Toxics

20 pages, 30581 KiB

Open AccessArticle

Hydrochemical Characteristics, Controlling Factors, and High Nitrate Hazards of Shallow Groundwater in an Urban Area of Southwestern China

by Chang Yang, Si Chen, Jianhui Dong, Yunhui Zhang, Yangshuang Wang, Wulue Kang, Xingjun Zhang, Yuanyi Liang, Dunkai Fu, Yuting Yan and Shiming Yang

Toxics 2025, 13(6), 516; https://doi.org/10.3390/toxics13060516 - 19 Jun 2025

Viewed by 336

Abstract

Groundwater nitrate (NO₃⁻) contamination has emerged as a critical global environmental issue, posing serious human health risks. This study systematically investigated the hydrochemical processes, sources of NO₃⁻ pollution, the impact of land use on NO₃⁻ pollution, [...] Read more.

Groundwater nitrate (NO₃⁻) contamination has emerged as a critical global environmental issue, posing serious human health risks. This study systematically investigated the hydrochemical processes, sources of NO₃⁻ pollution, the impact of land use on NO₃⁻ pollution, and drinking water safety in an urban area of southwestern China. Thirty-one groundwater samples were collected and analyzed for major hydrochemical parameters and dual isotopic composition of NO₃⁻ (δ¹⁵N-NO₃⁻ and δ¹⁸O-NO₃⁻). The groundwater samples were characterized by neutral to slightly alkaline nature, and were dominated by the Ca-HCO₃ type. Hydrochemical analysis revealed that water–rock interactions, including carbonate dissolution, silicate weathering, and cation exchange, were the primary natural processes controlling hydrochemistry. Additionally, anthropogenic influences have significantly altered NO₃⁻ concentration. A total of 19.35% of the samples exceeded the Chinese guideline limit of 20 mg/L for NO₃⁻. Isotopic evidence suggested that primary sources of NO₃⁻ in groundwater include NH₄⁺-based fertilizer, soil organic nitrogen, sewage, and manure. Spatial distribution maps indicated that the spatial distribution of NO₃⁻ concentration correlated strongly with land use types. Elevated NO₃⁻ levels were observed in areas dominated by agriculture and artificial surfaces, while lower concentrations were associated with grass-covered ridge areas. The unabsorbed NH₄⁺ from nitrogen fertilizer entered groundwater along with precipitation and irrigation water infiltration. The direct discharge of domestic sewage and improper disposal of livestock manure contributed substantially to NO₃⁻ pollution. The nitrogen fixation capacity of the grassland ecosystem led to a relatively low NO₃⁻ concentration in the ridge region. Despite elevated NO₃⁻ and F⁻ concentrations, the entropy weighted water quality index (EWQI) indicated that all groundwater samples were suitable for drinking. This study provides valuable insights into NO₃⁻ source identification and hydrochemical processes across varying land-use types. Full article

(This article belongs to the Special Issue Potentially Toxic Elements Pollution in Urban and Suburban Environments II)

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19 pages, 7507 KiB

Open AccessArticle

Integrated Deterministic and Probabilistic Methods Reveal Heavy Metal-Induced Health Risks in Guizhou, China

by Qinju Li, Dashuan Li, Zelan Wang, Dali Sun, Ting Zhang and Qinghai Zhang

Toxics 2025, 13(6), 515; https://doi.org/10.3390/toxics13060515 - 19 Jun 2025

Viewed by 367

Abstract

Due to high geological background and intensive mining activities, soils are prone to heavy metals (HMs) accumulation and ecological fragility in Guizhou Province, China. A total of 740 topsoil samples were therefore collected, and aimed to determine the concentrations of As, Cd, Cr, [...] Read more.

Due to high geological background and intensive mining activities, soils are prone to heavy metals (HMs) accumulation and ecological fragility in Guizhou Province, China. A total of 740 topsoil samples were therefore collected, and aimed to determine the concentrations of As, Cd, Cr, Hg, and Pb, estimate the ecological pollution, and evaluate the carcinogenic and non-carcinogenic health risks to humans. Results showed As (1.08%) and Cd (24.46%) in soil exceeded standards. The Igeo showed that Cr (1.49%) and Hg (31.62%) in soil were at light pollution levels; single factor pollution index (PI) showed that Cd (21.35%) in soil was mildly polluted; risk index (RI) as at a low risk level. Notably, both deterministic and Monte Carlo analyses revealed unacceptable carcinogenic risks for As and Cr in children, with traditional methods potentially underestimating As risks. Moreover, Target-Organ Toxicity Dose (TTD) revealed soil HMs as a higher risk to hematological health, with notable health risks posed by Pb in children. It is noted that spatial distribution analysis suggested that the southwestern region of Guizhou Province should be prioritized for health risk management and control. By integrating the uniqueness of geological environments, multi-dimensional health risk assessments, and spatial distributions, the present study provides a scientific basis for assessing HMs pollution risks and soil health risks in the karst regions. Full article

(This article belongs to the Special Issue Heavy Metal Contamination and Its Effects on Ecosystems and Human Health: Challenges and Solutions)

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10 pages, 1293 KiB

Open AccessReview

Nephrotoxicity and Modern Volatile Anesthetics: A Narrative Review

by Benedicte Hauquiert, Aurelien Gonze, Thibault Gennart, Emily Perriens, Sydney Blackman, Nathan De Lissnyder, Arnaud Robert, Julien Moury, Gauthier Nendumba, Ilann Oueslati, Priscilla Gillis, Ovidiu Vornicu, Anne-Sophie Dincq, Pierre Bulpa, Isabelle Michaux and Patrick M. Honore

Toxics 2025, 13(6), 514; https://doi.org/10.3390/toxics13060514 - 19 Jun 2025

Viewed by 396

Abstract

Volatile anesthetics, while increasingly utilized in intensive care medicine, are associated with significant renal adverse effects. A critical safety concern—particularly with sevoflurane—involves its potential impact on renal function. Pathophysiologically, inorganic fluoride levels exceeding 50 µmol/L are recognized as a threshold for nephrogenic diabetes [...] Read more.

Volatile anesthetics, while increasingly utilized in intensive care medicine, are associated with significant renal adverse effects. A critical safety concern—particularly with sevoflurane—involves its potential impact on renal function. Pathophysiologically, inorganic fluoride levels exceeding 50 µmol/L are recognized as a threshold for nephrogenic diabetes insipidus, a condition generally considered reversible. Additionally, the sevoflurane degradation product “compound A” has been implicated in direct renal tubular and glomerular toxicity. Specifically, exposure has been correlated with glomerular damage, evidenced by albuminuria, as well as injury to both proximal and distal tubules, indicated by elevated levels of α-glutathione-S-transferase. Postprandial glycosuria may also be observed. Unlike nephrogenic diabetes insipidus, the structural damage induced by compound A may result in irreversible renal impairment. Full article

(This article belongs to the Special Issue Nephrotoxicity Induced by Drugs and Chemicals in the Environment)

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15 pages, 842 KiB

Open AccessArticle

Bioassay Using the DR-EcoScreen System to Measure Dioxin-Related Compounds in Serum Samples from Individuals Exposed to Dioxins Originating from Agent Orange in Vietnam

by Masafumi Nakamura, Ryo Matsuda, Hoa Thi Vu, Tai Pham-The, Thao Ngoc Pham, Tomoya Takiguchi, Hisao Nishijo and Muneko Nishijo

Toxics 2025, 13(6), 513; https://doi.org/10.3390/toxics13060513 - 19 Jun 2025

Viewed by 628

Abstract

A bioassay for dioxin analysis of human samples has the advantages of cost effectiveness and requiring only a small sample volume. Using a DR-EcoScreen bioassay, we measured the biological equivalency (BEQ) levels in serum samples from 32 men exposed to dioxins in Bien [...] Read more.

