Search Results (541)

Quantum dots such as CdS QDs have been extensively studied using human cells, plants, and unicellular eukaryotes such as Saccharomyces cerevisiae, whereas ZnS QDs—considered low-toxicity alternatives to cadmium-based nanomaterials—remain comparatively underexplored. Following preliminary analyses of ZnS QDs’ effects on wild-type S. cerevisiae BY4742 growth, the Yeast Knock-Out collection, comprising ~4600 haploid mutants deleted in non-essential genes, was screened in the presence of ZnS QDs. Sensitive mutants were predominantly associated with mitochondrial functions, prompting further characterization of sod1Δ, glr1Δ, and of the hypersensitive mutant pos5Δ. This last mutant, which lacks a mitochondrial NADH kinase, showed hypersensitivity specific to ZnS QDs but not to CdS QDs or zinc sulfate (ZnSO₄). Flow cytometry analysis of the wild-type strain and the pos5Δ mutant detected no significant increase in reactive oxygen species after ZnS QD treatment. RNA-sequencing analyses of the wild-type strain and the pos5Δ mutant exposed to ZnS QDs (or ZnSO₄) revealed that ZnS QD exposure selectively modulated genes encoding mitochondrial proteins, metal-binding factors, and intracellular trafficking components. Comparison with published data on CdS QDs identified specific mechanisms involving protein synthesis and degradation. Saccharomyces cerevisiae once again proved its versatility for studying engineered nanomaterial interactions with biological systems. Full article

The orthogonal design further optimized the culture medium to a combination of ammonium nitrate, sucrose, and magnesium sulfate, achieving a mycelial growth rate of 1.379 mm/d. The mycelia of Gerhardtia borealis contained 26.01% crude protein, 6.03% crude fat, and 1.24% crude polysaccharides. A total of 17 amino acids were detected, with a total content of 26.09 g/kg. The iron and zinc contents in the mycelia were 28.09 mg/kg and 22.17 mg/kg, respectively. The concentrations of arsenic, cadmium, mercury, and lead were all below the national food safety limits. This study provides fundamental data supporting the domestication and functional utilization of Gerhardtia borealis as an edible and medicinal resource. Full article

Cadmium (Cd) and polystyrene (PS) microplastic co-contamination in agricultural soils poses a potential threat to food security. Some functional microorganisms in soil can alleviate the dual stress of Cd and PS on crops. In this study, a biofilm-forming bacterium, Enterobacter sp. W5, was isolated from heavy metal-contaminated rhizosphere soil. Strain W5 exhibited Cd removal efficiency (46.3%) and strong biofilm-forming capacity (OD₅₇₀ = 5.05), and it effectively colonized PS microplastic surfaces. XPS analysis detected bacterial functional groups (C–O–C, C=O) and PS-associated signals (O–C=O), which may act synergistically in Cd²⁺ adsorption. Furthermore, XPS and XRD analyses revealed the presence of Cd-containing precipitates (including CdS, CdO, and Cd₃(PO₄)₂). In hydroponic wheat experiments, W5 inoculation alleviated Cd-PS combined stress, thus significantly promoting plant growth and reducing Cd accumulation by 22.6% in roots and by 34.2% in aboveground tissues. Subcellular distribution analysis revealed that W5 enhanced Cd retention in root cell walls, thereby limiting its translocation to active cellular compartments. Proteomic analysis identified a set of 11 consistently downregulated proteins, including A0A3B6HQ68 and A0A3B6KJV9, which were enriched in secondary metabolite biosynthesis pathways. Bioinformatic analysis suggests that these proteins may be associated with Cd stress responses, though their exact roles remain to be verified. Collectively, this study provides a valuable microbial resource and mechanistic insights into the application of biofilm-forming bacteria for mitigating combined heavy metal–microplastic pollution in agricultural systems. Full article

This study assessed, in two coastal locations of Ecuador (Cerecita, Guayas; Bajada de Chanduy, Santa Elena), cadmium (Cd) occurrence in cacao cultivated soils, its transfer to plant tissues (leaves and cotyledon/beans), and its implications for producers’ economic sustainability. Twelve cacao-producing sites in Cerecita and eleven in Bajada de Chanduy were georeferenced, and thematic GIS maps were generated to identify potential Cd hotspots. Sampling comprised topsoil (0–10 cm), leaves (fourth fully expanded leaf), and dried/fermented beans, followed by laboratory Cd quantification. In addition, producer surveys were conducted to characterize productive and economic structure, the economic sustainability index (IK) was calculated using Sarandón’s methodology, and interviews with collectors and agri-export companies were performed. Soil Cd levels were comparable between locations (0.24–1.55 mg kg⁻¹), whereas higher concentrations were detected in cotyledons/beans (0.53–5.01 mg kg⁻¹) and leaves (1.13–11.07 mg kg⁻¹), following the pattern leaves > cotyledon > soil. From an economic perspective, all farms exhibited IK < 2, with a marked territorial gap (≈1.6 in Cerecita vs. ≈0.5 in Chanduy). Cadmium in cocoa beans poses a long-term risk to marketing; in addition, total cadmium in the soil did not consistently predict cadmium in the cotyledons, and adverse impacts are amplified in territories with limited economic capacity to respond. Full article

