between 6-199 g and 29-928 g for children and adults, respectively.

Hazard Analysis and Human Health Risk Assessment in the Mytilus Galloprovincialis and Rapana Venosa Species in the Black Sea's Türkiye Coastline by Multivariate Analysis.

In this study; fourteen potentially toxic elements (PTEs) levels are measured in Mytilus galloprovincialis (MG) and in Rapana venosa (RV) intensively consumed in eight cities on the Black Sea coast of Türkiye. Additionally, human health risk levels from mollusks species consumption were assessed using multiple approaches and by Geographical Information Systems, spatial distribution map of PTEs of the region was prepared. The average PTEs levels in the two mollusks species are listed in the following order: Fe > Al > Zn > Cu > As > Mn > B > Cd > Se > Ni > Cr > Pb > Co > Hg with the levels of 114.8 > 79.7 > 39.49 > 9.75 > 5.74 > 3.22 > 2.97 > 2.74 > 0.72 > 0.40 > 0.24 > 0.22 > 0.11 > 0.015µgg-1 ww, respectively. The average concentration level of essential metals (Cu, Mn, Zn, Co and Fe) and toxic metals (Cr, Hg, Ni, Pb, Cd and As) was measured as 238.73µgg-1 ww in RV and 114.86µgg-1 ww in MG. The cities with the highest metal pollution index (MPI) levels were Rize, Samsun, Kastamonu and Sinop, respectively. The MPI values in mollusks soft tissue were 1.25 in MG and 2.51 in RV. For fourteen PTEs, the MPI from metal intake by ingesting two crustacea species were over than 1, indicating risk from consumption. In addition to this, since the THQ value of Cd and hazard index (HI) were determined above 1, it can be said that it does pose public health risk for RV.

Assessment of heavy metals, PAHs, and pesticide levels in yerba mate on the European market.

Although yerba mate has been known and used for hundreds of years, not all of its properties have been fully understood yet. Yerba mate is a source of many desirable substances, but it may also contain toxic metals and other substances that are harmful to health. Fifteen samples of yerba mate tea from three South American countries were analyzed. The content of Cr, Ni, and Cd was determined using the AAS technique, while the PHA's content was determined with the gas chromatography method. Our studies show that some of the analyzed substances present in Ilex paraguariensis may exceed their acceptable levels specified in European standards established for the given substances. All analyzed samples contained the determined metals, where the concentrations of individual elements ranged from 1.92 ± 0.38 to 0.12 ± 0.05µg/g (for Cr), from 4.86 ± 0.28 to 1.72 ± 0.14µg/g (for Ni), and from 0.0008 ± 0.000 to 0.0695 ± 0.0745µg/g (for Cd). The total PAH content ranged from 0.064 to 0.585mg/kg. Yerba mate samples from Brazil were characterized by a lower PAH content (0.064-0.254mg/kg), compared with mate from Argentina and Paraguay (0.084-0.374 and 0.197-0.585mg/kg, respectively). Pesticide residues were found only in samples from Argentina and Paraguay, while samples from Brazil did not contain those compounds. Only four active substances belonging to the group of herbicides, fungicides, and insecticides were detected, two of them not approved for use in the EU: chlorpyrifos and fenbuconazole. The most frequently detected compounds in yerba mate samples were pendimethalin (in four samples), fluazifop-p-butyl and fenbuconazole (detected in two samples), and chlorpyrifos (in one sample).

Investigation of the relationship between lead exposure in heavy metals mixtures and the prevalence of stroke: a cross-sectional study

