Toxics

19 pages, 1647 KB

Open AccessArticle

Toxicokinetic Characterization of MDM Hydantoin via Stable Metabolite DMH: Population Modeling for Predicting Dermal Formaldehyde Formation

by Woohyung Jung, Jaewoong Lee, Woojin Kim, Seongwon Kim, Woojin Nam, In-Soo Myeong, Kwang Ho Kim, Soyoung Shin and Tae Hwan Kim

Toxics 2025, 13(11), 917; https://doi.org/10.3390/toxics13110917 (registering DOI) - 25 Oct 2025

Abstract

MDM hydantoin (MDMH), a formaldehyde-releasing preservative widely used in cosmetics, poses potential health risks due to its conversion to formaldehyde and systemically absorbed metabolites. Current safety assessments lack quantitative exposure data due to rapid degradation of MDMH in biological matrices. In the present [...] Read more.

MDM hydantoin (MDMH), a formaldehyde-releasing preservative widely used in cosmetics, poses potential health risks due to its conversion to formaldehyde and systemically absorbed metabolites. Current safety assessments lack quantitative exposure data due to rapid degradation of MDMH in biological matrices. In the present study, we developed a validated LC-MS/MS assay for simultaneous determination of MDMH and its stable metabolite DMH in rat plasma, and characterized their toxicokinetics using population modeling following intravenous and transdermal administration. MDMH exhibited extremely rapid elimination (t_1/2 = 0.4 ± 0.1 min) with near-complete conversion to DMH (97.6 ± 9.6%), while DMH demonstrated prolonged retention (t_1/2 = 174.2 ± 12.2 min) and complete bioavailability (100.9 ± 18.0%) after transdermal application. Population modeling estimated that 84% (relative standard error: 42.8%) of applied MDMH undergoes cutaneous absorption and metabolism to DMH and formaldehyde within skin tissues. This study demonstrates that stable metabolite monitoring combined with population modeling enables toxicokinetic characterization of rapidly degrading compounds following dermal exposure. Full article

(This article belongs to the Special Issue Advances in Computational Methods of Studying Exposure to Chemicals)

11 pages, 652 KB

Open AccessArticle

Multielement Composition Analysis of Cicada as an Edible Insect and Dietary Risk Assessment

by Guotao Ding, Mengyu Liu, Yanfei Fang, Peng Sun, Yonghong Han, Yingying Lian and Weihao Li

Toxics 2025, 13(11), 916; https://doi.org/10.3390/toxics13110916 (registering DOI) - 24 Oct 2025

Abstract

Cicadas are a traditional food in China. In this study, we performed multielement analysis on cicadas using Inductively Coupled Plasma–Mass Spectrometry (ICP-MS). In total, 40 cicada samples were collected in Hebei Province (China). Comparing the results of mushroom and vegetable samples selected as [...] Read more.

Cicadas are a traditional food in China. In this study, we performed multielement analysis on cicadas using Inductively Coupled Plasma–Mass Spectrometry (ICP-MS). In total, 40 cicada samples were collected in Hebei Province (China). Comparing the results of mushroom and vegetable samples selected as the standard foods among the eight food categories, which had the highest correlation with other food categories, there are 12 elements (Al, Mn, Zn, Cu, Cd, Ba, Se, V, As, Li, Pb and Co) in cicadas both higher than mushroom and vegetable samples, which a total of 25 elements were detected. The Principal Component Analysis (PCA), cluster analysis, and correlation analysis were used in the data analysis. HQ (Hazard quotient) value for Cd, As, Pb, and Al is 0.281 in males and is 0.324 in females. Concentrations of essential trace elements (Zn, Cu, and Se) in cicadas ranged from 1.7 to 101.9 times higher than those in mushrooms or vegetables. We analyzed in detail the two perspectives: one is the risk of potentially toxic elements, and the other is the enrichment of essential trace elements. In this study, we reveal that cicadas show a low risk of potentially toxic elements and high concentrations of essential trace elements, making them an edible insect. Full article

