Toxics

10 pages, 473 KB

Open AccessArticle

Framework for In Silico Toxicity Screening of Novel Odorants

by Isaac Mohar, Brad C. Hansen, Destiny M. Hollowed and Joel D. Mainland

Toxics 2025, 13(10), 902; https://doi.org/10.3390/toxics13100902 - 21 Oct 2025

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Toxicological risk assessment of chemicals without experimental toxicity data often relies on in silico predictions. However, models designed to predict inhalation toxicity associated with exposure to volatile chemicals in solution are unavailable. The aim of this research was to develop an approach to [...] Read more.

Toxicological risk assessment of chemicals without experimental toxicity data often relies on in silico predictions. However, models designed to predict inhalation toxicity associated with exposure to volatile chemicals in solution are unavailable. The aim of this research was to develop an approach to estimate toxicology-based maximum solution concentrations for novel odorants using in silico structure-based predictions. The decision trees were adapted from established open-source models for assessing mutagenicity (rule-based, ISS in vitro mutagenicity decision tree) and systemic toxicity (revised Cramer decision tree). These were implemented using Toxtree (v3.1.0), a freely available program. Thresholds of toxicologic concern (TTC) were then assigned based on the predicted hazard classification. We then used predicted vapor pressure derived from MPBPWIN™ using US EPA EPI Suite to calculate a solution concentration where inhalation exposure to a defined headspace volume would not exceed the TTC. The approach was evaluated using a published dataset of 143 chemicals with repeat exposure inhalation toxicity data, yielding health-protective predictions for 98.6% of the test set. This demonstrates that the proposed in silico approach enables the estimation of safe toxicology-based maximum solution concentrations for chemicals using open-source models and software. Full article

(This article belongs to the Collection Predictive Toxicology)

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18 pages, 4018 KB

Open AccessArticle

Concentration-Dependent Effects of Polyethylene Microplastics on Cadmium and Lead Bioavailability in Soil

by Zhenbo Wang, Sihan Liu, Peng Zhao, Guangxin Li, Ran Duan, Chang Li and Haichao Fu

Toxics 2025, 13(10), 901; https://doi.org/10.3390/toxics13100901 - 21 Oct 2025

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Abstract

The influence of microplastics (MPs) on the availability of soil heavy metals (HMs) is a current research hotspot, but how MPs regulate HM availability via soil properties and the bacterial community remains unclear. This study investigated the effects of polyethylene (PE) MP concentrations [...] Read more.

The influence of microplastics (MPs) on the availability of soil heavy metals (HMs) is a current research hotspot, but how MPs regulate HM availability via soil properties and the bacterial community remains unclear. This study investigated the effects of polyethylene (PE) MP concentrations on soil properties, bacterial communities, surface chemistry, and the speciation of cadmium (Cd) and lead (Pb) through soil incubation. Results indicated that as PE MP concentration increased, soil pH and cation exchange capacity declined, while organic carbon concentration increased. Available phosphorus and alkali–hydrolyzable nitrogen concentrations increased at 0.1% and 1% PE MPs, but decreased at 10% PE MPs. Bacterial community indices, including Simpson, ACE, and Chao1, increased at 0.1% and 1% PE MPs but decreased at 10% PE MPs. PE MPs (0.1% and 1%) reduced DTPA–Cd/Pb, promoting their transformation into stable forms and surface complexation with oxygen–containing groups. In contrast, 10% PE MPs disrupted the formation of PbO, PbCO₃, and Cd(OH)₂, producing the opposite effect. The random forest model revealed that soil organic carbon and available phosphorus were the primary factors influencing DTPA–Pb and DTPA–Cd, respectively. Partial least squares path modeling demonstrated that PE MPs altered the physicochemical characteristics of soil and structure of bacterial communities, ultimately impacting transformation of Cd and Pb speciation, with these changes being highly dependent on PE MP concentration. Full article

(This article belongs to the Special Issue Transformation Process and Toxic Effects of Pollutants in Agricultural Environment)

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20 pages, 2509 KB

Open AccessArticle

Potential Risks to Human Health Caused by the Use of Pesticides in Soils of Three Municipalities Impacted by Localized Malaria in the Brazilian Amazon

by Letícia Furtado dos Santos, Ricardo Jorge Amorim de Deus, Izis Mônica Carvalho Sucupira, Davi do Socorro Barros Brasil and Rosivaldo de Alcântara Mendes

Toxics 2025, 13(10), 900; https://doi.org/10.3390/toxics13100900 - 21 Oct 2025

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Abstract

Dichlorodiphenyltrichloroethane (DDT), used in the 20th century to combat malaria, is considered harmful to health and the environment. As an alternative, insecticides such as pyrethroids have been used, especially alphacypermethrin, which is applied in mosquito nets impregnated with long-lasting insecticide (LLIN). This study [...] Read more.

Dichlorodiphenyltrichloroethane (DDT), used in the 20th century to combat malaria, is considered harmful to health and the environment. As an alternative, insecticides such as pyrethroids have been used, especially alphacypermethrin, which is applied in mosquito nets impregnated with long-lasting insecticide (LLIN). This study analyzed the concentrations of DDT and alphacypermethrin in soils from three municipalities in the Legal Amazon (Mazagão, Porto Velho, and Cantá) using gas chromatography. The results showed the presence of DDT and metabolites, indicating slow degradation in the region, especially in Cantá, with an average of 2.694 mg/kg of total DDT. Alphacypermethrin stands out in Porto Velho, with an average of 0.364 mg/kg, possibly due to the use of LLINs. DDT did not represent a significant ecological risk in this study, but it did present risks to human health, mainly through food intake. The incremental lifetime cancer risk (ILCR) indicated potential danger, with values of up to 2.93 × 10⁻³ for DDT and 1.17 × 10⁻¹ for alphacypermethrin. The total non-carcinogenic risk index (HI) was extreme, with a maximum value of 336.61. The pesticides evaluated did not present an ecological risk, but they do pose risks to human health, indicating irregular use of LLINs and the need for continuous monitoring. Full article

(This article belongs to the Special Issue Emerging Environmental Pollutants and Their Impact on Human Health)

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21 pages, 1366 KB

Open AccessArticle

Robotic and On-Flow Solid Phase Extraction Coupled with LC-MS/MS for Simultaneous Determination of 16 PPCPs: Real-Time Monitoring of Wastewater Effluent in Korea

by Sook-Hyun Nam, Homin Kye, Juwon Lee, Eunju Kim, Jae-Wuk Koo, Jeongbeen Park, Yonghyun Shin, Jonggul Lee and Tae-Mun Hwang

Toxics 2025, 13(10), 899; https://doi.org/10.3390/toxics13100899 - 20 Oct 2025

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Abstract

Pharmaceuticals and personal care products (PPCPs) are recognized as emerging contaminants of concern, even at ultra-trace concentrations. However, the current detection systems are prohibitively expensive and typically rely on labor-intensive, lab-based workflows that lack automation in sample pretreatment. In this study, we developed [...] Read more.

Pharmaceuticals and personal care products (PPCPs) are recognized as emerging contaminants of concern, even at ultra-trace concentrations. However, the current detection systems are prohibitively expensive and typically rely on labor-intensive, lab-based workflows that lack automation in sample pretreatment. In this study, we developed a robotic and on-flow solid-phase extraction (ROF-SPE) system, fully integrated with online liquid chromatography-tandem mass spectrometry (LC-MS/MS), for the on-site and real-time monitoring of 16 PPCPs in wastewater effluent. The system automates the entire pretreatment workflow—including sample collection, filtration, pH adjustment, solid-phase extraction, and injection—prior to seamless coupling with LC–MS/MS analysis. The optimized pretreatment parameters (pH 7 and 10, 12 mL wash volume, 9 mL elution volume) were selected for analytical efficiency and cost-effectiveness. Compared with conventional offline SPE methods (~370 min), the total analysis time was reduced to 80 min (78.4% reduction), and parallel automation significantly enhanced the throughput. The system was capable of quantifying target analytes at concentrations as low as 0.1 ng/L. Among the 16 PPCPs monitored at a municipal wastewater treatment plant in South Korea, only sulfamethazine and ranitidine were not detected. Compounds such as iopromide, caffeine, and paraxanthine were detected at high concentrations, and seasonal variation patterns were also observed This study demonstrates the feasibility of a fully automated and on-site SPE pretreatment system for ultra-trace environmental analysis and presents a practical solution for the real-time monitoring of contaminants in remote areas. Full article

(This article belongs to the Special Issue Advances in Monitoring, Transformation and Ecological Risk Assessment of Pharmaceuticals and Personal Care Products in Aquatic Environments)

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23 pages, 473 KB

Open AccessArticle

Perinatal Exposure to Heavy Metals and Trace Elements of Preterm Neonates in the NICU: A Toxicological Study Using Multiple Biomatrices

by Melda Celik, Irem Iyigun, Siddika Songül Yalcin, Murat Cagan, Deniz Arca Cakir, Hasan Tolga Celik, Ozgur Deren and Pinar Erkekoglu

Toxics 2025, 13(10), 898; https://doi.org/10.3390/toxics13100898 - 20 Oct 2025

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Abstract

In this study we aimed to investigate the levels of selected heavy metals and trace elements (Hg, Pb, Cd, As, Mn, Se, and Cu) in three different biomatrices—maternal urine (Mu), neonatal urine (Nu), and cord blood—of preterm newborns born at less than 35 [...] Read more.

