Toxics

27 pages, 4385 KB

Open AccessArticle

Environmental Concentrations of PFOS Accumulate in the Euglena Eyespot and Impair Chloroplast ATP Synthase Activity: A Dual Impairment of Phototaxis and Photosynthetic Light Reactions

by Peirui Liu, Junfeng Wang, Yan Hong, Zilin Chen, Xiaoya Liu, Huayi Chen, Ganning Zeng and Xiangliang Pan

Toxics 2026, 14(6), 540; https://doi.org/10.3390/toxics14060540 - 22 Jun 2026

Viewed by 537

Abstract

Perfluorooctane sulfonate (PFOS) is a persistent organic pollutant widely detected in aquatic ecosystems, but its subcellular targets and the mechanisms by which it disrupts light resource utilization in photosynthetic protozoa remain poorly understood at concentrations spanning environmentally typical to supra-environmental levels. Here, Euglena [...] Read more.

Perfluorooctane sulfonate (PFOS) is a persistent organic pollutant widely detected in aquatic ecosystems, but its subcellular targets and the mechanisms by which it disrupts light resource utilization in photosynthetic protozoa remain poorly understood at concentrations spanning environmentally typical to supra-environmental levels. Here, Euglena gracilis G.A. Klebs was exposed to PFOS at concentrations spanning environmentally typical (0.5 µg/L), hotspot-relevant (5 µg/L), and supra-environmental (50 µg/L) levels. Subcellular distribution, phototaxis, photosynthetic light reactions, and energy metabolism were investigated using isolated chloroplast assays, transcriptomics, and proteomics. TEM-EDS mapping revealed pronounced fluorine signal enrichment, attributable to PFOS, in the eyespot and chloroplasts. Eyespot fluorine enrichment was associated with impaired phototactic motility and an altered light perception threshold. PFOS did not acutely inhibit the maximum photochemical efficiency of photosystem II (Fv/Fm); instead, a transient upregulation of photosynthesis-related genes was observed, which weakened with prolonged exposure, whereas the photosynthetic electron transport rate (ETR) was significantly reduced. PFOS significantly reduced ATP levels and ETR, while Fv/Fm remained unchanged and non-photochemical quenching (NPQ) was elevated. Isolated chloroplast assays revealed that PFOS inhibits Mg²⁺-dependent ATP hydrolytic activity in the chloroplast-enriched fraction and impairs thylakoid electron transport, consistent with impaired chloroplast ATP synthase function, though the specific molecular target and mechanism remain to be conclusively demonstrated. Transcriptomic and proteomic analyses revealed compensatory upregulation of photosynthesis pathways but suppression of ATP synthesis and redox homeostasis. Collectively, our results suggest that PFOS impairs chloroplast ATP synthase function, accompanied by reduced ETR and elevated NPQ. Together with the eyespot-associated phototaxis impairment, these effects suggest that PFOS may dually disrupt light acquisition (behavioral) and light conversion (physiological) in E. gracilis. This dual impairment may compromise the ecological fitness of Euglena in PFOS-contaminated environments, especially under prolonged exposure. It should be noted that the subcellular fluorine mapping is qualitative, the phototaxis assay reflects population-level responses, and the ATP synthase impairment interpretation is indirect; the proposed mechanistic model remains a hypothesis requiring further direct experimental validation. Full article

(This article belongs to the Special Issue Toxic Effects of Emerging Pollutants on Aquatic Organisms and Humans)

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21 pages, 2244 KB

Open AccessArticle

Heavy Metal(loid) Pollution Characteristics and Risk Assessment in the Water–Soil–Vegetable System of a Watershed in Southwest China

by Mengying Li, Jinjie Zhao, Wenjing Shen, Duanyang Yuan, Chengchen Wang and Ping Xiang

Toxics 2026, 14(6), 539; https://doi.org/10.3390/toxics14060539 - 22 Jun 2026

Viewed by 701

Abstract

Heavy metal(loid) pollution in watersheds surrounding mining areas originates from multiple and complex sources, posing persistent threats to terrestrial–aquatic ecosystems and human dietary safety. This study systematically investigated the pollution characteristics, spatial distribution, ecological risks and human health hazards of seven typical heavy [...] Read more.

Heavy metal(loid) pollution in watersheds surrounding mining areas originates from multiple and complex sources, posing persistent threats to terrestrial–aquatic ecosystems and human dietary safety. This study systematically investigated the pollution characteristics, spatial distribution, ecological risks and human health hazards of seven typical heavy metal(loid)s (As, Pb, Cr, Cd, Cu, Zn, and Ni) in the integrated water–soil–vegetable continuum of a mining-affected watershed in Southwest China. Field sampling was carried out in three functional zones with different mining disturbance intensities, and inductively coupled plasma mass spectrometry (ICP-MS) was used to detect heavy metal(loid) concentrations in all samples. Multiple pollution evaluation indices and the USEPA human health risk assessment model were adopted for comprehensive quantitative analysis. The results showed that 44.0% of surface water samples exceeded national permissible limits, with high-pollution areas concentrated in intensive mining zones, presenting moderate overall aquatic heavy metal(loid) pollution. Although the average concentrations of seven heavy metal(loid)s in riparian soils complied with Chinese agricultural soil screening standards, localized significant enrichment was observed for As (1.98 times), Cd (4.62 times), Cu (1.81 times), and Zn (2.72 times) compared with regional background values, causing mild comprehensive soil pollution. Farmland soils exhibited prominent Cu and Zn accumulation, and leafy vegetables in the study area suffered severe Pb and Cd pollution, with potential dietary exposure risks. Health risk assessment indicated that children face higher non-carcinogenic and carcinogenic risks than adults via soil hand-to-mouth exposure; dietary intake of vegetables leads to moderate carcinogenic risks for children caused by As and Ni exposure. Overall, this study clarifies the migration and enrichment rules of heavy metal(loid)s in the water–soil–vegetable system of mining watersheds, confirms the prominent ecological and human health risks of Cd, As and Pb in the study area, and provides targeted basic data for regional heavy metal(loid) pollution prevention and food safety management. Full article

