Toxics

16 pages, 911 KB

Open AccessArticle

Rearing Sea Urchins to Promote ‘Ready-to-Spawn’ Conditions for Ecotoxicological Surveys

by Roberta Miroglio, Pietro Soro, Lisa Zanetti, Laura Castellano, Natalia Perez, Erica Carlig, Marco Faimali and Chiara Gambardella

Toxics 2025, 13(8), 705; https://doi.org/10.3390/toxics13080705 - 21 Aug 2025

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Abstract

The sea urchin Paracentrotus lividus is a good model in ecotoxicology, but adults living along the Italian coasts have a limited reproductive period. In this species, natural or human-driven pressures may lead to limited gamete availability for ecotoxicological surveys. This study investigates the [...] Read more.

The sea urchin Paracentrotus lividus is a good model in ecotoxicology, but adults living along the Italian coasts have a limited reproductive period. In this species, natural or human-driven pressures may lead to limited gamete availability for ecotoxicological surveys. This study investigates the quality of early developmental stages of wild and cultured sea urchins to be used in ecotoxicology, avoiding field collection of mature specimens. Adult sea urchins were cultured in the laboratory for 2 years. Every 45 days, fertilization and larval quality were checked and compared to those from adults sampled in the wild. Fertilization was never affected, differently from development, which was impaired in the larvae obtained from sea urchins reared for more than one year. Fertilization and embryotoxicity were performed using copper nitrate in wild and cultured sea urchins. Fertilization did not differ up to ten months, while similar embryotoxicity was only found up to 5 months. This study promotes rearing sea urchins in ‘ready-to-spawn’ conditions for ecotoxicology surveys by recommending 10- and 5-month rearing times to assess fertilization and embryo toxicity, respectively. Here, we provided a baseline in marine ecotoxicology to obtain gametes on demand, irrespective of reproductive period and other pressures that may impact gamete availability. Full article

(This article belongs to the Section Ecotoxicology)

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15 pages, 2355 KB

Open AccessArticle

Biodegradation of Carbon Tetrachloride in Groundwater: Microbial Community Shifts and Functional Genes Involvement in Enhanced Reductive Dechlorination

by Zhengwei Liu, Mingbo Sun, Wei Wang, Shaolei Zhao, Yan Xie, Xiaoyu Lin, Jingru Liu and Shucai Zhang

Toxics 2025, 13(8), 704; https://doi.org/10.3390/toxics13080704 - 21 Aug 2025

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Abstract

Carbon tetrachloride (CT) is a toxic volatile chlorinated hydrocarbon, posing a serious hazard to ecosystem and human health. This study discussed the bioremediation possibility of groundwater contaminated by CT. Enhanced reductive dechlorination bioremediation (ERD) was used to promote the reductive dechlorination process of [...] Read more.

Carbon tetrachloride (CT) is a toxic volatile chlorinated hydrocarbon, posing a serious hazard to ecosystem and human health. This study discussed the bioremediation possibility of groundwater contaminated by CT. Enhanced reductive dechlorination bioremediation (ERD) was used to promote the reductive dechlorination process of CT by adding yeast extract as a supplementary electron donor. The microcosm samples of the Control and Experi group were setup in the experiment, and the CT degradation efficiency and microbial community structure changes over 150 days were monitored. The results showed that the Experi group achieved complete degradation of CT within 40 days, while the control group had no significant change. By analyzing the physical and chemical indexes such as VFAs, sulfate ions, oxidation–reduction potential, pH value and so on, the key changes in the degradation process of CT were revealed. Microbial community analysis showed that specific microorganisms such as Acinetobacter johnsonii, Aeromonas media and Enterobacter mori played a significant role in the degradation of CT. They may produce hydrogen through fermentation to provide electron donors for the reductive dechlorination of CT. In addition, the genes of reductive dehalogenase synthase related to CT degradation were also identified, which provided molecular evidence for understanding the biodegradation mechanism of CT. The results deliver a scientific basis for optimizing the bioremediation strategy of CT-contaminated groundwater. Full article

(This article belongs to the Special Issue Advances in Remediation of Environmental Pollutants in Soil-Water System)

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13 pages, 511 KB

Open AccessArticle

Depressive and Anxiety Symptoms Among Patients with Asbestos-Related Diseases in Korea

by Min-Sung Kang, Mee-Ri Lee and Young Hwangbo

Toxics 2025, 13(8), 703; https://doi.org/10.3390/toxics13080703 - 21 Aug 2025

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Abstract

Asbestos-related diseases (ARDs), including malignant mesothelioma, asbestos-related lung cancer, and asbestosis, are known for their long latency periods and poor prognoses. Although the physical effects of ARDs have been widely studied, limited research has examined the psychological burden faced by affected individuals. This [...] Read more.

Asbestos-related diseases (ARDs), including malignant mesothelioma, asbestos-related lung cancer, and asbestosis, are known for their long latency periods and poor prognoses. Although the physical effects of ARDs have been widely studied, limited research has examined the psychological burden faced by affected individuals. This study investigated depressive and anxiety symptoms among 275 patients officially recognized as asbestos victims in Korea. Mental health was assessed using the Korean version of the Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), and the Hospital Anxiety and Depression Scale (HADS). The analysis revealed that the mean ± standard deviation of depression and anxiety levels among patients with asbestos-related diseases were 8.06 ± 6.27 for PHQ-9, 6.02 ± 5.64 for GAD-7, 7.09 ± 5.44 for HADS-A, and 8.41 ± 5.47 for HADS-D. Patients with asbestosis had higher levels of depressive and anxiety symptoms than those with malignant mesothelioma or lung cancer, with symptom severity increasing alongside asbestosis grade. When compared with national data from the 2020–2021 Korea National Health and Nutrition Examination Survey (KNHANES), PHQ-9 and GAD-7 scores among ARD patients, particularly those with Grade 1 asbestosis, were higher than the scores reported for all major cancer types. These findings highlight the substantial psychological distress experienced by individuals with ARDs and emphasize the urgent need for targeted mental health interventions in this population. Full article

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

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17 pages, 3467 KB

Open AccessArticle

Opposite Interactive Effects of Heat Wave and Cold Spell with Fine Particulate Matter on Pneumonia Mortality

by Yi Zheng, Ruijun Xu, Yuling Chen, Yingxin Li, Yuxin Bi, Xiaohong Jia, Sirong Wang, Lu Luo, Jing Wei, Rui Wang, Chunxiang Shi, Ziquan Lv, Suli Huang, Gongbo Chen, Hong Sun, Bochao Sun, Nongping Feng and Yuewei Liu

Toxics 2025, 13(8), 702; https://doi.org/10.3390/toxics13080702 - 21 Aug 2025

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Abstract

Exposure to extreme temperature events (ETEs) and ambient fine particulate matter (PM_2.5) has been linked to an increased risk of pneumonia mortality, but their interactive effects remain largely unknown. We investigated 50,196 pneumonia deaths from 2015 to 2022 in Jiangsu province, [...] Read more.