In this study we aimed to investigate the levels of selected heavy metals and trace elements (Hg, Pb, Cd, As, Mn, Se, and Cu) in three different biomatrices—maternal urine (Mu), neonatal urine (Nu), and cord blood—of preterm newborns born at less than 35 weeks’ gestation who were staying in the NICU and their mothers, and the relationships of these elements with maternal and neonatal characteristics. Cord Pb, As, and Hg were significantly lower than in Mu, whereas Se and Cu were higher (p < 0.001). All elements were excreted more in Mu than in Nu (p < 0.001). Nu levels of Cd, Mn, Se, and Cu were lower, while As and Hg were higher than in cord blood. Nu metal excretion increased significantly over time (p < 0.001). Positive correlations were found between MuCu and NuCu (r_s = 0.35) and between maternal Se and maternal age (r_s = 0.41). NuHg, MuMn, and cord Mn showed negative correlations with penile length, and NuHg was also negatively correlated with anogenital distance. The first and second NuPb levels were positively correlated with birth weight percentile. The findings suggest transplacental transmission and ongoing exposure to heavy metals and trace elements in preterm infants, highlighting the importance of prenatal environmental exposure awareness for healthcare providers. Full article

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

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27 pages, 5955 KB

Open AccessArticle

Protective Role of Gallic Acid Against Corticosterone-Induced Hepatic Toxicity: Modulation of Oxidative Stress and Inflammatory Pathways in Wistar Rats

by Priyanka Tiwari, Prabhat Kumar, Saripella Srikrishna, Nikhat Jamal Siddiqi and Bechan Sharma

Toxics 2025, 13(10), 897; https://doi.org/10.3390/toxics13100897 - 20 Oct 2025

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Abstract

Corticosterone (CORT), a key stress hormone, is vital for energy balance, but prolonged exposure causes hyperglycemia, obesity, and hepatotoxicity. Gallic acid (GA), a natural polyphenol with antioxidant and anti-inflammatory properties, was evaluated for its hepatoprotective effects in Wistar rats. This study aimed to [...] Read more.

Corticosterone (CORT), a key stress hormone, is vital for energy balance, but prolonged exposure causes hyperglycemia, obesity, and hepatotoxicity. Gallic acid (GA), a natural polyphenol with antioxidant and anti-inflammatory properties, was evaluated for its hepatoprotective effects in Wistar rats. This study aimed to assess how GA protects against CORT-induced liver toxicity in Wistar rats and to explore its molecular interactions through in silico docking studies. Animals received CORT (15 and 30 mg kg⁻¹ body weight) orally for 21 days, with GA pretreatment in selected groups. Hepatic status was assessed via biochemical assays, molecular markers, histopathology, and in silico docking. CORT significantly increased body weight (15%), blood glucose (1.5-fold), malondialdehyde (MDA; 28%), and protein carbonyls (34%,) with a statistical significance, p < 0.05 and <0.01, while glutathione (41.4% to 52.1%) and antioxidant enzymes were significantly reduced (statistical p-value significance at levels of <0.05, <0.01, and <0.001). GA pretreatment restored glucose MDA, and GSH toward control (p < 0.01), and protected histological injury. Docking studies showed strong GA binding to Keap1 (−6.9 kcal/mol), IKKβ (−6.0 kcal/mol), and COX-1 (−6.2 kcal/mol), supporting its antioxidant and anti-inflammatory action. GA confers significant protection against CORT-induced hepatotoxicity, validated by both in vivo and in silico analyses. Full article

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29 pages, 7216 KB

Open AccessArticle

Thymoquinone Protective Effect Against Mercury-Induced Reproductive Derangement in Rats: In Vivo and In Silico Investigation

by Solomon Owumi, Moses Otunla, Pelumi Akindipe, Uche Arunsi, Jesutosin O. Babalola, Chioma E. Irozuru, Ahmad Altayyar, Bayode Oluwawibe, Olatunde Owoeye and Adegboyega K. Oyelere

Toxics 2025, 13(10), 896; https://doi.org/10.3390/toxics13100896 - 19 Oct 2025

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Abstract

Mercury exposure has been linked to male infertility. Given that mercury chloride (HgCl₂) may promote an oxido-inflammatory milieu associated with pathophysiological derangements, it is hypothesised that Thymoquinone (TQ), an antioxidant and anti-inflammatory agent, may mitigate the gradual harmful effects of mercury [...] Read more.

Mercury exposure has been linked to male infertility. Given that mercury chloride (HgCl₂) may promote an oxido-inflammatory milieu associated with pathophysiological derangements, it is hypothesised that Thymoquinone (TQ), an antioxidant and anti-inflammatory agent, may mitigate the gradual harmful effects of mercury exposure on rat testes, epididymis, and hypothalamus, as these organs are vital to reproductive function. To test this hypothesis, 40 rats (strain: Wistar; sex: male) were randomly assigned to five cohorts of eight rats each. After a 7-day acclimation, treatments were dispensed for 28 consecutive days accordingly: Cohort I: distilled water only, as control; Cohort II: HgCl₂ only (20 µg/mL); Cohort III: TQ only (2.5 mg/kg); Cohort IV: HgCl₂ + TQ (20 µg/mL + 2.5 mg/kg); and Cohort V: HgCl₂ + TQ (20 µg/mL + 5 mg/kg). Co-treatment with TQ preserved the body and organ weight of the HgCl₂ exposed animals. However, TQ did not reduce HgCl₂-induced dysfunction in sperm function and morphology. The serum follicle-stimulating hormone (FSH), luteinising hormone (LH), and testosterone were increased significantly (p < 0.05) by TQ co-treatment, while decreasing the prolactin level. TQ administration also increased (p < 0.05) testicular enzymes, including alkaline phosphatase (ALP), lactate dehydrogenase (LDH), acid phosphatase (ACP), and glucose-6-phosphate dehydrogenase (G6PD) activities, which HgCl₂ decreased. TQ administration increased (p < 0.05) HgCl₂-induced decreases in catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione (GSH), glutathione-s-transferase (GST), and total sulfhydryl group (TSH) levels in the testes, epididymis, and hypothalamus of experimental rats. Further, TQ reduced HgCl₂-mediated increases in RONS-reactive oxygen and nitrogen species; LPO–lipid peroxidation; PC–protein carbonyl formation; and XO–xanthine oxidase activity. Furthermore, levels of inflammatory biomarkers, including tumour necrosis factor alpha (TNF-α), nitric oxide (NO), interleukin-1 beta (IL-1β), and myeloperoxidase (MPO), were decreased (p < 0.05) in the co-treated groups, with a higher dose of TQ (5.0 mg/kg) showing a more pronounced protective effect. Additionally, TQ co-administration increased Bax and decreased Bcl-2 and p53 protein levels (p < 0.05), thereby protecting the rats’ testes, epididymis, and hypothalamus from HgCl₂-induced apoptosis. Molecular docking simulation analysis revealed TQ interaction dynamics with PPAR-α and PPAR-δ to suppress NF-kB-mediated pro-inflammatory sequela as well as activate Nrf-2-mediated antioxidant defence system. These predicted biological effects of TQ resonate with the findings from the in vivo studies. Therefore, supplementation with TQ may help reduce chemical-induced toxicities, including HgCl₂‘s reproductive toxicity. Full article

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

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15 pages, 3248 KB

Open AccessArticle

Toxic Metals in Surface Dust in Underground Parking Garages: Pollution Status, Risk and Disease Burden Assessment, and Source Apportionment

by Yong Wang, Tong Chao, Qidi Li, Zhiqiang Jiao, Xinling Ruan, Yuguang Wang, Shiji Ge and Yangyang Wang

Toxics 2025, 13(10), 895; https://doi.org/10.3390/toxics13100895 - 19 Oct 2025

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Abstract

Surface dust serves as a significant carrier and potential source of various pollutants in urban environments. However, limited attention has been paid to toxic metals in underground parking garages’ (UPGs) surface dust. In this study, thirty surface dust samples were collected from UPGs [...] Read more.

