Toxics

24 pages, 3598 KiB

Open AccessArticle

Assessment of Organic Pollutants Desorbed from Plastic Litter Items Stranded on Cadiz Beaches (SW Spain)

by Juan Manuel Traverso-Soto, Manuel Figueredo, Irene Punta-Sánchez, Olivia Campana, Elisabetta Ciufegni, Miriam Hampel, Joana Buoninsegni, Manuel A. Manzano Quiñones and Giorgio Anfuso

Toxics 2025, 13(8), 673; https://doi.org/10.3390/toxics13080673 (registering DOI) - 9 Aug 2025

Abstract

This paper constitutes a preliminary study that evaluates the organic pollutants desorbed from “fresh” plastic litter, i.e., recently stranded items, on three beaches in Cadiz (SW Spain): Bajo de Guia, La Jara, and La Puntilla. Beach litter items were collected and classified in [...] Read more.

This paper constitutes a preliminary study that evaluates the organic pollutants desorbed from “fresh” plastic litter, i.e., recently stranded items, on three beaches in Cadiz (SW Spain): Bajo de Guia, La Jara, and La Puntilla. Beach litter items were collected and classified in laboratory according to their composition and use. Leachates were obtained by stir bar sorptive extraction (SBSE) and analysed with gas chromatography–mass spectrometry (GC–MS). Fifty-five target organic compounds—including polycyclic aromatic hydrocarbons (PAHs), pesticides, fragrances, insect repellents, and UV filters—were quantified. Plastics accounted for the majority of litter by both number and weight. Cigarette butts and wipes were also prevalent and served as key sources of leachable PAHs. With respect to the main pollutants found in plastic films, hard plastics, and wipes, fragrances such as OTNE1 (1-Tetramethyl Acetyloctahydronaphthalene), OTNE2 (2-Tetramethyl Acetyloctahydronaphthalene), DEET (N, N-Diethyl-Meta-Toluamide), galaxolide, and tonalide were dominant, with concentrations exceeding 100 ng/g in some cases. DEET was the most common insect repellent detected. These findings underscore the role of beach litter, especially plastic waste, as a vector for persistent and emerging organic pollutants, highlighting the urgent need for improved waste management and monitoring practices to mitigate ecological risks associated with plastic pollution. Full article

(This article belongs to the Special Issue Emerging Methodologies in Toxicology for Environmental Safety Assessment)

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14 pages, 2118 KiB

Open AccessArticle

Effects of Diethylstilbestrol on Uterus Structure and Immunological Function in Mice During Early Pregnancy

by Jian Li, Ruiping Xu, Guan Wang, Yanhua Su, Yaoxing Chen and Jing Cao

Toxics 2025, 13(8), 672; https://doi.org/10.3390/toxics13080672 (registering DOI) - 9 Aug 2025

Abstract

Due to the growing environmental burden of endocrine-disrupting chemicals (EDCs), there is an increasing concern regarding the reproductive hazards posed by synthetic estrogens, particularly diethylstilbestrol (DES). However, the precise mechanisms by which DES disrupts uterine endocrine function and immune homeostasis leading to pregnancy [...] Read more.

Due to the growing environmental burden of endocrine-disrupting chemicals (EDCs), there is an increasing concern regarding the reproductive hazards posed by synthetic estrogens, particularly diethylstilbestrol (DES). However, the precise mechanisms by which DES disrupts uterine endocrine function and immune homeostasis leading to pregnancy failure remain unclear. Given that wild rodents serve as key reservoirs for zoonotic diseases such as plague, reproductive interventions targeting their pregnancy processes hold significant ecological implications for disease control. In this study, female mice in estrus were randomly divided into four experimental groups, receiving DES at doses of 0 (control), 0.02 (low), 0.2 (medium), and 2 mg/kg (high), respectively. For five consecutive days, mice were injected subcutaneously on a daily basis, with the goal of examining DES-related alterations in hormone secretion and local immune responses within the uterus and spleen. It was found that high-dose DES treatment significantly increased maternal body weight and spleen weight during early pregnancy (p < 0.05). Meanwhile, reproductive function declined progressively with increasing doses, as indicated by decreased ovarian and uterine weights, fewer embryos, and extended estrous cycle duration (p < 0.05). Hematoxylin and eosin staining revealed that high-dose DES markedly reduced uterine gland density at day P5, accompanied by epithelial vacuolar degeneration and nuclear pyknosis. The proportion of uterine glands relative to total uterine area also decreased significantly with increasing DES doses. Moreover, DES inhibited lymphocyte proliferation in both the uterus and spleen in a dose-dependent fashion, with ConA- and LPS-induced proliferation rates decreasing by 0.78–30.70% and 1.91–18.20%, respectively (p < 0.05). The proinflammatory cytokine IL-2 was significantly elevated by DES, whereas the anti-inflammatory cytokine IL-4 showed a notable decrease (p < 0.05). DES administration notably decreased uterine expression of proliferating cell nuclear antigen. In contrast, the numbers of B-cell lymphoma 2- and Bcl-2-associated X protein-positive cells rose, along with upregulated levels of inducible nitric oxide synthase. Furthermore, DES impaired antioxidant defenses in both the uterus and spleen, evidenced by the decreased activities of superoxide dismutase and glutathione peroxidase, reduced total antioxidant capacity, and elevated malondialdehyde levels. This study elucidates the multifaceted mechanisms by which DES impairs the early gestational reproductive environment, filling a critical knowledge gap regarding its interference with the uterus–immune axis, and expands the current understanding of the ecotoxicological impacts of endocrine-disrupting chemicals. Full article