(This article belongs to the Special Issue Health Risk Evaluation of Hazardous Substances in Food)

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12 pages, 5513 KB

Open AccessArticle

Sustainable Cyanobacterial Bloom Control: Inhibitory Effects of Nano Zero-Valent Iron on Microcystis aeruginosa and Metabolic Disruption

by Guoming Zeng, Zilong Ma, Xiaoling Lei, Yong Xiao, Da Sun and Yuanyuan Huang

Toxics 2025, 13(11), 915; https://doi.org/10.3390/toxics13110915 - 24 Oct 2025

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Abstract

The bloom of cyanobacteria has severely disrupted ecological balances, posing significant risks to human health and safety. However, there is currently a lack of environmentally friendly methods that can sustainably suppress these blooms over the long term. This study integrates untargeted metabolomics, Fourier-transform [...] Read more.

The bloom of cyanobacteria has severely disrupted ecological balances, posing significant risks to human health and safety. However, there is currently a lack of environmentally friendly methods that can sustainably suppress these blooms over the long term. This study integrates untargeted metabolomics, Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) to systematically characterize the responses of Microcystis aeruginosa to nano zero-valent iron (nZVI). Exposure to nZVI reprograms lipid and amino acid metabolism, coincides with the suppression of protein biosynthesis, and perturbs central pathways—including the tricarboxylic acid (TCA) cycle, photosynthesis, and carbohydrate metabolism—leading to disruptions in energy balance and metabolic homeostasis. FTIR and SEM provide complementary evidence of membrane compromise, with attenuation of -OH, -C-H, and C=O functional group signals, abnormal cell morphology, and progressive oxidative injury culminating in cell lysis and solute leakage. Together, these results support the inhibitory effect of nZVI on M. aeruginosa and provide insights to guide metabolomics studies of M. aeruginosa using nZVI. Full article

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14 pages, 1084 KB

Open AccessArticle

Atlantic Salmon (Salmo salar) GILL Primary Cell Culture Oxidative Stress and Cellular Damage Response Challenged with Oxytetracycline Antibiotic

by Luis Vargas-Chacoff, José Ramírez-Mora, Daniela Nualart, Francisco Dann and José Luis P. Muñoz

Toxics 2025, 13(11), 914; https://doi.org/10.3390/toxics13110914 - 24 Oct 2025

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Abstract

Salmon farming has been affected by various bacterial diseases, and the use of antibiotics (such as oxytetracycline “OTC”) to control these diseases has become necessary and thus routine. This study aimed to determine how the gill cells are affected by OTC in Salmo [...] Read more.

Salmon farming has been affected by various bacterial diseases, and the use of antibiotics (such as oxytetracycline “OTC”) to control these diseases has become necessary and thus routine. This study aimed to determine how the gill cells are affected by OTC in Salmo salar. Gill tissue culture was performed in periods of 0.5, 1, 3, 6, 12, and 24 h, assessing the enzymatic activity and mRNA expression of catalase (CAT), cytochrome p450, glutathione peroxidase (GPx), glutathione reductase (Gr), and superoxide dismutase (SOD), HSP70 and HSP90, in response to two doses of OTC: 0.25 (low), and 3 µL/mL (high). The results indicated that the enzymatic activity of SOD and CAT showed low enzyme activity at both doses. At the same time, GR presented varied response patterns depending on the time and dose of OTC used, contrary to GPx, which just increased the enzyme activity at early times. Although the mRNA expression presented the most precise pattern of expression, they were not in line with the enzymatic activities. The HSP70 and HSP90 mRNA expression response (as a cellular damage marker) increased mRNA levels at low and high doses, respectively, but at different times, alluding to a differentiated response given by the size of the chaperone. These results suggest an oxidative response of the gills to OTC exposure and constitute significant information on the amount of OTC used in aquaculture and on methods for improving the optimal dose of drugs, fish health, and, consequently, environmental health. Full article

(This article belongs to the Special Issue Pharmaceutical Pollutants: Environmental Fate, Risk Assessment and Sustainable Solutions)