Surface dust serves as a significant carrier and potential source of various pollutants in urban environments. However, limited attention has been paid to toxic metals in underground parking garages’ (UPGs) surface dust. In this study, thirty surface dust samples were collected from UPGs to determine the toxic metals contents, their risk and disease burden to local residents, and their potential source. The mean contents of V, Cr, Co, Ni, Cu, Zn, Cd, Sb, Pb, Hg, and As were 68.06, 126.48, 8.73, 27.68, 76.25, 287.07, 0.74, 4.28, 172.67, 0.24, and 8.66 mg/kg, respectively. Accumulation index revealed that the geoaccumulation index of Cr, Cu, Cd, Zn, Sb, Pb, and Hg ranged from 0.52 to 1.85. Pollution load index verified that the surface dust was slightly (56.67%), moderately (30.00%), or heavily polluted (13.33%). Risk assessment revealed that the total non-carcinogenic risks for children all exceeded the acceptable level (HI > 1.0). Notably, the carcinogenic burden reached 12.9 disability-adjusted life years per 100,000 population, with Cr contributing 84.1%. Furthermore, these toxic metals mainly derived from vehicle-related activities, use of coal, and the aging of decoration materials, and their accumulation in UPGs’ surface dust was almost unaffected by the essential conditions of residential areas. Full article

(This article belongs to the Special Issue Assessment and Remediation of Heavy Metal Contamination in Soil)

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24 pages, 2026 KB

Open AccessArticle

Mixture Effects of Commonly Applied Herbicides on County Level Obesity Rates in the United States: An Exploratory Ecologic Study (2013–2018)

by Sarah Otaru, Laura E. Jones and David O. Carpenter

Toxics 2025, 13(10), 894; https://doi.org/10.3390/toxics13100894 - 19 Oct 2025

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Abstract

Metabolic disorders such as obesity have increased globally in recent decades and are a major public health concern. Previous research suggests that herbicide exposures may contribute to metabolic dysfunction, but few studies have examined mixture effects of multiple herbicides on obesity at a [...] Read more.

Metabolic disorders such as obesity have increased globally in recent decades and are a major public health concern. Previous research suggests that herbicide exposures may contribute to metabolic dysfunction, but few studies have examined mixture effects of multiple herbicides on obesity at a population level. Using county-level data from 2013 to 2018, we examined the associations between obesity rates and the application of 13 commonly applied herbicides in the U.S. We first conducted adjusted single-pollutant mixed-effects models and then used quantile-based g-computation mixture modeling to assess combined herbicide mixture effects on county-level obesity rates. Models were adjusted for demographic and socioeconomic covariates and accounted for geographic clustering. Significant positive associations were identified between county-level obesity rates and applications of glyphosate, 2,4-D, atrazine, acetochlor, metolachlor, and several other herbicides in adjusted single-pollutant models. Glyphosate showed one of the strongest individual associations (β = 0.29 per standard deviation increase, 95% CI: 0.21–0.36). Increases in herbicide mixture were significantly associated with higher obesity rates (Psi = 0.71 per quantile exposure mixture, 95% CI: 0.65–0.76) from mixture modeling. Inclusion of significant interaction terms did not appreciably increase the mixture effect. Glyphosate, 2,4-D, metolachlor, dimethenamid-P, and glufosinate contributed most strongly to the weighted mixture effect. Mixture effects varied by rurality, with stronger associations observed in rural counties, particularly in micropolitan regions. Our findings highlight the importance of considering cumulative herbicide mixture exposures rather than individual chemicals in isolation. The observed rural–urban disparities emphasize the need for targeted public health interventions and policy actions in rural communities, which may be particularly vulnerable to the adverse metabolic impacts of herbicide mixtures. Full article

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

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18 pages, 1646 KB

Open AccessArticle

An In-Hospital Mortality Prediction Model for Acute Pesticide Poisoning in the Emergency Department

by Yoonseo Jeon, Da-Eun Kim, Inyong Jeong, Se-Jin Ahn, Nam-Jun Cho, Hyo-Wook Gil and Hwamin Lee

Toxics 2025, 13(10), 893; https://doi.org/10.3390/toxics13100893 - 18 Oct 2025

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Abstract

Pesticide poisoning remains a significant public health issue, characterized by high morbidity and mortality, particularly among patients presenting to the emergency department. This study aimed to develop a 14-day in-hospital mortality prediction model for patients with acute pesticide poisoning using early clinical and [...] Read more.

Pesticide poisoning remains a significant public health issue, characterized by high morbidity and mortality, particularly among patients presenting to the emergency department. This study aimed to develop a 14-day in-hospital mortality prediction model for patients with acute pesticide poisoning using early clinical and laboratory data. This retrospective cohort study included 1056 patients who visited Soonchunhyang University Cheonan Hospital between January 2015 and December 2020. The cohort was randomly divided into train (n = 739) and test (n = 317) sets using stratification by pesticide type and outcome. Candidate predictors were selected based on univariate Cox regression, LASSO regularization, random forest feature importance, and clinical relevance derived from established prognostic scoring systems. Logistic regression models were constructed using six distinct feature sets. The best-performing model combined LASSO-selected and clinically curated features (AUC 0.926 [0.890–0.957]), while the final model—selected for interpretability—used only LASSO-selected features (AUC 0.923 [0.884–0.955]; balanced accuracy 0.835; sensitivity 0.843; specificity 0.857; F1.5 score 0.714 at threshold 0.450). SHapley Additive exPlanations (SHAP) analysis identified paraquat ingestion, Glasgow Coma Scale, bicarbonate level, base excess, and alcohol history as major mortality predictors. The proposed model outperformed the APACHE II score (AUC 0.835 [0.781–0.888]) and may serve as a valuable tool for early risk stratification and clinical decision making in pesticide-poisoned patients. Full article

(This article belongs to the Special Issue Hazardous Effects of Pesticides on Human Health—2nd Edition)

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14 pages, 1904 KB

Open AccessArticle

Occurrence, Dominance, and Combined Use of Antibiotics in Aquaculture Ponds

by Emmanuel Bob Samuel Simbo, Zhiyuan Ma, Longxiang Fang, Sampa Morgan, Sahr Lamin Sumana, Meshack Chubwa Maguru, Mbonyiwe Chakanga, Haggai Gondwe, Alpha Thaimu Bundu, Liping Qiu, Chao Song and Shunlong Meng

Toxics 2025, 13(10), 892; https://doi.org/10.3390/toxics13100892 - 18 Oct 2025

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Abstract

Antibiotic use in aquaculture has become widespread to sustain production and control bacterial diseases, but it poses significant ecological and human health risks due to residue accumulation and resistance development. This study investigated the occurrence, dominance, and combined use of sulfonamide and fluoroquinolone [...] Read more.

Antibiotic use in aquaculture has become widespread to sustain production and control bacterial diseases, but it poses significant ecological and human health risks due to residue accumulation and resistance development. This study investigated the occurrence, dominance, and combined use of sulfonamide and fluoroquinolone antibiotics in freshwater fish aquaculture ponds around Wuxi, China. Here, the term aquaculture refers specifically to the controlled farming of freshwater fish species such as carp and crucian carp in managed pond systems. A total of 80 water samples (collected exclusively from pond waters) were obtained from 40 ponds during the high intensity rearing and harvest stage of fish. Residues of enrofloxacin and sulfonamide antibiotics were analyzed using a validated LC–MS/MS method with detection limits in the low nanogram-per-liter range. Results revealed that antibiotics were ubiquitous in pond waters, with enrofloxacin emerging as the dominant compound in August, reaching concentrations of up to 2.36 µg/L. By October, sulfonamides, particularly sulfamethoxazole and sulfadiazine, became more prevalent, with a maximum sulfadiazine concentration exceeding 4 µg/L. Multivariate analyses demonstrated a clear seasonal shift in antibiotic profiles, while correlation analyses indicated limited combined use in summer but notable co-occurrence of sulfonamides in autumn. These findings underscore that antibiotic application patterns in aquaculture are strongly linked to production stages, with potential consequences for environmental safety, resistance development, and food security. Effective monitoring, stricter regulation, and alternative disease management strategies are urgently required to mitigate risks and promote sustainable aquaculture practices. Full article

(This article belongs to the Special Issue Ecotoxicology of Pollutants of High Concern)

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17 pages, 2266 KB

Open AccessArticle

Trace Metals in Amazonian Rivers Sediments from Northern Brazil: Spatial-Temporal Variations, Sources, and Ecological Risks

by Larissa Costa de Souza, Camila Carneiro dos Santos, Neuton Trindade Vasconcelos Júnior, Kelson do Carmo Freitas Faial, José Augusto Martins Corrêa and Rosivaldo de Alcântara Mendes

Toxics 2025, 13(10), 891; https://doi.org/10.3390/toxics13100891 - 18 Oct 2025

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Abstract

Trace metal pollution has become an increasing concern in urban areas, mainly due to industrial activities and heightened human activities near water bodies. This study aimed to quantify the level of pollution caused by the trace metals Co, Cr, Cu, Mn, Ni, and [...] Read more.