(This article belongs to the Section Ecotoxicology)

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17 pages, 1492 KiB

Open AccessArticle

Coupled In Silico Toxicology Models Reveal Equivalent Ecological Risks from BPA and Its Alternatives in Chinese Surface Waters

by Jiawei Zhang, Jingzi Xiao, Huanyu Tao, Mengtao Zhang, Lu Lu and Changbo Qin

Toxics 2025, 13(8), 671; https://doi.org/10.3390/toxics13080671 (registering DOI) - 9 Aug 2025

Abstract

As bisphenol A (BPA) has gradually become restricted in production scenarios, the ecological risk level of its main replacement chemicals, i.e., bisphenol S (BPS) and bisphenol F (BPF), should be noted. To overcome the limitations of toxicity data, two kinds of in silico [...] Read more.

As bisphenol A (BPA) has gradually become restricted in production scenarios, the ecological risk level of its main replacement chemicals, i.e., bisphenol S (BPS) and bisphenol F (BPF), should be noted. To overcome the limitations of toxicity data, two kinds of in silico toxicology models (quantitative structure–activity relationship (QSAR) and interspecies correlation estimation (ICE) models) were used to predict enough toxicity data for multiple species. The accuracy of the coupled in silico toxicology models was verified by comparing experimental and predicted data results. Reliable predicted no-effect concentrations (PNECs) of 8.04, 35.2, and 34.2 μg/L were derived for BPA, BPS, and BPF, respectively, using species sensitivity distribution (SSD). Accordingly, the ecological risk quotient (RQ) values of BPA, BPS, and BPF for aquatic organisms were assessed in 32 major Chinese surface waters; they ranged from nearly 0 to 1.86, but were <0.1 in most cases, which indicated that the overall ecological risk level of BPA and its alternatives was low. However, in some cases, the ecological risks posed by BPA alternatives have reached equivalent levels to those posed by BPA (e.g., Liuxi River, Taihu Lake, and Pearl River), which requires further attention. This study provides evidence that the application of coupled in silico toxicology models can effectively predict toxicity data for new chemicals, avoiding time-consuming and laborious animal experiments. The main findings of this study can support environmental risk assessment and management for new chemicals that lack toxicity data. Full article

(This article belongs to the Section Emerging Contaminants)

23 pages, 4338 KiB

Open AccessArticle

Ozone Pollution in the Western Yangtze River Delta During the 2020 and 2021 Warm Seasons: Roles of Meteorology and Air Mass Transport

by Yuchen Wang, Ming Wang, Feng Ding, Xueqi Chen and Liangyu Zhang

Toxics 2025, 13(8), 670; https://doi.org/10.3390/toxics13080670 (registering DOI) - 9 Aug 2025

Abstract

Surface ozone (O₃), a key hurdle in air quality improvement in China, often displays regional pollution characteristics. This study investigated the influence of meteorological conditions and air mass transport on O₃ and non-methane hydrocarbons (NMHCs) concentrations in Nanjing, located in [...] Read more.

Surface ozone (O₃), a key hurdle in air quality improvement in China, often displays regional pollution characteristics. This study investigated the influence of meteorological conditions and air mass transport on O₃ and non-methane hydrocarbons (NMHCs) concentrations in Nanjing, located in the western Yangtze River Delta (YRD) region of China during April–September of 2020 and 2021 based on online observations of O₃ and its precursors and meteorological conditions, backward-trajectory analysis, and an observation-based box model (OBM). O₃ concentrations rose with temperature, albeit non-linearly. Southeastern trajectories constituted the most dominant air mass transport pathway (29.3%) and were associated with the highest O₃ concentrations. The concentration-weighted trajectory analyses of O₃ and NMHCs during four O₃ pollution episodes suggested that urban/industrial areas in central and eastern YRD were potential source regions. The OBM results indicated that while O₃ sensitivity was dominated by the NMHCs-limited regime, the relative contributions of three O₃ sensitivity regimes varied across air mass trajectory clusters. The southeastern air masses with long-range transport showed the highest frequency of the transition and NO_x-limited O₃ sensitivity regimes. These findings underscore the crucial role of regional air mass transport not only in determining O₃ and NMHCs concentrations but also in shaping O₃ formation sensitivity, highlighting the necessity of implementing regionally coordinated control strategies for effective O₃ and NMHCs pollution mitigation. Full article

(This article belongs to the Special Issue Concentration of VOCs in the Atmosphere and Its Environmental Exposure)

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13 pages, 730 KiB

Open AccessArticle

The TyG Index Mediates Air-Pollution-Associated Chronic Kidney Disease Incidence in HIV/AIDS Patients: A 20-Year Cohort Study

by Xiaoxia Liu, Xiuli Zhao, Lu Ye, Chengfeng Hu, Zhihao Xie, Jianan Ma, Xia Wang and Wei Liang

Toxics 2025, 13(8), 669; https://doi.org/10.3390/toxics13080669 - 8 Aug 2025

Abstract

Ambient air pollutants (APs) are associated with increased chronic kidney disease (CKD) risk in general populations, but their renal impact on HIV/AIDS patients remains understudied. This dynamic cohort included 7981 HIV/AIDS patients without baseline kidney disease from Wuhan and Zhenjiang, followed every 6 [...] Read more.