A bioassay for dioxin analysis of human samples has the advantages of cost effectiveness and requiring only a small sample volume. Using a DR-EcoScreen bioassay, we measured the biological equivalency (BEQ) levels in serum samples from 32 men exposed to dioxins in Bien Hoa and 32 unexposed men in Hanoi, Vietnam. For the Bien Hoa men, the World Health Organization toxic equivalent (WHO-TEQ) levels of dioxins had already been measured by instrumental analysis. The difference in fat-based BEQ levels between exposed and unexposed men was greater than for crude BEQ levels, with a strong correlation between fat-based BEQ and WHO-TEQ levels. The fat-based BEQ levels in Bien Hoa men with longer residency but lower WHO-TEQ levels were significantly higher than those in unexposed men and Bien Hoa men with shorter residency but higher WHO-TEQs, suggesting that fat-based BEQ may be an effective marker of dioxin-like activity. Additionally, comparisons of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and TEQs between shorter- and longer-residency groups indicated that higher levels of polychlorinated dibenzo-p-dioxins (PCDDs), particularly TCDD, contribute to increased BEQ levels. Taken together, the DR-EcoScreen bioassay may be useful to analyze dioxin-like activity associated with WHO-TEQs of men in a dioxin contamination hotspot originating from Agent Orange in Vietnam. Full article

(This article belongs to the Section Human Toxicology and Epidemiology)

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16 pages, 7517 KiB

Open AccessArticle

The Development and Toxicological Evaluation of Novel Polyurethane Materials

by Maolan Zhang, Xuanran Luo, Maocai Jiang, Yu Wen, Peng Wang, Peixing Chen and Da Sun

Toxics 2025, 13(6), 512; https://doi.org/10.3390/toxics13060512 - 18 Jun 2025

Viewed by 893

Abstract

Polyurethane (PU) is widely employed in the biomedical field. As application scenarios become increasingly complex, it is essential to modify PU to meet diverse requirements. Additionally, the degradation of PU is closely linked to the sustainability of its function, with degradation products having [...] Read more.

Polyurethane (PU) is widely employed in the biomedical field. As application scenarios become increasingly complex, it is essential to modify PU to meet diverse requirements. Additionally, the degradation of PU is closely linked to the sustainability of its function, with degradation products having a direct impact on adjacent tissues. In this study, a novel PU containing double bonds in its main chain was developed. We investigated the influence of various ratios of soft segment composition on the degradation performance of PU, maintaining a fixed ratio of soft to hard segments and utilizing specific synthesis methods. The structure and molecular weight of the PU were analyzed using FTIR, NMR, and GPC techniques. The results of physical and chemical performance tests indicated that an increase in polycaprolactone diol (PCL diol) content within the soft segment enhanced the mechanical properties, hydrophobicity, and degradation performance of the PU. A further assessment of the degradation toxicity of PU was carried out using zebrafish as a model organism. The findings indicated that the degradation solution of PU exhibited slight toxicity to zebrafish embryonic development over prolonged degradation periods. However, it also significantly enhanced the hatching of zebrafish embryos. In summary, the novel PU developed in this study demonstrates favorable biocompatibility, and the approach of introducing reaction sites or modifying the composition of its soft segments within the molecular structure offers a promising and effective strategy to address specific application requirements. Full article

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17 pages, 2178 KiB

Open AccessArticle

Tissue Element Levels and Heavy Metal Burdens in Bottlenose Dolphins That Stranded in the Mississippi Sound Surrounding the 2019 Unusual Mortality Event

by Nelmarie Landrau-Giovannetti, Ryanne Murray, Stephen Reichley, Debra Moore, Theresa Madrigal, Ashli Brown, Ashley Meredith, Christina Childers, Darrell Sparks, Moby Solangi, Anna Linhoss, Beth Peterman, Mark Lawrence and Barbara L. F. Kaplan

Toxics 2025, 13(6), 511; https://doi.org/10.3390/toxics13060511 - 18 Jun 2025

Viewed by 864

Abstract

In 2019, an unusual mortality event (UME) affected bottlenose dolphins (Tursiops truncatus) in the Mississippi Sound (MSS) following an extended dual opening of the Bonnet Carré Spillway (BCS), which prevents flooding in New Orleans. This resulted in low salinity, skin lesions, and [...] Read more.

In 2019, an unusual mortality event (UME) affected bottlenose dolphins (Tursiops truncatus) in the Mississippi Sound (MSS) following an extended dual opening of the Bonnet Carré Spillway (BCS), which prevents flooding in New Orleans. This resulted in low salinity, skin lesions, and electrolyte imbalances in dolphins. Additionally, the influx likely altered the MSS’s environmental chemical composition, including levels of heavy metals and metalloids; thus, we quantified heavy metals, metalloids, and essential elements in the tissues of dolphins that stranded in the MSS before and after the 2019 UME. We hypothesized that levels of heavy metals and metalloids (such as mercury (Hg), arsenic (As), lead (Pb), and cadmium (Cd)) would not show significant changes post-UME. Indeed, we found no major changes associated with the UME in most metals; sodium (Na) and magnesium (Mg) levels were lower in several tissues after 2019, which correlated with the average yearly salinity measured from the MSS. Toxic metals and metalloids were detectable with some changes over time; however, the selenium (Se):Hg molar ratio increased in some tissues post-2019. Additionally, we confirmed that Hg can bioaccumulate, with positive correlations between Hg levels and dolphin size as assessed by straight length. Overall, our findings indicate that freshwater incursions into the MSS can alter dolphin exposure to essential and toxic elements. Full article

(This article belongs to the Special Issue Micropollutants/Emerging Contaminants in Aquatic Environments: Occurrence, Environmental Fates, and Effects on Aquatic Organisms)

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12 pages, 1445 KiB

Open AccessArticle

Does Electromagnetic Pollution in the ART Laboratory Affect Sperm Quality? A Cross-Sectional Observational Study

by Giorgio Maria Baldini, Dario Lot, Daniele Ferri, Luigi Montano, Mario Valerio Tartagni, Antonio Malvasi, Antonio Simone Laganà, Mario Palumbo, Domenico Baldini and Giuseppe Trojano

Toxics 2025, 13(6), 510; https://doi.org/10.3390/toxics13060510 - 18 Jun 2025

Viewed by 504

Abstract

In recent decades, exposure to electromagnetic fields (EMFs) generated by standard devices has raised concerns about possible effects on reproductive health. This cross-sectional observational study examined the impact of EMFs on sperm motility in a sample of 102 healthy males aged 20–35 years [...] Read more.

In recent decades, exposure to electromagnetic fields (EMFs) generated by standard devices has raised concerns about possible effects on reproductive health. This cross-sectional observational study examined the impact of EMFs on sperm motility in a sample of 102 healthy males aged 20–35 years in the IVF laboratory. Semen samples were exposed to different sources of EMF for one hour, and motility was assessed immediately thereafter. The results showed a significant reduction in progressive sperm motility after exposure to EMFs generated by mobile phones and Wi-Fi repeaters in the laboratory. In contrast, other equipment showed no significant effects. The study demonstrated a statistically significant reduction in progressive sperm motility following in vitro exposure to electromagnetic fields (EMFs) emitted by mobile communication devices and wireless local area network access points. Conversely, other electromagnetic emitting devices evaluated did not elicit significant alterations in this parameter. These findings suggest a potential negative impact of specific EMF sources on semen quality, underscoring the necessity for further comprehensive research to elucidate the clinical implications and to develop potential mitigation strategies aimed at reducing risks to male reproductive health. This study discourages the introduction of mobile phones in IVF laboratories and recommends positioning Wi-Fi repeaters on the ceiling. Full article

(This article belongs to the Section Reproductive and Developmental Toxicity)

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12 pages, 1409 KiB

Open AccessArticle

Urban-Rural Differences in Indoor and Outdoor Air Quality: A Comparative Study in Bangladesh

by Masamitsu Kurata, Akira Hibiki, Kazushi Takahashi and Yutaka Matsumi

Toxics 2025, 13(6), 509; https://doi.org/10.3390/toxics13060509 - 17 Jun 2025

Viewed by 550

Abstract

Health hazards caused by indoor air pollution (IAP) remain a global concern, especially in developing countries. IAP has complex mechanisms related to outdoor air pollution (OAP) and various other factors, and their relationship needs to be clarified to examine effective policies. We conducted [...] Read more.