BackgroundThe adverse effects of environmental toxic metal exposure on human health are well-documented. However, the specific influence of heavy metal exposure on stroke prevalence remains underexplored.MethodsThis study utilized data from the National Health and Nutrition Examination Survey (NHANES) spanning from 2011 to 2018 to investigate the association between blood metal concentrations and the incidence of stroke. Four analytical approaches—logistic regression, Restricted Cubic Splines (RCS), Weighted Quantile Sum regression (WQS), and Bayesian Kernel Machine Regression (BKMR)—were employed to assess the relationship, with a mediation analysis conducted to explore the role of inflammatory markers in Pb exposure-induced stroke.ResultsAmong the 9,399 participants in this project, 421 (4.4%) were diagnosed with stroke. After adjusting for covariates, a multivariable logistic regression model identified a positive association between the logarithmic concentration of Pb and the incidence of stroke. Besides, the analysis conducted using both WQS and BKMR methodologies found a consistent positive association between the composite exposure to heavy metals and the frequency of stroke cases, with Pb emerging as the predominant factor in this relationship. An evident saturation phenomenon was noted in the correlation between lead exposure and the risk of stroke. Additionally, the interplay between Pb exposure and stroke manifestation was found to be partially mediated by inflammatory markers, which were responsible for 6.9% of the observed effect (95%CI:0.01, 0.24, P = 0.03).ConclusionThese findings indicate a notable contribution of Pb exposure to stroke risk, highlighting inflammation as a significant intermediary mechanism in the Pb exposure-stroke association.

New complete genome insights into Enterobacter roggenkampii FACU2: a potential player in cadmium bio-removal.

Industrial workplaces, particularly those involved in ore processing or smelting, pose a high risk of exposure to cadmium, a highly toxic metal. This study isolated and identified eight cadmium-resistant strains from industrial wastewater for their ability to resist cadmium. Enterobacter roggenkampii FACU2 demonstrated exceptional cadmium removal capabilities during our analysis, successfully eliminating 62% of the cadmium. Additionally, transmission electron microscopy (TEM) was utilized to examine the morphological change between the most and least efficient strains that responded to cadmium stress at the cellular level. Compared to the control bacteria, the treated bacteria exhibited notably higher levels of cadmium adsorption and accumulation within their cells. A complete genome analysis revealed that E. roggenkampii FACU2 has one chromosome and one plasmid with a size of 4,856,454bp and 80,926bp, respectively, in addition to harboring numerous heavy metal-resistant genes related to cadmium and other heavy metals. Moreover, the gene expression of four cadmium-resistant genes (czcA, cadA, czcC and czcD) showed that the high cadmium concentration led to a significant increase in czcA and cadA mRNA levels, thus indicating the activation of cadmium-resistant genes in the E. roggenkampii FACU2 compared to Enterobacter sp. strain FACU. Due to its ability to remove cadmium and other heavy metals, this strain holds promise as a source of genes for biological treatment methods. This application could contribute to environmental purification, ultimately benefiting human health.

Genetic and biochemical determinants in potentially toxic metals resistance and plant growth promotion in Rhizobium sp LBMP-C04.

The association of bacteria resistant to potentially toxic metals (PTMs) with plants to remove, transfer, or stabilize these elements from the soil is an appropriate tool for phytoremediation processes in metal-contaminated environments. The objective of this study was to evaluate the potential ofRhizobiumsp. LBMP-C04 forphytoremediation processes and plant growth promotion in metal-contaminated soils. Functional annotation allowed us to predict a variety of genes related to PTMs resistance and plant growth promotion in the bacterial genome. Resistance genes are mainly associated with DNA repair, and the import or export of metals in bacterial cells to maintain cell homeostasis. Genes that promote plant growth are related to mechanisms of osmotic stress tolerance, phosphate solubilization, nitrogen metabolism, biological nitrogen fixation, biofilm formation, heat shock responses, indole-3-acetic acid (IAA) biosynthesis, tryptophan, and organic acids metabolism. Biochemical tests indicated thatRhizobiumsp. LBMP-C04 can solubilize calcium phosphate and produce siderophores and IAAin vitroin the presence of the PTMs Cd2+,Cu2+,Cr3+,Cr6+, Zn2+, and Ni2+. Results indicate the possibility of usingRhizobiumsp. LBMP-C04 as a potentially efficient bacterium in phytoremediation processesin environments contaminated by PTMs and simultaneously promote plant growth.