Ambient air pollutants (APs) are associated with increased chronic kidney disease (CKD) risk in general populations, but their renal impact on HIV/AIDS patients remains understudied. This dynamic cohort included 7981 HIV/AIDS patients without baseline kidney disease from Wuhan and Zhenjiang, followed every 6 months with fasting blood tests to assess the triglyceride-glucose (TyG) index and estimated glomerular filtration rate (eGFR). Monthly average exposures to six APs were estimated from geocoded residential addresses. Modified Poisson regression models were used to assess associations between cumulative AP exposure and CKD incidence, with mediation analysis conducted to explore the potential role of the TyG index. Weighted quantile sum regression was applied to evaluate the joint effects of six APs. During the follow-up period, 168 new cases of CKD were identified. Each interquartile range increase in PM_2.5, PM₁₀, and SO₂ corresponded to a 16.5%, 18.9%, and 9.7% higher CKD risk, respectively, with the TyG index mediating 10.21%, 9.16%, and 5.14% of these associations. PM_2.5 demonstrated the highest attribution weight (44.4%) for CKD risk elevation in mixed-exposure models. Chronic ambient AP exposure, particularly PM_2.5, synergistically elevates CKD risk in HIV/AIDS patients with glucolipid dysregulation potentially being involved, necessitating targeted air quality policies to mitigate AP impacts on this vulnerable population. Full article

18 pages, 1698 KiB

Open AccessArticle

Effects of Tarragon Hydrodistillate and Essential Oil on Aquatic Ecosystems

by Andrijana Pujicic, Bianca-Vanesa Agachi, Constantina-Bianca Vulpe and Adriana Isvoran

Toxics 2025, 13(8), 668; https://doi.org/10.3390/toxics13080668 - 8 Aug 2025

Abstract

Tarragon extracts, especially from Artemisia dracunculus, have shown their potential as natural pesticides and can harm aquatic ecosystems. In addition, waste from tarragon essential oil production can also contribute to aquatic pollution if not properly managed. In this study, a hydrodistillate and [...] Read more.

Tarragon extracts, especially from Artemisia dracunculus, have shown their potential as natural pesticides and can harm aquatic ecosystems. In addition, waste from tarragon essential oil production can also contribute to aquatic pollution if not properly managed. In this study, a hydrodistillate and a commercial tarragon essential oil were considered to evaluate their effects on aquatic ecosystems. A growth inhibition test was performed using Lemna minor to evaluate the potential ecotoxicity of tarragon extracts, and a biochemical test was performed to investigate the potential effects of the lowest volume of oil, which did not cause any visible impact on this organism. The results showed that the hydrodistillate did not show toxic effects on L. minor, but the essential oil demonstrated potential ecotoxicity, with volumes of 0.5 µL and above leading to percentage reductions in frond numbers of 50% and higher. The biochemical assay revealed no significant differences between the negative control and the lowest volume of oil tested, suggesting the absence of biochemical effects at low exposure levels. The effects of compounds identified at higher concentrations in the tarragon extracts on other aquatic organisms were predicted using the admetSAR3.0 tool, and potential toxicity against numerous aquatic organisms was emphasized, particularly for cis-beta-ocimene, trans-beta-ocimene, and caryophyllene oxide. These findings emphasize the need for careful consideration of both the application dose and disposal practices of tarragon-based products. Full article

(This article belongs to the Special Issue Impact of Pollutants on Aquatic Ecosystems and Food Safety)

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26 pages, 928 KiB

Open AccessReview

A Review on the Degradation of Antibiotic Resistance Genes During Composting of Livestock Manure

by Enwang Zhao, Yongchao Li, Jin Zhang and Bing Geng

Toxics 2025, 13(8), 667; https://doi.org/10.3390/toxics13080667 - 8 Aug 2025

Abstract

As emerging pollutants, antibiotic resistance genes (ARGs) have been recognized as originating from diverse sources. Among these, the use of livestock feed and veterinary drugs was identified as the primary source of ARGs in livestock manure. ARGs were found to be widely distributed [...] Read more.

As emerging pollutants, antibiotic resistance genes (ARGs) have been recognized as originating from diverse sources. Among these, the use of livestock feed and veterinary drugs was identified as the primary source of ARGs in livestock manure. ARGs were found to be widely distributed in global environments, particularly in agriculture-related soils, water bodies, and the atmosphere, posing potential threats to ecological environments and human health. This paper reviewed the degradation mechanisms of ARGs during aerobic composting of livestock manure and the safety evaluation of compost products. Aerobic composting was demonstrated to be an effective method for degrading ARGs, primarily through mechanisms such as high-temperature elimination of ARG-carrying microorganisms, reduction in host bacterial abundance, and inhibition of horizontal gene transfer. Factors including the physicochemical properties of the composting substrate, the use of additives, and the presence of antibiotic and heavy metal residues were shown to influence the degradation efficiency of ARGs, with compost temperature being the core factor. The safety of organic fertilizers encompassed multiple aspects, including heavy metal content, seed germination index, and risk assessments based on ARG residues. The analysis indicated that deficiencies existed in areas such as the persistence of thermotolerant bacteria carrying ARGs, the dissemination of extracellular antibiotic resistance genes (eARGs), and virus-mediated gene transfer. Future research should focus on (1) the removal of thermotolerant bacteria harboring ARGs; (2) the decomposition of eARGs or the blocking of their transmission pathways; (3) the optimization of ultra-high temperature composting parameters; and (4) the analysis of interactions between viruses and resistant hosts. This study reviews the mechanisms, influencing factors, and safety assessment of aerobic composting for degrading ARGs in livestock manure. It not only deepens the understanding of this important environmental biotechnology process but also provides a crucial knowledge base and practical guidance for effectively controlling ARG pollution, ensuring agricultural environmental safety, and protecting public health. Additionally, it clearly outlines the key paths for future technological optimization, thus holding significant implications for the environment, agriculture, and public health. Full article