Exposure to extreme temperature events (ETEs) and ambient fine particulate matter (PM_2.5) has been linked to an increased risk of pneumonia mortality, but their interactive effects remain largely unknown. We investigated 50,196 pneumonia deaths from 2015 to 2022 in Jiangsu province, China, with a time-stratified case-crossover design. An individual-level exposure to heat wave, cold spell, and PM_2.5 was assessed at each subject’s residential address using validated grid datasets. Conditional logistic regression models integrated with a distributed lag nonlinear model were used to quantitatively estimate both independent and interactive effects. With different ETE definitions, the cumulative odds ratio (OR) of pneumonia mortality associated with heat wave and cold spell ranged from 1.22 (95% confidence interval [CI]: 1.14, 1.31) to 1.60 (1.40, 1.81), and from 1.08 (1.002, 1.17) to 1.18 (1.01, 1.38), respectively, while the OR for PM_2.5 ranged from 1.013 (1.006, 1.021) to 1.016 (1.009, 1.024). We observed a synergistic effect (relative excess risk due to interaction [RERI] ranging from 0.40 [0.06, 0.76] to 1.16 [0.41, 2.09]) of co-exposure to heat wave and PM_2.5, as well as an antagonistic effect (RERI ranging from −0.20 [−0.40, −0.03] to −1.02 [−1.78, −0.38]) of co-exposure to cold spell and PM_2.5 on pneumonia mortality. It was estimated that up to 6.49% of pneumonia deaths were attributable to heat wave and PM_2.5 exposures. We found that heat wave and cold spell interacted oppositely with PM_2.5 to increase the odds of pneumonia mortality, highlighting the needs to reduce co-exposures to heat wave and PM_2.5. Full article

(This article belongs to the Special Issue Airway Exposure to Pollution from Ambient Particulate Matter (PM) and Health Effects)

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21 pages, 15682 KB

Open AccessArticle

Influence of Microplastics on Manifestations of Experimental Chronic Colitis

by Natalia Zolotova, Maria Silina, Dzhuliia Dzhalilova, Ivan Tsvetkov, Nikolai Fokichev and Olga Makarova

Toxics 2025, 13(8), 701; https://doi.org/10.3390/toxics13080701 - 21 Aug 2025

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Abstract

Environmental pollution with microplastics (MPs) can have a negative impact on human health. Certain findings point to the relationship between MP and the development of inflammatory bowel diseases (IBD). We investigated the effect of MP consumption on the severity of chronic colitis in [...] Read more.

Environmental pollution with microplastics (MPs) can have a negative impact on human health. Certain findings point to the relationship between MP and the development of inflammatory bowel diseases (IBD). We investigated the effect of MP consumption on the severity of chronic colitis in male C57BL/6 mice. The MP effect was modeled by drinking water consumption with a suspension of 5 μm PS particles at a concentration of 10 mg/L replacement for 12 weeks. Chronic colitis was induced by three seven-day cycles of 1% DSS consumption (starting from the 8th, 29th and 50th days of the experiment). We investigated inflammatory infiltration, the goblet cell volume fraction and the highly sulfated and neutral mucins content in them, the endocrine cell number, the ulcerative-inflammatory process prevalence, changes in the gene’s expression encoding tight junction proteins, glycocalyx components proapoptotic factor Bax and proliferation marker Mki67 in the colon, and TNFα, IL-1β, IL-6 and IL-10 cytokines content in the serum. In healthy mice, MP did not cause pathological changes in the colon; however, indirect data indicate an increase in colon permeability. In chronic colitis, MP leads to higher prevalence of all pathological changes in general, and ulcers in particular, in a greater number of crypt abscesses and enteroendocrine cells. MP consumption leads to a more severe chronic colitis course. Full article

(This article belongs to the Special Issue Environmental Contamination, Toxic Effect, and Risk Assessment of Microplastics and Plastic Additives)

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18 pages, 5709 KB

Open AccessArticle

Polystyrene Microplastic Interferes with Yolk Reserve Utilisation in Early Artemia salina Nauplii

by Chiara Maria Motta, Chiara Fogliano, Marco Trifuoggi, Maria Toscanesi, Anja Raggio, Simona Di Marino, Paola Venditti, Gianluca Fasciolo, Bice Avallone and Rosa Carotenuto

Toxics 2025, 13(8), 700; https://doi.org/10.3390/toxics13080700 - 20 Aug 2025

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Abstract

Polystyrene microfragments are among the most common plastic pollutants globally. They significantly affect aquatic life, harming various organs and tissues. In this study, we examined the effects of 3 µm polystyrene beads (MPs, 20 µg/L) on development and yolk resorption in pre-feeding nauplii [...] Read more.

Polystyrene microfragments are among the most common plastic pollutants globally. They significantly affect aquatic life, harming various organs and tissues. In this study, we examined the effects of 3 µm polystyrene beads (MPs, 20 µg/L) on development and yolk resorption in pre-feeding nauplii of Artemia salina, a lecithotrophic crustacean used in toxicity testing. Results showed a reduced hatching rate, slower growth, and the onset of oxidative stress. Histological analysis revealed no significant morphological alteration; however, yolk platelets lost N-acetyl galactosamine (galNAc), and resorption was delayed. Lectin staining also showed a reduction in N-acetyl glucosamine (glcNAc) in the gut brush border, indicating impaired gut function. Gas chromatography detected the release of nanogram amounts of toxic volatile compounds (VOCs, ethylbenzene, xylene, benzaldehyde, and styrene) into the culture medium. In conclusion, the data demonstrate a delay in larval yolk resorption that can likely be attributed to the release of VOCs, which induce oxidative stress. Further research is urgently needed, given the potential biological and ecological implications of this finding. Full article

(This article belongs to the Special Issue Ecotoxicological Effects of Anthropogenic Contaminants in Aquatic Organisms)

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18 pages, 5474 KB

Open AccessArticle

Toxicological Mechanisms of Uranium-Induced Apoptosis in HK-2 Cells: A Proteomics and Metabolomics Study

by Zihuan Wang, Yongxiang Huang, Yue Zhang, Xuejuan Wu, Yuanyuan Yang, Jiayu Song, Kunling Guo, Mingyuan Wang, Junjie Chen and Shirong Qiang

Toxics 2025, 13(8), 699; https://doi.org/10.3390/toxics13080699 - 20 Aug 2025

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Abstract

The rapid development of the nuclear industry and mining has increased environmental radioactive contamination, posing potentially ecological risks and health threats to humans. Uranium compounds are known to exhibit selective nephrotoxicity, but their toxicological processes and mechanisms still remain poorly understood and controversial. [...] Read more.

The rapid development of the nuclear industry and mining has increased environmental radioactive contamination, posing potentially ecological risks and health threats to humans. Uranium compounds are known to exhibit selective nephrotoxicity, but their toxicological processes and mechanisms still remain poorly understood and controversial. In this study, the uranyl-induced toxicity in human renal tubular epithelial cells (HK-2) were explored using flow cytometry, DAPI staining, and comet assays. Our results demonstrate that uranium exposure primarily triggers apoptosis. Kyoto Encyclopedia of Genes and Genomes pathway enrichment and protein–protein interaction (PPI) analyses revealed significant associations with DNA damage. Moreover, aberrant expression of ABC transporters (e.g., ABCB7) and mitochondrial-related proteins confirms uranium-induced mitochondrial dysfunction. Gene Ontology functional annotation implicated extrinsic apoptotic signaling pathways in uranium-induced cell death. The downregulation of the UBL5 protein also pointed to endoplasmic reticulum stress-mediated apoptosis. In summary, uranium exposure can induce the apoptosis of HK-2 cells through intrinsic pathways by damaging DNA and mitochondria and disrupting protein synthesis, with secondary contributions from endoplasmic reticulum stress and extrinsic apoptotic signaling. Full article

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

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45 pages, 1479 KB

Open AccessReview

Insects as Sentinels of Oxidative Stress Induced by Environmental Contaminants: Biomarkers and Analytical Approaches

by Marcello Messi, Roberta Giorgione and Maria Luisa Astolfi

Toxics 2025, 13(8), 698; https://doi.org/10.3390/toxics13080698 - 20 Aug 2025

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Abstract

Despite their crucial biological role as metabolites, reactive oxygen and reactive nitrogen species (ROS and RNS) can have a negative effect on organisms when their cellular contents overwhelm the normal equilibrium provided by antioxidant defenses. Important biomolecules, such as lipids, proteins, and nucleic [...] Read more.