(1) Background: Highway toll plazas are environments impacted by atmospheric pollutants that may affect workers’ health. However, there are still few studies on these environments. This study evaluated particulate matter (PM) concentrations by size fraction (PM_10–9.0 to PM_0.43) and associated arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb) and vanadium (V) at two toll plazas in Brazil. (2) Methods: PM and trace element concentrations were compared between dry and rainy seasons, and a health risk assessment was conducted for toll collectors based on inhalation exposure. (3) Results: PM_10–2.5 concentrations ranged from 31.8 to 360 µg m⁻³ in the dry season and from non-detectable to 287 µg m⁻³ in the rainy season. PM_2.5 levels varied between 14.9 and 150 µg m⁻³ (dry) and 3.46–174 µg m⁻³ (rainy). Although trace element concentrations were within Occupational Safety and Health Administration (OSHA) limits, the hazard quotient (HQ) for manganese and arsenic exceeded unity (HQ > 1), indicating potential health risks. (4) Conclusions: These findings suggest that toll plaza workers may experience increased inhalation-related risk under the exposure assumptions used. Improved ventilation and protective measures, including the use of protective screens, are recommended to reduce occupational exposure. Full article

Spectral chest radiography with photon-counting detectors (PCDs) enables energy-resolved acquisition for bone/soft-tissue separation, but quantitative performance depends on detector cross-talk and the selected material decomposition algorithm. We performed a controlled simulation study comparing a conventional low-order polynomial decomposition model with two machine learning regressors (multilayer perceptron (MLP) and support vector regression (SVR)) for a cadmium telluride (CdTe) PCD. A Geant4-derived detector response model, coupled with a charge-transport model, was integrated into a physics-forward model including charge sharing and Poisson quantum noise. Digital LucAl/IEC 62220-2-1 phantoms with aluminum and polymethyl methacrylate inserts were used for quantitative bias/root mean square error (RMSE) evaluation, and task-based low-contrast detectability that was evaluated using an exponential transformation of the free-response operating characteristic (EFROC) method using a matched-filter template. Performance was evaluated over clinically relevant dose levels (0.07–7.5 mAs), calibration grid densities ($3\times 3$ to $8\times 8$), and numbers of energy thresholds ($M=2$–6). Polynomial decomposition was stable under sparse calibration, whereas ML methods benefited strongly from denser calibration and additional thresholds; SVR achieved the lowest RMSE under dense calibration, while MLP produced smoother maps and improved soft-tissue detectability at low-to-intermediate dose. At high dose, all methods approached near-ideal detection performance. These results quantify practical trade-offs between calibration requirements, quantitative accuracy, and low-contrast detectability for PCD-based spectral chest radiography. Full article

The uniformity of local photoelectric properties in infrared detectors is critical for detection sensitivity. However, micro-nano-scale surface abnormalities introduced during mercury cadmium telluride (HgCdTe) fabrication systematically degrade in-plane photoelectric response consistency. To overcome the optical diffraction limits of standard far-field metrology, we utilized a cryogenic scattering-type scanning near-field optical microscopy (Cryo-SNOM) system to achieve the first super-resolution, in situ imaging of local near-field photocurrent in HgCdTe photoconductive detectors at 10 K. Device-level measurements reveal that sub-wavelength surface protrusions (~tens of nanometers high) act as strong recombination centers, suppressing local photocurrent and causing a consistent 10~20% relative signal attenuation compared to planar regions. Power and bias-dependent testing indicate these defects function as unsaturated linear recombination states. Increasing bias voltage amplifies the coupling between the external field and the defect’s built-in field, broadening the local depletion region and driving a non-linear escalation in the attenuation ratio. This study establishes quantitative engineering tolerances for morphological deviations at the nanoscale, providing critical criteria for the chip integration, structural optimization, and precision manufacturing of high-performance infrared sensing arrays. Full article