Preliminary Study on the Measurement of Cadmium Levels in Scavenger Hair at Sukawinatan Landfill Palembang

Cadmium (Cd) is a toxic heavy metal with the potential to contaminate the environment, particularly in landfill sites using open dumping systems, such as the Sukawinatan Landfill in Palembang. This study aims to measure Cd levels in scavengers’ hair as an indicator of heavy metal exposure. A cross-sectional study design was conducted in January 2024, with hair samples collected from five respondents using purposive sampling techniques. Cd levels were measured using the Atomic Absorption Spectrophotometry (AAS) method. The results showed that Cd levels in the scavengers' hair ranged from 0.31 to 0.99 ppm, exceeding the normal limit set which is <0.10 ppm. The duration of work as a scavenger was identified as the dominant factor influencing Cd levels, although anomalies were observed in younger scavengers with high exposure intensity. These findings suggest that the working environment at the landfill significantly contributes to the accumulation of Cd in the body. This study provides preliminary insights into the health risks faced by scavengers at the Sukawinatan Landfill, which can serve as a basis for developing policies and mitigation measures to improve scavengers' occupational health and safety.

The Use of Diatomite-Based Composites for the Immobilization of Toxic Heavy Metals in Industrial Wastes Using Post-Flotation Sediment as an Example

Composite materials based on diatomite (DT) with the addition of biochar (BC), dolomite (DL), and bentonite (BN) were developed. The effect of chemical modification on the chemical structure of the resulting composites was investigated, and their influence on heavy metal immobilization and the ecotoxicity of post-flotation sediments was evaluated. It was demonstrated that the chemical modifications resulted in notable alterations to the chemical properties of the composites compared to pure DT and mixtures of DT with BC, DL, and BN. An increase in negative charge was observed in all variants. The addition of BC introduced valuable chemically and thermally resistant organic components into the composite. Among the chemical modifications, composites with the addition of perlite exhibited the lowest values of negative surface charge, which was attributed to the dissolution and transformation of silicon compounds and traces of kaolinite during their initial etching with sodium hydroxide. The materials exhibited varying efficiencies in metal immobilization, which is determined by both the type of DT additive and the type of chemical modification applied. The greatest efficacy in reducing the mobility of heavy metals was observed in the PFS with the addition of DT and BC without modification and with the addition of DT and BC after the modification of H2SO4 and H2O2: Cd 8% and 6%; Cr 71% and 69%; Cu 12% and 14%; Ni 10% and Zn 15%; and 4% and 5%. In addition, for Zn and Pb, good efficacy in reducing the content of mobile forms of these elements was observed for DT and DL without appropriate modification: 4% and 20%. The highest reduction in ecotoxicity was observed in the PFS with the addition of DT and BC, followed by BN and DL, which demonstrated comparable efficacy to materials with DT and BN.

Ecological Disturbances and Adaptation of Mangroves in High-Disturbance Urban Areas of Navi Mumbai in India

Mangroves are coastal ecosystems characterized by salt-tolerant intertidal forest structures that serve as vital buffer zones between the coastal waters and human habitats. They expose an evolutionary course spanning around 60 million years, leading to the emergence of tailored adaptations like salt-excreting glands and prop roots. Despite widespread acknowledgment of their value, mangroves are swiftly declining due to coastal development and climate change. Rapid urbanization has increased anthropogenic pressures on these ecosystems, yet comprehensive assessments of their resilience in highly disturbed environments remain limited. This study looks at the ecological health of mangrove populations across three sites in Navi Mumbai, areas facing high urban and industrial growth. The analysis revealed elevated Zn (-0.88, p < 0.001), Cu (-0.73, p < 0.01), Pb (-0.70, p < 0.05), and Mn (-0.76, p < 0.01) correlating with reduced plant height, alongside consistently acidic water pH (mean = 5.93) and high salinity (range: 35–40 PSU). These conditions amplify metal mobility and toxicity, disrupting pneumatophore function, and lowering DO (mean = 3.8 mg/L), reflecting ecological degradation. Despite these stressors, mangrove populations exhibited decent growth traits, demonstrating a capacity for urban adaptation. Regulations of industrial discharge to reduce heavy metal specifically zinc contamination, coupled with targeted restoration efforts focusing on enhancing mangrove density and structural integrity, are essential to sustain these ecosystems.