Despite their crucial biological role as metabolites, reactive oxygen and reactive nitrogen species (ROS and RNS) can have a negative effect on organisms when their cellular contents overwhelm the normal equilibrium provided by antioxidant defenses. Important biomolecules, such as lipids, proteins, and nucleic acids (i.e., DNA), can be damaged by their oxidative effects, resulting in malfunction or a shorter lifespan of cells and, eventually, of the whole organism. Oxidative stress can be defined as the consequence of an imbalance of pro-oxidants and antioxidants due to external stress sources (e.g., exposure to xenobiotics, UV radiation, or thermic stress). It can be evaluated by monitoring specific biomarkers to determine the state of health of breathing organisms. Assessments of ROS, RNS, specific degenerative oxidative reaction products, and antioxidant system efficiency (antioxidant enzyme activities and antioxidant compound contents) have been extensively performed for this purpose. A wide variety of analytical methods for measuring these biomarkers exist in the literature; most of these methods involve indirect determination via spectrophotometric and spectrofluorometric techniques. This review reports a collection of studies from the last decade regarding contaminant-induced oxidative stress in insects, with a brief description of the analytical methods utilized. Full article

(This article belongs to the Section Ecotoxicology)

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16 pages, 1363 KB

Open AccessArticle

Soil Quality and Trace Element Risk in Urban and Rural Kitchen Gardens: A Comparative Analysis

by Diego Arán, Osvaldo Santos, Rodrigo Feteira-Santos, Yacine Benhalima and Erika S. Santos

Toxics 2025, 13(8), 697; https://doi.org/10.3390/toxics13080697 - 20 Aug 2025

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Abstract

The development and use of urban spaces for food production is increasing in response to the search for healthier foods and contact with nature. These spaces can be created or built on materials of various types, which might contain potentially toxic elements (PTEs). [...] Read more.

The development and use of urban spaces for food production is increasing in response to the search for healthier foods and contact with nature. These spaces can be created or built on materials of various types, which might contain potentially toxic elements (PTEs). This study focuses on the evaluation of soil fertility and contamination levels in urban and rural kitchen gardens in Lisbon, Portugal. Soils of twenty kitchen gardens (n_urban = 15; n_rural = 5) were sampled, and their physicochemical characteristics and the contents of PTEs in the total and available fractions were analyzed. The results were used to calculate contamination indices and associated ecological risk. The soils of the urban and rural kitchen gardens had a neutral pH, with the presence of carbonate forms, and moderate-to-high organic matter contents, although with a clear nutritional imbalance. Regarding PTEs, both urban and rural kitchen gardens soils showed elevated levels of certain elements (e.g., Cr, Ni, Cu), exceeding the maximum allowable values established by Portuguese regulations. However, the available fraction of these elements was generally low. Contamination indices ranged from mild to considerable in isolated cases, with no general multi-element contamination or ecological risk. This suggests that associated environmental and health risks are minimal, although periodic monitoring of kitchen gardens’ soil quality is necessary to ensure and maximize the health benefits. Full article

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

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18 pages, 3564 KB

Open AccessArticle

Towards Animal-Free Toxicology: Establishment of Two Larval Brown Trout Cell Lines for Environmental Risk Assessment

by Bianka Grunow, Valeria Di Leonardo and Katrin Tönißen

Toxics 2025, 13(8), 696; https://doi.org/10.3390/toxics13080696 - 20 Aug 2025

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Abstract

Advances in cell culture technology have led to fish cell lines being used as cost-effective, reproducible, and ethically favourable instruments in ecotoxicology. The development of new lines contributes to reducing animal experiments and improves model diversity. The brown trout (Salmo trutta), [...] Read more.

Advances in cell culture technology have led to fish cell lines being used as cost-effective, reproducible, and ethically favourable instruments in ecotoxicology. The development of new lines contributes to reducing animal experiments and improves model diversity. The brown trout (Salmo trutta), an important bioindicator due to its sensitivity to pollutants, is still underrepresented in cell culture systems. In this study, two novel larvae-derived cell lines, STRlar1 and STRlar2, were established and maintained for over 40 passages. Although derived from sibling larvae of the same parental strain, the two lines showed marked differences in growth dynamics and toxicological responses to ethanol, dimethyl sulfoxide, isopropanol, and acetone. STRlar2 showed greater sensitivity to all chemicals tested, while STRlar1 exhibited longer proliferation and higher impedance, suggesting stronger substrate adhesion. These differences emphasise the importance of cellular heterogeneity, even in closely related lines. Our results underline the need to carefully validate new in vitro models and caution against relying on single cell lines. To improve the robustness and reliability of ecotoxicological assessments, we recommend the use of multiple independently derived lines that better reflect biological variability and reflect in vivo complexity. Full article

(This article belongs to the Section Ecotoxicology)

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18 pages, 2147 KB

Open AccessReview

Recent Advances in Heavy Metal Stabilization and Resource Recovery from Municipal Solid Waste Incineration Fly Ash

by Yunfei He, Yue Jiang, Lingwei Ren, Chenyiyi Qian, Han Zhang, Yuchi Zhong, Xuetong Qu, Jibo Dou, Shuai Zhang, Jiafeng Ding and Hangjun Zhang

Toxics 2025, 13(8), 695; https://doi.org/10.3390/toxics13080695 - 20 Aug 2025

Viewed by 595

Abstract

Municipal solid waste incineration fly ash (MSWI FA) is recognized as a hazardous solid waste due to its enrichment in toxic heavy metals and high leaching potential. This review systematically summarizes the current understanding of heavy metal occurrence in MSWI FA and associated [...] Read more.

Municipal solid waste incineration fly ash (MSWI FA) is recognized as a hazardous solid waste due to its enrichment in toxic heavy metals and high leaching potential. This review systematically summarizes the current understanding of heavy metal occurrence in MSWI FA and associated environmental risks. Solidification and stabilization methods, such as cement-based curing and chemical immobilization, are widely applied due to their cost-effectiveness and operability, though their long-term stability and recovery potential remain limited. Thermal treatment technologies, including sintering, vitrification, thermal separation, and molten salt processes, have shown excellent performance in reducing volume and enhancing the immobilization or recovery of heavy metals. However, these methods are often limited by high energy demands and operational complexity. Recently, emerging technologies such as electrodialysis, bioleaching, and electrokinetic remediation have demonstrated promising capabilities for selective metal recovery under relatively mild conditions. Nevertheless, these novel approaches remain at an early stage of development and have thus far been validated only at the laboratory or pilot scale. Overall, integrating multiple treatment technologies while advancing resource-oriented and low-carbon approaches will be essential for the sustainable management of MSWI FA. Full article

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

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25 pages, 609 KB

Open AccessReview

Aquatic Microcosms in Ecotoxicology: The Community-Level Ecological Risk Assessment of Pollutants

by Dongning Yang, Yin Hou, Chao Wei, Jianan Ling and Xin Zheng

Toxics 2025, 13(8), 694; https://doi.org/10.3390/toxics13080694 - 20 Aug 2025

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Abstract

Microcosm technology serves as a sophisticated tool for simulating natural ecosystems, facilitating the examination of pollutants’ ecological impacts across population, community, and ecosystem scales. Currently, this technology finds extensive application in ecological toxicology and ecological risk assessment research. This concise review highlights the [...] Read more.

Microcosm technology serves as a sophisticated tool for simulating natural ecosystems, facilitating the examination of pollutants’ ecological impacts across population, community, and ecosystem scales. Currently, this technology finds extensive application in ecological toxicology and ecological risk assessment research. This concise review highlights the utility of microcosm technology in ecotoxicology, detailing the establishment of aquatic microcosms and analyzing key research trends to assess the ecological impacts of pollutants. It emphasizes the evaluation of pesticides, industrial chemicals, and heavy metals, providing a comparative analysis of safety thresholds derived from microcosm studies versus other methods. Finally, the review underscores the four urgent directions for future exploration: (a) track pollutant metabolites in microcosms; (b) develop microcosms with diverse species for natural ecosystem mimicry; (c) use DNA macrobarcoding to assess zooplankton and link it to species abundance; (d) study reasons behind no observed effect concentration (NOEC) vs. the 95% harmless concentration (HC5) values in microcosm studies. The determination of these directions helps to fill the gaps in understanding the fate and effects of pollutants within controlled ecosystem simulations. Full article

(This article belongs to the Special Issue Environmental Toxicology and Risk Assessment of Priority Substances)

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34 pages, 7893 KB

Open AccessReview

New Horizons in Skin Sensitization Assessment of Complex Mixtures: The Use of New Approach Methodologies Beyond Regulatory Approaches

by Argel Islas-Robles, Meera Ramani, Jakeb Phillips and Gertrude-Emilia Costin

Toxics 2025, 13(8), 693; https://doi.org/10.3390/toxics13080693 - 20 Aug 2025

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Abstract

Skin sensitization is a complex biological process induced by a wide range of chemicals, from single molecules to complex mixtures and finished products. While single chemical entities were used to design and validate sophisticated safety assessment assays, complex chemistries have proven challenging to [...] Read more.