(This article belongs to the Special Issue Soil Heavy Metal Pollution and Human Health)

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14 pages, 653 KB

Open AccessArticle

Sludge Retention Time Governs Ectoine Synthesis and Pollutant Removal in Halophilic Activated Sludge Treating High-Salinity Wastewater

by Min Ren, Sifan Liu, Huining Zhang, Kefeng Zhang, Baolan Hu, Chenhao Zhang, Bixiao Ji, Yan Li and Jianqing Ma

Toxics 2026, 14(6), 538; https://doi.org/10.3390/toxics14060538 - 22 Jun 2026

Viewed by 471

Abstract

In the treatment of high-salinity wastewater, the removal of nitrogen and organic pollutants remains a challenge, while the production of value-added compounds, such as ectoine from halophilic bacteria, offers a promising resource recovery pathway. In this study, halophilic activated sludge enriched with Thauera [...] Read more.

In the treatment of high-salinity wastewater, the removal of nitrogen and organic pollutants remains a challenge, while the production of value-added compounds, such as ectoine from halophilic bacteria, offers a promising resource recovery pathway. In this study, halophilic activated sludge enriched with Thauera as the dominant strain was cultivated in a sequencing batch reactor (SBR) to treat synthetic high-salinity wastewater (30 g/L NaCl) under different sludge retention times (SRTs). The optimal nitrogen and organic carbon removal performances were achieved at an SRT of 10 days, with an ammonia nitrogen removal rate of 77.67% and a total organic carbon (TOC) removal rate of 72.51%. Ectoine production was strongly SRT dependent, as volumetric ectoine concentration was ~2 mg/L at 5 d SRT, almost undetectable at 10 d SRT, ~10 mg/L at 16 d SRT, and peaked at 21.5 mg/L at 22 d SRT. Short SRTs favored dynamic ectoine utilization for osmoprotection and metabolic stability, whereas long SRTs led to passive ectoine accumulation and deteriorated treatment performance. The system realized stable short-cut heterotrophic nitrification with negligible nitrite and nitrate accumulation, indicating direct conversion of ammonia to gaseous nitrogen. These results demonstrate that SRT regulation effectively balances ectoine synthesis and pollutant removal, providing a feasible strategy for resource-oriented treatment of high salinity wastewater. Full article

(This article belongs to the Special Issue Bioremediation Technologies for Aquaculture Pollutants)

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19 pages, 17110 KB

Open AccessArticle

Interpretable Machine Learning and Spatiotemporal Modeling of Meteorological and Environmental Drivers for Tuberculosis Incidence in China

by Zihao Wang, Siyuan Li, Xiaotong Jiang, Kang Hu and Yangzhou Wu

Toxics 2026, 14(6), 537; https://doi.org/10.3390/toxics14060537 - 21 Jun 2026

Viewed by 592

Abstract

Tuberculosis (TB) remains a major public health burden in China. Although meteorological and environmental factors are recognized to influence TB transmission, their non-linear effects and spatiotemporal heterogeneity have not been fully elucidated. Based on monthly TB incidence data from 31 provinces in China [...] Read more.

Tuberculosis (TB) remains a major public health burden in China. Although meteorological and environmental factors are recognized to influence TB transmission, their non-linear effects and spatiotemporal heterogeneity have not been fully elucidated. Based on monthly TB incidence data from 31 provinces in China during 2005–2020, this study systematically investigated these effects by integrating nine meteorological and air pollution variables within a combined machine learning and spatial statistical modeling framework. The results indicated that the Extreme Gradient Boosting (XGBoost) model effectively captured the complex non-linear relationships between environmental exposure and TB incidence. SHAP interpretability analysis identified surface pressure (SP), vegetation coverage, and PM_2.5 as the key drivers and revealed pronounced nonlinear response patterns and threshold effects. In particular, the promoting effect of PM_2.5 on TB incidence increased sharply at medium-to-high concentration levels. To further investigate spatial and temporal non-stationarity, Geographically and Temporally Weighted Regression (GTWR) was applied. The results demonstrated strong spatiotemporal heterogeneity in driver effects across provinces. The influence of PM_2.5 showed a consistently positive association with TB incidence and exhibited a distinct temporal evolution characterized by an initial strengthening before 2015 followed by a weakening thereafter, closely aligning with China’s air pollution control process. These findings provide new insights into the nonlinear and spatiotemporally heterogeneous effects of meteorological and environmental factors on TB incidence and support the development of more targeted, region-specific TB prevention strategies. Full article

(This article belongs to the Special Issue Air Pollutants: Sources, Characteristics, Environmental Impacts and Human Health Risks)

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14 pages, 20386 KB

Open AccessArticle

A 3D Graphene Oxide Model Reveals Fine Particulate Matter Induced Cell Cycle Dysregulation in Neural Stem Cells

by Siqi Li, Huiyun Chang, Mengjie Gao, Wenlou Zhang, Furong Deng, Fengge Chen, Xiaoman Zhu, Yu Song, Hong Zhang, Shaojie Liu, Ying Mu, Hui Ma and Ying Zhang

Toxics 2026, 14(6), 536; https://doi.org/10.3390/toxics14060536 - 21 Jun 2026

Viewed by 483

Abstract

Fine particulate matter (PM_2.5) exposure increases the risk of neurodevelopmental abnormalities by disrupting neural stem cell (NSC) proliferation and cell cycle homeostasis, which are critical for normal neurodevelopment. This study investigated the impact of fine particulate matter (PM_2.5) on [...] Read more.