Trace metal pollution has become an increasing concern in urban areas, mainly due to industrial activities and heightened human activities near water bodies. This study aimed to quantify the level of pollution caused by the trace metals Co, Cr, Cu, Mn, Ni, and Zn in surface sediments of Aurá and Guamá rivers, as well as Guajará Bay, in the metropolitan region of Belém (Northern Brazil). A total of 33 sediment samples were collected—14 from the Aurá River, 7 from the Guamá River, and 12 from Guajará Bay—during both the wet and dry seasons to capture seasonal variability. The studied trace metals were measured through inductively coupled plasma optical emission spectrometry (ICP-OES), and the decreasing order of concentration detected was the following: Mn > Zn > Cr > Ni > Co > Cu. To assess the degree of pollution, three geochemical indicators were employed: the Geoaccumulation Index (Igeo), which compares observed concentrations with natural background levels to classify contamination severity; the Enrichment Factor (EF), which helps distinguish between natural and anthropogenic sources of metals using a reference element (typically aluminum or iron); and the Mean-ERM-Quotient, which evaluates the potential ecotoxicological risk of the metals based on benchmark values for adverse effects on aquatic organisms. Based on these indicators, the sediments of the studied area can be classified as showing “moderate contamination and enrichment”. The metals Zn and Cu exhibited the highest degrees of enrichment, likely of anthropogenic origin. Overall, this study revealed that areas closer to sites of intense human activity are more susceptible to trace metal contamination, especially during the wet season. Frequent monitoring of areas classified as “contaminated” and time-series data are necessary to examine more deeply the pollution of river sediments and their potential changes concerning shifts in the status of urbanization and industrialization. Full article

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

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15 pages, 3962 KB

Open AccessArticle

Removal Efficiency and Mechanism for Cl⁻ from Strongly Acidic Wastewater by VC-Assisted Cu₂O: Comparison Between Synthesis Methods

by Ying Yu, Dong Li, Jialin Ma, Zhoujing Yan, Haoran Liu, Wenyue Dou and Haotian Hao

Toxics 2025, 13(10), 890; https://doi.org/10.3390/toxics13100890 - 17 Oct 2025

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Abstract

The discharge of strongly acidic industrial wastewater containing high concentration of chloride ions (Cl⁻) has become one of the major environmental challenges faced globally. For the removal of extremely stable Cl⁻ in acidic aqueous conditions, precipitation method possesses major advantages [...] Read more.

The discharge of strongly acidic industrial wastewater containing high concentration of chloride ions (Cl⁻) has become one of the major environmental challenges faced globally. For the removal of extremely stable Cl⁻ in acidic aqueous conditions, precipitation method possesses major advantages of strong adaptability and simple operation. This study proposed a novel cuprous oxide (Cu₂O) method assisted by ascorbic acid (VC) for the removal of Cl⁻ from strongly acidic wastewater. First, liquid-phase reduction was chosen as the optimal Cu₂O synthesis method based on product purity and composition. Then, parameter optimization results show that increased reagent dosage and acidity significantly enhanced Cl⁻ removal efficiency, while other factors had negligible impacts. After treatment with the sole addition of Cu₂O, the dosed Cu₂O existed in four forms, including cuprous chloride (CuCl), copper ion (Cu²⁺), elemental copper (Cu⁰), and Cu₂O, among which the generation of Cu²⁺ and Cu⁰, through the oxidation and disproportionation of cuprous ion (Cu⁺), served as the main reason for the unsatisfactory efficiency in the removal of Cl⁻. Fortunately, VC is precisely capable of inhibiting the side reactions of Cu⁺, and under the assistance of 0.10 g VC, the removal of Cl⁻ by Cu₂O was greatly improved with the multiple of theoretical reagent dosage decreasing from 12 to 3, the residual concentration of Cu²⁺ decreasing from 1197 to 18.4 mg/L and the residual concentration of Cl⁻ decreasing from 88.4 to 53.8 mg/L, thus validating the feasibility of this method. Full article

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

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27 pages, 3674 KB

Open AccessArticle

Advanced Catalytic Peroxymonosulfate Activation via Zeolite-Supported Cu₃Mn-Layered Double Hydroxide for Enhanced Oxidative Degradation of Bisphenol A (BPA)

by Qiuyi Li, Chongmin Liu, Meina Liang, Mi Feng, Zejing Xu, Dunqiu Wang and Saeed Rad

Toxics 2025, 13(10), 889; https://doi.org/10.3390/toxics13100889 - 17 Oct 2025

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Abstract

The widespread presence of bisphenol A (BPA), a persistent endocrine-disrupting pollutant, in aquatic environments poses significant ecological and health risks, necessitating its effective removal. However, conventional remediation technologies are often hampered by catalysts with narrow pH adaptability and poor stability. In this study, [...] Read more.

The widespread presence of bisphenol A (BPA), a persistent endocrine-disrupting pollutant, in aquatic environments poses significant ecological and health risks, necessitating its effective removal. However, conventional remediation technologies are often hampered by catalysts with narrow pH adaptability and poor stability. In this study, a novel catalyst, Zeolite-supported Cu₃Mn-layered double hydroxide (LDH), was fabricated using the co-precipitation method. The synthesized catalyst was applied to activate peroxymonosulfate (PMS), effectively enabling decomposition of BPA by advanced oxidation processes. The composite material was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM), which confirmed the successful synthesis of the zeolite-supported Cu₃Mn-LDH. The catalyst exhibited high activity in both neutral and strongly alkaline environments, achieving complete degradation of 10 mg⋅L⁻¹ bisphenol A (BPA) within 40 min and a 98% total organic carbon (TOC) removal rate when both the PMS and catalyst were dosed at 0.15 g⋅L⁻¹. Singlet oxygen was detected as the primary reactive species responsible for BPA degradation, as verified by quenching experiments and EPR analysis, which also identified the presence of sulfate (SO₄^•−), hydroxyl (•OH), and superoxide (•O₂⁻) radicals. The catalyst exhibited excellent reusability, maintaining high catalytic efficiency over two consecutive cycles with minimal performance loss. Gas chromatography-mass spectrometry (GC-MS) analysis revealed five intermediate products, enabling the proposal of potential BPA degradation pathways. This work not only presents a novel synthetic approach for zeolite-supported LDH composites, but also offers a promising strategy for the efficient removal of BPA from aqueous systems through AOPs. Full article

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

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12 pages, 631 KB

Open AccessReview

Neurotoxic Effects of Bisphenol (BPA): Mini-Reviews

by Luciana Veras de Aquino Figueirôa, Tiago da Silva Teófilo, Jael Soares Batista, Ana Caroline Maia Oliveira Ramos, Gustavo Coringa de Lemos, Salvador Viana Gomes Junior, Guilherme Braga Silva Lima, Jose Leonilson Feitosa, Ana Beatriz da Silva, Larissa Nayara de Souza, Roque Ribeiro da Silva Júnior, Maria Irany Knackfuss, Edson Fonseca Pinto, Ellany Gurgel Cosme do Nascimento, Thales Allyrio Araújo de Medeiros Fernandes and Fausto Pierdoná Guzen

Toxics 2025, 13(10), 888; https://doi.org/10.3390/toxics13100888 - 17 Oct 2025

Viewed by 335

Abstract

Introduction: Bisphenol A (BPA) is a synthetic compound widely used in plastics and epoxy resins, and human exposure is virtually unavoidable. Numerous studies indicate that even doses below current regulatory limits may elicit neurotoxic effects, impairing learning, memory, and synaptic plasticity. Methodology: This [...] Read more.