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20 pages, 581 KB

Open AccessReview

Cellular Impact of Micro(nano)plastics on Human Health: A Review

by Longxiao Liu, Pengcheng Tu, Huixia Niu, Xueqing Li, Xin Gong, Zhijian Chen, Mingluan Xing, Lizhi Wu and Xiaoming Lou

Toxics 2025, 13(11), 913; https://doi.org/10.3390/toxics13110913 (registering DOI) - 23 Oct 2025

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Abstract

Micro(nano)plastics (MNPs), as a globally emerging environmental pollutant, are now ubiquitous in natural environments and can continuously enter the human body through ingestion, inhalation, and dermal contact. This widespread exposure has raised significant concerns regarding the potential health risks posed by MNPs. Although [...] Read more.

Micro(nano)plastics (MNPs), as a globally emerging environmental pollutant, are now ubiquitous in natural environments and can continuously enter the human body through ingestion, inhalation, and dermal contact. This widespread exposure has raised significant concerns regarding the potential health risks posed by MNPs. Although epidemiological studies are still in the early stages, accumulating in vitro cellular experiments have provided key evidence suggesting that nano- to micro-sized plastic particles can cross physiological barriers in the human body. These particles enter cells via endocytosis or direct penetration through the cell membrane, triggering toxic effects such as oxidative stress, immune responses, mitochondrial dysfunction, and DNA damage, which can potentially lead to cell apoptosis. These findings highlight that the direct interaction between MNPs and human cells could be a core mechanism underlying their potential health hazards. This review systematically summarizes the toxic effects of MNPs exposure on various human cell types, exploring the underlying molecular mechanisms and providing insights for future research into the toxicological impacts of MNPs and their implications for human health risk assessment. Full article

(This article belongs to the Section Emerging Contaminants)

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14 pages, 1772 KB

Open AccessArticle

Effect of Nitric Acid-Modified Multi-Walled Carbon Nanotube Capping on Copper and Lead Release from Sediments

by Xiang Chen, Dongdong Zhu, Xiaohui You, Yan Wang, Li Zhou and Xiaoshuai Hang

Toxics 2025, 13(11), 912; https://doi.org/10.3390/toxics13110912 - 23 Oct 2025

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Abstract

Nitric acid-treated multi-walled carbon nanotubes (CNTs) have been extensively utilized for removing dissolved heavy metals from aqueous systems; however, their use as a capping material to immobilize heavy metals in sediments has rarely been investigated. Consequently, the impact of CNTs on millimeter-scale variations [...] Read more.

Nitric acid-treated multi-walled carbon nanotubes (CNTs) have been extensively utilized for removing dissolved heavy metals from aqueous systems; however, their use as a capping material to immobilize heavy metals in sediments has rarely been investigated. Consequently, the impact of CNTs on millimeter-scale variations in pore-water heavy metal concentrations along sediment profiles remains poorly understood. In this study, CNTs were applied as a capping agent, and microelectrodes combined with high-resolution diffusive equilibrium in thin-film (HR-Peeper) samplers were employed to simultaneously obtain vertical profiles of pH, soluble copper (Cu) and lead (Pb), and dissolved oxygen (DO) in sediments in order to assess the effectiveness of CNTs in controlling the mobility of Cu and Pb. The results revealed that CNTs application markedly reduced the concentrations of soluble Cu and Pb, with maximum reduction rates of 58.69% and 64.97%, respectively. Compared with the control treatment, CNTs capping decreased the maximum release fluxes of soluble Cu and Pb by 3.78 and 1.91 µg·m⁻²·d⁻¹, respectively. Moreover, CNTs treatment enhanced the stable fractions of Cu and Pb within sediments, thereby improving the sediment’s capacity to retain these metals. Overall, this study demonstrates that CNTs can serve as an effective capping material to inhibit the leaching of Cu and Pb from sediments, offering a promising strategy for the in situ remediation of heavy metal-contaminated sediments. Full article