Health hazards caused by indoor air pollution (IAP) remain a global concern, especially in developing countries. IAP has complex mechanisms related to outdoor air pollution (OAP) and various other factors, and their relationship needs to be clarified to examine effective policies. We conducted an indoor and outdoor air monitoring survey in urban, peri-urban, and rural areas in Bangladesh, one of the countries with the most severe air pollution. The results show that IAP is more severe in urban households than in rural households, with a five-fold difference in daily indoor

{P M}_{2.5}

concentration between 117

μ g / m^{3}

and 22

μ g / m^{3}

, respectively. Regression analysis reveals that IAP is strongly associated with OAP and is hardly affected by solid fuels used in well-ventilated outside kitchens. Our findings support the view that the mitigation of IAP in developing countries can be achieved not only through a transition to clean fuels, which often entails substantial costs, but also through more practical and accessible alternatives, such as the use of outdoor kitchens, electric fans, and careful management of behaviors such as indoor smoking and mosquito coil use. Full article

(This article belongs to the Special Issue Source and Components Analysis of Aerosols in Air Pollution)

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17 pages, 2269 KiB

Open AccessArticle

Organophosphate Flame Retardants in Indoor Dust in the Tampa Bay (Florida) Area

by Adebayo Solanke, Lukasz Talalaj, Claire Graham and Henry Alegria

Toxics 2025, 13(6), 508; https://doi.org/10.3390/toxics13060508 - 16 Jun 2025

Viewed by 437

Abstract

As polybrominated diphenyl ethers were phased out as flame retardants and plasticizers, increasing quantities of organophosphate triesters (OPEs) have been used as replacements. Despite a surge in reports on levels and profiles of OPEs, especially in indoor environments, and the potential exposure, there [...] Read more.

As polybrominated diphenyl ethers were phased out as flame retardants and plasticizers, increasing quantities of organophosphate triesters (OPEs) have been used as replacements. Despite a surge in reports on levels and profiles of OPEs, especially in indoor environments, and the potential exposure, there are still understudied areas with no data on the levels of these chemicals. We carried out the first study investigating levels and profiles of OPEs in indoor dust from such an area, the Tampa Bay (Florida) area. ∑₁₃OPEs measured at each site ranged from 545 to 502,086 ng g⁻¹, with overall medians and means over 64 sites of 15,447 and 36,135 ng g⁻¹, respectively. Alkyl OPEs were predominant, with lesser levels of chlorinated and aryl OPEs. Median levels were highest for tris (2-butoxyethyl) phosphate (TBOEP) and triphenyl phosphate (TPHP) at 4641 and 1046 ng g⁻¹, respectively; lower for tris(1,3–dichloro-2-propyl) phosphate (TDCIPP), tris(2-chloropropyl) phosphate (T2CPP), and tris (2-chloroisopropyl) phosphate (TCIPP) at 530, 458, and 360 ng g⁻¹, respectively; with others ranging from 2 to 85 ng g⁻¹. There were differences in levels in different microenvironments (urban versus suburban; non-residential versus residential; apartments versus single-family homes; daycares versus residences and university rooms; building age; and rooms with different floor material). Estimated daily intakes for median and higher exposure scenarios for ∑₁₃OPEs (in ng kg⁻¹ bw day⁻¹) were 12 and 552 for toddlers and 6 and 451 for adults, respectively. TBOEP accounted for 30% of total intake for toddlers and adults in a mean exposure scenario but 90% for high exposure scenario. Full article

(This article belongs to the Section Emerging Contaminants)

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14 pages, 1781 KiB

Open AccessArticle

Analysis of Mercury Concentration in Cosmetic Clays

by Agnieszka Fischer, Barbara Brodziak-Dopierała, Wiktoria Jańska, Luiza Jeyranyan and Beata Malara

Toxics 2025, 13(6), 507; https://doi.org/10.3390/toxics13060507 - 16 Jun 2025

Viewed by 370

Abstract

(1) Background: Clays are popular raw materials of natural origin used in cosmetology, beauty salons, and home care. They have moisturizing, soothing, cleansing, disinfecting, detoxifying, and regenerating properties, and can be used externally in the form of poultices or internally in solution form. [...] Read more.

(1) Background: Clays are popular raw materials of natural origin used in cosmetology, beauty salons, and home care. They have moisturizing, soothing, cleansing, disinfecting, detoxifying, and regenerating properties, and can be used externally in the form of poultices or internally in solution form. Though they are characterized by a rich and diverse mineral composition and are considered safe for the body, their use can expose users to harmful elements including mercury. (2) Materials and methods: This study analyzed mercury (Hg) concentrations in samples of cosmetic clays available on the Polish market. Hg analysis was performed using the AAS method with an AMA 254 analyzer. The clays differed in type/color and were purchased from different manufacturers. (3) Results: The mean Hg content in all the tested samples was 28.91 µg/kg, with a range of changes of 1.87–200.81 µg/kg. The highest concentrations of Hg were found in green (AM = 53.26 µg/kg) and white (AM = 52.80 µg/kg) clays, while the lowest were detected in purple (AM = 2.56 µg/kg) and blue (AM = 3.69 µg/kg) clays. The differences in Hg content between individual types of clay were statistically significant. (4) Conclusions: Due to the presence of Hg found in all the samples of cosmetic clay tested, it is likely that these products need to be tested for their metal contents. Full article

(This article belongs to the Special Issue Mercury Cycling and Health Effects—2nd Edition)

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13 pages, 2396 KiB

Open AccessArticle

Toxic Effects of p-Chloroaniline on Cells of Fungus Isaria fumosorosea SP535 and the Role of Cytochrome P450

by Shicong Huang, Jiahui Gao, Lin Zhou, Liujian Gao, Mengke Song and Qiaoyun Zeng

Toxics 2025, 13(6), 506; https://doi.org/10.3390/toxics13060506 - 16 Jun 2025

Viewed by 493

Abstract

Efficient methods to remediate PCA (p-chloroaniline)-polluted environments are urgent due to the widespread persistence and toxicity of PCA in the environment. Microbial degradation presents a promising approach for remediating PCA pollution. However, the PCA-degrading fungi still have yet to be explored. This study [...] Read more.

Efficient methods to remediate PCA (p-chloroaniline)-polluted environments are urgent due to the widespread persistence and toxicity of PCA in the environment. Microbial degradation presents a promising approach for remediating PCA pollution. However, the PCA-degrading fungi still have yet to be explored. This study confirmed the highly PCA-degrading efficiency of an isolated fungus, Isaria fumosorosea SP535. This fungus can achieve a PCA degradation efficiency of 100% under optimal conditions characterized by an initial PCA concentration of 1.0 mM, pH of 7.0 and a temperature of 25 °C. SEM and TEM analyses revealed that the toxicity of PCA resulted in roughened surfaces of Isaria fumosorosea SP535 hyphae, voids in the cytoplasm, and thickened cell walls. PCA addition significantly elevated the activities of cytochrome P450 monooxygenase in both cell-free extracts and microsomal fractions in the media, suggesting the important role of the P450 system in PCA metabolization by Isaria fumosorosea SP535. The results provide a microbial resource and fundamental knowledge for addressing PCA pollution. Full article

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19 pages, 931 KiB

Open AccessArticle

Widespread Contamination by Anticoagulant Rodenticides in Insectivorous Wildlife from the Canary Islands: Exploring Alternative Routes of Exposure

by Beatriz Martín Cruz, Andrea Acosta Dacal, Ana Macías-Montes, Cristian Rial-Berriel, Manuel Zumbado, Luis Alberto Henríquez-Hernández, Ramón Gallo-Barneto, Miguel Ángel Cabrera-Pérez and Octavio P. Luzardo

Toxics 2025, 13(6), 505; https://doi.org/10.3390/toxics13060505 - 15 Jun 2025

Viewed by 489

Abstract

Research on anticoagulant rodenticides (ARs) in wildlife has primarily focused on apex predators, with less attention given to their potential integration into lower trophic levels and the associated exposure pathways. At the base of the terrestrial food web, invertebrates have been suggested as [...] Read more.

Research on anticoagulant rodenticides (ARs) in wildlife has primarily focused on apex predators, with less attention given to their potential integration into lower trophic levels and the associated exposure pathways. At the base of the terrestrial food web, invertebrates have been suggested as potential vectors of ARs to insectivorous species such as small mammals, reptiles, and birds. To explore this hypothesis, we analyzed the presence of nine anticoagulant rodenticides—including both first-generation (FGARs) and second-generation (SGARs) rodenticides—in 36 liver samples from Yemen chameleons (Chamaeleo calyptratus) and 98 liver samples from six non-raptorial, predominantly insectivorous bird species from the Canary Islands. Through HPLC-MS/MS analysis, only SGARs were detected in both animal groups collected between 2021 and 2024. Approximately 80% of reptiles and 40% of birds tested positive for at least one SGAR, with brodifacoum being the most frequently detected compound. In more than 90% of positive cases, it was found as the sole contaminant, while co-occurrence with other SGARs was uncommon. Additionally, most concentrations were below 50 ng/g wet weight, except for two bird specimens, suggesting heterogeneous exposure scenarios and potential variability in contamination sources across individuals. These findings provide evidence of AR integration at the base of the terrestrial food web in the Canary Islands and suggest secondary exposure via invertebrates as a plausible route of contamination. Further research directly analyzing invertebrate samples is needed to confirm their role as vectors of ARs to insectivorous wildlife in insular ecosystems. Full article

(This article belongs to the Section Ecotoxicology)

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14 pages, 998 KiB

Open AccessArticle

The Paradox of Clean Eating: Neuroactive Dysbiosis and Pesticide Residues in Fruit- and Vegetable-Based Diets

by Ramona Alina Tomuța, Andrada Florina Moldovan, Loredana Matiș, Lavinia Maris, Timea Claudia Ghitea and Florin Banica

Toxics 2025, 13(6), 504; https://doi.org/10.3390/toxics13060504 - 15 Jun 2025

Viewed by 464

Abstract

(1) Background: Exposure to pesticide residues through food remains a critical issue in public health, especially given their potential cumulative neurotoxic effects. (2) Methods: This study investigated the presence of pesticide residues in commonly consumed vegetables, fruits, and cereals based on official laboratory [...] Read more.