Introduction: Bisphenol A (BPA) is a synthetic compound widely used in plastics and epoxy resins, and human exposure is virtually unavoidable. Numerous studies indicate that even doses below current regulatory limits may elicit neurotoxic effects, impairing learning, memory, and synaptic plasticity. Methodology: This mini-review. Searches were conducted in PubMed, the Virtual Health Library (VHL/BVS), and ScienceDirect, using MeSH descriptors related to “Bisphenol A,” “Neurotoxicity Syndromes,” “Central Nervous System,” and “Prefrontal Cortex,” combined with Boolean operators. We included studies published between 2007 and 2025, available in English, Portuguese, or Spanish, and focused on the neurotoxic effects of BPA. After screening and application of the eligibility criteria, twelve articles were selected. Results: The analyzed studies show that BPA exposure, even at low concentrations, compromises neuronal survival, dendritic density, and synaptic plasticity. In animal models, cognitive deficits were observed in memory and learning tasks, associated with increased oxidative stress and alterations in molecular pathways such as AMPK, HO-1, and nNOS/Keap1/Nrf2. In cell cultures, BPA induced apoptosis, autophagy dysfunction, cytoskeletal reorganization, and loss of synaptic proteins. The effects were dose-dependent and, in some cases, sex-dependent. Conclusions: BPA exhibits significant neurotoxic potential, affecting both the development and function of the central nervous system. These findings underscore the need to revise current safety limits and reinforce the importance of public policies regulating BPA use, as well as encouraging the search for safer alternatives. Full article

(This article belongs to the Section Neurotoxicity)

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13 pages, 2253 KB

Open AccessArticle

Genetic Damage to Human Lymphocytes Induced by Contaminated Water in Populations Surrounding Lake Chapala and the Santiago River, Jalisco, México

by Mónica Reynoso-Silva, Carlos Alvarez-Moya, Fernando Manuel Guzmán-Rubio, Daniela Guadalupe Velázquez-Cruz, Daniel Moreno-Del Río, Blanca Catalina Ramírez-Hernández, Lucía Barrientos-Ramírez, José de Jesús Vargas-Radillo, Paulina Beatriz Gutiérrez-Martínez and Mario Alberto Ruíz-López

Toxics 2025, 13(10), 887; https://doi.org/10.3390/toxics13100887 - 17 Oct 2025

Viewed by 441

Abstract

Polluted water in the Chapala–Santiago basin (CSB) contains several genotoxic substances that present risks to human health, particularly among residents of communities surrounding Lake Chapala and the Santiago River, where a high prevalence of cancer has been documented. For this reason, it is [...] Read more.

Polluted water in the Chapala–Santiago basin (CSB) contains several genotoxic substances that present risks to human health, particularly among residents of communities surrounding Lake Chapala and the Santiago River, where a high prevalence of cancer has been documented. For this reason, it is necessary to study the genotoxic activity of these waters and the genetic damage in inhabitants of the surrounding populations. This study assessed the genotoxicity of water in various communities in the CSB and evaluated DNA damage to lymphocytes in residents of nearby locations. The alkaline comet assay was employed to evaluate water genotoxicity and DNA damage to lymphocytes in residents living near these waters. A standardized questionnaire was distributed to participants of this study to evaluate their exposure to polluted water. Significant genotoxic activity (p < 0.05) was observed in the lymphocytes of individuals exposed to contaminated water (tail length in Puente Grande 27.88 ± 5.4 compared to 3.77 ± 1.64 of negative control), along with notable DNA damage (p ≤ 0.05) to the lymphocytes of residents living in proximity to these waters (tail length in Juanacatlán 12.3 ± 3.4 compared to 1.4 ± 0.74 of negative control). The waters of the CSB possess the capacity to cause DNA damage; meanwhile, genotoxicity increases from Chapala to El Salto due to the additional input of genotoxic contaminants, thereby elevating the cancer risk for the exposed population. The comet test proved to be a useful tool that allowed data to be obtained quickly and reliably. Full article

(This article belongs to the Topic Aquatic Emerging Contaminants and Their Ecotoxicological Consequences, 2nd Edition)

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17 pages, 1489 KB

Open AccessArticle

Embryonic Benzo[a]pyrene Exposure Induces Multigenerational Reproductive Effects on Adult Male Medaka: Phenotypic and Transcriptomic Insights

by Yinhua Chen, Yi Yang, Xian Qin, Jiangang Wang, Guanglong Tang, Rim EL Amouri, Jiayang Chen, Jack Chi-Ho Ip, Wenhua Liu and Jiezhang Mo

Toxics 2025, 13(10), 886; https://doi.org/10.3390/toxics13100886 - 17 Oct 2025

Viewed by 288

Abstract

Benzo[a]pyrene (B[a]P), a ubiquitous environmental pollutant, poses a significant threat to male reproductive health, but the underlying latent molecular mechanisms remain virtually unknown. This study investigated the effects of embryonic B[a]P exposure on testicular function and spermatogenesis in F0 and F1 adult male [...] Read more.

Benzo[a]pyrene (B[a]P), a ubiquitous environmental pollutant, poses a significant threat to male reproductive health, but the underlying latent molecular mechanisms remain virtually unknown. This study investigated the effects of embryonic B[a]P exposure on testicular function and spermatogenesis in F0 and F1 adult male medaka (Oryzias latipes). Embryos were exposed to sublethal concentrations (2.5, 20, and 80 μg/L) for 8 days and then raised in clean water until they reached adulthood. Transcriptomic analysis of F0 testicular tissues revealed widespread dysregulation of critical pathways. Exposure impaired the brain–pituitary–gonadal axis by disrupting GnRH signaling and downregulating genes encoding key steroidogenic enzymes (CYP17A1, HSD3B2), indicating suppressed testosterone biosynthesis. Concurrently, pathways essential for cellular energy metabolism (AMPK signaling, insulin signaling), amino acid biosynthesis, and cytoskeletal organization (actin cytoskeleton, focal adhesion) were profoundly altered. Furthermore, B[a]P activated apoptotic pathways and disrupted the balance between cell survival (PI3K-Akt signaling) and death, compromising spermatogenic cell fate. These molecular disruptions manifested in drastic physiological impairments, including a reduced gonadosomatic index, decreased sperm motility, and compromised fertilization success in F0 males, although these effects were recovered in the F1 generation. This study provides a comprehensive molecular basis for the long-term reproductive toxicity of early-life B[a]P exposure. Full article

(This article belongs to the Special Issue Environmental Contaminants and Human Health—2nd Edition)

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12 pages, 256 KB

Open AccessEssay

The PFAS Conundrum—Of Logic, Science, Policy

by Jaap C. Hanekamp, Lucas Bergkamp, William M. Briggs and Moira Wilson

Toxics 2025, 13(10), 885; https://doi.org/10.3390/toxics13100885 - 16 Oct 2025

Viewed by 405

Abstract

The comprehensive (“universal”) PFAS ban proposed by the EU raises questions of a scientific, philosophical, regulatory, and policy nature. This overview scrutinizes the proposal and finds it wanting in each of these respects. The grouping of all PFAS is based on a methodology [...] Read more.