(This article belongs to the Special Issue Heavy Metals and Emerging Contaminants in Aquatic and Soil Environments: Migration, Transformation, Ecological Risks, and Remediation)

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17 pages, 4716 KB

Open AccessArticle

Specific Hepatorenal Toxicity and Cross-Species Susceptibility of Eight Representative Pesticides

by Yue Liu, Ning Xu, Xinyu Song, Muchen Deng, Ranfeng Sun, Peilong Wang and Lidong Cao

Toxics 2025, 13(11), 911; https://doi.org/10.3390/toxics13110911 - 23 Oct 2025

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Abstract

Chronic exposure to pesticides poses significant hepatorenal toxicity risks, yet a systematic comparison of their effects across species and tissues is lacking. In this study, we systematically evaluated the cytotoxicity of eight pesticides using human (CCC-HEL-1 hepatocytes; 293T renal cells) and rodent (IAR [...] Read more.

Chronic exposure to pesticides poses significant hepatorenal toxicity risks, yet a systematic comparison of their effects across species and tissues is lacking. In this study, we systematically evaluated the cytotoxicity of eight pesticides using human (CCC-HEL-1 hepatocytes; 293T renal cells) and rodent (IAR hepatocytes; NRK renal cells) cellular models. Our results showed substantial variations in potency, with chlorothalonil exhibiting the highest toxicity (IC50 = 32.55 mg/L in 293T cells) and chlorpyrifos the lowest (IC50 = 444.5 mg/L in 293T cells). Principal component analysis revealed distinct species- and tissue-specific response patterns, highlighting the unique resistance of NRK cells. Mechanistic investigations demonstrated organ-specific biomarker alterations, such as elevated hepatic ALP and suppressed renal KIM-1. Remarkably, the MRP2 transporter exhibited tissue-specific divergence, being significantly downregulated in renal cells (all 8 pesticides, p < 0.005) and most hepatic cells (7/8 pesticides, p < 0.05), while propiconazole uniquely upregulated it in hepatocytes (1.5-fold, p < 0.05). Collectively, these findings offer critical mechanistic insights into pesticide-specific toxicity and cross-species susceptibility, providing valuable data to improve human health risk assessment in food safety and toxicology. Full article

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

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19 pages, 6007 KB

Open AccessArticle

The EIF2α-PERK Signaling Pathway Mediates Manganese Exposure-Induced A1-Type Astrocytes Activation via Endoplasmic Reticulum Stress

by Jing Wang, Tingting Guo, Yang Hu, Congcong Zhuang, Peng Su and Xinqin Liu

Toxics 2025, 13(11), 910; https://doi.org/10.3390/toxics13110910 - 23 Oct 2025

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Abstract

Elevated exposure to manganese (Mn) has been linked to a broad spectrum of neurological disorders, including motor dysfunction. Neuroinflammation with excessively activated astrocytes plays a critical role in the pathogenesis and progression of neurodegenerative diseases. Astrocyte-mediated neuroinflammation plays a dual role due to [...] Read more.

Elevated exposure to manganese (Mn) has been linked to a broad spectrum of neurological disorders, including motor dysfunction. Neuroinflammation with excessively activated astrocytes plays a critical role in the pathogenesis and progression of neurodegenerative diseases. Astrocyte-mediated neuroinflammation plays a dual role due to distinct astrocyte phenotypes, including deleterious A1 and neuroprotective A2. Our previous studies have confirmed that Mn induces activation of astrocytes in the central nervous system, and endoplasmic reticulum (ER) stress has been verified to regulate A1 activation; however, the molecular mechanisms underlying Mn-induced neurotoxicity remain incompletely understood. We establish in vivo and in vitro Mn exposure models and observed that Mn induced A1 activation of astrocytes in both models, with upregulation of A1-specific markers. Sub-cellular morphological analysis showed Mn-induced ER stress in A1-type astrocytes. We found that EIF2α-PERK signaling pathways are activated in astrocytes and drive ER stress and mitochondrial impairment. Suppression of astrocytic PERK, using either ISRIB or GSK2606414, alleviates Mn-induced ER stress and A1 activation, which in turn mitigates the motor deficits induced by Mn exposure. These findings reveal that inhibition of PERK can ameliorate Mn-induced neurotoxicity by suppressing astrocyte activation and preserving organelle homeostasis, offering a potential therapeutic strategy to mitigate the harmful effects of Mn toxicity. Full article