(1) Background: Exposure to pesticide residues through food remains a critical issue in public health, especially given their potential cumulative neurotoxic effects. (2) Methods: This study investigated the presence of pesticide residues in commonly consumed vegetables, fruits, and cereals based on official laboratory reports and evaluated the intestinal microbiome profiles of individuals whose diets consisted of over 50% plant-based foods. (3) Results: Analytical results from accredited laboratories in Romania demonstrated that all tested food samples were compliant with European regulations (Regulation (EC) 396/2005), with either undetectable or below-quantification-limit pesticide residues. However, organophosphates such as chlorpyrifos and diazinon were frequently tested, indicating persistent regulatory concern due to their known neurotoxic potential. A parallel analysis of stool samples revealed significant imbalances in neuroactive gut bacteria, including consistently low levels of Bifidobacterium and Lactobacillus species, and elevated levels of Oscillibacter and Alistipes, which are implicated in modulating GABA and serotonin pathways. Markers of proinflammatory activity, such as LPS-positive bacteria and histamine producers, were also elevated. (4) Conclusions: These findings suggest that even in diets rich in plant-based foods, microbial dysbiosis with neuroactive relevance can occur, potentially linked to environmental or dietary factors. The study underscores the need for a comprehensive evaluation of food safety and microbiome function as interconnected determinants of neurological health. Full article

(This article belongs to the Section Neurotoxicity)

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20 pages, 4387 KiB

Open AccessArticle

Modification of Biochar Catalyst Using Copper for Enhanced Catalytic Oxidation of VOCs

by Nan Liu, Jin Zhang, Ya-Lan Cai, Ji-Guo Zhang, Du-Juan Ouyang, Shao-Bo Wang, Qi-Man Xu, Jia-Jun Hu, Di-Ming Chen, Guo-Wen Wang and Ji-Xiang Li

Toxics 2025, 13(6), 503; https://doi.org/10.3390/toxics13060503 - 14 Jun 2025

Cited by 1 | Viewed by 580

Abstract

Recently, research has increasingly focused on the introduction of non-precious metals and developing highly stable carriers to enhance catalyst performance. In this study, we successfully synthesized copper (Cu)-modified biochar catalysts utilizing a sequential approach involving enzymatic treatment, liquid impregnation, and activation processes, which [...] Read more.

Recently, research has increasingly focused on the introduction of non-precious metals and developing highly stable carriers to enhance catalyst performance. In this study, we successfully synthesized copper (Cu)-modified biochar catalysts utilizing a sequential approach involving enzymatic treatment, liquid impregnation, and activation processes, which effectively enhanced the dispersion and introduction efficiency of Cu onto the biochar, thereby reducing the requisite Cu loading while maintaining high catalytic activity. The experimental results showed that the toluene degradation of 10%Cu@BCL was three times higher than that of unmodified activated carbon (AC) at 290 °C. A more uniform distribution of Cu was obtained by the enzymatic and activation treatments, optimizing the catalyst’s structural properties and reducing the amount of Cu on the biochar. Moreover, the transformation between various oxidation states of Cu (from Cu⁰/Cu(I) to Cu(II)) facilitated the electron transfer during the degradation of toluene. To further understand the catalytic mechanisms, density functional theory (DFT) calculations were employed to elucidate the interactions between toluene molecules and the Cu-modified biochar surface. These findings reveal that the strategic modification of biochar as a carrier not only enhances the dispersion and stability of active metal species but contributes to improved catalytic performance, thereby enhancing its degradation efficiency for VOCs in high-temperature conditions. Full article

(This article belongs to the Section Toxicity Reduction and Environmental Remediation)

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14 pages, 4066 KiB

Open AccessArticle

Microplastics in Stormwater: Sampling and Methodology Challenges

by Andres Sanchez Garcia, Huayun Zhou, Cesar Gomez-Avila, Tariq Hussain, Aryan Roghani, Danny Reible and Balaji Anandha Rao

Toxics 2025, 13(6), 502; https://doi.org/10.3390/toxics13060502 - 14 Jun 2025

Viewed by 582

Abstract

Stormwater runoff is a significant source of microplastics to surface water. This study addresses challenges in the sampling, treatment, and characterization of microplastics in existing stormwater control measures across various regions in the United States. Stormwater sediment samples were collected via traditional stormwater [...] Read more.

Stormwater runoff is a significant source of microplastics to surface water. This study addresses challenges in the sampling, treatment, and characterization of microplastics in existing stormwater control measures across various regions in the United States. Stormwater sediment samples were collected via traditional stormwater sampling approaches for particulate and inorganic contamination with portable automatic samplers, analyzed using visible and fluorescence microscopy with Nile red as a selective stain, and subsequently confirmed through Raman spectroscopy. The inclusion of laboratory and field blanks enabled the identification of contamination at key steps during sample handling. The results reveal that the filtration process is a significant source of laboratory contamination, while the sampling process itself could be a primary contributor to overall sample contamination. Additionally, it was found that using green fluorescence as the sole emission wavelength may underestimate MP quantities, as some particles emit fluorescence exclusively in the red spectrum. Raman analysis revealed interferences caused by pigments and additives in plastics, along with challenges evaluating particles in the low micron range (≤10 microns), which complicates a comprehensive analysis. The findings of this study emphasize the importance of implementing strong quality assurance and control measures when assessing the levels of microplastics in the environment, including sample collection, processing, and analysis. Full article

(This article belongs to the Special Issue Contaminants of Emerging Concern (CECs) in the Water Cycle)

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21 pages, 2219 KiB

Open AccessArticle

Association of Per- and Polyfluoroalkyl Substances with Pan-Cancers Associated with Sex Hormones

by Elizabeth Olarewaju and Emmanuel Obeng-Gyasi

Toxics 2025, 13(6), 501; https://doi.org/10.3390/toxics13060501 - 14 Jun 2025

Viewed by 533

Abstract

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous environmental contaminants with potential endocrine-disrupting properties. This study examines the association between exposure to multiple PFASs and pan-cancers associated with sex hormones (PCSH) while accounting for potential non-linear relationships and interactions. We analyzed data from the [...] Read more.

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous environmental contaminants with potential endocrine-disrupting properties. This study examines the association between exposure to multiple PFASs and pan-cancers associated with sex hormones (PCSH) while accounting for potential non-linear relationships and interactions. We analyzed data from the National Health and Nutrition Examination Survey (NHANES), spanning two-year cycles from 1999 to 2012 and including 14,373 participants. Serum concentrations of six PFAS—perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorohexanesulfonic acid (PFHxS), perfluorodecanoic acid (PFDE), perfluorononanoic acid (PFNA), and perfluoroundecanoic acid (PFUA)—were assessed for their relationship with PCSH. The statistical analyses included descriptive statistics, Spearman and Pearson correlation analyses, and both linear and logistic regression models. Additionally, Bayesian kernel machine regression (BKMR) was applied to capture potential nonlinear relationships and interactions. The initial t-tests showed a statistically significant difference in PFOS levels between individuals with and without PCSH (p = 0.0022), with higher mean PFOS levels in the PCSH group. Chi-square tests revealed a significant association between ethnicity and PCSH (p < 0.001). Linear and logistic regression analyses revealed significant associations for PFOS. BKMR analysis identified PFOA as having the highest posterior inclusion probability, indicating its importance in explaining PCSH risk. Univariate exposure-response analysis revealed limited individual PFAS effects. However, bivariate analysis indicated a complex U-shaped interaction pattern among many joint PFAS assessments. The overall exposure effect analysis suggested that the combined impact of all PFASs was more strongly associated with PCSH at exposure levels below the 0.5 quantile compared to higher levels. Single-variable interaction analyses highlighted PFOA and PFOS as the most interactive PFASs when evaluating their interaction with combined exposure to all other PFASs. In summary, while the initial findings suggested a positive association between PFOS and PCSH, the BKMR analysis revealed complex non-linear relationships and interactions among PFAS. These findings highlight the importance of evaluating PFASs as a mixture rather than as individual chemicals and using techniques that can capture non-linear relationships and interactions. Full article