Skin sensitization is a complex biological process induced by a wide range of chemicals, from single molecules to complex mixtures and finished products. While single chemical entities were used to design and validate sophisticated safety assessment assays, complex chemistries have proven challenging to test in practice using these methods. These assays range from in silico and in chemico methods to cell-based and reconstructed tissues-based approaches and target the key events now grouped within the Adverse Outcome Pathway. We focused our analysis on the use of New Approach Methodologies for skin sensitization assessments of complex mixtures, botanicals, medical and wearable devices, agrochemicals, and pollutants. We present the defined approaches that integrate these technologies, aligning with the principles of the replacement, reduction, and refinement of animal testing. We also detail the known challenges posed by these product classes in terms of testing and data interpretation. Our analysis indicates that validated and non-validated NAMs have shown some success in predicting skin sensitization potential across the product categories reviewed. Full article

(This article belongs to the Section Novel Methods in Toxicology Research)

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22 pages, 1405 KB

Open AccessArticle

Associations Between Indoor Air Pollution and Urinary Volatile Organic Compound Biomarkers in Korean Adults

by Byung-Jun Cho and Seon-Rye Kim

Toxics 2025, 13(8), 692; https://doi.org/10.3390/toxics13080692 - 20 Aug 2025

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Abstract

Volatile organic compounds (VOCs) are common indoor air pollutants known to pose significant health risks, yet little is known about how internal exposure varies across populations and environments. This study investigated the associations between indoor air pollutants and urinary VOC biomarkers in a [...] Read more.

Volatile organic compounds (VOCs) are common indoor air pollutants known to pose significant health risks, yet little is known about how internal exposure varies across populations and environments. This study investigated the associations between indoor air pollutants and urinary VOC biomarkers in a nationally representative sample. We analyzed data from 1880 adults in the eighth Korea National Health and Nutrition Examination Survey (2020–2021) who completed an indoor air quality (IAQ) survey and provided urine samples, assessing the influence of sociodemographic, behavioral, and environmental factors. Indoor concentrations of PM_2.5, CO₂, formaldehyde, total VOCs, benzene, ethylbenzene, toluene, xylene, and styrene were measured, alongside the urinary concentrations of nine VOC biomarkers. Associations between pollutants, sociodemographic variables, and biomarkers were evaluated using univariate and multivariable linear regression with Bonferroni correction. Older age, female, lower socioeconomic status (SES), and smoking were associated with higher urinary VOC biomarker concentrations, with smoking showing the strongest associations. Indoor ethylbenzene, styrene, benzene, and CO₂ were also associated with multiple metabolites. These findings indicated significant associations between household air pollutants and urinary VOC metabolites, with disparities by age, sex, SES, and smoking status, underscoring the importance of targeted IAQ interventions for vulnerable populations. Full article

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

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15 pages, 2208 KB

Open AccessArticle

The Significant Impact of Biomass Burning Emitted Particles on Typical Haze Pollution in Changsha, China

by Qu Xiao, Hui Guo, Jie Tan, Zaihua Wang, Yuzhu Xie, Honghong Jin, Mengrong Yang, Xinning Wang, Chunlei Cheng, Bo Huang and Mei Li

Toxics 2025, 13(8), 691; https://doi.org/10.3390/toxics13080691 - 20 Aug 2025

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Abstract

In this study, typical haze pollution influenced by biomass burning (BB) activities in Changsha in the autumn of 2024 was investigated through the mixing state and evolution process of BB particles via the real-time measurement of single-particle aerosol mass spectrometry (SPAMS). From the [...] Read more.

In this study, typical haze pollution influenced by biomass burning (BB) activities in Changsha in the autumn of 2024 was investigated through the mixing state and evolution process of BB particles via the real-time measurement of single-particle aerosol mass spectrometry (SPAMS). From the clean period to the haze period, the PM_2.5 concentration increased from 25 μg·m⁻³ at 12:00 to 273 μg·m⁻³ at 21:00 on 12 October, and the proportion of total BB single particles in the total detected particles increased from 17.2% to 54%. This indicates that the rapid increase in PM_2.5 concentration was accompanied by a concurrent increase in the contribution of particles originating from BB sources. The detected BB particles were classified into two types based on their mixing states and temporal variations: BB1 and BB2, which accounted for 71.7% and 28.3% of the total BB particles, respectively. The analysis of backward trajectories and fire spots suggested that BB1 particles originated from straw burning emissions at northern Changsha, while BB2 particles were primarily related to local nighttime cooking emissions in Changsha. In addition, a special type of K-containing single particles without K cluster ions was found closely associated with BB1 type particles, which were designated as secondarily processed BB particles (BB-sec). The BB-sec particles contained abundant sulfate and ammonium signals and showed lagged appearance after the peak of BB1-type particles, which was possibly due to the aging and formation of ammonium sulfate on the freshly emitted particles. In all, this study provides insights into understanding the substantial impact of BB sources on regional air quality during the crop harvest season and the appropriate disposal of crop straw, including conversion into high-efficiency fuel through secondary processing or clean energy via biological fermentation, which is of great significance for the mitigation of local haze pollution. Full article

(This article belongs to the Topic The Effect of Particulate Matter and Climate Change, and the Corresponding Health Management)

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15 pages, 1920 KB

Open AccessArticle

Monitoring of PCDD/Fs and PCBs in European Eels (Anguilla anguilla) from Lake Garda: A Persistent Environmental Concern

by Federica Gallocchio, Marzia Mancin, Aurora Boscolo Anzoletti, Roberto Angeletti, Giancarlo Biancotto, Giorgio Fedrizzi, Mara Gasparini, Barbara Angelone, Silvana Bontacchio, Sabrina Di Millo, Francesca Cito, Gianfranco Diletti and Giuseppe Arcangeli

Toxics 2025, 13(8), 690; https://doi.org/10.3390/toxics13080690 - 19 Aug 2025

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Abstract

This study investigates the concentrations and patterns of dioxins and dioxin-like PCBs (TEQ Diox+PCB-DL) and non-dioxin-like PCBs (PCB-NDL) in eels from Lake Garda, assessing their relationship with biometric and lipid parameters. TEQ Diox+PCB-DL levels ranged from 1.70 to 77.1 pg/g (median: 9.90 pg/g), [...] Read more.

This study investigates the concentrations and patterns of dioxins and dioxin-like PCBs (TEQ Diox+PCB-DL) and non-dioxin-like PCBs (PCB-NDL) in eels from Lake Garda, assessing their relationship with biometric and lipid parameters. TEQ Diox+PCB-DL levels ranged from 1.70 to 77.1 pg/g (median: 9.90 pg/g), while PCB-NDL levels spanned from 14.0 to 1620 ng/g (median: 65.5 ng/g). Significant, albeit low, correlations were found: length and weight were negatively correlated, and lipid content was positively correlated, with both contaminants. Multivariable regression confirmed length and lipid percentage as significant predictors, although the models explained a limited proportion of variance (R²: 0.23 and 0.17). Classification-based analyses showed that irregularly contaminated eels were shorter and had a higher lipid content. Multinomial logistic regression supported these findings, but showed limited predictive accuracy (AUC = 0.63). Notably, 28 out of 90 samples exceeded the EU regulatory limit for TEQ Diox+PCB-DL, and several surpassed the threshold for PCB-NDL, highlighting potential public health risks. Given the lipophilic nature and toxicity of these compounds, continued monitoring is warranted. The findings underscore the need for broader environmental assessments to better understand pollutant dynamics and support regulatory actions, including the extended ban on eel fishing in the region. Full article

(This article belongs to the Special Issue Toxic Pollutants and Ecological Risk in Aquatic Environments)

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24 pages, 2083 KB

Open AccessFeature PaperArticle

Distribution of Legacy and Emerging PFASs in a Terrestrial Ecosystem Located near a Fluorochemical Manufacturing Facility

by Jodie Buytaert, Marcel Eens, Lieven Bervoets and Thimo Groffen

Toxics 2025, 13(8), 689; https://doi.org/10.3390/toxics13080689 - 19 Aug 2025

Viewed by 395

Abstract

This study investigated the distribution of 29 legacy and emerging per- and polyfluoroalkyl substances (PFASs) in soil, nettles, invertebrates, and plasma and feathers of great tits (Parus major) of a terrestrial ecosystem near a fluorochemical plant. Additionally, the vertical distribution of [...] Read more.