The comprehensive (“universal”) PFAS ban proposed by the EU raises questions of a scientific, philosophical, regulatory, and policy nature. This overview scrutinizes the proposal and finds it wanting in each of these respects. The grouping of all PFAS is based on a methodology that is only loosely science based. The scientific data on PFAS do not support the open-ended definition and the drastic restrictions that would be imposed by the proposal. To illustrate the weak scientific basis, we look more closely at the immunotoxicity claims as found in a few landmark epidemiological papers. We find these claims not well-founded and methodologically lacking. Also, we scrutinize a few animal studies and comment on their results. Detecting PFAS in multiple matrices is briefly looked at. The analytical context of detectability, quantifiability, measurement precision, and reproducibility of results of PFAS present in especially complex matrices (e.g., foods, soil, waxes, and fats) poses quite the challenge. Experimental uncertainties are reported to be extremely high. Disregarding the key distinctions between hazard and risk and between potential hazard and hazard, the proposal treats all PFASs, broadly defined, as presenting hazards based on an assumed common property: persistence. On this and other grounds, including the requirement of “unacceptable risk”, the proposed ban fails to meet the requirements imposed by the REACH Regulation. From a public policy perspective, the costs of the proposal would appear to eclipse any advantages for human health and the environment. Thus, we conclude that the proposed PFAS ban is problematic from these key perspectives. Full article

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

4 pages, 160 KB

Open AccessEditorial

Toxicity and Human Health Assessment of Air Pollutants

by Ting Wang, Tingting Ku and Jia Xu

Toxics 2025, 13(10), 884; https://doi.org/10.3390/toxics13100884 - 16 Oct 2025

Viewed by 367

Abstract

Air pollution has been shown to be responsible for the morbidity and mortality of a variety of major diseases [...] Full article

(This article belongs to the Special Issue Toxicity and Human Health Assessment of Air Pollutants)

20 pages, 3011 KB

Open AccessArticle

Tert-Butylhydroquinone (TBHQ) Suppresses LPS- and Poly (I:C)-Induced RAW 264.7 Macrophage Activation Through Reduced NF-κB/Type 1 Interferon and Enhanced Antioxidant-Related Pathways

by Alyssa M. Whisel and Charles D. Rice

Toxics 2025, 13(10), 883; https://doi.org/10.3390/toxics13100883 - 16 Oct 2025

Viewed by 507

Abstract

The global demand for processed foods has increased reliance on synthetic phenolic antioxidants (SPAs), including tert-butylhydroquinone (TBHQ), a widely used additive to prevent lipid oxidation and extend shelf life. TBHQ is considered safe at present regulated levels; however, studies suggest potential adverse effects, [...] Read more.

The global demand for processed foods has increased reliance on synthetic phenolic antioxidants (SPAs), including tert-butylhydroquinone (TBHQ), a widely used additive to prevent lipid oxidation and extend shelf life. TBHQ is considered safe at present regulated levels; however, studies suggest potential adverse effects, including oxidative stress, genotoxicity, and impacts on immune function, raising concerns about human health and ecological risks. Herein, we investigated the immunomodulatory effects of TBHQ on RAW 264.7 murine macrophages pre-exposed to 0.1, 1, and 5 µM TBHQ and then stimulated with lipopolysaccharide (LPS) or polyinosinic-polycytidylic acid (poly I:C, PIC) to model bacterial and viral immune challenges. We then used functional assays and transcriptomic profiling to assess inflammatory responses and oxidative stress signaling. TBHQ reduced nitric oxide production and IL-10 secretion at the highest non-cytotoxic dose, and enhanced phagocytosis and IL-6 secretion at the lowest concentrations. Overall, transcriptomics revealed significant downregulation of proinflammatory pathways and induction of glutathione and xenobiotic metabolism. Pre-treatment with TBHQ increased gene transcript counts of key metabolic genes/transporters such as Cbr3, Adh7, Gstp1/3, Gsta3, Hmox1 and Gclm. Following treatment with LPS or PIC several genes for classical proinflammatory chemokines and cytokines such as Cxcl2, Ccl2, Ccl12, Acod1, Ptgs2, Nos2, and Il6 were downregulated. Genes involved in NF-κB signaling, such as Nfkbia, Nfkb1, and Ikbke were also downregulated. Our study suggests that the induction of Nrf2-related antioxidant pathways by TBHQ is the main driver for reduced inflammatory signaling in macrophages. Full article

(This article belongs to the Section Agrochemicals and Food Toxicology)

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15 pages, 2156 KB

Open AccessArticle

Phytotoxic Effects and Microbial Responses to Ciprofloxacin and Its Removal by Hydrilla verticillata

by Linzhi Lu, Rong Huang, Liang Wan, Guijia Li, Zhenhao Xu and Jiahao Guo

Toxics 2025, 13(10), 882; https://doi.org/10.3390/toxics13100882 - 16 Oct 2025

Viewed by 248

Abstract

Ciprofloxacin (CIP), a widely used fluoroquinolone antibiotic, is frequently detected in aquatic environments, raising concerns over its ecological risks. In this study, the submerged macrophyte Hydrilla verticillata was employed to investigate its capacity for CIP removal and the associated ecotoxicological effects. A series [...] Read more.

Ciprofloxacin (CIP), a widely used fluoroquinolone antibiotic, is frequently detected in aquatic environments, raising concerns over its ecological risks. In this study, the submerged macrophyte Hydrilla verticillata was employed to investigate its capacity for CIP removal and the associated ecotoxicological effects. A series of batch experiments were conducted to evaluate plant growth, photosynthetic efficiency, oxidative stress responses, CIP biodegradation pathways, and shifts in epiphytic microbial communities. Results showed that CIP significantly inhibited the growth of H. verticillata, with inhibition rates of plant length and fresh weight reaching 15.8% and 29.7%, respectively, at 5 mg/L. Photosynthetic parameters were severely suppressed. Fv/Fm represented the maximum quantum efficiency of PSII, significantly decreased by 94.3% at 10 mg/L, while chlorophyll a and b contents declined by up to 36.1% and 31.2%, respectively, compared to control. Antioxidant responses showed H. verticillata undergo peroxidation damage. Biodegradation analysis revealed that H. verticillata effectively removed CIP from water, with maximum removal rates of 37% at 1 mg/L and 31% at 5 mg/L under high biomass (4.2 g) conditions. CIP accumulation was higher in stems than in leaves, and three biodegradation intermediates (C306, C263, and C248) were identified, suggesting a degradation pathway involving piperazine ring cleavage, de-ethylation, and deamination. High-throughput sequencing further indicated that CIP exposure reduced bacterial diversity and richness on H. verticillata surfaces, while promoting antibiotic-resistant taxa such as Actinobacteria and Bacteroidota. These findings highlight the potential role of H. verticillata in antibiotic-contaminated water remediation. Full article

(This article belongs to the Section Ecotoxicology)

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13 pages, 1776 KB

Open AccessArticle

Development of a Highly Specific Immunoassay for Residual Venom Detection of the Toxic Jellyfish Nemopilema nomurai

by Yi Wang, Yinuo Liu, Xiaochuan Hou, Ying Ge, Xiao Peng, Fengling Yang, Liang Xiao, Juan Höfer, Fei Wang and Jingbo Chen

Toxics 2025, 13(10), 881; https://doi.org/10.3390/toxics13100881 - 16 Oct 2025

Viewed by 244

Abstract

Accurate detection of residual jellyfish venom is crucial for species identification and clinical management post-envenomation. We developed a highly specific immunoassay for Nemopilema nomurai venom using polyclonal antibodies (titer: 1:256,000). The established i-ELISA exhibited linear detection (0–20 ng/mL) with low variability (intra-plate CV: [...] Read more.

Accurate detection of residual jellyfish venom is crucial for species identification and clinical management post-envenomation. We developed a highly specific immunoassay for Nemopilema nomurai venom using polyclonal antibodies (titer: 1:256,000). The established i-ELISA exhibited linear detection (0–20 ng/mL) with low variability (intra-plate CV: 0.77–2.78%; inter-plate CV: 2.25–5.17%). The kit demonstrated remarkable thermal stability (<15% signal decay after 6 days at 37 °C; detectable positivity through Day 9), suggesting >1-year shelf life at 4 °C. It showed significantly higher sensitivity for N. nomurai venom than venoms from Rhopilema esculentum, Chrysaora quinquecirrha, Cyanea melanaster, scorpions, or bees (p < 0.01). Validation in murine/human skin envenomation models and serum from systemically intoxicated mice confirmed the reproducibility and stability of residual toxins. This study developed a highly sensitive, specific, reproducible, and stable i-ELISA for Nemopilema nomurai venom, providing a methodological basis for creating diagnostic kits for marine envenomation. Full article

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19 pages, 2442 KB

Open AccessFeature PaperArticle

Spatiotemporal Evolution and Integrated Risk Assessment of Potentially Toxic Element Pollution in Coastal Waters: A Case Study of Bohai Bay Cases in China

by Limei Qu, Jianbiao Peng, Pifu Cong and Yanan Huang

Toxics 2025, 13(10), 880; https://doi.org/10.3390/toxics13100880 - 15 Oct 2025

Viewed by 355

Abstract

Under the increasing pressures of land-based pollution and intensive coastal development, marine ecosystems are facing unprecedented challenges, highlighting the urgent need for enhanced protection and management of marine environmental quality. This study examines the spatiotemporal distribution and pollution risks of seven potentially toxic [...] Read more.