(This article belongs to the Section Emerging Contaminants)

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19 pages, 9490 KiB

Open AccessArticle

Source Analysis of Ozone Pollution in Liaoyuan City’s Atmosphere Based on Machine Learning Models and HYSPLIT Clustering Method

by Xinyu Zou, Xinlong Li, Dali Wang and Ju Wang

Toxics 2025, 13(6), 500; https://doi.org/10.3390/toxics13060500 - 13 Jun 2025

Viewed by 615

Abstract

Firstly, this study investigates the spatiotemporal distribution characteristics of the ozone (O₃) pollution in Liaoyuan City using monitoring data from 2015 to 2024. Then, three machine learning models (ML)—random forest (RF), support vector machine (SVM), and artificial neural network (ANN)—are employed [...] Read more.

Firstly, this study investigates the spatiotemporal distribution characteristics of the ozone (O₃) pollution in Liaoyuan City using monitoring data from 2015 to 2024. Then, three machine learning models (ML)—random forest (RF), support vector machine (SVM), and artificial neural network (ANN)—are employed to quantify the influence of meteorological and non-meteorological factors on O₃ concentrations. Finally, the HYSPLIT clustering method and CMAQ model are utilized to analyze inter-regional transport characteristics, identifying the causes of O₃ pollution. The results indicate that O₃ pollution in Liaoyuan exhibits a distinct seasonal pattern, with the highest concentrations found in spring and summer, peaking in the afternoon. Among the three ML models, the random forest model demonstrates the best predictive performance (R² = 0.9043). Feature importance identifies NO₂ as the primary driving factor, followed by meteorological conditions in the second quarter and land surface characteristics. Furthermore, regional transport significantly contributes to O₃ pollution, with approximately 80% of air mass trajectories in heavily polluted episodes originating from adjacent industrial areas and the sea. The combined effects of transboundary precursors and O₃ transport with local emissions and meteorological conditions further increase the O₃ pollution level. This study highlights the need to strengthen coordinated NO_X and VOCs emission reductions and enhance regional joint prevention and control strategies in China. Full article

(This article belongs to the Special Issue Classical Environmental Process Modeling, Interpretable Machine Learning, and Their Integrative Innovations—Targeting Atmospheric, Water, and Soil)

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18 pages, 1047 KiB

Open AccessArticle

Heavy Metal Contamination in Yogurt from Lebanon: Evaluating Lead (Pb) and Cadmium (Cd) Concentrations Across Multiple Regions

by Sandra Sarkis, Rayan Kashmar, Nikolaos Tzenios, Maha Hoteit, Tony Tannous and Joseph Matta

Toxics 2025, 13(6), 499; https://doi.org/10.3390/toxics13060499 - 13 Jun 2025

Cited by 1 | Viewed by 603

Abstract

The toxicity of metals such as lead (Pb) and cadmium (Cd) makes heavy metal contamination in food products a major health concern. The aim of this study is to measure the levels of Pb and Cd in yogurt samples that were collected from [...] Read more.

The toxicity of metals such as lead (Pb) and cadmium (Cd) makes heavy metal contamination in food products a major health concern. The aim of this study is to measure the levels of Pb and Cd in yogurt samples that were collected from 11 distinct Lebanese locations and determine their compliance with the legal limits set by the European Commission (0.02 mg/kg for Pb and 0.005 mg/kg for Cd). A total of 165 yogurt samples were examined using atomic absorption spectrophotometry (AAS). Interestingly, the findings showed that 10.9% of samples had Pb concentrations over the allowable limit; the highest amounts were observed in Baalbeck-Hermel (0.118 mg/kg), North Area (0.125 mg/kg), and South Lebanon (0.115 mg/kg). In addition, the highest detected concentrations of Cd were found in North Area (0.094 mg/kg), Baalbeck-Hermel (0.076 mg/kg), and Akkar (0.042 mg/kg), with 14.5% of samples above the limit. The results show regional differences in contamination, which are probably caused by industrial emissions, agricultural activities, and environmental pollution. To better understand the potential health implications, the estimated daily intake (EDI) of Pb and Cd through yogurt consumption was calculated and compared to international health-based guidance values. Although the EDI values suggest a low risk from yogurt alone, the findings highlight the importance of cumulative exposure and emphasize the necessity of regular monitoring and stricter implementation of food safety laws to decrease exposure to heavy metals through dairy intake. Full article

(This article belongs to the Special Issue Toxicity and Safety Assessment of Exposure to Heavy Metals)

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23 pages, 1729 KiB

Open AccessArticle

Pharmaceutical Contaminants Occurrence and Ecological Risk Assessment Along the Romanian Black Sea Coast

by Vasile-Ion Iancu, Laura-Florentina Chiriac, Iuliana Paun, Cristina Dinu, Florinela Pirvu, Victor Cojocaru, Anda Gabriela Tenea and Ioana Antonia Cimpean

Toxics 2025, 13(6), 498; https://doi.org/10.3390/toxics13060498 - 13 Jun 2025

Viewed by 443

Abstract

The work aimed to investigate the presence of pharmaceutical compounds from the anti-inflammatory class in seawater from the Romanian Black Sea coast and to assess the ecological risk of these substances on the most sensitive organisms. Using the solid-phase extraction technique (SPE) followed [...] Read more.

The work aimed to investigate the presence of pharmaceutical compounds from the anti-inflammatory class in seawater from the Romanian Black Sea coast and to assess the ecological risk of these substances on the most sensitive organisms. Using the solid-phase extraction technique (SPE) followed by liquid chromatography separation and mass spectrometry detection (LC-MS/MS) of the compounds, the concentrations of these contaminants in selected seawater samples were determined. Ibuprofen was the most commonly detected compound with a frequency of 42.9%, followed by ketoprofen at 31.0.%, diclofenac at 23.8%, and naproxen at 21.4%. The maximum concentrations of pharmaceutical products varied between 13.4 ng/L ketoprofen and 13,575 ng/L caffeine. The order of decreasing maximum concentrations of pharmaceutical compounds in the water of the Black Sea was CAF > IBU > NAP > DIC > KET. The dominant and ubiquitous compound that was determined with the maximum concentration values was caffeine. Strong correlations were observed between three compounds (naproxen: diclofenac, diclofenac: ketoprofen) suggesting the same pollution source. Through the ecological risk assessment, it was observed that both caffeine and ibuprofen can generate high ecological risks for some echinoderms, crustaceans, and fish. Full article

(This article belongs to the Special Issue Pharmaceuticals in the Aquatic Environment: Monitoring, Impacts and Ecological Risk)

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17 pages, 304 KiB

Open AccessArticle

Risk Assessment of Potentially Toxic Heavy Metals in Wheat (Triticum aestivum L.) Grown in Soils Irrigated with Paper Mill Effluent

by Mohssen Elbagory, Amal Zayed, Nagwa El-Khateeb, Sahar El-Nahrawy, Alaa El-Dein Omara, Ibrahim Mohamed, Marwa Yasien Helmy Elbyaly, Mahmoud El-Sharkawy, Jogendra Singh, Ana Dzaja, Boro Mioč and Ivan Širić

Toxics 2025, 13(6), 497; https://doi.org/10.3390/toxics13060497 - 13 Jun 2025

Viewed by 351

Abstract

Unregulated irrigation with partially industrial effluents may lead to heavy metal contamination in crops and pose significant human health risks, especially in developing countries like India. Therefore, the present study aimed to quantify six heavy metals (Cd, Cr, Cu, Fe, Mn, and Zn) [...] Read more.