Fine particulate matter (PM_2.5) exposure increases the risk of neurodevelopmental abnormalities by disrupting neural stem cell (NSC) proliferation and cell cycle homeostasis, which are critical for normal neurodevelopment. This study investigated the impact of fine particulate matter (PM_2.5) on NSC proliferation and cell cycle using a three-dimensional (3D) graphene oxide (GO) scaffold that mimics the NSC microenvironment. PM_2.5 exposure led to concentration-dependent decreases in NSC viability and induced G0/G1 phase arrest via the marked downregulation of Cyclin D1-Cdk4 and Cyclin E-Cdk2, which critically impact G1/S transition. NSCs in 3D GO scaffolds maintained higher expression of key cell cycle regulators (Cyclin A, Cdk1/Cdk2, APC, and Cdc20) and superior cell viability when suffering PM_2.5 exposure, demonstrating the 3D culture environment was beneficial for NSC proliferation. We speculate that the 3D culture environment is more favorable and protective for cell proliferation. Therefore, these findings highlight the utility of the 3D GO scaffold for studying PM_2.5 effects on growing neural stem cells. This work provides a physiologically relevant in vitro platform that captures microenvironment-dependent neurotoxic responses, consequently offering valuable mechanistic insights into PM_2.5-induced developmental neurotoxicity. Full article

(This article belongs to the Section Neurotoxicity)

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20 pages, 8763 KB

Open AccessArticle

Storage-Dependent Changes in Microplastic-Associated Recoverable Residues in Yogurt Containing Bifidobacterium longum subsp. infantis

by Yasin Akkemik, Sedat Özcan, Veysel Doğan, Sedat Gökmen, Enis Fuat Tüfekci and Salih Erat

Toxics 2026, 14(6), 535; https://doi.org/10.3390/toxics14060535 - 20 Jun 2026

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Abstract

Microplastics (MPs) are increasingly detected in dairy products, raising food-safety concerns. Their behavior in complex food matrices and interactions with probiotic microorganisms remain poorly understood. This exploratory study evaluated storage-dependent changes in operationally defined, digestion-resistant recoverable residues in yogurt containing Bifidobacterium longum subsp. [...] Read more.

Microplastics (MPs) are increasingly detected in dairy products, raising food-safety concerns. Their behavior in complex food matrices and interactions with probiotic microorganisms remain poorly understood. This exploratory study evaluated storage-dependent changes in operationally defined, digestion-resistant recoverable residues in yogurt containing Bifidobacterium longum subsp. infantis (ATCC 15697). Yogurt samples were prepared with polypropylene (PP), polyethylene (PE), and polystyrene (PS), individually and in combination, and analyzed over 21 days of refrigerated storage. Gravimetric values served as relative, operational indicators of recoverable residues—not validated absolute polymer masses—while polymer identity was qualitatively confirmed by pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS). B. longum subsp. infantis remained viable throughout storage (6.3–8.2 log₁₀ CFU/g). All MP-containing groups showed consistent storage-associated decreases in recoverable residue fractions, greatest in PP, followed by PE and PS; probiotic-free controls remained stable. Polymer-specific Py-GC/MS signals were detectable at all time points. Because polymer identity was retained and the workflow was not validated for absolute recovery, findings are interpreted as storage-associated changes in extractability, filterability, and/or residue recovery—not as polymer degradation, mineralization, or biological removal. These in vitro observations are limited to the yogurt matrix and do not support extrapolation to livestock exposure, human dietary risk, or farm-to-fork transfer. Within these limits, the findings provide a preliminary, hypothesis-generating perspective on probiotic–microplastic interactions in fermented dairy products. Full article

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

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26 pages, 2943 KB

Open AccessArticle

Multi-Element Exposure in a High-Altitude Páramo Mining District and Oxidative Stress Biomarkers in Gold Miners

by Lyda Espitia-Pérez, Luz Helena Sánchez Rodríguez, Hugo Brango, Pedro Espitia-Pérez, Dina Ricardo-Caldera, Laura Andrea Rodríguez-Villamizar and Álvaro J. Idrovo

Toxics 2026, 14(6), 534; https://doi.org/10.3390/toxics14060534 - 20 Jun 2026

Viewed by 854

Abstract

Artisanal and small-scale gold mining (ASGM) generates complex metal mixtures, yet their biological effects remain poorly characterized in high-altitude populations, where occupational exposure occurs against a hypoxic environmental background. This study evaluated 49 occupationally exposed gold miners from the Vetas–California mining district, near [...] Read more.