Water resources face a significant environmental challenge: pollution from microplastics (MP) and heavy metals (HM). These elements pose a dual threat to ecosystems and public health. Microplastics, defined as particles smaller than 5 mm, are of anthropogenic origin, resulting from the degradation of plastics by environmental factors such as solar radiation and friction with the surrounding environment, as well as from their addition to cosmetic and textile products. These materials have been widely detected in drinking water and everyday foods. Heavy metals, high-density elements $(>5{\mathrm{g}/\mathrm{cm}}^3)$, while naturally present in the Earth’s crust, are also generated in large quantities through human activity. Their toxicological risk lies in their ability to accumulate and efficiently move through the trophic chain. Due to the risks to public health and the impacts these pose to ecosystems, it is necessary to continue seeking solutions that enable their monitoring and detection. As a contribution, this work presents a methodology for detecting microplastics and heavy metals in seawater using different machine learning models and an electronic tongue coupled to a sensor network. Two different types of heavy metals, primarily zinc (Zn) and cadmium (Cd), as well as microplastic particles composed of expanded polystyrene (EPS), were detected under controlled conditions simulating different types of water. Atomic absorption spectroscopy (AAS) confirmed the concentrations of the heavy metals studied, supporting machine-learning classification of contaminated waters. Microplastics exhibited strong metal adsorption, influenced by the physicochemical properties of the water. Overall, AUC values above $90\%$ were obtained for seven different models, demonstrating the reliability of the electronic tongue in conjunction with classical machine learning techniques for detecting these elements. Full article

Human milk (HM) is recognized as the optimal source of nutrition for infants, providing essential nutrients, bioactive compounds, and immunological protection crucial for proper growth and development. However, due to increasing environmental pollution, HM may also serve as a vector for exposure to toxic substances, including heavy metals. These contaminants originate from both current environmental exposure and long-term accumulation in maternal tissues, which may be mobilized during pregnancy and lactation. Objectives: The aim of this review was to comprehensively analyze the occurrence, sources, and determinants of heavy and toxic metals in human milk, with particular emphasis on maternal–infant transfer pathways and geographical variability of exposure. Methods: A structured narrative review with systematic literature search elements was conducted using PubMed, Scopus, and Web of Science databases. The search covered studies published between 2010 and 2025 and was limited to articles written in English. The search strategy included terms related to human milk and heavy metal exposure (Pb, Cd, Hg, As, Cr, Al). Predefined inclusion and exclusion criteria were applied, and a qualitative synthesis of environmental, dietary, physiological, and lifestyle-related determinants, as well as geographical variability, was performed. Results: The available evidence indicates that heavy metals are commonly detected in human milk worldwide, with concentrations strongly influenced by environmental pollution, maternal diet, and lifestyle factors. Under typical exposure conditions, reported concentration ranges are approximately 2–5 µg/L for lead (Pb), 1.4–1.7 µg/L for mercury (Hg), and below 1 µg/L for cadmium (Cd). However, substantially higher levels have been reported in highly contaminated regions, with extreme values exceeding 1000 µg/L for Pb and 100 µg/L for Hg in isolated cases. Key exposure pathways include contaminated food, drinking water, air pollution, and endogenous mobilization of metals stored in maternal tissues (particularly bone and adipose tissue). Significant geographical variability was observed, with higher concentrations reported in industrialized and mining regions. Infants represent a highly vulnerable population due to immature detoxification systems, increased gastrointestinal absorption, and ongoing neurodevelopment, which may amplify toxic effects even at low exposure levels. Conclusions: Although human milk remains the gold standard for infant nutrition, the presence of heavy metals highlights the need for continuous environmental monitoring and preventive strategies aimed at reducing maternal exposure. The benefits of breastfeeding clearly outweigh the potential risks; however, minimizing environmental contamination remains a critical public health priority. Future research should focus on standardizing analytical methods, improving biomonitoring strategies, and better characterizing long-term health outcomes associated with early-life exposure to toxic metals. Full article