(This article belongs to the Special Issue Antibiotics and Resistance Genes in Environment)

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20 pages, 7313 KiB

Open AccessArticle

Integrated Modeling of Composition-Resolved Source Apportionment and Dynamic Projection for Ozone Pollution in Datong

by Xiaofeng Yao, Tongshun Han, Zexuan Yang, Xiaohui Zhang and Liang Pei

Toxics 2025, 13(8), 666; https://doi.org/10.3390/toxics13080666 - 8 Aug 2025

Abstract

Growing ozone (O₃) pollution in industrial cities urgently requires in-depth mechanistic research. This study utilized multi-year observational data from Datong City, China, from 2020 to 2024, integrating time trend diagnostics, correlation dynamics analysis, Environmental Protection Agency Positive Matrix Factorization 5.0 (EPA [...] Read more.

Growing ozone (O₃) pollution in industrial cities urgently requires in-depth mechanistic research. This study utilized multi-year observational data from Datong City, China, from 2020 to 2024, integrating time trend diagnostics, correlation dynamics analysis, Environmental Protection Agency Positive Matrix Factorization 5.0 (EPA PMF 5.0) model simulations, and a grey prediction model (GM (1,1)) projection method to reveal the coupling mechanisms among O₃ precursors. Key breakthroughs include the following: (1) A ratio of volatile organic compounds (VOCs) to nitrogen oxides (NO_x) of 1.5 clearly distinguishes between NO_x-constrained (winter) and VOC-sensitive (summer) modes, a conclusion validated by the strong negative correlation between O₃ and NO_x (r = −0.80, p < 0.01) and the dominant role of NO titration. (2) Aromatic compounds (toluene, xylene) used as solvents in industrial emissions, despite accounting for only 7.9% of VOC mass, drove 37.1% of ozone formation potential (OFP), while petrochemical and paint production (accounting for 12.2% of VOC mass) contributed only 0.3% of OFP. (3) Quantitative analysis of OFP using PMF identified natural gas/fuel gas use and leakage (accounting for 34.9% of OFP) and solvent use (accounting for 37.1% of OFP) as key control targets. (4) The GM (1,1) model predicts that, despite a decrease in VOC concentrations (−15.7%) and an increase in NO_x concentrations (+2.4%), O₃ concentrations will rise to 169.7 μg m⁻³ by 2025 (an increase of 7.4% compared to 2024), indicating an improvement in photochemical efficiency. We have established an activity-oriented prioritization framework targeting high-OFP species from key sources. This provides a scientific basis for precise O₃ emission reductions consistent with China’s 15th Five-Year Plan for synergistic pollution/carbon governance. Full article

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

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9 pages, 1972 KiB

Open AccessCommunication

Proteomic Analysis of Heavy Metal-Induced Toxicity Using the Cellular Slime Mould Dictyostelium discoideum: Effects of Copper Exposure on Aggregation and Protein Expression

by Atsuko Itoh, Koji Kurihara and Ryo Shoji

Toxics 2025, 13(8), 665; https://doi.org/10.3390/toxics13080665 - 8 Aug 2025

Abstract

The cellular slime mould Dictyostelium discoideum is a soil-dwelling eukaryotic organism that undergoes distinctive morphological changes during starvation, making it a promising candidate for bioassay development. In this study, we evaluated the effects of copper (Cu) exposure on the morphological transformation of D. [...] Read more.

The cellular slime mould Dictyostelium discoideum is a soil-dwelling eukaryotic organism that undergoes distinctive morphological changes during starvation, making it a promising candidate for bioassay development. In this study, we evaluated the effects of copper (Cu) exposure on the morphological transformation of D. discoideum and performed a comparative proteomic analysis. Copper exposure on agar media delayed aggregate formation by 3.5 h compared to the controls. Approximately 280 protein spots were detected using immobilised pH gradient two-dimensional gel electrophoresis followed by silver staining. Three spots disappeared upon exposure to Cu. Based on isoelectric point and molecular weight analyses, the proteins were predicted to be formin-1, a cytoplasmic regulator of adenylyl cyclase (CRAC), and a tetratricopeptide repeat (TPR)-containing protein. Formin-1 and CRAC are involved in aggregation processes. These findings suggest that Cu disrupts aggregation-related protein expression in D. discoideum and highlight the potential of D. discoideum-based bioassays using proteomic biomarkers for environmental monitoring. Full article

(This article belongs to the Section Ecotoxicology)

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13 pages, 5445 KiB

Open AccessArticle

Association of 6:2 Fluorotelomer Ethoxylate Exposure with Serum Lipids in General Adults

by Yan Wu, Qianjin Li, Rendi Deng, Rui Wang, Junfen Fu, Fangfang Ren and Hangbiao Jin

Toxics 2025, 13(8), 664; https://doi.org/10.3390/toxics13080664 - 7 Aug 2025

Abstract

A series of 6:2 fluorotelomer ethoxylates (FTEOs) has been recently detected in human serum. Whether it has the potential to disrupt lipid metabolism in human populations remains largely unexplored. This study quantified serum concentrations of 6:2 FTEOs in 237 healthy Chinese adults, examined [...] Read more.