This study investigated the distribution of 29 legacy and emerging per- and polyfluoroalkyl substances (PFASs) in soil, nettles, invertebrates, and plasma and feathers of great tits (Parus major) of a terrestrial ecosystem near a fluorochemical plant. Additionally, the vertical distribution of PFASs in soil was assessed, as well as taxon-specific differences among terrestrial invertebrate species. Finally, associations between soil and biota, and among biological matrices, were assessed. Most accumulation profiles were dominated by long-chained PFASs, mainly perfluorooctane sulfonic acid (PFOS), while short-chained PFASs were less detected. Long-chained perfluoroalkyl carboxylic acids (PFCAs) adsorbed in the upper soil layers, while short-chained PFAS and perfluoroalkyl sulfonic acids (PFSAs) tended to migrate deeper. The several taxon-specific differences were likely due to dietary differences. Significant associations, especially for long-chained PFCAs and PFOS, were found among most matrices. This indicates that (1) these PFASs found in these matrices are most likely originating from the same pollution source, (2) there is a possible transfer of these PFASs between matrices, (3) there is bioaccumulation from one to another matrix, and (4) some matrices might be used as proxies to estimate PFAS concentrations in other terrestrial matrices. Finally, feathers accumulated more PFASs than plasma, as they were most likely exposed through different routes of exposure and PFAS affinity. Therefore, they are not suitable for internal PFAS monitoring but can provide complementary information about the exposure and about the presence/absence of PFASs in certain habitats. Full article

(This article belongs to the Special Issue Per- and Polyfluoroalkyl Substances: Ecological Impacts and Human Health Risks)

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21 pages, 1307 KB

Open AccessArticle

Effects of Environmental Cadmium Exposure Sufficient to Induce Renal Tubular Dysfunction on Bone Mineral Density Among Female Farmers in Cadmium-Polluted Areas in Northern Japan

by Hyogo Horiguchi, Etsuko Oguma, Kayoko Miyamoto, Yoko Hosoi and Fujio Kayama

Toxics 2025, 13(8), 688; https://doi.org/10.3390/toxics13080688 - 18 Aug 2025

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Abstract

In the Japanese Multi-Centered Environmental Toxicant Study (JMETS) conducted in five areas across Japan, we demonstrated that bone mineral density (BMD) in female farmers without renal tubular dysfunction was not adversely affected by exposure to low to moderate levels of cadmium (Cd). We [...] Read more.

In the Japanese Multi-Centered Environmental Toxicant Study (JMETS) conducted in five areas across Japan, we demonstrated that bone mineral density (BMD) in female farmers without renal tubular dysfunction was not adversely affected by exposure to low to moderate levels of cadmium (Cd). We then expanded JMETS to the most Cd-polluted area in northern Japan, Akita prefecture, with area A as the control and areas B and C as Cd-polluted areas (Cd exposure levels: B < C), which also covered more female farmers with a wider age range (20–82 years) and Cd exposure sufficient to induce renal tubular dysfunction. We selected 1267 eligible subjects in the three areas and classified them by age and menstrual status. The distribution of blood and urinary Cd levels over the areas was A < B < C (blood Cd: 2.10, 3.78, and 3.39 µg/L, and urinary Cd: 3.02, 4.29, and 6.15 µg/g cr., respectively; p < 0.05), with the steepest age-dependent increase in area C, particularly in older postmenopausal subjects with a urinary Cd level around the threshold for renal tubular dysfunction. Urinary α1-microglobulin (α1MG) and ß2-microglobulin (ß2MG) levels in the three areas also showed age-dependent increases, with higher levels being observed in areas B and C than in area A. Furthermore, ß2MG levels in older postmenopausal subjects were significantly higher in area C than in area A (273 and 157 μg/g cr., respectively, p < 0.05). Age-dependent decreases in BMD were noted in all areas, with rapid reductions from peri- to postmenopausal subjects; however, marked differences in each age class were not observed among the three areas. In multiple regression models of BMD in all subjects using age, body weight, grip, urinary creatinine, urinary α1MG or ß2MG, and blood or urinary Cd as independent variables, urinary α1MG and ß2MG levels correlated with BMD, whereas blood and urinary Cd levels did not. Moreover, age and body weight correlated more strongly with BMD than blood and urinary Cd levels. Therefore, Cd, not only at a low level but also at a level that was sufficient to deteriorate renal tubular function, did not affect bones. These results provide further support for Cd exposure itself not directly affecting bones. Full article

(This article belongs to the Special Issue Cadmium Pollution and Occupational Exposure)

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22 pages, 767 KB

Open AccessArticle

Leachability and Health Risk Assessment of Cadmium and Other Heavy Metals in Agricultural Soils from the Mae Tao Watershed, Northern Thailand

by Nipada Santha, Thanan Watcharamai, Rungroj Benjakul and Schradh Saenton

Toxics 2025, 13(8), 687; https://doi.org/10.3390/toxics13080687 - 18 Aug 2025

Viewed by 543

Abstract

Decades of unregulated zinc mining activities in the Mae Tao watershed, located in Mae Sot District, Tak Province, northern Thailand, have resulted in the pervasive contamination of agricultural soils with heavy metals, particularly cadmium (Cd), zinc (Zn), lead (Pb), and manganese (Mn). This [...] Read more.

Decades of unregulated zinc mining activities in the Mae Tao watershed, located in Mae Sot District, Tak Province, northern Thailand, have resulted in the pervasive contamination of agricultural soils with heavy metals, particularly cadmium (Cd), zinc (Zn), lead (Pb), and manganese (Mn). This legacy pollution has significantly impacted multiple environmental compartments—including surface water, groundwater, and sediments—and poses chronic health risks to local populations. This study investigates the key geochemical and physicochemical factors governing the leachability and mobility of these metals from contaminated soils and evaluates the associated human health risks. Controlled leaching experiments demonstrated that ionic strength exerts a more pronounced influence on metal mobilization than pH or other tested variables, suggesting that the electrolyte composition of pore water plays a dominant role in heavy metal transport. Despite elevated total concentrations of Cd, Zn, Pb, and Mn in the soils, hazard quotient (HQ) calculations indicated no significant non-carcinogenic risk under typical exposure scenarios. However, Cd exhibited a carcinogenic risk above the acceptable threshold at both average and peak soil concentrations, underscoring its potential to adversely affect human health. These findings enhance the understanding of heavy metal behavior in contaminated agroecosystems and provide a scientific basis for targeted risk management and long-term monitoring strategies in the Mae Sot region. Full article

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

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18 pages, 7416 KB

Open AccessArticle

Properties and Mechanisms of TBBPA and TBBPS Adsorption onto Various Soils in China

by Qi Wang, Aiguo Gu, Hongzhen Lian and Jie Zou

Toxics 2025, 13(8), 686; https://doi.org/10.3390/toxics13080686 - 18 Aug 2025

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Abstract

Understanding the differences in the adsorption behaviors of tetrabromobisphenol A (TBBPA) and tetrabromobisphenol S (TBBPS) on soils is critical for assessing their environmental mobility and risks. This study investigated the adsorption characteristics and patterns of TBBPA/S across various soil types. Adsorption kinetics analysis [...] Read more.