Artisanal and small-scale gold mining (ASGM) generates complex metal mixtures, yet their biological effects remain poorly characterized in high-altitude populations, where occupational exposure occurs against a hypoxic environmental background. This study evaluated 49 occupationally exposed gold miners from the Vetas–California mining district, near the Santurbán páramo in Colombia, and 25 non-exposed individuals from a comparable high-altitude area. Hair concentrations of essential and toxic elements were quantified by ICP-MS, and serum catalase (CAT), superoxide dismutase (SOD), reduced glutathione (GSH), oxidized glutathione (GSSG), and the GSH/GSSG ratio were assessed. Miners showed a distinct multielement profile, with a higher toxic-metal burden and a dominant mixture mainly characterized by Fe, Mn, As, Pb, Cd, and Hg. CAT and SOD activities did not differ markedly between groups, although SOD activity decreased along the main exposure gradient among exposed workers. In contrast, glutathione-related biomarkers showed a more consistent exposure-related pattern, with higher GSSG and a lower GSH/GSSG ratio, suggesting a shift toward a more oxidized glutathione redox status. Together with positive within-group associations between selected elements and the GSH/GSSG ratio, these results are consistent with a mixture-associated perturbation of glutathione redox homeostasis, with heterogeneous adaptive responses. Overall, this study supports the use of integrated biomonitoring strategies and highlights glutathione-related markers as potential indicators of early redox perturbation in high-altitude mining populations. Full article

(This article belongs to the Special Issue Occupational Exposure to Heavy Metals in Environmentally Vulnerable Areas)

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29 pages, 4393 KB

Open AccessArticle

Time- and Temperature-Dependent Effects of PHBV on Physiological Responses in Brine Shrimp

by Natalia S. Buzzi, Anna Jáuregui, Anna Marín, Juan C. Navarro, Mar Llorca, Myriam Lizanda, María Constanza Díaz Andrade, Ana Carolina Moya, José Gámez-Pérez, Luis Cabedo and Inmaculada Varó

Toxics 2026, 14(6), 533; https://doi.org/10.3390/toxics14060533 - 20 Jun 2026

Viewed by 1989

Abstract

Aquatic organisms are exposed to multiple stressors, including microplastic pollution and rising temperatures. Bioplastics like Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) are considered sustainable alternatives to conventional plastics, although their biological effects remain poorly understood. This study evaluated the effects of PHBV microplastics on Artemia franciscana under [...] Read more.

Aquatic organisms are exposed to multiple stressors, including microplastic pollution and rising temperatures. Bioplastics like Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) are considered sustainable alternatives to conventional plastics, although their biological effects remain poorly understood. This study evaluated the effects of PHBV microplastics on Artemia franciscana under different temperature and exposure conditions. Organisms were exposed to 25 and 100 mg·L⁻¹ PHBV for 7, 14, and 21 days at 25 °C and for 14 days at 29 °C. Growth, development, antioxidant enzyme (CAT, GST) and esterase activities (ChE, CbE), lipid peroxidation (LPO), gut histology, fatty acid profiles and polymer particle length distributions were assessed. Growth and development increased with PHBV concentration, exposure time, and temperature. Enzymatic activities and LPO were significantly affected by these factors, although no evidence of oxidative damage was detected. Marked gut lesions were observed at 100 mg·L⁻¹ PHBV at 29 °C after 14 days. Fatty acid profiles were mainly influenced by time and temperature, while high PHBV levels were associated with additional, more subtle changes in long-chain polyunsaturated fatty acids. PHBV particle length distributions also varied depending on exposure conditions. These findings suggest that PHBV induces physiological responses distinct from those typically reported for conventional microplastics and highlight the importance of considering multiple stressors in ecotoxicological studies. Full article

(This article belongs to the Special Issue Hazardous Pollutants in Marine Ecosystems)

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16 pages, 3903 KB

Open AccessArticle

Spatial Distribution, Risk Assessment, and Source Apportionment of Heavy Metals in Soils from the Sorghum Cultivation Base in the Chishui River Basin, China

by Ziping Pan, Xiu Li, Yilu Yuan, Junchen Zhang, Yuting Jiang and Zengping Ning

Toxics 2026, 14(6), 532; https://doi.org/10.3390/toxics14060532 - 20 Jun 2026

Viewed by 562

Abstract

The Chishui River Basin, a core production area for Chinese sauce-aroma Baijiu (exemplified by Moutai), supports sorghum cultivation critical to the liquor’s distinctive quality. The soil environment quality within this region, therefore, directly impacts the safety and quality of both raw material and [...] Read more.

The Chishui River Basin, a core production area for Chinese sauce-aroma Baijiu (exemplified by Moutai), supports sorghum cultivation critical to the liquor’s distinctive quality. The soil environment quality within this region, therefore, directly impacts the safety and quality of both raw material and the final distilled spirit. To underpin the safe production and sustainable development of this iconic beverage, it is essential to assess soil heavy metal contamination in the soils and quantify the contributions from various sources. In this study, 172 surface soil samples were collected from typical sorghum planting bases in the Renhuai area. Concentrations of eight heavy metals (loids) (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) were determined. The contamination status was evaluated using the geostatistical inverse distance weighting interpolation, the Nemerow pollution index (P_N), and the potential ecological risk index (RI). Source identification and quantification were performed using the positive matrix factorization receptor model (PMF). Results revealed significant enrichment of Cd and Hg in the soil, with mean concentrations 2.07 times and 2.54 times the soil background values for Guizhou Province, respectively. Pollution index results (P_i, P_N) indicated that soil Cd contamination is relatively severe, whereas contamination from other elements is minimal. Overall, approximately 86.5% of the study area was classified as clean or only slightly polluted. Cd poses a moderate ecological risk and was the primary contributor to the total ecological hazard. Other elements exhibited lower risk, resulting in a slight overall potential ecological risk. The soil environmental quality in certified organic sorghum bases was generally favorable. PMF analysis identified three principal sources: historic industrial emissions and traffic-related sources (contributing 46%), weathering of carbonate rocks combined with agricultural activities (37%), and natural background coupled with organic fertilizer application (17%). In conclusion, while the overall soil heavy metal pollution level in the sorghum planting areas is low, the notable enrichment and higher ecological risk of Cd necessitate enhanced dynamic monitoring and targeted risk control measures to ensure long-term soil health and product safety. Full article