A series of 6:2 fluorotelomer ethoxylates (FTEOs) has been recently detected in human serum. Whether it has the potential to disrupt lipid metabolism in human populations remains largely unexplored. This study quantified serum concentrations of 6:2 FTEOs in 237 healthy Chinese adults, examined the gender- and age-specific differences in serum levels of 6:2 FTEOs, and investigated the associations between serum levels of 6:2 FTEOs and lipid profiles for the first time. Nine 6:2 FTEO homologues were detected in collected human serum, with detection frequencies of 22–81%. 6:2 FTEO8 and 6:2 FTEO9 were the more abundant 6:2 FTEO homologues in human serum, displaying the mean levels of 0.69 ng/mL (range < LOD–7.36 ng/mL) and 0.71 ng/mL (<LOD–8.12 ng/mL), respectively. Male participants had much higher (p < 0.05) mean serum levels of 6:2 FTEO6 (0.61 vs. 0.31 ng/mL), 6:2 FTEO7 (0.44 vs. 0.21 ng/mL), 6:2 FTEO8 (0.91 vs. 0.38 ng/mL), and 6:2 FTEO11 (0.35 vs. 0.18 ng/mL) than female subjects. Correlation analysis revealed a significantly positive relationship (p < 0.01) between the age of participants and human serum concentrations of 6:2 FTEO6–6:2 FTEO11. Multivariate linear regression identified significant positive associations between specific 6:2 FTEO homologues (e.g., 6:2 FTEO6, 6:2 FTEO8–6:2 FTEO10) and elevated total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglyceride levels. Full article

(This article belongs to the Section Exposome Analysis and Risk Assessment)

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18 pages, 2230 KiB

Open AccessArticle

Exposure of Domestic Cats (Felis catus) to Rodenticidal Compounds

by Vesna Cerkvenik-Flajs, Detlef Schenke, Simona Korenjak-Černe, Anton Perpar, Jens Jacob, Susanne Schwonbeck, Sven Kleine Bardenhorst, Torsten Hahn, Marko Cvetko and Mitja Gombač

Toxics 2025, 13(8), 663; https://doi.org/10.3390/toxics13080663 - 7 Aug 2025

Abstract

Anticoagulant rodenticides (ARs) are highly effective, but can be of environmental concern due to primary and secondary non-target exposure, with the latter possible being relevant to domestic cats. Therefore, liver residues of ARs and an alternative rodenticide, α-chloralose, were systematically monitored in domestic [...] Read more.

Anticoagulant rodenticides (ARs) are highly effective, but can be of environmental concern due to primary and secondary non-target exposure, with the latter possible being relevant to domestic cats. Therefore, liver residues of ARs and an alternative rodenticide, α-chloralose, were systematically monitored in domestic cats for the first time in the current study. In 2021 and 2022, the carcasses of 99 cats were collected in Slovenia and liver residues were measured by using solid supported liquid–liquid extraction and LC-MS/MS. The results show that 65% of cats carried at least one rodenticide. The second-generation ARs brodifacoum and bromadiolone were most prevalent and found in 53.5 and 25.3% of the samples, respectively. Of first-generation ARs, coumatetralyl was the most prevalent (21.2% of cats). More compounds were detected at high human population density, low farm density and in rural versus intermediate landscapes, but no effect was found for livestock density. Similar trends were found for the presence of brodifacoum, bromadiolone and all rodenticides combined. Farm density was negatively correlated with brodifacoum liver concentration. Individual factors (cat age, sex, outdoor activity) did not matter. The results indicate that a reasonably populated rural landscape, and not the rural or intermediate environment as such, is the main driver of cat exposure to ARs. The risk quotient (RQ) of worst-case acute brodifacoum poisoning was 1506. In summary, a potential environmental problem is globally highlighted for cats that is probably related to secondary exposure to ARs, with a pattern different to that seen in wild predators. Cats are an appropriate sentinel species for assessing rodenticide exposure and endangerment in the environment. Full article

(This article belongs to the Section Exposome Analysis and Risk Assessment)

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17 pages, 4939 KiB

Open AccessArticle

Distinct Effects of PFOS and OBS on Neurotoxicity via PMK-1 Mediated Pathway in Caenorhabditis elegans

by Jiahong Jiang, Qi Liu, Boxiang Zhang, Lei Zhao and Dan Xu

Toxics 2025, 13(8), 662; https://doi.org/10.3390/toxics13080662 - 6 Aug 2025

Abstract

Sodium p-perfluorous nonenoxybenzenesulfonate (OBS) has been proposed as a substitute for perfluorooctanesulfonic acid (PFOS), yet it has garnered increasing attention due to its environmental persistence and potential toxicity. Despite these concerns, the neurotoxic mechanisms of OBS remain unclear. This study investigates and compares [...] Read more.