Cadmium (Cd) is a ubiquitous heavy metal environmental toxicant, and exposure poses a persistent public health concern due to its bioaccumulative properties. However, the impact of maternal Cd exposure on mammary gland function during lactation remains insufficiently understood. In this study, we investigated the effects of Cd exposure during pregnancy and lactation on mammary gland development, hormonal homeostasis, and lactational performance using a drinking water exposure model. Pregnant 7-week-old ICR mice were randomly assigned into Control and Cd groups. The Control group received standard drinking water, while the Cd group was administered water supplemented with Cd (12 mg/L). Results demonstrated that maternal Cd exposure markedly reduced maternal and offspring weight, respectively. Histological analysis revealed that Cd exposure resulted in decreased numbers of mammary alveoli and widened interstitial spaces, indicating impaired mammary development. In addition, Cd exposure markedly compromised lactational performance, as reflected by reduced milk yield and decreased levels of milk protein, fat, and lactose across multiple lactation stages. Integrated metabolomic and transcriptomic analyses further revealed substantial alterations in hormonal profiles and metabolic pathways associated with mammary gland function. Notably, Cd accumulation was detected in mammary tissue and milk, accompanied by transcriptional changes in genes involved in milk synthesis and lipid metabolism. In conclusion, these findings indicated that maternal Cd exposure during pregnancy and lactation is associated with structural and functional alterations of the mammary gland, leading to reduced lactational performance and impaired offspring growth. The findings contribute to a better understanding of the risks posed by environmental Cd exposure, emphasizing the need for effective public health strategies to mitigate its impact on maternal and infant health. Full article

Severe heavy metal contamination affects the karst landscapes of Guangxi Zhuang Autonomous Region, China, which are highly polluted and complex. However, integrated assessments of heavy metal sources, distribution, ecological risks, and speciation in karst agricultural soils remain limited. Additionally, there is a gap regarding the interactions between cadmium (Cd), zinc (Zn), and selenium (Se) in natural rice fields. This study employed the pollution load index (PLI), ecological risk index (RI), and Positive Matrix Factorization (PMF) models to evaluate the sources and characteristics of heavy metal contamination in farmland soils. The results showed significant pollution in agricultural soils of Guangxi karst due to Cd, chromium (Cr), copper (Cu), and nickel (Ni). Among these, Cd poses the highest ecological risk. Heavy metal accumulation in the surface soil far exceeds that in deeper layers, and the main sources of Cd were contributed from soil parent material and agricultural activities. Speciation analysis revealed the high bioavailability of Cd, while Zn and Se existed in more stable forms. Despite elevated soil Cd levels, rice grains remained within the safety limits. Using transmission electron microscopy (TEM), Cd was primarily detected in the cell walls of rice stems and husks, which was attributed to Zn’s competitive uptake, reducing Cd absorption and Se forming complexes with Cd to enhance its fixation. Statistical correlations revealed positive associations between Cd in soil and rice. Cd also demonstrated a positive correlation with Se, but a negative correlation with Zn, suggesting a synergistic mechanism between Zn and Se that acts to mitigate the absorption of Cd. This study provides practical guidance for managing farmland soil heavy metal contamination and protecting agricultural soil resources in the karst areas. Full article

Potentially toxic elements (PTEs) in mining-impacted wetlands can transfer from soil and water to forage and grazing livestock, resulting in dietary exposure for nearby communities. In this study, arsenic (As), lead (Pb), and cadmium (Cd) were quantified in key environmental matrices (soil, surface water, and forage) and in sheep tissues (liver, kidney, and muscle) from six georeferenced grazing sites in the Ite coastal wetland (Tacna, Peru) during the dry season. Samples were acid-digested following U.S. EPA protocols and analyzed by atomic absorption spectrometry (AAS) under QA/QC procedures (certified reference materials, blanks, duplicates, and matrix spikes); matrix-specific detection and quantification limits are reported. Arsenic dominated the contamination profile (forage: 428.6 mg kg⁻¹, dry weight; soil: 48.61 mg kg⁻¹; water: 0.97 mg L⁻¹) and was detected in sheep tissues (kidney: 0.1577 mg kg⁻¹; muscle: 0.1538 mg kg⁻¹; liver: 0.0644 mg kg⁻¹). Lead and cadmium were <LOQ in muscle and liver but were measurable in kidney (Pb: 0.0415 mg kg⁻¹; Cd: 0.0011 mg kg⁻¹). To support the interpretation of trophic transfer, screening transfer/bioaccumulation metrics (soil-to-forage, forage-to-tissue, and water-to-tissue) were calculated. Human dietary exposure was screened using estimated daily intake (EDI), hazard quotient (HQ), and margin of exposure (MOE). Because arsenic speciation was not measured, inorganic arsenic (iAs) risk was evaluated as a conservative upper bound (100% iAs) and through sensitivity scenarios (10–50% iAs). Under a high-meat-consumption scenario (300 g day⁻¹), the upper-bound assumption yielded HQ = 2.2 and MOE = 0.46; however, scenario analyses indicate that risk conclusions are highly dependent on the assumed iAs fraction. Overall, the results identify arsenic as a priority contaminant and support targeted grazing management, the provision of low-arsenic water sources, and remediation and monitoring actions to reduce exposure in vulnerable rural communities. Full article