Understanding the differences in the adsorption behaviors of tetrabromobisphenol A (TBBPA) and tetrabromobisphenol S (TBBPS) on soils is critical for assessing their environmental mobility and risks. This study investigated the adsorption characteristics and patterns of TBBPA/S across various soil types. Adsorption kinetics analysis indicated that the adsorption of TBBPA/S on soils followed pseudo-secondary-order kinetics. Isotherm results revealed that the Langmuir model described TBBPA adsorption more accurately, while the Freundlich model was a better fit for TBBPS adsorption, suggesting distinct adsorption mechanisms due to their differing properties. Correlation analysis and principal component analysis (PCA) were performed to identify the key soil physicochemical properties influencing TBBPA/S adsorption. The results showed that TBBPA adsorption was inversely correlated with soil pH and positively correlated with clay content. In contrast, TBBPS adsorption displayed negative correlations with soil pH and sand content, and positive correlations with amorphous iron, amorphous aluminum, and free iron content. Further analysis of different treated soil fractions demonstrated that soil organic matter dominated the adsorption of TBBPA/S, with humic acid playing a more significant role than humin. The adsorption behavior characteristics of TBBPA/S on different soils provide fundamental data for understanding their environmental fate in soil systems. Full article

(This article belongs to the Section Emerging Contaminants)

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19 pages, 629 KB

Open AccessArticle

Pesticide and Liver Biomarkers Among Ecuadorian Adolescents and Adults Living in Agricultural Settings

by Priyanka Mehta, Rajendra P. Parajuli, Briana N. C. Chronister, Kun Yang, Dana B. Barr, Xin M. Tu, Dolores Lopez-Paredes and Jose R. Suarez-Lopez

Toxics 2025, 13(8), 685; https://doi.org/10.3390/toxics13080685 - 18 Aug 2025

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Abstract

Background: Experimental studies suggest that some insecticides, fungicides, and herbicides can result in liver cell death, but population-based evidence is lacking. We investigated associations between urinary pesticide metabolites and liver biomarkers among adolescents and adults in an Ecuadorian agricultural area. Methods: We examined [...] Read more.

Background: Experimental studies suggest that some insecticides, fungicides, and herbicides can result in liver cell death, but population-based evidence is lacking. We investigated associations between urinary pesticide metabolites and liver biomarkers among adolescents and adults in an Ecuadorian agricultural area. Methods: We examined participants in 2016 (N = 528, 11–17 years) and 2022 (N = 505, 17–24 years). Plasma alanine aminotransferase (ALT), aspartate aminotransferase, soluble cytokeratin-18, and erythrocytic acetylcholinesterase were measured. Urinary biomarkers included four organophosphates, six neonicotinoids, three pyrethroids, two herbicides, and two fungicides. Generalized estimating equation (GEE) models examined associations and introduced sex and age interaction terms and quadratic terms. Quantile g-computation evaluated the effects of pesticide mixtures. Results: No significant associations were observed between pesticide biomarkers and liver biomarkers in longitudinal or cross-sectional analyses. A curvilinear association was found between 3-phenoxybenzoic acid (3-PBA; pyrethroid) and ALT (β_quadratic = −0.35, 95% CI: [−0.67, −0.04]) in 2016, but not in 2022. Sex modified the associations of 3-PBA with AST, ALT, and CK18-M65 in adolescents (2016), with non-significant positive associations observed in males and non-significant negative associations observed in females. No pesticide mixture effects were observed. Conclusions: Urinary biomarkers of various insecticides, herbicides, fungicides, and their mixtures were not associated with liver biomarkers among adolescents and young adults in agricultural settings. These largely null findings, consistent across time points, suggest background-level exposures in these settings possibly do not harm liver health in this population, though effects at higher exposures cannot be ruled out. Full article

(This article belongs to the Special Issue Environmental Toxicology and Risk Assessment of Priority Substances)

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26 pages, 2291 KB

Open AccessArticle

Genome-Scale Metabolic Modeling Predicts Per- and Polyfluoroalkyl Substance-Mediated Early Perturbations in Liver Metabolism

by Archana Hari, Michele R. Balik-Meisner, Deepak Mav, Dhiral P. Phadke, Elizabeth H. Scholl, Ruchir R. Shah, Warren Casey, Scott S. Auerbach, Anders Wallqvist and Venkat R. Pannala

Toxics 2025, 13(8), 684; https://doi.org/10.3390/toxics13080684 - 17 Aug 2025

Viewed by 742

Abstract

Per- and polyfluoroalkyl substances (PFASs) are widespread in the environment, bioaccumulate in humans, and lead to disease and organ injury, such as liver steatosis. However, we lack a clear understanding of how these chemicals cause organ-level toxicity. Here, we aimed to analyze PFAS-induced [...] Read more.

Per- and polyfluoroalkyl substances (PFASs) are widespread in the environment, bioaccumulate in humans, and lead to disease and organ injury, such as liver steatosis. However, we lack a clear understanding of how these chemicals cause organ-level toxicity. Here, we aimed to analyze PFAS-induced metabolic perturbations in male and female rat livers by combining a genome-scale metabolic model (GEM) and toxicogenomics. The combined approach overcomes the limitations of the individual methods by taking into account the interaction between multiple genes for metabolic reactions and using gene expression to constrain the predicted mechanistic possibilities. We obtained transcriptomic data from an acute exposure study, where male and female rats received a daily PFAS dose for five consecutive days, followed by liver transcriptome measurement. We integrated the transcriptome expression data with a rat GEM to computationally predict the metabolic activity in each rat’s liver, compare it between the control and PFAS-exposed rats, and predict the benchmark dose (BMD) at which each chemical induced metabolic changes. Overall, our results suggest that PFAS-induced metabolic changes occurred primarily within the lipid and amino acid pathways and were similar between the sexes but varied in the extent of change per dose based on sex and PFAS type. Specifically, we identified that PFASs affect fatty acid-related pathways (biosynthesis, oxidation, and sphingolipid metabolism), energy metabolism, protein metabolism, and inflammatory and inositol metabolite pools, which have been associated with fatty liver and/or insulin resistance. Based on these results, we hypothesize that PFAS exposure induces changes in liver metabolism and makes the organ sensitive to metabolic diseases in both sexes. Furthermore, we conclude that male rats are more sensitive to PFAS-induced metabolic aberrations in the liver than female rats. This combined approach using GEM-based predictions and BMD analysis can help develop mechanistic hypotheses regarding how toxicant exposure leads to metabolic disruptions and how these effects may differ between the sexes, thereby assisting in the metabolic risk assessment of toxicants. Full article

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

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15 pages, 2450 KB

Open AccessArticle

Health Risk Assessment of Toluene and Formaldehyde Based on a Short-Term Exposure Scenario: A Comparison of the Reference Concentration, Reference Dose, and Minimal Risk Level

by Ji-Eun Moon, Si-Hyun Park, Young-Hyun Kim, Hyeok Jang, Ji-Yun Jung, Sung-Won Yoon and Cheol-Min Lee

Toxics 2025, 13(8), 683; https://doi.org/10.3390/toxics13080683 - 16 Aug 2025

Viewed by 452

Abstract

Conventional health risk assessments do not adequately reflect short-term exposure characteristics following chemical accidents. We aimed to evaluate the efficacy of existing assessment methods and propose a more suitable risk assessment approach for short-term exposure to hazardous chemicals. We analyzed foundational studies used [...] Read more.

Conventional health risk assessments do not adequately reflect short-term exposure characteristics following chemical accidents. We aimed to evaluate the efficacy of existing assessment methods and propose a more suitable risk assessment approach for short-term exposure to hazardous chemicals. We analyzed foundational studies used to derive reference concentration (RfC), reference dose (RfD), and minimal risk level (MRL) values and applied these health guidance values (HGVs) to a hypothetical chemical accident scenario. An analysis of the studies underlying each HGV revealed that, except for the RfC for formaldehyde and the RfD for toluene, all values were derived under research conditions comparable to their respective exposure durations. Given the differing toxicity mechanisms between acute and chronic exposures, MRLs that were aligned with the corresponding exposure durations supported more appropriate risk management decisions. The health risk assessment results showed that RfC/RfD-based hazard quotients (HQs) were consistently higher than MRL-based HQs across all age groups and both substances, indicating that RfC/RfD values tend to yield more conservative risk estimates. For formaldehyde, the use of RfC instead of MRL resulted in an additional 208 tiles (2.08 km²) being classified as areas of potential concern (HQ > 1) relative to the MRL-based evaluation. These findings highlighted that the selection of HGVs can significantly influence the spatial extent of areas of potential concern, potentially altering health risk determinations for large population groups. This study provides a scientific basis for improving exposure and risk assessment frameworks under short-term exposure conditions. It also serves as valuable foundational data for developing effective and rational risk management strategies during actual chemical accidents. To the best of our knowledge, this is the first study to apply MRLs to a short-term chemical accident scenario and directly compare them with traditional reference values. Full article

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

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31 pages, 3109 KB

Open AccessArticle

Spatial-Temporal Forecasting of Air Pollution in Saudi Arabian Cities Based on a Deep Learning Framework Enabled by AI

by Rafat Zrieq, Souad Kamel, Faris Al-Hamazani, Sahbi Boubaker, Rozan Attili and Marcos J. Araúzo-Bravo

Toxics 2025, 13(8), 682; https://doi.org/10.3390/toxics13080682 - 16 Aug 2025

Viewed by 531

Abstract

Air pollution is steadily increasing due to industrialization, economic activities, and transportation. High levels pose a significant threat to human health and well-being worldwide. Saudi Arabia is a growing country with air quality indices ranging from moderate to unhealthy. Although there are many [...] Read more.