(This article belongs to the Special Issue The Toxicity of Heavy Metals and Chemical Pollutants in Agricultural Soil and Plants: Ecological Risks and Remediation)

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28 pages, 9131 KB

Open AccessArticle

Common and Unique Respiratory Health Risk Induced by Urban-Rural PM_2.5 in the Chengdu-Chongqing Economic Circle

by Xuan Li, Zhipeng Wang, Yuhan Feng, Mi Tian, Shike Shang, Yang Chen, Jingli Qian, Shumin Zhang and Yulan Yang

Toxics 2026, 14(6), 531; https://doi.org/10.3390/toxics14060531 - 20 Jun 2026

Viewed by 678

Abstract

Fine particulate matter with a diameter ≤2.5 μm (PM_2.5) pollution poses a global public health crisis, demonstrating significant threats to human health. This study focused on the strategically important Chengdu-Chongqing Economic Circle in western China, systematically comparing the toxic effects of [...] Read more.

Fine particulate matter with a diameter ≤2.5 μm (PM_2.5) pollution poses a global public health crisis, demonstrating significant threats to human health. This study focused on the strategically important Chengdu-Chongqing Economic Circle in western China, systematically comparing the toxic effects of urban and rural PM_2.5 across five levels. PMF and regression analysis were used to identify source contributions, dual-omics to pinpoint key molecules, and epidemiological data with a GAM model to assess health risks. Findings demonstrate that rural PM_2.5 possesses greater biotoxicity than its urban counterpart. Cytotoxicity in urban and rural PM_2.5 originated from road dust/vehicle emissions and biomass burning, respectively. Subsequently, integrated omics and molecular biology analyses identify kinesin family member 20A (KIF20A) as a shared key target, which mediates toxicity induced by both urban and rural PM_2.5. Finally, epidemiological analysis reveals that females and ≥65 years old exhibit relatively high sensitivity to urban PM_2.5 exposure trends, with rhinitis showing a comparatively higher impact among various related diseases. The novelty of this work lies in its pioneering application of a multi-tiered investigative approach. This approach spans “environmental samples-cellular mechanisms-population health” within the Chengdu-Chongqing economic circle context, systematically elucidating common and distinct respiratory health risk of urban and rural PM_2.5. This work offers a vital scientific foundation for advancing region-specific, precise air pollution prevention and control measures. Full article

(This article belongs to the Special Issue Atmospheric Emissions Characteristics and Its Impact on Human Health—2nd Edition)

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18 pages, 6194 KB

Open AccessEditor’s ChoiceArticle

Life Stage-Dependent Toxicity and Interactions of Scrubber-Related Metal Mixtures in Marine Zooplankton

by Esther Bautista-Chamizo, María Cabrera-Bayarri, Enrique Nebot and Javier Moreno-Andrés

Toxics 2026, 14(6), 530; https://doi.org/10.3390/toxics14060530 - 19 Jun 2026

Viewed by 863

Abstract

The adoption of exhaust gas cleaning systems (scrubbers) in maritime transport generates a complex metal-laden washwater that may pose a noteworthy threat to marine ecosystems. This study assessed the acute toxic effects (LC₅₀, 48 h) of four prevalent metals detected in [...] Read more.

The adoption of exhaust gas cleaning systems (scrubbers) in maritime transport generates a complex metal-laden washwater that may pose a noteworthy threat to marine ecosystems. This study assessed the acute toxic effects (LC₅₀, 48 h) of four prevalent metals detected in scrubber washwater—vanadium (V), iron (Fe), nickel (Ni), and zinc (Zn)—both individually and as a realistic mixture. For this purpose, multiple life stages of Artemia franciscana (nauplii, juveniles, and adults) and the rotifer Brachionus plicatilis have been tested under laboratory conditions. All metals induced concentration-dependent toxicity, but sensitivities varied through life stages and species tested. The sensitivity to contaminants generally decreased as the organism’s developmental stage progressed. Consequently, three different orders of toxicity can be detected. The order of metal toxicity (from highest to lowest toxicity, based on 48 h LC₅₀ values) was V > Fe > Ni > Zn for nauplii; V > Zn > Fe > Ni for juveniles and adults; and Fe > V > Zn > Ni for B. plicatilis. The Cumulative Toxic Unit (CTU) approach was utilized to compare the predicted additive effect with observed mixture toxicity. This analysis revealed a complex, life stage-dependent interaction; while antagonism dominated in nauplii (suggesting chemical mitigation), juveniles and adults of A. franciscana and the rotifer (B. plicatilis) exhibited significant synergism, amplifying the total toxicity beyond prediction. This study demonstrates that early life stages and small zooplankton are the most sensitive bioindicators of scrubber-related metal contamination, highlighting the potential ecological risk posed by metal-rich, acidic scrubber discharges that may enhance metal bioavailability and toxicity in marine environments. Full article

(This article belongs to the Section Ecotoxicology)

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29 pages, 7094 KB

Open AccessArticle

In Silico Prediction of Chronic Oral Reference Doses for PIANO Target Analytes

by Paul D. Rockswold, Gregory J. Joseph, Elaine A. Merrill, Christopher S. Waldron and James S. Smith, Jr.

Toxics 2026, 14(6), 529; https://doi.org/10.3390/toxics14060529 - 18 Jun 2026

Viewed by 1276

Abstract

Characterizing the human health risk posed by constituents in drinking water is often challenging due to a lack of published toxicity values. The PIANO (Paraffin, Isoparaffin, Aromatic, Naphthene, and Olefin) analytical method measures nearly 300 compounds in JP-5 jet fuel, 43 of which [...] Read more.