Sodium p-perfluorous nonenoxybenzenesulfonate (OBS) has been proposed as a substitute for perfluorooctanesulfonic acid (PFOS), yet it has garnered increasing attention due to its environmental persistence and potential toxicity. Despite these concerns, the neurotoxic mechanisms of OBS remain unclear. This study investigates and compares the neurotoxic effects and mechanisms of OBS and PFOS in Caenorhabditis elegans. L4-stage worms were exposed to OBS (0.1–100 μM) or PFOS (100 μM) for 24 h. Neurobehavioral analysis showed that OBS exposure induced concentration-dependent neurobehavioral deficits, with 100 μM OBS significantly reducing pharyngeal pumping rate (29.8%), head swing frequency (23.4%), and body bending frequency (46.6%), surpassing the effects of PFOS. Both compounds decreased the fluorescence intensity of dopaminergic, glutamatergic, and γ-aminobutyric acid neurons and downregulated neurotransmitter-associated genes. They also increased ROS generation and inhibited antioxidant gene expression. Molecular docking revealed that OBS had a stronger binding affinity to p38 MAPK key protein (PMK-1) than PFOS. OBS and PFOS upregulated pmk-1 and skn-1, modulating oxidative stress and neuronal function. pmk-1 mutation differentially affected OBS-induced neurobehavioral changes and gene expression alterations. Our findings indicate that OBS exhibits stronger neurotoxicity than PFOS in Caenorhabditis elegans, mediated through the PMK-1 pathway. These results highlight the need for further investigation into the safety of OBS as a PFOS alternative. Full article

(This article belongs to the Special Issue Molecular Mechanisms of PFAS-Induced Toxicity and Carcinogenicity)

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45 pages, 2241 KiB

Open AccessReview

Extraction Methods of Emerging Pollutants in Sewage Sludge: A Comprehensive Review

by Tatiana Robledo-Mahón, Filip Mercl, Nallanthigal Sridhara Chary, Jiřina Száková and Pavel Tlustoš

Toxics 2025, 13(8), 661; https://doi.org/10.3390/toxics13080661 - 5 Aug 2025

Abstract

Sewage sludge (SS) is commonly applied as a soil amendment. This practice has raised concern about the dissemination of emerging pollutants (EPs). EPs include compounds such as flame retardants, plasticizers, pharmaceuticals, and personal care products, among others, which may pose risks to human [...] Read more.

Sewage sludge (SS) is commonly applied as a soil amendment. This practice has raised concern about the dissemination of emerging pollutants (EPs). EPs include compounds such as flame retardants, plasticizers, pharmaceuticals, and personal care products, among others, which may pose risks to human health and ecosystems. The complexity of the SS matrix, combined to the absence of an international legislation framework, makes it necessary to evaluate the techniques available for detecting these contaminants. Detection is typically performed using sensitive analytical techniques; however, the extraction strategy selected remains a crucial step. This review aims to compile different methodologies for the determination of EPs in SS, focusing on extraction strategies reported between 2010 and 2025. Ultrasound-assisted extraction (UAE), pressurized liquid extraction (PLE), and microwave-assisted extraction (MAE) are the most widely used strategies for EPs. UAE is considered the most preferable option, as it enables the extraction of a wide range of compounds without the need for expensive equipment. Among novel techniques, the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method is especially promising, as it is applicable to multiple target compounds. This review provides up-to-date information that can support the development of routine and standardized methodologies for the characterization of EPs in SS. Full article

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

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20 pages, 489 KiB

Open AccessArticle

Development of Preliminary Candidate Surface Guidelines for Air Force-Relevant Dermal Sensitizers Using New Approach Methodologies

by Andrew J. Keebaugh, Megan L. Steele, Argel Islas-Robles, Jakeb Phillips, Allison Hilberer, Kayla Cantrell, Yaroslav G. Chushak, David R. Mattie, Rebecca A. Clewell and Elaine A. Merrill

Toxics 2025, 13(8), 660; https://doi.org/10.3390/toxics13080660 - 2 Aug 2025

Abstract

Allergic contact dermatitis (ACD) is an immunologic reaction to a dermal chemical exposure that, once triggered in an individual, will result in an allergic response following subsequent encounters with the allergen. Air Force epidemiological consultations have indicated that aircraft structural maintenance workers may [...] Read more.

Allergic contact dermatitis (ACD) is an immunologic reaction to a dermal chemical exposure that, once triggered in an individual, will result in an allergic response following subsequent encounters with the allergen. Air Force epidemiological consultations have indicated that aircraft structural maintenance workers may experience ACD at elevated rates compared to other occupations. We aimed to better understand the utility of non-animal testing methods in characterizing the sensitization potential of chemicals used during Air Force operations by evaluating the skin sensitization hazard of Air Force-relevant chemicals using new approach methodologies (NAMs) in a case study. We also evaluated the use of NAM data to develop preliminary candidate surface guidelines (PCSGs, maximum concentrations of chemicals on workplace surfaces to prevent induction of dermal sensitization) for chemicals identified as sensitizers. NAMs for assessing skin sensitization, including in silico models and experimental assays, were leveraged into an integrated approach to predict sensitization hazard for 19 chemicals. Local lymph node assay effective concentration values were predicted from NAM assay data via previously published quantitative models. The derived values were used to calculate PCSGs, which can be used to compare the presence of these chemicals on work surfaces to better understand the risk of Airmen developing ACD from occupational exposures. Full article