Unregulated irrigation with partially industrial effluents may lead to heavy metal contamination in crops and pose significant human health risks, especially in developing countries like India. Therefore, the present study aimed to quantify six heavy metals (Cd, Cr, Cu, Fe, Mn, and Zn) in soil and wheat irrigated with paper mill effluent, assess plant responses, and evaluate associated health risks for consumers. For this, a field study was conducted across ten sites (five effluent-irrigated, five borewell-irrigated as control), analyzing soil and wheat tissues for metal concentrations and calculating risk indices including bioaccumulation factor (Bf), translocation factor (Tf), Dietary Intake of Metals (DIM < 1), Health Risk Index (HRI < 1), and Target Hazard Quotient (THQ < 1). Results indicated high concentrations of Cd and Cr in effluent-irrigated soils and wheat tissues (root > stem > leaves > grains) compared to control sites, with some values exceeding permissible limits. Although the THQ values for heavy metals were below 1, indicating a low immediate health risk, concentrations of Cd and Cr in both soil and crop tissues exceeded acceptable safety standards. This study provides empirical evidence supporting the need for effluent treatment and policy interventions to mitigate agricultural contamination from the use of industrial effluents and protect public health. Full article

(This article belongs to the Special Issue Environmental Contaminant Exposure and Intake from Agricultural Products)

19 pages, 6387 KiB

Open AccessArticle

Degradation of Low-Molecular-Weight Diesel Fractions (C₁₀−C₁₆ Alkane) Drives Cd Stabilization and Pb Activation in Calcareous Soils from Karst Areas

by Yiting Huang, Yankui Tang, Zhenze Xie, Jipeng Wu, Jiajie Huang and Shaojiang Nie

Toxics 2025, 13(6), 496; https://doi.org/10.3390/toxics13060496 - 13 Jun 2025

Viewed by 511

Abstract

The influence of petroleum hydrocarbons (PHCs) on the transport and transformation of heavy metals may limit bioremediation efficiency. The mechanisms by which PHC degradation intermediates control heavy metal distribution in calcareous soils from karst areas require further exploration. This study systematically investigated how [...] Read more.

The influence of petroleum hydrocarbons (PHCs) on the transport and transformation of heavy metals may limit bioremediation efficiency. The mechanisms by which PHC degradation intermediates control heavy metal distribution in calcareous soils from karst areas require further exploration. This study systematically investigated how compositional changes in diesel fuel during aging regulated the fate of Cd and Pb in calcareous soils. The results demonstrated that the low-molecular-weight fractions of diesel fuel (C₁₀−C₁₆) were preferentially degraded. This degradation process altered zeta potential, cation exchange capacity (CEC), and pH, thereby promoting Cd stabilization through electrostatic attraction and speciation transformation. Particularly, reducible Cd content showed a strong positive correlation with C₁₆ content (r = 0.88, p < 0.05). Furthermore, the degradation of C₁₀−C₁₆ fractions caused Pb transformation from residual to bioavailable fractions by stimulating microbial activity. Residual Pb content was positively correlated with C₁₀−C₁₆ fractions (r = 0.55, p < 0.05). Notably, dissolved organic matter (DOM) and CaCO₃ content in calcareous soils enhanced Cd and Pb adsorption, thereby weakening the interactions between these metals and C₁₀−C₁₆ fractions. Consequently, multiple linear regression (MLR) models relying exclusively on C₁₀−C₁₆ degradation parameters showed poor fitting coefficients for Cd/Pb mobility. The present work provides scientific guidance for heavy metal bioremediation in calcareous soils. Full article

(This article belongs to the Section Toxicity Reduction and Environmental Remediation)

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12 pages, 2105 KiB

Open AccessArticle

Occurrence and Drivers of Antibiotic Resistance Genes Carried by Bacteriophages in Soils Following Different Fertilization Treatments

by Mingdi Zhang, Yajie Guo, Yue Zhang, Xueying Hu, Shoutao Cheng and Xuming Wang

Toxics 2025, 13(6), 495; https://doi.org/10.3390/toxics13060495 - 13 Jun 2025

Viewed by 426

Abstract

Fertilization has an important effect on soil antibiotic resistance. Most recent studies have focused on antibiotic resistance genes (ARGs) harbored by bacteria (bARGs); however, little is known about ARGs carried by soil bacteriophages (pARGs) under different fertilization treatments. Here, 24 pARG subtypes were [...] Read more.

Fertilization has an important effect on soil antibiotic resistance. Most recent studies have focused on antibiotic resistance genes (ARGs) harbored by bacteria (bARGs); however, little is known about ARGs carried by soil bacteriophages (pARGs) under different fertilization treatments. Here, 24 pARG subtypes were quantified in soils with long-term application of different fertilizers using droplet digital PCR (ddPCR). The results showed that the detection rates of the target ARGs in bacteriophages were 66.67%, 70.83%, and 75.00% in unfertilized, chemically fertilized, and organically fertilized soils, respectively. The total abundance of pARGs in soils amended with organic fertilizer was significantly higher than that in unfertilized and chemically fertilized soils. The multidrug resistance gene (mexF) exhibited the highest abundance in soils amended with organic fertilizer. A significant positive correlation was observed between bARGs and pARGs, and the detected pARG subtype abundances were one to two orders of magnitude lower than those of the corresponding bARGs. The results of variation partitioning analysis revealed that the interaction between the bacterial community and soil properties drove the variation in soil pARGs. Our findings indicate that bacteriophages are important vectors of ARGs, in addition to bacteria, in agricultural soils, and their contribution to antibiotic resistance should not be overlooked. Full article

(This article belongs to the Special Issue Exposure and Toxicity of Emerging Organic Pollutants in Environment and Human)

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14 pages, 2532 KiB

Open AccessArticle

Distribution, Diversity, and Ecological Risks of Microplastics in Mangrove Ecosystems of a Southeastern Chinese Estuary

by Fengrun Wu, Chengyi Zhang, Xueyan Li, Sha Liu, Jinpu Wang and Weiqi Huang

Toxics 2025, 13(6), 494; https://doi.org/10.3390/toxics13060494 - 12 Jun 2025

Viewed by 441

Abstract

Mangrove ecosystems, serving as critical barriers at land–sea interfaces, face increasing threats from microplastic pollution. This study investigates the spatial distribution, diversity, and ecological risks of microplastics in sediments from the Zhangjiang Estuary mangroves, in southeastern China. Sampling was conducted along two gradients: [...] Read more.

Mangrove ecosystems, serving as critical barriers at land–sea interfaces, face increasing threats from microplastic pollution. This study investigates the spatial distribution, diversity, and ecological risks of microplastics in sediments from the Zhangjiang Estuary mangroves, in southeastern China. Sampling was conducted along two gradients: upstream–downstream and interior–edge habitats. The results revealed an average microplastic abundance of 219.5 ± 21.7 items·kg⁻¹, dominated by fragments (53.3%) and fibers (35.0%). Additionally, 27.8% of the particles were in the 63–200 μm range, while 38.3% fell within the 200–500 μm range. A longitudinal decline in abundance from upstream to downstream was observed. Meanwhile, interior habitats exhibited significantly higher microplastic accumulation (292.86 ± 31.49 items·kg⁻¹) than edge zones (142.50 ± 17.87 items·kg⁻¹) (p < 0.05). The diversity index decreased downstream, with higher diversity in interior habitats, likely due to reduced terrestrial microplastic inputs and stronger tidal sorting in those areas. The ecological risk assessments indicated lower risks in Zhangjiang mangroves compared to global counterparts, though risks were elevated in interior habitats due to higher abundances of hazardous polymers (PVC, PS, PE). This study highlights the role of mangroves as microplastic sinks and advocates for multidimensional risk assessments integrating physical characteristics to guide conservation strategies in vulnerable estuarine ecosystems. Full article

(This article belongs to the Special Issue Microplastic Pollution and Impact on Aquatic and Terrestrial Ecosystems)

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21 pages, 659 KiB

Open AccessReview

Metal-Induced Genotoxic Events: Possible Distinction Between Sporadic and Familial ALS

by William Wu Kim, Gregory Zarus, Breanna Alman, Patricia Ruiz, Moon Han, Paul Mehta, Chao Ji, Hoormat Qureshi, James Antonini and Mohammad Shoeb

Toxics 2025, 13(6), 493; https://doi.org/10.3390/toxics13060493 - 12 Jun 2025

Viewed by 645

Abstract

Metal exposure is a potential risk factor for amyotrophic lateral sclerosis (ALS). Increasing evidence suggests that elevated levels of DNA damage are present in both familial (fALS) and sporadic (sALS) forms of ALS, characterized by the selective loss of motor neurons in the [...] Read more.