Characterizing the human health risk posed by constituents in drinking water is often challenging due to a lack of published toxicity values. The PIANO (Paraffin, Isoparaffin, Aromatic, Naphthene, and Olefin) analytical method measures nearly 300 compounds in JP-5 jet fuel, 43 of which have published oral reference doses (RfDs). The remaining compounds are typically assigned surrogate toxicity values. We predict RfDs for 290 PIANO compounds using Quantitative Structure–Activity Relationship (QSAR) models based on stepwise linear regression of 2-dimensional molecular descriptors (MDs) and published toxicity values. Five training groups, created by randomly selecting 80% of the non-PIANO compounds and 50% of the 43 PIANO compounds that have RfDs within a master dataset of 1113 compounds, were used to develop five QSAR models. We used the geometric means of four QSAR model results of sufficient quality to predict RfDs for compounds lacking toxicological information. For compounds with known RfDs, 884 (79%) were within 8-fold of published RfDs, well within the acknowledged uncertainty inherent in published RfDs. Our approach has applicability beyond PIANO compounds and represents a new alternative methodology (NAM) that may be used to reduce uncertainty in human health risk assessment and guide regulatory decisions. Full article

(This article belongs to the Special Issue Human Exposure and Computational Modeling of Persistent Organic Pollutants (POPs))

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21 pages, 404 KB

Open AccessEditor’s ChoiceReview

Human Exposure Pathways to Per- and Polyfluoroalkyl Substances (PFASs)—A Comprehensive Review of Sources, Physicochemical Properties, and Human Health Risk Assessment

by Andrzej R. Reindl and Jakub A. Zduńczuk

Toxics 2026, 14(6), 528; https://doi.org/10.3390/toxics14060528 - 18 Jun 2026

Viewed by 2245

Abstract

Per- and polyfluoroalkyl substances (PFASs) present a critical challenge to global public health and environmental integrity due to the exceptional stability of the carbon–fluorine (C–F) bond. This review synthesizes current knowledge on PFAS physicochemical properties, exposure pathways, and toxicological outcomes, while evaluating global [...] Read more.

Per- and polyfluoroalkyl substances (PFASs) present a critical challenge to global public health and environmental integrity due to the exceptional stability of the carbon–fluorine (C–F) bond. This review synthesizes current knowledge on PFAS physicochemical properties, exposure pathways, and toxicological outcomes, while evaluating global regulatory efficacy. A central problem addressed in this review is the widening discrepancy between rigid, yet deeply fragmented, international regulatory frameworks and the increasingly complex, non-linear epidemiological data regarding PFAS health risks. While historical paradigms focused heavily on direct carcinogenicity, recent high-resolution data reveal significant heterogeneity and methodological inconsistencies in cancer links. Instead, robust evidence points to severe systemic toxicities—including hepatotoxicity, immunotoxicity, and maternal–fetal disruptions—frequently driven by mixture co-exposures and sex-specific metabolic dimorphisms. Furthermore, the industrial transition to short-chain substitutes has inadvertently compounded the crisis due to their high environmental mobility and resistance to conventional water treatment. By critically evaluating these toxicological and regulatory contradictions, this review demonstrates that current substance-by-substance legislative models fail to mitigate real-world pollution trends. Ultimately, we emphasize the urgent need to transition to holistic mixture modeling, implement unified class-based global regulations, and accelerate advanced destructive remediation technologies to mineralize the resilient C–F bond. Full article

(This article belongs to the Section Emerging Contaminants)

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18 pages, 29937 KB

Open AccessArticle

Spectral Characteristics of Dissolved Organic Matter and Their Associations with Heavy Metal Distribution in Multi-Media of a Typical Frozen Eutrophic Lake

by Zhijian Lv, Xuezheng Yu, Weiying Feng, Yu Qiao, Chia Min Ho, Jiayue Gao, Fanhao Song, Wenhuan Yang and Sundaravelpandian Kalaipandian

Toxics 2026, 14(6), 527; https://doi.org/10.3390/toxics14060527 - 18 Jun 2026

Viewed by 647

Abstract

In cold arid regions, the relationships between dissolved organic matter (DOM) characteristics and heavy metal distributions across ice, water, and sediment interfaces remain insufficiently resolved. This study characterized DOM spectral features and examined their associations with measured metal distributions in a typical frozen [...] Read more.

In cold arid regions, the relationships between dissolved organic matter (DOM) characteristics and heavy metal distributions across ice, water, and sediment interfaces remain insufficiently resolved. This study characterized DOM spectral features and examined their associations with measured metal distributions in a typical frozen eutrophic lake using excitation–emission matrices coupled with parallel factor analysis (EEMs-PARAFAC), ultraviolet-visible absorption spectroscopy (UV-Vis), and Fourier-transform infrared spectroscopy (FTIR). Protein-like substances dominated ice DOM, whereas water and sediment-derived DOM contained more humified fluorescent components. Fluorescence indices confirmed a primarily biological origin across all media, with ice showing the highest autochthonous microbial contribution (BIX = 1.23) but the lowest humification (HIX = 0.26), suggesting a greater contribution of recently produced protein-like fluorescent DOM in the ice samples. Water DOM showed the highest average HIX (1.88), followed by sediment-derived DOM (0.61) and ice DOM (0.26). The measured hydrochemical conditions, including weak alkalinity, elevated total dissolved solids (TDS), and locally low dissolved oxygen, provide environmental context for differences in metal distributions. Exploratory Spearman analysis at 17 matched water stations identified the strongest DOM–metal associations for HIX-As (rho = 0.474, p = 0.054) and FI-Zn (rho = 0.471, p = 0.056), indicating that DOM optical properties provide testable indicators of metal-distribution patterns but should be combined with direct binding and speciation measurements for mechanistic confirmation. Because ice was collected in January 2021, whereas water and sediment were collected in October 2020, cross-medium differences are interpreted as between-campaign associations rather than synchronous partitioning. These findings provide a basis for targeted winter monitoring and future binding, speciation, and freeze-concentration experiments in shallow eutrophic lakes. Full article