(This article belongs to the Section Neurotoxicity)

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14 pages, 1028 KB

Open AccessArticle

Tobacco Smoke Exposure Biomarker Profiles and Healthcare Utilization Patterns Among U.S. Children

by Ashley L. Merianos, Georg E. Matt, Roman A. Jandarov and E. Melinda Mahabee-Gittens

Toxics 2025, 13(11), 909; https://doi.org/10.3390/toxics13110909 - 23 Oct 2025

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Abstract

This study aimed to examine the associations between distinct tobacco smoke exposure (TSE) biomarkers and healthcare utilization patterns in U.S. children ages 3–11 years with and without current asthma. Secondary data from the 2013–2016 National Health and Nutrition Examination Survey were analyzed (N [...] Read more.

This study aimed to examine the associations between distinct tobacco smoke exposure (TSE) biomarkers and healthcare utilization patterns in U.S. children ages 3–11 years with and without current asthma. Secondary data from the 2013–2016 National Health and Nutrition Examination Survey were analyzed (N = 2838). TSE biomarkers included serum cotinine, urinary total nicotine equivalents (TNE2), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), the NNAL/TNE2 ratio, and the N-acetyl-S-(2-cyanoethyl)-L-cysteine (2CyEMA)/TNE2 ratio. We conducted Poisson regression analyses to examine the associations between each biomarker and healthcare visits and hospitalizations within the past 12 months, adjusting for sociodemographic and home TSE covariates. Children without asthma who had higher urinary TNE2 levels (adjusted incidence rate ratio [aIRR] = 1.03, 95% confidence interval [CI] = 1.02–1.04) and children with asthma who had higher urinary 2CyEMA/TNE2 ratio levels (aIRR = 1.05, 95%CI = 1.03–1.07) were at an increased risk of having more healthcare visits. Children without asthma who had higher serum cotinine (aIRR = 1.21, 95%CI = 1.07–1.37) and higher 2CyEMA/TNE2 ratio levels (aIRR = 1.25, 95%CI = 1.14–1.37) were at an increased risk of hospitalizations. Children with asthma who had higher NNAL/TNE2 ratio levels (aIRR = 1.52, 95%CI = 1.11–2.09) were at increased risk of hospitalizations. It is important to consider comprehensive biomarkers of TSE in children, such as TNE, tobacco-specific nitrosamines, and volatile organic compounds, along with healthcare utilization patterns. Child TSE reduction policies are urgently needed. Full article

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15 pages, 1455 KB

Open AccessArticle

First Human Biomonitoring Evidence of Strobilurin Fungicide Exposure in South China: Impact on Oxidative Stress and Liver Damage

by Bo Zhang, Shuai Feng, Yanxia Gao, Wenxi Xie, Yiyu Chen and Shiming Song

Toxics 2025, 13(11), 908; https://doi.org/10.3390/toxics13110908 - 23 Oct 2025

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Abstract

Background: Strobilurin fungicides (SFs) are widely detected in the environment, but data on their occurrence in humans and potential health effects are scarce. Objective: This study aimed to characterize the exposure to SFs in a human population from South China and to investigate [...] Read more.