Heavy metal contamination of foods remains a persistent global challenge for food safety and public health, driven by industrialization, mining activities, intensive agriculture, and ongoing environmental degradation. This scoping review synthesizes peer-reviewed literature on the occurrence of priority toxic metals—arsenic, cadmium, lead, mercury, and nickel—in food matrices, with emphasis on contamination pathways, analytical detection strategies, and documented human health effects. The reviewed studies reveal widespread accumulation of heavy metals in staple foods, including cereals, vegetables, seafood, and processed products, with concentrations frequently approaching or exceeding international regulatory limits, particularly in regions exposed to strong anthropogenic pressure. Conventional laboratory-based techniques, such as atomic absorption spectrometry and inductively coupled plasma methods, remain the reference standards for quantitative determination and regulatory compliance; however, their application to large-scale or continuous monitoring is often constrained by cost, infrastructure, and operational complexity. Consequently, increasing attention has been directed toward emerging detection approaches, including portable X-Ray fluorescence, Raman/SERS spectroscopy, electrochemical biosensors, electronic tongues, and in situ magnetic measurements, as complementary tools for rapid screening and field-based surveillance. Among these, environmental magnetism and in situ magnetic techniques stand out as non-destructive, low-cost proxies capable of identifying metal-associated particulate contamination linked to food production systems. Chronic dietary exposure to heavy metals is consistently associated with neurotoxicity, nephrotoxicity, carcinogenicity, and oxidative stress, underscoring the need for integrated, multi-tiered monitoring frameworks to support early detection, risk assessment, and prevention. Full article

The focus of modern livestock production is increasingly shifting toward improving animal health, welfare, and product quality through the use of natural feed ingredients. Pumpkin (Cucurbita spp.) and its seeds are of interest because they contain biologically active compounds, including tocopherols and phenolic antioxidants. This study evaluated the effects of pumpkin seed cake (PSC) in rabbit diets on blood parameters, oxidative status, and trace element distribution in tissues. Sixty Popielno White rabbits were initially assigned to three dietary groups: control (0% PSC), 5% PSC, and 10% PSC. At 90 days of age, samples from 30 rabbits (10 per group) were collected and analysed. PSC supplementation significantly increased red blood cell count, haemoglobin, haematocrit, and platelet indices (p ≤ 0.05), indicating affected haematological status. It also reduced (p ≤ 0.05) urea, triglycerides, total cholesterol, and LDL cholesterol. Antioxidant status significantly improved, as indicated by higher superoxide dismutase activity and ferric-reducing antioxidant power, together with lower malondialdehyde levels (p ≤ 0.05). Mineral analysis showed lower manganese concentrations in muscle and kidney tissues; cadmium remained low, and lead was below the detection limit in muscle and liver samples. Overall, PSC may be considered a promising feed ingredient that supports haematological status, antioxidant protection, and metabolic balance under the conditions of the present study. Full article

The term ‘superfoods’ refers to a rapidly expanding group of food products that have gained increasing global interest due to their high nutritional value and association with health-oriented dietary patterns. Many superfoods, particularly grains and seeds, are rich sources of essential minerals, plant protein, dietary fibre, and bioactive compounds, making them valuable components of gluten-free, vegetarian, and vegan diets. The aim of this study was to evaluate the elemental composition of selected superfood grains and seeds and to verify the reliability of manufacturers’ declarations. The analyses confirmed that the investigated samples possess a rich macro- and trace elemental composition, with pronounced differences among product groups. Based on median concentrations, pumpkin and hemp seeds were characterized by generally high levels of Mg, K, P, Fe, Mn, and Zn, whereas chia seeds exhibited notably elevated Ca content. In contrast, quinoa and amaranth showed comparatively lower elemental concentrations. Most of the results obtained for the analysed products are within the permissible deviation from the value declared on the packaging, as specified in the relevant EU regulations. The presence of potentially toxic elements, including Al, Pb, and Cd, was also detected. Cadmium accumulation was of particular concern in flax seeds, where all samples exceeded the limit of quantification and approached permissible levels. Principal component analysis revealed clear clustering patterns, indicating similarities between amaranth and quinoa, as well as between hemp and pumpkin seeds, while chia and flax seeds formed distinct groups. These results highlight both the nutritional potential of superfoods and the necessity for independent verification of their elemental composition. Full article