(This article belongs to the Section Ecotoxicology)

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4 pages, 148 KB

Open AccessEditorial

Assessment and Remediation of Heavy Metal Contamination in Soil

by Yangyang Wang

Toxics 2026, 14(6), 526; https://doi.org/10.3390/toxics14060526 - 17 Jun 2026

Viewed by 677

Abstract

Anthropogenic activities, including industrial production, mineral exploitation, metal smelting, agricultural fertilizer and pesticide application, as well as livestock and poultry breeding, have released large amounts of heavy metals into the environment [...] Full article

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

19 pages, 9555 KB

Open AccessArticle

Unraveling the Origins and Drivers of Potentially Toxic Elements (PTEs): A Sequential Framework Integrating Receptor Model and Machine Learning

by Jingyun Wang, Xiaofeng Zhao, Jiufen Liu, Yunxian Yan, Wei Zhao, Chuanbo Xia, Jianye Zheng and Jiwei Liu

Toxics 2026, 14(6), 525; https://doi.org/10.3390/toxics14060525 - 17 Jun 2026

Viewed by 651

Abstract

Source apportionment and the elucidation of driving mechanisms are essential for targeted soil pollution management. This study investigated surface soils across six towns in southern Shimen County, northwestern Hunan Province, where 662 samples were collected to determine the concentrations of As, Cd, Cr, [...] Read more.

Source apportionment and the elucidation of driving mechanisms are essential for targeted soil pollution management. This study investigated surface soils across six towns in southern Shimen County, northwestern Hunan Province, where 662 samples were collected to determine the concentrations of As, Cd, Cr, Cu, Ni, Pb, and Zn. Multivariate statistics and the APCS-MLR receptor model were integrated to quantify pollution sources, while three machine learning models (RF, XGBoost, and LightGBM) were applied to identify key drivers of the spatial enrichment of Cd. Results showed that Cd was significantly enriched, with a mean concentration of 0.43 mg/kg (3.41 times the provincial background value). The mean concentrations of As, Cr, Cu, Ni, Pb and Zn were 11.97 mg/kg, 81.01 mg/kg, 24.15 mg/kg, 49.25 mg/kg, 29.56 mg/kg and 76.77 mg/kg, respectively, and these PTEs remained at normal background levels. Significant inter-element correlations indicated common sources. Three primary sources were quantified—natural parent material (43.83%), mining activities (30.99%), and mixed sources of coal mining and agricultural inputs (7.84%), with 17.34% attributed to unidentified mixed sources. Natural sources dominated the geogenic enrichment of Cd, Cu, Ni, Pb, and Zn; mining activities governed the accumulation of As, Cr, Cu, and Pb; a mixed source of coal mining and agricultural practices contributed substantially to Cd enrichment. Machine learning identified PM10, topography, strata, and soil type as dominant drivers, with their total feature importance reaching 70.05%. Among these factors, natural factors and anthropogenic factors accounted for 44.23% and 55.77% of the total feature importance, in turn revealing coupled natural–anthropogenic controls. This study establishes an integrated framework linking source apportionment and driver identification, providing scientific insights for potentially toxic elements (PTEs) control in analogous mining–agricultural regions. Full article

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

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13 pages, 1326 KB

Open AccessArticle

Occurrence, Bioaccumulation and Dietary Exposure Assessment of Legacy and Emerging Per- and Polyfluoroalkyl Substances (PFAS) in Freshwater Fish from Zhejiang Markets: Implications for Human Health Risks

by Hexiang Zhang, Yibin Zheng, Xiaojuan Qi, Lili Chen, Jiang Chen, Jikai Wang, Yue He and Bing Zhu

Toxics 2026, 14(6), 524; https://doi.org/10.3390/toxics14060524 - 17 Jun 2026

Viewed by 756

Abstract

This article assesses per- and polyfluoroalkyl substances (PFAS) exposure levels, distribution, bioaccumulation characteristics, and health risks in freshwater fish from Zhejiang Province, China. A total of 240 market-sourced fish samples (covering carnivorous, omnivorous, and herbivorous species) collected between 2022 and 2024 were analyzed [...] Read more.

This article assesses per- and polyfluoroalkyl substances (PFAS) exposure levels, distribution, bioaccumulation characteristics, and health risks in freshwater fish from Zhejiang Province, China. A total of 240 market-sourced fish samples (covering carnivorous, omnivorous, and herbivorous species) collected between 2022 and 2024 were analyzed for 24 PFAS congeners, including four emerging alternatives. The results revealed widespread PFAS contamination, with a detection frequency of 77.5% and median total PFAS (Σ₂₄PFAS) concentration of 2.95 ng/g. Hexafluoropropylene oxide dimer acid (HFPO-DA), perfluorooctane sulfonate (PFOS), and perfluoroundecanoic acid (PFUnDA) were the most frequently detected congeners. PFOS exhibited the highest median concentrations in carnivorous and omnivorous fish, whereas PFUnDA was the dominant contaminant in filter-feeding and herbivorous fish. No significant difference in Σ₂₄PFAS concentrations was observed among fish with different feeding habits, but highly significant spatial variation was found. Long-chain PFAS concentrations were significantly higher than those of short-chain PFAS and emerging alternatives, with their proportion decreasing at lower trophic levels. The estimated daily intake of Σ₂₄PFAS and Σ₄PFAS for freshwater fish consumers averaged 0.14 and 0.042 ng/kg bw/day, respectively, with approximately 0.16% of the assessed individuals exceeding the recommended threshold. This study provides critical data to support food safety management and risk mitigation strategies. Full article