Metal exposure is a potential risk factor for amyotrophic lateral sclerosis (ALS). Increasing evidence suggests that elevated levels of DNA damage are present in both familial (fALS) and sporadic (sALS) forms of ALS, characterized by the selective loss of motor neurons in the brain, brainstem, and spinal cord. However, identifying and differentiating initial biomarkers of DNA damage response (DDR) in both forms of ALS remains unclear. The toxicological profiles from the Agency for Toxic Substances and Disease Registry (ATSDR) and our previous studies have demonstrated the influence of metal exposure-induced genotoxicity and neurodegeneration. A comprehensive overview of the ATSDR’s toxicological profiles and the available literature identified 15 metals (aluminum (Al), arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), mercury (Hg), nickel (Ni), selenium (Se), uranium (U), vanadium (V), and zinc (Zn)) showing exposure-induced genotoxicity indicators associated with ALS pathogenesis. Genetic factors including mutations seen in ALS types and with concomitant metal exposure were distinguished, showing that heavy metal exposure can exacerbate the downstream effect of existing genetic mutations in fALS and may contribute to motor neuron degeneration in sALS. Substantial evidence associates heavy metal exposure to genotoxic endpoints in both forms of ALS; however, a data gap has been observed for several of these endpoints. This review aims to (1) provide a comprehensive overview of metal exposure-induced genotoxicity in ALS patients and experimental models, and its potential role in disease risk, (2) summarize the evidence for DNA damage and associated biomarkers in ALS pathogenesis, (3) discuss possible mechanisms for metal exposure-induced genotoxic contributions to ALS pathogenesis, and (4) explore the potential distinction of genotoxic biomarkers in both forms of ALS. Our findings support the association between metal exposure and ALS, highlighting under or unexplored genotoxic endpoints, signaling key data gaps. Given the high prevalence of sALS and studies showing associations with environmental exposures, understanding the mechanisms and identifying early biomarkers is vital for developing preventative therapies and early interventions. Limitations include variability in exposure assessment and the complexity of gene–environment interactions. Studies focusing on longitudinal exposure assessments, mechanistic studies, and biomarker identification to inform preventative and therapeutic strategies for ALS is warranted. Full article

(This article belongs to the Section Metals and Radioactive Substances)

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18 pages, 6109 KiB

Open AccessArticle

The Impact of Boron Carbide Nanoparticle (B4C-NPs) Toxicity on Caenorhabditis elegans Models

by Sen-Ting Huang, Erin P. Bulaon, Kai-Jie Yang, Adriana Taw, Lemmuel L. Tayo, Ping-Heng Hsieh, Jen-Hsiung Tsai, Jian-He Lu, Jheng-Jie Jiang, Hsing-Hsien Wu and How-Ran Chao

Toxics 2025, 13(6), 492; https://doi.org/10.3390/toxics13060492 - 12 Jun 2025

Viewed by 490

Abstract

Boron carbide (B4C) is a widely recognized ceramic prized for its remarkable properties, including exceptional hardness, low density, and excellent chemical and mechanical stability. To date, limited research has explored the possible health risks associated with B4C nanoparticles (B4C-NPs). This study utilized a [...] Read more.

Boron carbide (B4C) is a widely recognized ceramic prized for its remarkable properties, including exceptional hardness, low density, and excellent chemical and mechanical stability. To date, limited research has explored the possible health risks associated with B4C nanoparticles (B4C-NPs). This study utilized a Caenorhabditis elegans (C. elegans) in vivo model to investigate the toxicological effects of B4C-NPs at concentrations of 40, 80, 160, and 320 mg/L. Larval nematodes were subjected to prolonged exposure, and their locomotion (head thrashing and body bending), reproduction (brood size), development (body length), lifespan, and gene expression (linked to oxidative stress, metal detoxification, apoptosis, and neurotransmitter synthesis) were assessed. Regarding survival rates, lethality was significantly increased to 5.41% at 320 mg/L of B4C-NPs and lifespan was significantly shortened across all concentrations compared with the controls. Development and reproduction showed slight reductions between 40 and 320 mg/L, while locomotion was markedly impaired at the doses from 80 to 320 mg/L. Gene expression related to antioxidants, apoptosis, cell cycle arrest, neurotransmitter synthesis, and metal detoxification rose significantly at 160–320 mg/L in C. elegans, suggesting that B4C-NPs may induce reproductive and neurological toxicity, delay development, reduce lifespan, and potentially cause genotoxicity in C. elegans. Full article

(This article belongs to the Special Issue Toxicity Assessment and Safety Management of Nanomaterials)

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18 pages, 1544 KiB

Open AccessArticle

Associations Between Individual Health Risk Perceptions and Biomarkers of PAH Exposure Before and After PM_2.5 Pollution in the Suburbs of Chiang Mai Province

by Sobia Kausar, Xianfeng Cao, Sumed Yadoung, Anurak Wongta, Kai Zhou, Natthapol Kosashunhanan and Surat Hongsibsong

Toxics 2025, 13(6), 491; https://doi.org/10.3390/toxics13060491 - 11 Jun 2025

Cited by 1 | Viewed by 546

Abstract

This study examines how seasonal air pollution affects health perceptions, risk awareness, and preventive behaviors among a sample of 150 individuals, particularly within vulnerable people living in Thailand. Many participants were older adults (54.7% aged ≥ 60), female (76.7%), and had a low [...] Read more.

This study examines how seasonal air pollution affects health perceptions, risk awareness, and preventive behaviors among a sample of 150 individuals, particularly within vulnerable people living in Thailand. Many participants were older adults (54.7% aged ≥ 60), female (76.7%), and had a low income (less than 10,000 THB/month (USD 295), 92.6%). Polycyclic Aromatic Hydrocarbon (PAH) exposure, as indicated by urinary 1-Hydroxypyrene (1-OHP), significantly increased during high-pollution periods (p < 0.001), while benzo[a]pyrene diol epoxide (BPDE) levels did not show significant changes. Farmers exhibited the highest PAH exposure (p = 0.018). Risk perception and preventive behavior scores rose from 0.711 to 0.748 and from 0.505 to 0.707, respectively. Notable items with high factor loadings included “burning pollutes the air and spreads pollution” (Q2.1 = 0.998) and “avoid burning of any kind” (Q4.2 = 1.007). Neurological symptoms, such as loss of consciousness, increased from 0.956 to 1.049, while respiratory problems like pneumonia went up from 0.673 to 1.07. Environmental risk knowledge-related perceptions experienced a slight decline (from 0.609 to 0.576). These results highlight the need for targeted education through community workshops and strategies like mask distribution, indoor air filtration, and early warning systems for vulnerable populations. Full article

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16 pages, 4589 KiB

Open AccessArticle

Immunotoxicity of Four Per- and Polyfluoroalkyl Substances Following 28-Day Oral Repeat Dosing in Rats Assessed by the Anti-Sheep Red Blood Cell IgM Response

by Michael F. Hughes, Michael J. DeVito, Grace Patlewicz, Russell S. Thomas, Linda D. Adams, Jeffrey L. Ambroso, Xi Yang, Bindu G. Upadhyay, Stefanie C. M. Burleson and Elaina M. Kenyon

Toxics 2025, 13(6), 490; https://doi.org/10.3390/toxics13060490 - 10 Jun 2025

Viewed by 494

Abstract

Some PFASs are immunotoxic in rodent models and associated with diminished vaccine response in exposed humans. This study assessed the immunotoxicity of four PFASs via the T cell-dependent IgM antibody response (TDAR) to sheep red blood cells (SRBCs) in adult male rats following [...] Read more.