Background: Strobilurin fungicides (SFs) are widely detected in the environment, but data on their occurrence in humans and potential health effects are scarce. Objective: This study aimed to characterize the exposure to SFs in a human population from South China and to investigate their potential association with biomarkers of oxidative stress and liver damage. Methods: In a cross-sectional study, we analyzed serum samples from healthy participants and secondary nonalcoholic fatty liver disease (S-NAFLD) patients. Concentrations of SFs and oxidative stress biomarkers including 8-iso-prostaglandin-F2α (8-PGF_2α), 11β-prostaglandin F2α (11-PGF_2α), 15(R)-prostaglandin F2α (15-PGF_2α), and 8-oxo-7,8-dihydro-20-deoxyguanosine (8-OHdG) were measured. Associations between SF exposure, liver function biomarkers, and S-NAFLD prevalence were assessed using multivariate regression models. A mediation analysis was conducted to explore the role of oxidative stress. Results: Azoxystrobin (AZ), fluoxastrobin (FLUO), and fenamidone (FE) were the predominant compounds, with median concentrations ranging from 0.016 to 0.042 ng/mL. Significant positive correlations were observed between all frequently detected SFs and oxidative stress biomarkers (p < 0.05). FE was associated with a modest, albeit statistically significant, prevalence of S-NAFLD. AZ and FE were also found to be statistically significantly associated with altered levels of direct bilirubin (DBIL, FDR-q < 0.05). The exploratory mediation analysis indicated a statistically significant indirect effect (17.1% to 31.2%), suggesting that lipid peroxidation biomarkers could serve as potential mediators between AZ exposure and DBIL levels. Conclusions: This study provides the first evidence of widespread SF exposure in a South Chinese population and reveals significant associations with oxidative stress and AZ exposure with liver function biomarkers (i.e., DBIL), with exploratory analyses suggesting a potential mediating role of oxidative stress in this relationship. However, the cross-sectional design precludes causal inference, and the modest effect sizes warrant cautious interpretation. These findings highlight the need for further longitudinal research to confirm the hepatotoxicity of SFs in humans. Full article

(This article belongs to the Special Issue Biological Risk Monitoring of Exposure to Chemical Pollutants and/or Physical Agents: 2nd Edition)

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13 pages, 1888 KB

Open AccessArticle

The Effects of Urbanization on Chronic Kidney Disease and Renal Function Decline: Findings from a Nation-Wide Longitudinal Study

by Wei Liang, Dong Hou, Xiaoyu Li, Jiayi Qiu, Mei Wang, Xiuli Zhao, Shouxin Peng and Guangyu Lu

Toxics 2025, 13(11), 907; https://doi.org/10.3390/toxics13110907 - 23 Oct 2025

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Abstract

Chronic kidney disease (CKD) has become a global public health concern, especially in developing countries. Although previous studies have suggested a link between urbanization and CKD, the existing evidence remains limited and inconsistent. We selected a sub-cohort of 5298 participants from the China [...] Read more.

Chronic kidney disease (CKD) has become a global public health concern, especially in developing countries. Although previous studies have suggested a link between urbanization and CKD, the existing evidence remains limited and inconsistent. We selected a sub-cohort of 5298 participants from the China Health and Retirement Longitudinal Study (CHARLS). All participants had normal renal function at baseline (2011) and were followed up in 2015, with renal biomarkers measured twice. Urbanization was assessed at the city level using the average nighttime light index (ANLI), derived from calibrated long-term satellite remote sensing data. Logistic regression models were used to examine the association between urbanization and CKD. Our results showed that a 0.1-unit increase in ANLI was associated with a 7.3% increase in the relative risk of CKD in the fully adjusted model (OR: 1.073, 95% CI: 1.045, 1.101). Subgroup analyses indicated that females (OR: 1.106, 95% CI: 1.068, 1.145) and urban residents (OR: 1.101, 95% CI: 1.060, 1.143) were at higher risk. We also found the synergistic amplification effects of heavier air pollution (PM_2.5 and NO₂) and elevated temperatures on this association. Our findings provide robust evidence of a positive association between urbanization and CKD among middle-aged and elderly adults in China. More scientific and specific health investment is needed with urbanization process simultaneously. Full article

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

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23 pages, 795 KB

Open AccessReview

Environmental Occurrence, Influencing Factors, and Toxic Effects of 6PPD-Q

by Tengwen Yin, Ying Liang, Yanju Liu, Jia Liu and Xuedong Wang

Toxics 2025, 13(11), 906; https://doi.org/10.3390/toxics13110906 - 22 Oct 2025

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Abstract

The antioxidant N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD) is widely incorporated into tires to extend their service life. However, in the presence of ozone, it is readily transformed into N-(1,3-dimethylbutyl)-N′-phenyl-p-benzoquinone (6PPD-Q). Owing to the large-scale production and [...] Read more.