Air pollution is steadily increasing due to industrialization, economic activities, and transportation. High levels pose a significant threat to human health and well-being worldwide. Saudi Arabia is a growing country with air quality indices ranging from moderate to unhealthy. Although there are many monitoring stations distributed throughout the country, mathematical modeling of air pollution is still crucial for health and environmental decision-making. From this perspective, in this study, a data-driven approach based on pollutant records and a Deep Learning (DL) Long Short-Term Memory (LSTM) algorithm is carried out to perform temporal modeling of selected pollutants (PM₁₀, PM_2.5, CO and O₃) based on time series combined with a spatial modeling focused on selected cities (Riyadh, Jeddah, Mecca, Rabigh, Abha, Dammam and Taif), covering ~48% of the total population of the country. The best forecasts were provided by LSTM in cases where the datasets used were of relatively large size. Numerically, the obtained performance metrics such as the coefficient of determination (R²) ranged from 0.2425 to 0.8073. The best LSTM results were compared to those provided by two ensemble methods, Random Forest (RF) and eXtreme Gradient Boosting (XGBoost), where the merits of LSTM were confirmed mainly in terms of its ability to capture hidden relationships. We also found that overall, meteorological factors showed a weak association with pollutant concentrations, with ambient temperature exerting a moderate influence. However, incorporating ambient temperature into LSTM models did not lead to a significant improvement in predictive accuracy. The developed approach can be used to support decision-making in environmental and health domains, as well as to monitor pollutant concentrations based on historical time series records. Full article

(This article belongs to the Special Issue Unraveling the Health Impacts of Air Pollution: Assessments and Mechanisms)

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45 pages, 1602 KB

Open AccessReview

Mechanisms and Genetic Drivers of Resistance of Insect Pests to Insecticides and Approaches to Its Control

by Yahya Al Naggar, Nedal M. Fahmy, Abeer M. Alkhaibari, Rasha K. Al-Akeel, Hend M. Alharbi, Amr Mohamed, Ioannis Eleftherianos, Hesham R. El-Seedi, John P. Giesy and Hattan A. Alharbi

Toxics 2025, 13(8), 681; https://doi.org/10.3390/toxics13080681 - 16 Aug 2025

Viewed by 1053

Abstract

The escalating challenge of resistance to insecticides among agricultural and public health pests poses a significant threat to global food security and vector-borne disease control. This review synthesizes current understanding of the molecular mechanisms underpinning resistance, including well-characterized pathways such as target-site mutations [...] Read more.

The escalating challenge of resistance to insecticides among agricultural and public health pests poses a significant threat to global food security and vector-borne disease control. This review synthesizes current understanding of the molecular mechanisms underpinning resistance, including well-characterized pathways such as target-site mutations affecting nicotinic acetylcholine receptors (nAChRs), acetylcholinesterase (AChE), voltage-gated sodium channels (VGSCs), and γ-aminobutyric acid (GABA) receptors, and metabolic detoxification mediated by cytochrome P450 monooxygenases (CYPs), esterases, and glutathione S-transferases (GSTs). Emerging resistance mechanisms are also explored, including protein sequestration by odorant-binding proteins and post-transcriptional regulation via non-coding RNAs, such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Focused case studies on Aedes aegypti and Spodoptera frugiperda illustrate the complex interplay of genetic and biochemical adaptations driving resistance. In Ae. aegypti, voltage-gated sodium channel (VGSCs) mutations (V410L, V1016I, F1534C) combined with metabolic enzyme amplification confer resistance to pyrethroids, accompanied by notable fitness costs and ecological impacts on vector populations. In S. frugiperda, multiple resistance mechanisms, including overexpression of cytochrome P450 genes (e.g., CYP6AE43, CYP321A8), target-site mutations in ryanodine receptors (e.g., I4790K), and behavioral avoidance, have rapidly evolved across global populations, undermining the efficacy of diamide, organophosphate, and pyrethroid insecticides. The review further evaluates integrated pest management (IPM) strategies, emphasizing the role of biopesticides, biological control agents, including entomopathogenic fungi and parasitoids, and molecular diagnostics for resistance management. Taken together, this analysis underscores the urgent need for continuous molecular surveillance, the development of resistance-breaking technologies, and the implementation of sustainable, multifaceted interventions to safeguard the long-term efficacy of insecticides in both agricultural and public health contexts. Full article

(This article belongs to the Special Issue Impacts of Agrochemicals on Insects and Soil Organisms)

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15 pages, 1845 KB

Open AccessArticle

Risk and Burden of Preterm Birth Associated with Prenatal Exposure to Ambient PM_2.5: National Birth Cohort Analysis in the Iranian Population

by Ling Tong, Yalin Zhang, Yang Yuan, Fatemeh Mayvaneh and Yunquan Zhang

Toxics 2025, 13(8), 680; https://doi.org/10.3390/toxics13080680 - 15 Aug 2025

Viewed by 468

Abstract

Preterm birth (PTB) is a major global public health concern with substantial impacts on neonatal morbidity and mortality. There is a growing body of evidence linking maternal exposure to fine particulate matter (PM_2.5) with PTB, and national birth cohort data from [...] Read more.

Preterm birth (PTB) is a major global public health concern with substantial impacts on neonatal morbidity and mortality. There is a growing body of evidence linking maternal exposure to fine particulate matter (PM_2.5) with PTB, and national birth cohort data from the Middle East remains sparse. We analyzed 3,839,531 singleton live births in Iran from 2013 to 2018. Monthly PM_2.5 concentrations during pregnancy were estimated using validated spatiotemporal models. Associations between prenatal PM_2.5 exposure and multiple PTB subtypes, moderate to late (MPTB), very (VPTB), and extremely preterm birth (EPTB), were assessed using multivariable logistic regression. A 10 μg/m³ increase in PM_2.5 was associated with increased odds of PTB (odds ratio [OR] = 1.048, 95% confidence interval [CI]: 1.044–1.051), MPTB (OR = 1.046, 95% CI: 1.042–1.049), VPTB (OR = 1.059, 95% CI: 1.048–1.070), and EPTB (OR = 1.064, 95% CI: 1.047–1.081), respectively. Age- and trimester-stratified analyses showed greater exposure-related risks among mothers aged 25–34 and during mid-pregnancy. We observed consistent evidence for a J-shaped exposure–risk pattern in overall and subgroup populations, suggesting a PM_2.5 threshold near 40 μg/m³. From 2013 to 2018, 6716 (95% CI: 5336–8678) PTB cases, representing 2.7% (95% CI: 2.2–3.5%) of total PTB, were attributable to PM_2.5 exposure exceeding the WHO first-stage interim target (IT1, 35 μg/m³). Our results suggested improved ambient PM_2.5 quality may substantially reduce PTB burden in Iran. Full article

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16 pages, 2190 KB

Open AccessArticle

Potentially Toxic Element Migration Characteristics and Bioavailability in Soils of the Black Shale Region, Western Zhejiang Province, China

by Huanyuan Chen, Baoliang Chen, Chunlei Huang, Xinzhe Lu, Ruosong Zou and Yutong Wei

Toxics 2025, 13(8), 679; https://doi.org/10.3390/toxics13080679 - 14 Aug 2025

Viewed by 503

Abstract

Some soil heavy metal pollution, such as As (Arsenic) and Cd (cadmium), in the black shale areas of western Zhejiang, exhibits significant geological background characteristics, yet the migration patterns and bioavailability are unclear. This study systematically integrated geochemical investigations of the rock-weathered soil–water–soil [...] Read more.