Under the increasing pressures of land-based pollution and intensive coastal development, marine ecosystems are facing unprecedented challenges, highlighting the urgent need for enhanced protection and management of marine environmental quality. This study examines the spatiotemporal distribution and pollution risks of seven potentially toxic elements (Hg, Cd, Pb, Cr, As, Zn, and Cu) in the coastal waters of Bohai Bay, China, based on monitoring data collected from 2020 to 2023. Results show a significant decline in annual average concentrations of Pb (from 3.23 ± 1.11 μg/L to 0.10 ± 0.06 μg/L) and Hg (from 0.05 ± 0.02 μg/L to 0.01 ± 0.00 μg/L), reflecting effective pollution control measures. In contrast, Cu concentrations nearly doubled, rising from 0.90 ± 0.50 μg/L in 2020 to 1.98 ± 0.42 μg/L in 2023, while Zn exhibited a “V”-shaped fluctuation over the study period. Spatially, Zn, Pb, and Hg displayed pronounced clustering patterns, with coefficients of variation (CV) of 1.04, 1.49, and 1.17, respectively. The Pollution Load Index (PLI) decreased from 1.82 in 2020 to 0.94 in 2023, indicating an overall improvement in ecological quality. However, the Risk Index (RI) reached a maximum of 672.5 at Site 11 in 2020, with Hg and Cd contributing 49.6% and 22.7% to the total risk, respectively. Health risk assessment revealed non-carcinogenic risks (Hi) below the safety threshold (Hi < 1) across all sites. In contrast, carcinogenic risks (CR) ranged from 5.7 × 10⁻⁴ to 9.1 × 10⁻⁴, approaching the acceptable upper limit of 10⁻³, primarily due to dermal exposure to Hg and the high toxicity of Cd. Principal Component Analysis (PCA) suggested familiar sources for Hg, Pb, and Zn, whereas As appeared to originate from distinct pathways. Overall, this study establishes an integrated “pollution–ecological–health” assessment framework, offering scientific support for targeted pollution prevention and zonal management strategies in coastal environments. Full article

(This article belongs to the Special Issue Multi-Media Environmental Pollution and Health Risks: Tracing, Effects, and Collaborative Governance)

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22 pages, 803 KB

Open AccessArticle

New Insights into Biochemical, Genotoxic, and Analytical Aspects of Low-Level Imidacloprid Exposure in Liver and Kidney Tissue of Adult Male Wistar Rats

by Anja Katić, Vilena Kašuba, Nevenka Kopjar, Blanka Tariba Lovaković, Gordana Mendaš, Vedran Micek, Mirta Milić, Alica Pizent, Suzana Žunec and Ana Lucić Vrdoljak

Toxics 2025, 13(10), 879; https://doi.org/10.3390/toxics13100879 - 15 Oct 2025

Viewed by 316

Abstract

Besides its neurotoxic action and selective toxicity on insecticidal nicotinic acetylcholine receptors, recent studies have shown that imidacloprid may cause other adverse effects in mammals. In the present study, cholinesterase activity, oxidative stress response, genotoxicity in the liver and kidney, and imidacloprid levels [...] Read more.

Besides its neurotoxic action and selective toxicity on insecticidal nicotinic acetylcholine receptors, recent studies have shown that imidacloprid may cause other adverse effects in mammals. In the present study, cholinesterase activity, oxidative stress response, genotoxicity in the liver and kidney, and imidacloprid levels in the urine, liver, and kidney of male Wistar rats orally administered with 0.06, 0.8, and 2.25 mg imidacloprid/kg bw/day for 28 days were evaluated. Imidacloprid urine mass concentrations in treated rats increased dose-dependently. Exposure to 0.8 mg imidacloprid/kg bw/per day significantly decreased cholinesterase activities in the liver and kidney. Reactive oxygen species levels decreased significantly in the liver at the same dose. Lipid peroxidation was significantly reduced in the liver at two higher doses. No significant changes in glutathione levels or the activities of superoxide dismutase and catalase were observed. A significant decrease in the activity of glutathione peroxidase was detected in the liver at the highest dose. DNA damage was low in both liver and kidney. Exposure to imidacloprid at studied experimental conditions did not cause a significant oxidative stress response and resulted in low genotoxic effects in the liver and kidney of rats, indicating that these organs are less susceptible to adverse imidacloprid effects at such low doses. Full article

(This article belongs to the Section Agrochemicals and Food Toxicology)

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16 pages, 1689 KB

Open AccessArticle

Extended Environmental Multimedia Modeling System (EEMMS) with Analytic Hierarchy Process for Dual Evaluation of Energy Consumption and Pollutants in Solid Waste

by Jing Yuan, Heng Wang and Meifeng Chen

Toxics 2025, 13(10), 878; https://doi.org/10.3390/toxics13100878 - 15 Oct 2025

Viewed by 307

Abstract

The dual assessment of environmental risks and energy consumption of solid waste is crucial for ensuring environmental safety and energy consumption management. Using risk assessment tools to inform best management practices for reclamation is very important. In this paper, a former Extended Environmental [...] Read more.

The dual assessment of environmental risks and energy consumption of solid waste is crucial for ensuring environmental safety and energy consumption management. Using risk assessment tools to inform best management practices for reclamation is very important. In this paper, a former Extended Environmental Multimedia Modeling System (EEMMS) combined with the Monte Carlo Method (MCM) of risk assessment was further used for exploring the fate and migration of pollutant leakage in the CFSWMA landfill. Specifically, MODFLOW combined with the EEMMS–MCM system has been applied using Biochemical Oxygen Demand (BOD) as a typical indicator to model the behavior of leachate components. An EEMMS–MCM integrated risk assessment for a 20-year period was conducted. The case study of BOD emissions from the CFSWMA landfill shows that even the leachate did not have a serious impact on Canadian territory during the 20 years; however, non-sorption chemicals are mainly affected by the groundwater flow, whereas sorption chemicals are affected by the partition coefficient (or sorption). Further, this study introduces energy consumption factors such as soil and surface water bodies, and constructs an integrated dual assessment framework for the environmental risks and energy consumption of pollutants. In summary, by integrating the EEMMS pollutant migration model with an environmental risk and energy consumption assessment, a dual assessment of environmental risks and energy consumption is achieved. Full article

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

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28 pages, 7287 KB

Open AccessArticle

Investigating the Spectral Characteristics of High-Temperature Gases in Low-Carbon Chemical Pool Fires and Developing a Spectral Model

by Gengfeng Jiang, Zhili Chen, Yaquan Liang, Peng Li, Qiang Liu and Lv Zhou

Toxics 2025, 13(10), 877; https://doi.org/10.3390/toxics13100877 - 14 Oct 2025

Viewed by 246

Abstract

Low-carbon chemical fires pose significant hazards, and remote sensing of high-temperature gas emissions from these fires is a critical method for identifying and assessing their environmental impact. Analyzing the spectral characteristics of gases produced by low-carbon chemical pool fires and developing spectral radiation [...] Read more.

Low-carbon chemical fires pose significant hazards, and remote sensing of high-temperature gas emissions from these fires is a critical method for identifying and assessing their environmental impact. Analyzing the spectral characteristics of gases produced by low-carbon chemical pool fires and developing spectral radiation models can establish a foundation for remote pollution monitoring. However, such studies remain scarce. Using a custom-built high-temperature gas spectroscopy platform, this study extracts spectral features of gases emitted by low-carbon chemical pool fires. We investigate spectral interference mechanisms among combustion products and develop a high-precision spectral radiation model to support remote fire pollution monitoring. Experimental results reveal distinct spectral bands for key gases: CO₂ peaks near 2.7 μm and 4.35 μm, SO₂ at 4.05 μm, 7.5 μm, and 9.0 μm, NO at 5.5 μm, and NO₂ at 3.6 μm and 6.3 μm. The proposed spectral radiation model accurately simulates the position and shape of spectral peaks. For carbon disulfide and acetonitrile combustion products, the model achieves prediction accuracies of 83.4–96.9% and 79.2–95.3%, respectively. Full article

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14 pages, 1561 KB

Open AccessFeature PaperArticle

The Unhappy Effects of the Antidepressant Fluoxetine on the Freshwater Microalga Raphidocelis subcapitata

by Manuela D. Machado and Eduardo V. Soares

Toxics 2025, 13(10), 876; https://doi.org/10.3390/toxics13100876 - 14 Oct 2025

Viewed by 267

Abstract

Pharmaceuticals can be found in the aquatic environment and cause unwanted effects on organisms. The present work aimed to characterize the toxic mode of action of the antidepressant fluoxetine (FLX) on the freshwater microalga Raphidocelis subcapitata. With this aim, the microalga was [...] Read more.