The antioxidant N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD) is widely incorporated into tires to extend their service life. However, in the presence of ozone, it is readily transformed into N-(1,3-dimethylbutyl)-N′-phenyl-p-benzoquinone (6PPD-Q). Owing to the large-scale production and widespread utilization of rubber-related products, 6PPD-Q is continuously released into the environment with tire and road wear particles, becoming ubiquitous across multiple environmental compartments. It possesses bioaccumulation potential and exhibits significant toxicity, while multiple exposure pathways enable it to enter human body, posing risks to public health. This review summarizes the environmental distribution of 6PPD-Q in atmospheric, aquatic, and terrestrial systems, and examines key factors influencing its occurrence, including precipitation patterns, traffic characteristics, sunlight, and particle size. The toxicological effects of 6PPD-Q are also discussed. Based on these findings, a comprehensive management framework encompassing “source reduction—process regulation—end-of-pipe treatment” is proposed. Finally, current knowledge gaps are identified and future research directions are highlighted. Full article

(This article belongs to the Special Issue Occurrence, Fate, Bioaccumulation and Toxic Effects of 6PPDQ)

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15 pages, 1564 KB

Open AccessCommunication

Preliminary Identification of PFAS and Other Emerging Contaminants in the French Broad River, NC Post-Hurricane Helene

by Imari Walker-Franklin, Samantha Blake, Evan Thorp and Shea Tuberty

Toxics 2025, 13(11), 905; https://doi.org/10.3390/toxics13110905 - 22 Oct 2025

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Abstract

Hurricanes are increasingly impacting inland water systems, yet their role in mobilizing anthropogenic contaminants remains insufficiently characterized. This study presents a preliminary assessment of organic contaminant loading in the French Broad River, North Carolina, 15 days after flooding from Hurricane Helene. Surface water [...] Read more.

Hurricanes are increasingly impacting inland water systems, yet their role in mobilizing anthropogenic contaminants remains insufficiently characterized. This study presents a preliminary assessment of organic contaminant loading in the French Broad River, North Carolina, 15 days after flooding from Hurricane Helene. Surface water samples from five sites were analyzed using liquid chromatography–high-resolution mass spectrometry. Targeted analysis quantified 11 per- and polyfluoroalkyl substances (PFASs), with summed concentrations ranging from 1.49 to 70.8 ng/L. One downstream site exhibited the highest burden, where PFOSs and PFOA exceeded U.S. EPA drinking water maximum contaminant levels. Non-targeted analysis (NTA) and suspect screening identified 468 compounds, with 96 structurally annotated at high confidence. Of these, a large proportion were associated with medium to high hazard potential, particularly for acute aquatic toxicity (69%), developmental toxicity (64%), mutagenic genotoxicity (49%), endocrine disruption (35%), skin irritation (27%), eye irritation (26%), and carcinogenicity (17%). Four EPA priority pollutants—4-nitrophenol, 2,4,6-trichlorophenol, pentachlorophenol, and dibutyl phthalate—were also detected. Site-specific chemical profiles suggested inputs from flood-damaged wastewater infrastructure and plastic debris. These findings highlight the susceptibility of freshwater systems to contaminant mobilization during extreme flooding and demonstrate the value of combining NTA and cheminformatics for post-disaster monitoring. Full article

(This article belongs to the Special Issue State-of-the-Art Environmental Chemical Exposomics and Metabolomics—2nd Edition)

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11 pages, 6975 KB

Open AccessArticle

Dissolution of Microparticles of Cadmium, Lead and Thallium in Water

by Gennadii L. Bykov and Boris G. Ershov

Toxics 2025, 13(11), 904; https://doi.org/10.3390/toxics13110904 - 22 Oct 2025

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Abstract

Anthropogenic activity seriously damages the environment. Cadmium, lead, and thallium are toxic elements that are especially hazardous for nature. In polluted air, they are present in the form of microparticles 2–3 μm in size and belong to the PM_2.5 fraction. Such particles [...] Read more.