SOIL POLLUTION AND HEAVY METAL CONTAMINATION: INSIGHT FROM EFFLUENT DISCHARGED FROM CHALLAWA INDUSTRIAL AREA, NIGERIA

The discharge of industrial wastewater represents a significant source of environmental pollution, particularly in developing regions where regulatory enforcement is often insufficient. This study examined the chemical characteristics of effluent discharged from three locations (LA, LB, and LC) close to the Challawa Industrial Area in Kano, Nigeria, and determined their effects on nearby soil. Effluent samples were analysed for pH, biochemical oxygen demand (BOD), phosphates (PO), nitrates (NO-N) and critical toxic heavy metals (HMs) such as lead (Pb), chromium (Cr), copper (Cu), Zinc (Zn) and cadmium (Cd). Simultaneously, soil samples from three locations near the discharge point were evaluated for pH, total nitrogen (TN), and total phosphorus (TP). The results revealed that effluent concentrations of HMs and nutrients far exceeded the permissible limits of the National Environmental Standards and Regulations Enforcement Agency. The Pb (90.79 mg/L), Cd (10.06 g/L), Zn (33.43 mg/L), Cr (4.49 mg/L), and Cu (12.76 mg/L) concentrations were well above the regulatory limits of 0.05 mg/L, 0.01 mg/L, 0.05 mg/L, 0.01 mg/L, and 0.02 mg/L, respectively. The Phosphate (299.74 mg/L) and nitrate (381.97 mg/L) levels also exceeded NESREA standards, indicating a significant risk of eutrophication in nearby water bodies. Regression analysis revealed that higher pH tended to increase the concentration of both nutrients, with P showing a more consistent and stronger association (p<0.05) than nitrogen. This study, therefore, highlight that HMs contamination is evident in the soils around the study area, posing risks to soil fertility and agricultural productivity.

Adsorption of lead (II) in a single and multi-metal system by hydrochar from pulp and paper sludge

AbstractLead (II) is one of the most toxic heavy metals found in South African wastewater due to various mining activities. Hence, effective and cheaper methods are needed to treat this wastewater before it is released to the environment. The effectiveness of hydrochar, synthesised from pulp and paper sludge, as an adsorbent for lead (II) removal from synthetic wastewater was determined. The effect of adsorbent dosage, solution pH, lead (II) initial concentration and time on the adsorption of lead by the hydrochar was investigated. The hydrochar was synthesised at 180, 220 and 250 °C. The most favourable hydrothermal carbonisation (HTC) temperature to synthesise pulp and paper sludge hydrochar for lead (II) adsorption was 180 °C based on the temperatures investigated. The hydrochar synthesised at 180 °C were modified with sodium hydroxide to improve its metal uptake. FTIR results showed that the NaOH modification increased the concentration of oxygen containing functional groups. Furthermore, the BET surface area of the hydrochar increased after modification. The hydrochar had a cellulose crystalline structure. The sodium hydroxide modification increased the maximum adsorption capacity from 24.72 to 37.32 mg.g−1. Moreover, the modified hydrochar synthesised at 180 °C (HC-180-NaOH) was effective in the adsorption of lead (II) in the presence of copper (II), cadmium (II) and zinc (II) where the affinity of the heavy metals towards the hydrochar was lead (II) > copper (II) > cadmium (II) ≈ zinc (II). Hence, the hydrochar, synthesised from waste material, is a potential adsorbent for the adsorption of lead (II) in industrial wastewater. Graphical abstract

Natural Low-Melting Mixture Solvents for Green Recovery of Spent All-Solid-State Sodium-Ion Batteries with Superior Efficiency over Lithium-Ion Batteries.