(This article belongs to the Special Issue Applicability of New Approach Methodologies (NAMs) to Skin Sensitization: Insights from Industry and Regulatory Perspectives)

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40 pages, 1142 KiB

Open AccessReview

The Blurred Lines Between New Psychoactive Substances and Potential Chemical Weapons

by Loreto N. Valenzuela-Tapia, Cristóbal A. Quintul, Nataly D. Rubio-Concha, Luis Toledo-Ríos, Catalina Salas-Kuscevic, Andrea V. Leisewitz, Pamela Cámpora-Oñate and Javier Campanini-Salinas

Toxics 2025, 13(8), 659; https://doi.org/10.3390/toxics13080659 - 1 Aug 2025

Abstract

The historical use of toxic chemicals to cause intentional harm has evolved from blister agents in World War I to highly lethal organophosphates and emerging families of chemicals, such as Novichok. In turn, medical or recreational substances like fentanyl, lysergamides, and phencyclidine pose [...] Read more.

The historical use of toxic chemicals to cause intentional harm has evolved from blister agents in World War I to highly lethal organophosphates and emerging families of chemicals, such as Novichok. In turn, medical or recreational substances like fentanyl, lysergamides, and phencyclidine pose a growing risk of hostile use, particularly related to the rapid proliferation of new psychoactive substances (NPSs). A narrative literature review was conducted covering specialized databases (PubMed, ScienceDirect, SciELO, Google Scholar) and sources from international organizations (OPCW, UNODC, ONU), analyzing historical and recent cases of the use of nerve agents in conflicts and the use of NPSs for hostile purposes. The main families of conventional agents (G, V, A series, and Novichok) and NPSs (lysergamides, PCP, fentanyl derivatives) were identified, highlighting their ease of synthesis, high toxicity profiles, and the regulatory gaps that facilitate their illicit production. In this scenario, it is essential to strengthen regulatory frameworks, surveillance systems, and ethical protocols in chemical research, as well as to promote international cooperation to prevent these substances from becoming chemical threats. Full article

(This article belongs to the Section Drugs Toxicity)

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20 pages, 1087 KiB

Open AccessFeature PaperReview

Visceral, Neural, and Immunotoxicity of Per- and Polyfluoroalkyl Substances: A Mini Review

by Pietro Martano, Samira Mahdi, Tong Zhou, Yasmin Barazandegan, Rebecca Iha, Hannah Do, Joel Burken, Paul Nam, Qingbo Yang and Ruipu Mu

Toxics 2025, 13(8), 658; https://doi.org/10.3390/toxics13080658 - 31 Jul 2025

Abstract

Per- and polyfluoroalkyl substances (PFASs) have gained significant attention due to their widespread distribution in the environment and potential adverse health effects. While ingestion, especially through contaminated drinking water, is considered the primary route of human exposure, recent research suggests that other pathways, [...] Read more.

Per- and polyfluoroalkyl substances (PFASs) have gained significant attention due to their widespread distribution in the environment and potential adverse health effects. While ingestion, especially through contaminated drinking water, is considered the primary route of human exposure, recent research suggests that other pathways, such as inhalation and dermal absorption, also play a significant role. This review provides a concise overview of the toxicological impacts of both legacy and emerging PFASs, such as GenX and perfluorobutane sulfonic acid (PFBS), with a particular focus on their effects on the liver, kidneys, and immune and nervous systems, based on findings from recent in vivo, in vitro, and epidemiological studies. Despite the transition to PFAS alternatives, much of the existing toxicity data focus on a few legacy compounds, such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), which have been linked to adverse immune outcomes, particularly in children. However, evidence for carcinogenic risk remains limited to populations with extremely high exposure levels, and data on neurodevelopmental effects remain underexplored. While epidemiological and experimental animal studies supported these findings, significant knowledge gaps persist, especially regarding emerging PFASs. Therefore, this review examines the visceral, neural, and immunotoxicity data for emerging PFASs and mixtures from recent studies. Given the known risks from well-studied PFASs, a precautionary principle should be adopted to mitigate human health risks posed by this large and diverse group of chemicals. Full article

(This article belongs to the Section Emerging Contaminants)

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12 pages, 736 KiB

Open AccessArticle

Visual Search Test for Residents Chronically Exposed to Methylmercury in the Minamata Area

by Shigeru Takaoka and Kenta Matsunaga

Toxics 2025, 13(8), 657; https://doi.org/10.3390/toxics13080657 - 31 Jul 2025

Abstract

In individuals exposed to relatively mild methylmercury, even if they appeared to be independent in activities of daily living (ADL), slower judgment and motor responses in daily activities were observed, suggesting potential cognitive impairment. To quantitatively assess this impairment, we measured reaction time [...] Read more.