Anthropogenic activity seriously damages the environment. Cadmium, lead, and thallium are toxic elements that are especially hazardous for nature. In polluted air, they are present in the form of microparticles 2–3 μm in size and belong to the PM_2.5 fraction. Such particles can be transported over long distances, penetrate into water and dissolve, and then enter the food chain. This poses a severe threat to human and animal health due to the bioaccumulation of metals. Therefore, it is important to study the properties of toxic metals of this size. In this work, we developed a radiation–chemical method for obtaining microparticles of cadmium, lead, and thallium corresponding to the PM_2.5 fraction and studied their properties in aqueous solutions. In the absence of oxygen, the metals do not dissolve. Over time, they agglomerate and settle. When exposed to air, the particles quickly dissolve in water, usually within a few minutes. This process involves the disappearance of small particles and a decrease in the size of larger ones. The rate of dissolution increases in the Pb-Cd-Tl series. Cadmium dissolves approximately 4–5 times faster than lead, and thallium more than 10 times faster. Acidification of water accelerates this process. Studying the properties of microparticles of heavy metals is important for assessing their migration in the environment, health risks, and developing methods for preventing pollution. Full article

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

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28 pages, 10777 KB

Open AccessArticle

Molecular Determinants of Per- and Polyfluoroalkyl Substances Binding to Estrogen Receptors

by Sahith Mada, Samuel Jordan, Joshua Mathew, Coby Loveranes, James Moran, Harrish Ganesh and Sivanesan Dakshanamurthy

Toxics 2025, 13(11), 903; https://doi.org/10.3390/toxics13110903 - 22 Oct 2025

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Abstract

Per- and polyfluoroalkyl substances (PFAS) are environmentally persistent organofluorines linked to cancer, organ dysfunction, and other health problems. This study used quantitative structure–property relationship (QSPR) and quantitative structure–activity relationship (QSAR) modeling to examine the binding of PFAS to estrogen receptor alpha (ERα) and [...] Read more.

Per- and polyfluoroalkyl substances (PFAS) are environmentally persistent organofluorines linked to cancer, organ dysfunction, and other health problems. This study used quantitative structure–property relationship (QSPR) and quantitative structure–activity relationship (QSAR) modeling to examine the binding of PFAS to estrogen receptor alpha (ERα) and beta (ERβ). Molecular docking of 14,591 PFAS compounds was performed, and docking scores were used as a measure of receptor affinity. QSPR models were built for two datasets: the ERα and ERβ top binders (TBs), and a set of commonly exposed (CE) PFAS. These models quantified how chemical descriptors influence binding affinity. Across the models, higher density and electrophilicity indicated positive correlations with affinity, while surface tension indicated negative correlations. Electrostatic descriptors, including HOMO energy and positive Fukui index (F⁺ max), were part of the models but showed inconsistent trends. The CE QSPR models displayed correlations that conflicted with those of the TB models. Following QSPR analysis, 66 QSAR models were developed using a mix of top binders and experimental data. These models achieved strong performance, with R² values averaging 0.95 for training sets and 0.78 for test sets, that indicated reliable predictive ability. To improve generalizability, large-set QSAR models were created for each receptor. After outlier removal, these models reached R² values of 0.68–0.71, which supports their use in screening structurally diverse PFAS. Overall, QSPR and QSAR analyses reveal key chemical features that influence PFAS–ER binding. This predictive approach provides a scalable framework to assess the binding interactions of structurally diverse PFAS to ERs and other nuclear receptors. All the codes, data, and the GUI visualization of the results are freely available at sivaGU/QSPR-QSAR-Molecular-Visualization-Tool. Full article

(This article belongs to the Collection Predictive Toxicology)

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