Spent all-solid-state sodium-ion batteries (ASIBs) containing toxic and precious metal would be produced significantly and lead to resource waste and environmental pollution as the wide application of ASIBs in the near future. Therefore, it is necessary to develop green strategy for recovery of ASIBs. Here, we propose a safe, mild and green strategy to recover toxic and precious metals from cathode/solid electrolyte of ASIBs by using natural low-melting mixture solvents (LoMMSs) with high selectivity and high leaching efficiency. Natural LoMMSs are abundant, natural available, cheap, non-flammable, biodegradable and biocompatible. Results show that natural LoMMSs could leach nearly 100% Na and achieve superhigh Na/Zr selectivity of up to 58 from ASIBs at mild temperature, outperforming the recycling efficiency and selectivity of lithium-ion batteries cathode. More importantly, we find that water could be used as a green and low-cost anti-solvent to precipitate the extracted metal from the leachate with low-energy consumption at room temperature. This work provides a cost-effective, energy-saving, mild, green strategy for the recovery of cathode/solid electrolyte from spent ASIBs with high safety and high selectivity.

Essential and toxic metal concentrations in biological samples of multiple sclerosis patients: A systematic review and meta-analysis.

The role of trace elements and toxic metals on human health has been extensively discussed concerning disease pathogenesis and risk factors of diseases. In this systematic review and meta-analysis, we aimed to investigate arsenic (As), cadmium (Cd), lead (Pb), iron (Fe), zinc (Zn), and magnesium (Mg) levels in individuals with multiple sclerosis (MS) and healthy controls. We searched different databases/search engines for this systematic review and meta-analysis, including Web of Science, PubMed, Scopus, and Google Scholar, until June 27, 2024. Out of 5466 studies identified, 65 met our eligibility criteria and were included in the systematic review. For the meta-analysis, 58 studies with 10420 participants (5316 multiple sclerosis patients and 5104 healthy controls) had adequate data for inclusion. Results from the pooled data, analyzed using a random-effects model, revealed higher levels of As (Hedge's g = 4.00 μg/l, 95% CI = 2.03 to 5.98, P <0.001; I2 = 97.69%, P<0.001) and Cd (Hedge's g = 1.20 μg/l, 95% CI = 0.13 to 2.27, P = 0.028; I2 = 97.99%, P<0.001) in multiple sclerosis patients compared to healthy ones. However, no significant differences were observed in the concentrations of Zn, Fe, Mg, and Pb between the two groups. This study identified elevated As and Cd levels in MS patients, indicating the need for targeted interventions and public health guidelines for toxic metal exposure. Limiting exposure to contaminated environments and maintaining essential element levels through natural resources or supplements is essential, as there may be a possible relationship between multiple sclerosis and the concentrations of these elements in humans.

Review of Correlations Between Telomere Length and Metal Exposure Across Distinct Populations

Telomere length (TL) predicts the onset of replicative senescence, and its shortening is a limiter on the number of divisions individual somatic cells can perform. Metal-induced genotoxic events are discussed in Agency for Toxic Substances and Disease Registry’s (ATSDR) toxicological profiles. In vivo and in vitro toxicological studies suggest the correlation between toxic metals and TL. However, the correlation between TL and exposure to toxic metals in human populations is unclear despite decades of observational research. We conducted a literature search within the ATSDR toxicological profiles and PubMed database for peer-reviewed articles as of 04/2023 discussing TL and metal exposure in human populations. Through review of the 272 publications meeting these criteria, we identified 25 observational studies that considered the correlation between TL and exposure to some or all of six metals: cadmium (Cd), arsenic (As), nickel (Ni), selenium (Se), lead (Pb), and cesium (Cs). Because reported effect sizes were often not comparable across studies, we performed a sign test based on the reported significance for each metal–TL correlation. We found that Cd was consistently significantly correlated with shorter telomeres (p = 0.016). However, no consistent linear relationship was observed between TL and any of the other metals considered. Exploring this association can enhance our understanding of how metal exposure may influence TL dysfunction. Our findings suggest that Cd exposure contributes to shorter TL, which may affect the DNA damage response (DDR) resulting in numerous chronic health conditions. Further, we highlight inconsistencies in findings on the correlation between metal exposure and TL across different populations and exposure levels. This suggests that correlations between some metals and TL may vary across populations, and that correlations may change at different exposure levels. Also, our findings suggest the need for further research on the potential for nonlinear relationships and non-additive effects of co-exposure to multiple hazardous metals, which could explain the inconsistencies observed across studies. The inconsistent incidences of metal–TL correlations justify additional exploration into the complex interaction between metals and TL.