In individuals exposed to relatively mild methylmercury, even if they appeared to be independent in activities of daily living (ADL), slower judgment and motor responses in daily activities were observed, suggesting potential cognitive impairment. To quantitatively assess this impairment, we measured reaction time (RT) in a visual search test, as a visual cognitive ability test. The study participants included 24 residents from contaminated areas with sensory impairments in the limbs but no visual field defects (E group), as well as 12 individuals from non-contaminated areas (Group C). The 24 participants from contaminated areas were further divided into two groups: 12 without hand motor coordination disorders (Group E-HA) and 12 with such disorders (Group E+HA). Participants were instructed to search for the target letter “Z” on a computer screen, and the visual stimuli consisted of two, six, or ten alphabet letters. An equal number of trials contained “Z” and did not contain “Z,” for a total of thirty trials, which were conducted twice. RT was significantly longer in Group E+HA, followed by Group E-HA, and then Group C. However, in the second test, RT decreased in all cases, with a greater reduction in the exposed groups compared to the control group. These results suggest that methylmercury exposure may cause cognitive impairment, yet it also possesses plasticity. Full article

(This article belongs to the Special Issue Health Effects of Exposure to Environmental Pollutants—2nd Edition)

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19 pages, 2104 KiB

Open AccessFeature PaperArticle

Presence of Micro- and Nanoplastics Affects Degradation of Chlorinated Solvents

by Fadime Kara Murdoch, Yanchen Sun, Mark E. Fuller, Larry Mullins, Amy Hill, Jacob Lilly, John Wilson, Frank E. Löffler and Katarzyna H. Kucharzyk

Toxics 2025, 13(8), 656; https://doi.org/10.3390/toxics13080656 - 31 Jul 2025

Abstract

Microplastics (MPs) and nanoplastics (NPs) can affect microbial abundance and activity, likely by damaging cell membrane components. While their effects on anaerobic digestion are known, less is understood about their impact on microbes involved in contaminant bioremediation. Chlorinated volatile organic contaminants (CVOCs) such [...] Read more.

Microplastics (MPs) and nanoplastics (NPs) can affect microbial abundance and activity, likely by damaging cell membrane components. While their effects on anaerobic digestion are known, less is understood about their impact on microbes involved in contaminant bioremediation. Chlorinated volatile organic contaminants (CVOCs) such as tetrachloroethene (PCE) and explosives like hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) are common in the environment, and their bioremediation is a promising cleanup strategy. This study examined how polystyrene (PS) and polyamide 6 (PA6) MPs and NPs influence CVOC and RDX biodegradation. PS particles did not inhibit the CVOC-degrading community SDC-9, but PA6 MPs impaired the reductive dechlorination of trichloroethene (TCE) to cis-1,2-dichloroethene (cis-DCE), causing a “cis-DCE stall” with no further conversion to vinyl chloride (VC) or ethene. Only 45% of TCE was dechlorinated to cis-DCE, and Dehalococcoides mccartyi abundance dropped 1000-fold in 35 days with PA6 MPs. In contrast, neither PA6 nor PS MPs and NPs affected RDX biotransformation. These results highlight the significant impact of PA6 MPs on CVOC biodegradation and the need to consider plastic pollution in environmental management. Full article

(This article belongs to the Special Issue Novel Technologies for Degradation of Organic Pollutants)

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20 pages, 6694 KiB

Open AccessFeature PaperArticle

Spatiotemporal Assessment of Benzene Exposure Characteristics in a Petrochemical Industrial Area Using Mobile-Extraction Differential Optical Absorption Spectroscopy (Me-DOAS)

by Dong keun Lee, Jung-min Park, Jong-hee Jang, Joon-sig Jung, Min-kyeong Kim, Jaeseok Heo and Duckshin Park

Toxics 2025, 13(8), 655; https://doi.org/10.3390/toxics13080655 - 31 Jul 2025

Abstract

Petrochemical complexes are spatially expansive and host diverse emission sources, making accurate monitoring of volatile organic compounds (VOCs) challenging using conventional two-dimensional methods. This study introduces Mobile-extraction Differential Optical Absorption Spectroscopy (Me-DOAS), a real-time, three-dimensional remote sensing technique for assessing benzene emissions in [...] Read more.

Petrochemical complexes are spatially expansive and host diverse emission sources, making accurate monitoring of volatile organic compounds (VOCs) challenging using conventional two-dimensional methods. This study introduces Mobile-extraction Differential Optical Absorption Spectroscopy (Me-DOAS), a real-time, three-dimensional remote sensing technique for assessing benzene emissions in the Ulsan petrochemical complex, South Korea. A vehicle-mounted Me-DOAS system conducted monthly measurements throughout 2024, capturing data during four daily intervals to evaluate diurnal variation. Routes included perimeter loops and grid-based transects within core industrial zones. The highest benzene concentrations were observed in February (mean: 64.28 ± 194.69 µg/m³; geometric mean: 5.13 µg/m³), with exceedances of the national annual standard (5 µg/m³) in several months. Notably, nighttime and early morning sessions showed elevated levels, suggesting contributions from nocturnal operations and meteorological conditions such as atmospheric inversion. A total of 179 exceedances (≥30 µg/m³) were identified, predominantly in zones with benzene-handling activities. Correlation analysis revealed a significant relationship between high concentrations and specific emission sources. These results demonstrate the utility of Me-DOAS in capturing spatiotemporal emission dynamics and support its application in exposure risk assessment and industrial emission control. The findings provide a robust framework for targeted management strategies and call for integration with source apportionment and dispersion modeling tools. Full article

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

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