Pharmaceuticals can be found in the aquatic environment and cause unwanted effects on organisms. The present work aimed to characterize the toxic mode of action of the antidepressant fluoxetine (FLX) on the freshwater microalga Raphidocelis subcapitata. With this aim, the microalga was exposed to low levels (µg/L) of FLX for 72 h. Exposure to 20–30 µg/L FLX arrested algal growth, which can be explained by the blockage of algal nuclear division. In addition, FLX (15–30 µg/L) deeply altered the alga’s metabolism, which was reflected by an increase in esterase activity, mitochondrial dysfunction (hyperpolarization of inner mitochondrial membrane), and reduction in the content of photosynthetic pigments: chlorophyll a (chla) and carotenoids (car). A sharp decline in photosynthetic performance, revealed by the reduction in maximum photochemical quantum yield (F_v/F_m), effective photochemical quantum yield (ΦPSII), and photosynthetic electron transport rate (ETR) of photosystem II (PSII), was also observed. FLX, at 30 µg/L, induced the intracellular accumulation of reactive oxygen species (ROS) and lipid peroxidation, with a marginal loss (1%) of cell membrane integrity. The results presented here contribute to the elucidation of the toxic mode of action of FLX on the microalgae R. subcapitata and, simultaneously, warn of the negative impact of the presence of pharmaceutical compounds in freshwater aquatic environments. Full article

(This article belongs to the Section Emerging Contaminants)

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16 pages, 2155 KB

Open AccessArticle

Toxicological Evaluation and Antimicrobial Activity of a Natural Thymol–Eucalyptol-Based Mixture

by Boris Lira-Mejía, Luis Barrios-Arpi, Carlos Villaorduña, Tatiana Ancajima, José-Luis Rodríguez, Alejandro Romero, Víctor Puicón and Hugo Patiño

Toxics 2025, 13(10), 875; https://doi.org/10.3390/toxics13100875 - 14 Oct 2025

Viewed by 430

Abstract

Currently, safe alternatives with very low toxicity and good antimicrobial activity are being sought to replace chemical compounds that can be harmful to animal and human health. For this reason, this study evaluated the safety and biofunctional microbiocidal potential of an extract composed [...] Read more.

Currently, safe alternatives with very low toxicity and good antimicrobial activity are being sought to replace chemical compounds that can be harmful to animal and human health. For this reason, this study evaluated the safety and biofunctional microbiocidal potential of an extract composed of thymol and eucalyptol. Toxicity tests showed low toxicity in both chickens (2000 mg/kg bw) and Artemia salina (EC₅₀ = 2003 mg/L) and Daphnia magna (EC₅₀ = 87 mg/L), indicating a safe usage profile. Oxidative stress biomarkers (nitrite and MDA) and antioxidant enzymes (SOD and catalase) improved in treated chickens at 20 days of age. The hematological and biochemical parameters of the treated birds showed normal values similar to those of the control group chickens, with better protein levels and lower AST levels. Histology of the kidney, intestine, and liver showed no changes in any group, confirming the absence of systemic adverse effects. At the molecular level, an improvement in the expression of tight junction proteins (claudin and occludin) was observed, suggesting a strengthening of the intestinal barrier integrity. Finally, the extract demonstrated an antimicrobial effect (E. coli, C. perfringens, Salmonella sp. and Pseudomonas sp.) comparable to that of organic acids commonly used as food preservatives, positioning it as a promising alternative in applications. Full article

(This article belongs to the Special Issue Mechanisms of Toxicity of Chemical Compounds and Natural Compounds)

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19 pages, 1030 KB

Open AccessArticle

Zebrafish Embryo Developmental Toxicity Assay (ZEDTA) for Regulatory Testing—Protocol Optimization and Historical Control Data

by Daphne van den Oetelaar, Marysia Agnieszka Tobor-Kapłon, Mèlanie Reijnaers and Manon Beekhuijzen

Toxics 2025, 13(10), 874; https://doi.org/10.3390/toxics13100874 - 14 Oct 2025

Viewed by 449

Abstract

The Zebrafish Embryo Developmental Toxicity Assay (ZEDTA) is a promising and innovative method with potential to replace the screening of teratogenic substances in mammals during preclinical development. However, a harmonized and validated protocol does not exist for the ZEDTA, and data on the [...] Read more.

The Zebrafish Embryo Developmental Toxicity Assay (ZEDTA) is a promising and innovative method with potential to replace the screening of teratogenic substances in mammals during preclinical development. However, a harmonized and validated protocol does not exist for the ZEDTA, and data on the background incidence of spontaneous malformations are not readily accessible. Therefore, the aim of this research was twofold: (1) to optimize the ZEDTA protocol and (2) to generate historical control data. The most optimal results were achieved by exposing zebrafish larvae in 24-well plates at a temperature of 26 °C in combination with the renewal of test solutions after 48 h of exposure. Furthermore, the use of 0.5% v/v DMSO did not induce more malformations or mortality than exposure to standard ISO medium. In total, 26 valid experiments were conducted using the optimized ZEDTA protocol. An overall mortality of 3.5% was recorded after 96 h of exposure. Malformations were observed in 7.6% of all surviving larvae. The most frequently observed abnormalities included yolk sac deformation (4.0%), followed by tail (2.8%), heart (2.6%), and head malformations (1.6%). The optimized protocol was considered effective in supporting an optimal development rate of exposed zebrafish larvae, with low mortality and minimal background malformations. These findings indicate a low level of confounding factors and high reliability of results, making an essential step in the refinement of ZEDTA toward global harmonization and regulatory acceptance. Full article

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

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22 pages, 1371 KB

Open AccessReview

Environmental and Human Health Risks of 6PPD and 6PPDQ: Assessment and Implications

by Sainan Zhang, Jiayue Tang, Zhiying Qiu, Xia Huo, Dongling Liu and Xiang Zeng

Toxics 2025, 13(10), 873; https://doi.org/10.3390/toxics13100873 - 14 Oct 2025

Viewed by 563

Abstract

This review aims to synthesize current knowledge on the environmental contaminants N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD) and its quinone derivative (6PPDQ) derived from tire wear particles (TWPs), focusing on their environmental distribution, transformation, human exposure pathways, toxicological effects, and health risks to ecological and human health. [...] Read more.

This review aims to synthesize current knowledge on the environmental contaminants N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD) and its quinone derivative (6PPDQ) derived from tire wear particles (TWPs), focusing on their environmental distribution, transformation, human exposure pathways, toxicological effects, and health risks to ecological and human health. A comprehensive literature review was conducted, compiling and analyzing data from environmental monitoring studies, toxicological assessments on aquatic and mammalian models, and emerging human biomonitoring research. Key findings on concentrations, toxicological endpoints (e.g., LC50, oxidative stress, genotoxicity), and exposure pathways were evaluated. 6PPD and its transformation product 6PPDQ are ubiquitous environmental pollutants found in air, water, soil, sediment, and dust. 6PPDQ is notably highly toxic to aquatic organisms, with an acute LC50 of 790 ng/L for coho salmon. Human exposure to these compounds occurs through inhalation, ingestion, and dermal contact, and their presence has been confirmed in human matrices including blood, urine, and cerebrospinal fluid. Toxicological studies, primarily on model organisms, indicate that 6PPD and 6PPDQ can induce oxidative stress, cause DNA damage, and disrupt metabolic and neurological functions. Adverse outcomes such as intestinal toxicity, reproductive impairment, neurobehavioral changes, and potential carcinogenicity have been observed. However, direct evidence of their health impacts on humans remains limited. 6PPD and 6PPDQ pose significant and widespread ecological risks, with 6PPDQ representing a particularly potent aquatic toxicant. While human exposure is confirmed, the full scope of human health implications is not yet well understood. The review highlights the need for longitudinal environmental tracking, mechanistic studies, and refined exposure models to inform regulatory actions and mitigate risks. Addressing these challenges is essential to mitigate the ecological and health burdens posed by 6PPD and 6PPDQ. This study underscores the global societal importance of addressing 6PPD-related pollution—a pervasive and transboundary environmental challenge stemming from universal tire wear. Full article

(This article belongs to the Special Issue Health Risks and Toxicity of Emerging Contaminants)

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Toxics, Volume 13, Issue 10 (October 2025) – 96 articles

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