Elemental Distribution in Tissues of Shorthorn Sculpins (Myoxocephalus scorpius) from Kongsfjorden in Svalbard

The shorthorn sculpin (Myoxocephalus scorpius) is considered a suitable sentinel species for marine pollution in the Arctic due to its ecology and stationary habits. To evaluate its role as a bioindicator for potential natural and anthropic impacts on the marine ecosystem of the Kongsfjorden (Svalbard, Norwegian Arctic), 33 female and male specimens of shorthorn sculpins were collected in July 2018 in proximity of the Ny-Ålesund international research facility and analyzed for the content of 25 major and trace elements and methylmercury (MeHg) in the muscle, liver, gonads, and gills by using spectroscopic techniques. Most elements had their maximum average concentrations in the gills (Al, Cr, Fe, Mn, Na, Ni, Pb, Se, Si, Sr, and V), while the livers featured higher contents of some toxic and heavy metals (As, Cd, Cu, Mo, and Zn). The muscle was characterized by high contents of Ca, K, and Mg, while Ba, Co, and P were mostly concentrated in the gonads. The gonads presented higher concentrations of Cr, K, Mg, Ni, P, and V for the males and Co, Cu, Fe, Mn, and Se for the females. Both the total Hg and MeHg concentrations in the muscle correlated with the fish size, indicating bioaccumulation, although high Se/Hg molar ratios (11.0 ± 2.2) suggested a low toxic potential of mercury.

Green and sustainable synthesis of 3,4-Dihydropyrimidin-2(1H)-ones/thiones via the Biginelli reaction using L-arabinose as a renewable catalyst under solvent-free conditions

In the pursuit of sustainable methodologies in organic synthesis, the application of renewable and biodegradable catalysts has received significant attention. This work processes the synthesizing of 3,4-dihydropyrimidin-2(1H)-ones/thiones using L-arabinose, an environment-friendly catalyst via the Biginelli reaction in a solvent-free environment is reported herein. L-arabinose, a naturally occurring sugar, efficiently catalyzes the condensation reaction between β-ketoesters and aldehyde with urea or thiourea to form DHPMs with high yields and excellent atom economy. The reaction proceeds efficiently at mild temperatures, and the catalyst is easily regenerated, enabling multiple catalytic cycles. The use of L-arabinose avoids not only toxic solvents and metal catalysts but also processes green chemistry due to the exploitation of renewable resources. It is a significant step forward in the domain of sustainable catalysis and provides an environmentally benign and operationally simple procedure for the synthesis of DHPMs.

A Preliminary Health Risk Assessment of Heavy Metal Contamination in Chembarambakkam Lake, Tamil Nadu, South India