Some soil heavy metal pollution, such as As (Arsenic) and Cd (cadmium), in the black shale areas of western Zhejiang, exhibits significant geological background characteristics, yet the migration patterns and bioavailability are unclear. This study systematically integrated geochemical investigations of the rock-weathered soil–water–soil system to reveal the migration mechanisms and the species of the potentially toxic elements (PTEs) in black shale regions. The results showed that strongly acidic drainage (pH = 3.9) released from black shale weathering led to significant enrichment of Cd and As in soils. The mean Cd concentration (0.84 mg/kg) was 3.3 times higher than the Zhejiang background value, with active speciation (exchangeable fraction and humic acid-bound fraction) dominating during migration. This research provides a scientific basis for PTE prevention and control in geologically high-background regions. Full article

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

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15 pages, 1069 KB

Open AccessArticle

Mercury Bioaccumulation in Mangrove Oysters (Crassostrea rhizophorae) (Guilding, 1828) and Associated Human Exposure from the Parnaíba River Delta, Equatorial Coast of Brazil

by Thays Thayanne Luz-Santos, Victor Lacerda Moura, Moisés Fernandes Bezerra and Luiz Drude de Lacerda

Toxics 2025, 13(8), 678; https://doi.org/10.3390/toxics13080678 - 14 Aug 2025

Viewed by 561

Abstract

The present study quantifies mercury (Hg) concentrations in mangrove oysters (Crassostrea rhizophorae) and assesses their potential as biomonitors of Hg contamination in the Parnaíba River Delta (PRD), located on the equatorial coast of Brazil (ECB). The highest Hg concentrations occurred in [...] Read more.

The present study quantifies mercury (Hg) concentrations in mangrove oysters (Crassostrea rhizophorae) and assesses their potential as biomonitors of Hg contamination in the Parnaíba River Delta (PRD), located on the equatorial coast of Brazil (ECB). The highest Hg concentrations occurred in the smallest individuals’ size class (20–40 mm) from the main channel of the Parnaíba River (52.1 to 195.4 ng g⁻¹ w.w.), whereas the largest individuals’ size class (larger than 60 mm) exhibited the lowest Hg concentrations (35.2–114 ng g⁻¹ w.w.). There was a significant correlation between Hg concentrations and shell sizes, either when considering all size classes or when considering only individuals of size classes smaller than 40 mm. Oysters larger than 40 mm did not present any significant correlation between Hg concentrations and size. In addition to size, higher concentrations were observed at the freshwater–seawater transition in the main channel sites. These maximum suspended particulate zones, with bottom sediment resuspension, can favor Hg adsorption to fine particles, increasing the bioavailability of Hg. A regional comparison of Hg concentrations in mangrove oysters from the ECB suggests they are efficient biomonitors at a regional level. In contrast, the environmental dynamics of the PRD, with high variability within sites, hampered its use at the local level. Mangrove oysters from the PRD are shown to be safe for human consumption, as far as Hg exposure is concerned, and the presented risk assessment shows no excessive exposure, even at high-frequency consumption rates. Full article

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

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22 pages, 11494 KB

Open AccessArticle

Lycium barbarum Polysaccharide Improves Iron Homeostasis in Spermatocytes and Sertoli Cells via NRF2 to Alleviate DEHP-Induced Male Reproductive Toxicity in Mice

by Zhen Zhang, Yitong Shang, Hong Yang, Liyang Ding, Yu Deng, Bo Xu and Xufeng Fu

Toxics 2025, 13(8), 677; https://doi.org/10.3390/toxics13080677 - 14 Aug 2025

Viewed by 458

Abstract

Male infertility, as a globally significant reproductive health issue, remains idiopathic in over 40% of cases. Reproductive disorders in males induced by environmental pollutants, such as di(2-ethylhexyl) phthalate (DEHP), have garnered considerable attention in recent years. DEHP induces testicular oxidative stress and ferroptosis [...] Read more.

Male infertility, as a globally significant reproductive health issue, remains idiopathic in over 40% of cases. Reproductive disorders in males induced by environmental pollutants, such as di(2-ethylhexyl) phthalate (DEHP), have garnered considerable attention in recent years. DEHP induces testicular oxidative stress and ferroptosis via its active metabolite MEHP, thereby leading to spermatogenic dysfunction. Lycium barbarum polysaccharide (LBP), a traditional food and medicine homologous substance, exhibits potential antioxidant and reproductive protective properties. However, the underlying mechanism by which LBP intervenes in the toxicity induced by DEHP remains to be elucidated. This study explored the protective effect and molecular mechanism of LBP on DEHP-induced testicular injury through in vivo and in vitro experiments. The result showed that DEHP exposure (150 mg/L in free drinking water for 6 weeks) significantly decreased testicular weight, sperm concentration, and sperm motility in mice, while DEHP exposure induced pathological damage to testicular tissue, as evidenced by cavitation of seminiferous tubules, reduced numbers of spermatocytes, and vacuolar degeneration of Sertoli cells. However, LBP (450 mg/L) treatment significantly reversed testicular damage and sperm parameters. In vitro, MEHP reduced the viability of GC2 cells (spermatocyte cell line) and TM4 cells (Sertoli cell line), and LBP significantly restored cell activity. Mechanistically, exposure to DEHP/MEHP results in iron overload (elevated levels of free Fe²⁺), lipid peroxidation (increased MDA and reduced GSH), and dysregulated expression of key proteins involved in ferroptosis and iron homeostasis within the testis and cells. Furthermore, it was demonstrated that when NRF2 was specifically inhibited by ML385 or silenced via siRNA, the protective effects of LBP were abrogated, thereby validating the critical role of NRF2 in the regulation of iron homeostasis by LBP. In conclusion, LBP mitigates DEHP-induced testicular injury by activating NRF2 to regulate iron homeostasis in Sertoli cells and spermatocytes cells. This study not only offers a potential strategy for the prevention and treatment of male reproductive disorders caused by DEHP exposure, but also underscores the reproductive protective effects and application prospects of LBP in this context. Full article

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

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16 pages, 2114 KB

Open AccessArticle

Impaired Reproductive Performance of Waterbirds in Metal-Contaminated Tropical Rice Agroecosystems: Evidence from Little Egrets (Egretta garzetta)

by Hanxun Qiu, Xin Huang, Chuanbiao Xu and Jiliang Zhang

Toxics 2025, 13(8), 676; https://doi.org/10.3390/toxics13080676 - 13 Aug 2025

Viewed by 416

Abstract

Heavy metal pollution in rice fields is a major concern; however, little research has addressed its exposure and risk to waterbirds inhabiting rice fields. We investigated the accumulation of heavy metals (Cd, Pb, As, Cr, Cu, and Zn) in sediment, water, food, feces, [...] Read more.

Heavy metal pollution in rice fields is a major concern; however, little research has addressed its exposure and risk to waterbirds inhabiting rice fields. We investigated the accumulation of heavy metals (Cd, Pb, As, Cr, Cu, and Zn) in sediment, water, food, feces, feathers, and eggshell samples collected from different nesting sites (Chongwei Village and Wuji Village) of little egrets (Egretta garzetta) on Hainan Island, China, and compared the differences in their breeding parameters and eggshell quality. Higher levels of heavy metals were observed in all samples except feces from Wuji Village compared to those from Chongwei Village. As, Cd, and Pb exhibited little bioaccumulation in all feather and eggshell samples, whereas Cr concentrations in feather samples from both heronries and eggshell samples in Wuji Village exceeded the toxicity threshold in birds, indicating that the high maternal Cr was transferred to eggs in Wuji Village. Significantly lower hatching and breeding success rates were observed in Wuji Village than in Chongwei Village, which may be closely related to Cr contamination. This study revealed that waterbirds breeding in rice fields are under threat from heavy metal contamination and highlighted the suitability of bird feathers and eggshells as biomonitors of the environment. Full article

(This article belongs to the Section Ecotoxicology)

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Toxics, Volume 13, Issue 8 (August 2025) – 97 articles

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