Some PFASs are immunotoxic in rodent models and associated with diminished vaccine response in exposed humans. This study assessed the immunotoxicity of four PFASs via the T cell-dependent IgM antibody response (TDAR) to sheep red blood cells (SRBCs) in adult male rats following 28-day oral repeat dosing. The PFASs included 1H,1H,9H-perfluorononyl acrylate (PFNAC), 1H,1H,2H,2H-perfluorohexyl iodide (PFHI), 2-chlorotetrafluoropropionic acid (CTFPA), and 3,3,4,4,5,5,5-heptafluoropentan-2-one (MHFPK), administered in corn oil. The positive control was cyclophosphamide (CPS). Rats were dosed with vehicle or PFAS from Days 0 to 27. On Day 22, an immunogenic dose of SRBCs was administered intravenously. Positive control animals were administered CPS by intraperitoneal injection from Days 22–27. On Day 28, the animals were euthanized; blood, thymus, and spleen samples were collected and weighed. Serum IgM was quantified by enzyme-linked immunosorbent assay. Body weights were unaffected in PFAS-treated rats, except for 3 and 10 mg/kg/day PFNAC-treated rats on Days 24, 27, and 28. Relative spleen and thymus weights and serum IgM levels were not affected by the PFASs at the doses tested, whereas CPS-treated animals had significant decreases in these parameters. The rat TDAR, as assessed by the anti-SRBC IgM response, was not affected by these four PFAS test agents following a 28-day oral exposure. Full article

(This article belongs to the Special Issue PFAS Toxicology and Metabolism—2nd Edition)

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16 pages, 832 KiB

Open AccessArticle

Association of Urinary Cadmium and Antimony with Osteoporosis Risk in Postmenopausal Brazilian Women: Insights from a 20 Metal(loid) Biomonitoring Study

by Carlos Tadashi Kunioka, Vanessa Cristina de Oliveira Souza, Bruno Alves Rocha, Fernando Barbosa Júnior, Luís Belo, Maria Conceição Manso and Márcia Carvalho

Toxics 2025, 13(6), 489; https://doi.org/10.3390/toxics13060489 - 10 Jun 2025

Viewed by 515

Abstract

Osteoporosis is a major public health concern, particularly among postmenopausal women. Environmental exposure to metals has been proposed as a potential contributor to osteoporosis, but human data remain limited and inconsistent. This study investigated changes in urinary concentrations of 20 metal(loid)s in patients [...] Read more.

Osteoporosis is a major public health concern, particularly among postmenopausal women. Environmental exposure to metals has been proposed as a potential contributor to osteoporosis, but human data remain limited and inconsistent. This study investigated changes in urinary concentrations of 20 metal(loid)s in patients with osteoporosis, as well as the association of these elements with bone mineral density (BMD), in a cohort of 380 postmenopausal women aged 50–70 years from Cascavel, Paraná, Brazil. Demographic, lifestyle, and clinical data were collected, and urinary concentrations of aluminum (Al), barium (Ba), cadmium (Cd), cobalt (Co), cesium (Cs), copper (Cu), mercury (Hg), lithium (Li), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), rubidium (Rb), antimony (Sb), selenium (Se), tin (Sn), strontium (Sr), thallium (Tl), uranium (U), and zinc (Zn) were measured by inductively coupled plasma mass spectrometry. BMD was assessed at the lumbar spine, femoral neck, and total hip using dual-energy X-ray absorptiometry. Osteoporosis was diagnosed in 73 participants (19.2%). Osteoporotic women had significantly higher urinary concentrations of Cd, Mn, Pb, Sb, Sn, and Zn (p < 0.05). Statistically significant negative correlations were observed between BMD and urinary concentrations of Al, Cd, Hg, Mn, Sb, and U. After adjustment for confounders, elevated urinary concentrations of Cd, Mn, Pb, and Sb remained independently and significantly associated with higher odds of osteoporosis, with Cd (aOR = 1.495; p = 0.026) and Sb (aOR = 2.059; p = 0.030) showing the strongest associations. In addition, women with urinary concentrations above the 90th percentile for both Cd and Sb had a significantly higher prevalence of osteoporosis compared to those with lower levels (44.4% vs. 18.0%; p = 0.011). Longitudinal studies are needed to confirm causality and inform prevention strategies. Full article

(This article belongs to the Special Issue Heavy Metal Contamination and Its Effects on Ecosystems and Human Health: Challenges and Solutions)

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16 pages, 4138 KiB

Open AccessArticle

PM2.5 Induced Nasal Mucosal Barrier Dysfunction and Epithelial–Mesenchymal Transition to Promote Chronic Rhinosinusitis Through IL4I1-AhR Signaling Pathway

by Yue Wang, Bowen Zheng, Panhui Xiong, Yijun Liu, Longlan Shu, Yang Shen, Tao Lu and Yucheng Yang

Toxics 2025, 13(6), 488; https://doi.org/10.3390/toxics13060488 - 10 Jun 2025

Viewed by 812

Abstract

Environmental pollutants like PM2.5 contribute to chronic rhinosinusitis (CRS). The aryl hydrocarbon receptor (AhR), a contaminant sensor linked to tryptophan metabolites, is regulated by IL4I. However, how PM2.5 stimulation via IL4I1 influences AhR activation and CRS pathogenesis remains unclear. This study explored the [...] Read more.

Environmental pollutants like PM2.5 contribute to chronic rhinosinusitis (CRS). The aryl hydrocarbon receptor (AhR), a contaminant sensor linked to tryptophan metabolites, is regulated by IL4I. However, how PM2.5 stimulation via IL4I1 influences AhR activation and CRS pathogenesis remains unclear. This study explored the IL4I1-AhR pathway in CRS using patient tissues, HNEpCs, and murine models. Methods included IHC, qRT-PCR, and WB under PM2.5 exposure, with further investigation into downstream effects on CYP1B1 and epithelial–mesenchymal transition (EMT). Significant upregulation of IL4I1, AhR, and CYP1B1 was observed in CRS tissues, with higher expression levels in CRS patients. Exposure to PM2.5 activated the IL4I1-AhR pathway, leading to decreased E-cadherin, increased N-cadherin and vimentin, and impaired nasal mucosal barrier function. In vitro experiments demonstrated that PM2.5-induced EMT in HNEpCs was mediated by IL4I1-dependent AhR activation. CH223191 reduced cell migration and EMT, while IL4I1 knockdown attenuated AhR activation and EMT marker expression. Murine models further confirmed that PM2.5 exacerbated nasal polyp formation and tissue remodeling via the IL4I1-AhR pathway. This study underscores the critical role of the IL4I1-AhR signaling pathway in PM2.5-induced nasal mucosal barrier dysfunction and EMT in CRS. IL4I1, as an upstream regulator of AhR, promotes EMT and nasal mucosal barrier disruption. Full article

(This article belongs to the Section Air Pollution and Health)

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21 pages, 10345 KiB

Open AccessArticle

Intratracheal Administration of Polystyrene Micro(nano)plastics with a Mixed Particle Size Promote Pulmonary Fibrosis in Rats by Activating TGF-β1 Signaling and Destabilizing Mitochondrial Dynamics and Mitophagy in a Dose- and Time-Dependent Manner

by Shuang Xia, Chunli Yuan, Wei Long, Zongcheng Wu, Xiuqin Li, Nan Wang, Mumu Gao, Zhe Li, Peilun Li, Peng Liu, Xiaoxi Qu and Lina Sun

Toxics 2025, 13(6), 487; https://doi.org/10.3390/toxics13060487 - 9 Jun 2025

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Abstract

Background: Microplastics (MPs) can be inhaled by people. However, the relationships between long-term exposure to inhaled MPs, pulmonary fibrosis, and mitochondrial dysfunction are not completely clear. Methods: SD rats were exposed to a 0.0125, 0.125, 0.31, or 1.25 mg/day dosage of mixed polystyrene [...] Read more.

Background: Microplastics (MPs) can be inhaled by people. However, the relationships between long-term exposure to inhaled MPs, pulmonary fibrosis, and mitochondrial dysfunction are not completely clear. Methods: SD rats were exposed to a 0.0125, 0.125, 0.31, or 1.25 mg/day dosage of mixed polystyrene MPs (PS-MPs), with the particle sizes ranging from 500 nm to 4 µm, via intratracheal administration, for 7 to 35 consecutive days. Results: PS-MPs with particle sizes ranging from 1 µm to 4 µm were deposited in the lungs. The contents of NFκB-mediated proinflammatory cytokines were increased in the lungs of the rats after 7 days of PS-MP exposure. After exposure to PS-MPs, the degree of collagen deposition and the expression of TGF-β1/Smad increased significantly, and the levels of phosphorylated Akt (p-Akt) and nuclear β-catenin decreased significantly. The number of healthy mitochondria decreased, the expression of mitochondrial fission and fusion proteins increased, and the level of PINK1/Parkin-mediated mitophagy decreased in the lungs of the rats after 7 days of PS-MP exposure. A benchmark dose (BMD) of 0.151 mg/day and a benchmark dose lower confidence limit (BMDL) of 0.031 mg/day were identified on the basis of the subchronic effects of the intratracheal administration of the PS-MPs. Conclusions: Our study provides an in-depth understanding of the potential impacts of MP pollution on respiratory diseases. Full article

(This article belongs to the Special Issue Health Effects and Toxicology Studies of Emerging Contaminants)

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Toxics, Volume 13, Issue 6 (June 2025) – 99 articles

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