Chembarambakkam Lake, an important freshwater reservoir in Chennai that provides drinking water to the city, has noticed a decline in water quality as a result of heavy metal pollution. This study aimed to evaluate the heavy metal contamination in the environment of Chembarambakkam Lake with a health risk assessment. This study involved a comprehensive analysis of toxic heavy metal levels in five waters, sediments, and commercially available freshwater fish samples, considering their bioaccumulation and potential risks to human health. We observed lead (Pb), cadmium (Cd), zinc (Zn), and copper (Cu) concentrations in water, sediments, and various fish species, including tilapia (Mozambique Tilapia), wild carp (Hemiculter leucisulus), pearl-spot (Etroplus maculatus), spotted barb (Barbodes binotatus), and snakehead murrel (Channa Striate). The results indicated that, in order of prominence, the metals in the water were Cu &gt; Zn &gt; Pb &gt; Cd, whereas those found in sediments were Zn &gt; Cu &gt; Pb &gt; Cd. The metal concentration in the sediments varied between Cd (0.52–0.82 µg/g), Cu (13.75–38.07 µg/g), Pb (1.30–3.74 µg/g), and Zn (12.60–61.12 µg/g). Similarly, the metal concentrations in the water varied between Cd (0.63–0.72 µg/L), Cu (5.35–55.17 µg/L), Pb (BDL–12.39 µg/L), and Zn (0.62–1.49 µg/L). The order of metals in the fish was Zn &gt; Cd &gt; Cu &gt; Pb. The Cd concentration ranged from 0.3 to 0.60 µg/g, Cu was from BDL to 0.72 µg/g, Pb was from BDL–0.68 µg/g, and Zn was from 13.32–48.48 µg/g. The Cd and Zn concentrations were consistently the highest across the fish, sediment, and water samples. These findings shed light on the health risks associated with heavy metal pollution in Chembarambakkam Lake and suggest the need for potential bioremediation approaches.

Heavy Metals and Associated Risks of Wild Edible Mushrooms Consumption: Transfer Factor, Carcinogenic Risk, and Health Risk Index

This research aims to investigate the heavy metals (i.e., Cd, Cr, Cu, Ni, and Pb) in the fruiting bodies of six indigenous wild edible mushrooms including Agaricus bisporus, Agaricus campestris, Armillaria mellea, Boletus edulis, Macrolepiota excoriate, and Macrolepiota procera, correlated with various factors, such as the growth substrate, the sampling site, the species and the morphological part (i.e., cap and stipe), and their possible toxicological implications. Heavy metal concentrations in mushroom (228 samples) and soil (114 samples) were determined by Inductively Coupled Plasma—Mass Spectrometry (ICP-MS). In the first part of the study, the soil contamination (index of geo-accumulation, contamination factor, and pollution loading index) and associated risks (chronic daily dose for three exposure pathways—ingestion, dermal, and inhalation; hazard quotient of non-cancer risks and the carcinogenic risks) were calculated, while the phytoremediation capacity of the mushrooms was determined. At the end of these investigations, it was concluded that M. procera accumulates more Cd and Cr (32.528% and 57.906%, respectively), M. excoriata accumulates Cu (24.802%), B. edulis accumulates Ni (22.694%), and A. mellea accumulates Pb (18.574%), in relation to the underlying soils. There were statistically significant differences between the stipe and cap (i.e., in the cap subsamples of M. procera, the accumulation factor for Cd was five times higher than in the stipe subsamples). The daily intake of toxic metals related to the consumption of these mushrooms with negative consequences on human health, especially for children (1.5 times higher than for adults), was determined as well.

Enhancing the oil extraction process and exploring phytochemical composition and bioactivities of bitter melon seeds (Momordica charantia L.)

This study was conducted to determine the phytochemical composition of bitter melon seeds (Momordica charantia L.) grown in Long An province (Vietnam), to investigate optimal conditions for lipid extraction, and to evaluate the extracted lipid’s quality. The seeds had a moisture content of 5.27%, total ash of 1.85%, total flavonoid content of 91.10 mg/100 g, and total polyphenol content of 478.95 mg/100 g. The seeds were also free of highly toxic metals such as lead and cadmium. Using the Soxhlet method, optimal lipid extraction was achieved with a material-to-solvent ratio of 1:80 (w/v) over 4 hours, resulting in a lipid extraction efficiency of 13.74%. The acid, saponification, ester, and peroxide values were 1.01 mg KOH/g, 355.60 mg KOH/g, 354.59 mg KOH/g, and 3.82 meq O2/kg, respectively, in compliance with the quality requirements of Vietnam and Codex standards. The extracted lipids had antioxidant activity at an IC50 value of 119 mg/mL and inhibited the growth of two microbial strains Staphylococcus aureus and Bacillus subtilis subsp. spizizenii. These findings suggest that bitter melon oil has potential applications in the food, pharmaceutical, and cosmetic industries.