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

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18 pages, 1118 KB

Open AccessArticle

In Vitro Genotoxicity Assessment of Commercially Available Graphene Quantum Dots in Human Peripheral Blood Cells and Salivary Leukocytes

by Tamara Ćetković Pećar, Irma Durmišević, Mirta Milić, Anja Haverić, Maida Hadžić Omanović, Sanjin Gutić, Bojana Žegura and Sanin Haverić

Toxics 2026, 14(6), 523; https://doi.org/10.3390/toxics14060523 - 15 Jun 2026

Viewed by 904

Abstract

Commercially available graphene quantum dots (GQDs) are promising nanomaterials for applications in research and preclinical diagnostics, drug delivery, and bioimaging. Their bioactivity is highly dependent on dose, route of exposure, duration, cell type, uptake mechanisms, tissue and cellular distribution, and physicochemical properties. This [...] Read more.

Commercially available graphene quantum dots (GQDs) are promising nanomaterials for applications in research and preclinical diagnostics, drug delivery, and bioimaging. Their bioactivity is highly dependent on dose, route of exposure, duration, cell type, uptake mechanisms, tissue and cellular distribution, and physicochemical properties. This study aimed to evaluate genotoxic, cytotoxic, and cytostatic endpoints of blue- (B-GQDs) and green-emitting (G-GQDs) GQDs in human blood and salivary leukocytes. GQDs were tested at concentrations ranging from 2.5 to 100 µg/mL using distinct treatment periods. Fourier transform infrared spectroscopy (FTIR), trypan blue exclusion, comet, and cytokinesis-block micronucleus cytome (CBMN cyt) assays were performed. FTIR analysis revealed that G-GQDs, unlike B-GQDs, exhibit an absorption band typically associated with amine functional groups, which may contribute to their pronounced genotoxic effects. Peripheral blood mononuclear cells and salivary leukocytes showed higher sensitivity to G-GQDs compared to whole blood samples. Although no cytotoxic effects were observed, both GQDs induced significant DNA damage, with G-GQDs demonstrating greater genotoxic potential. These findings demonstrate that GQDs can induce DNA damage in the absence of detectable cytotoxic effects under the conditions tested, highlighting the importance of considering both physicochemical properties and cellular models in the safety assessment of nanomaterials. Full article

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

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35 pages, 10116 KB

Open AccessReview

Microplastic Contamination in Amphibians and Reptiles: An Ecotoxicological Synthesis of Exposure, Mechanisms, and Risk Implications

by Ahmet Ali Berber, Cansu Akbulut, Şefika Nur Demir and Muammer Kurnaz

Toxics 2026, 14(6), 522; https://doi.org/10.3390/toxics14060522 - 15 Jun 2026

Cited by 2 | Viewed by 1173

Abstract

Microplastic (MP) contamination has become a defining feature of twenty-first century environmental change, yet the toxicological and ecological consequences for amphibians and reptiles—two vertebrate classes already facing severe extinction pressures—remain fragmented across taxa, regions, and methodological traditions. Here, we synthesize field and experimental [...] Read more.

Microplastic (MP) contamination has become a defining feature of twenty-first century environmental change, yet the toxicological and ecological consequences for amphibians and reptiles—two vertebrate classes already facing severe extinction pressures—remain fragmented across taxa, regions, and methodological traditions. Here, we synthesize field and experimental evidence from five continents to provide a taxonomically balanced, mechanistically grounded, and geographically explicit assessment of MP exposure, bioaccumulation, and toxicity in herpetofauna, drawing on a structured literature search in Web of Science, Scopus, and PubMed (January 2015—March 2026). Field detection rates of MPs in amphibian larvae range from 26% in conservatively screened Central European populations to 73–80% in anuran tadpoles from high-anthropogenic-pressure Anatolian catchments, with fibrous polyethylene terephthalate (PET), polyethylene (PE), and polypropylene (PP) particles dominating the detected burden. Mechanistic evidence converges on oxidative stress cascades, hypothalamic–pituitary–thyroid axis disruption, gut and cutaneous microbiome dysbiosis, and compromised antiviral and antifungal immunity, with the latter potentially amplifying vulnerability to Batrachochytrium dendrobatidis and to ranavirus. Among reptiles, sea turtles display near-universal MP ingestion with documented maternal transfer to eggs; freshwater turtles, terrestrial squamates, and crocodilians remain critically understudied. Three structural asymmetries constrain current ecotoxicological risk characterization: taxonomic bias toward anurans and sea turtles, geographic bias toward the Global North, and experimental bias toward acute, supra-environmental laboratory exposures using pristine, single-polymer particles that fail to capture the chemical complexity of weathered field mixtures. We argue that MP burden may warrant consideration as a candidate stressor criterion within IUCN Red List assessments and within environmental risk assessment frameworks for freshwater and terrestrial biodiversity once a robust quantitative relationship between MP burden and demographic decline or population-level fitness has been established, and propose six hypothesis-driven research priorities: methodological standardization, reptile toxicokinetics, transgenerational epigenetics, MP–pathogen microbiome interactions and their translation into population viability models, temperature × MP interaction under climate warming, and population-genetic consequences of contemporary MP-driven selection, as the most tractable avenues for ecotoxicological progress and for the development of herpetofauna-specific risk characterization frameworks. Full article

(This article belongs to the Topic Microplastics Across Ecosystems: Multidisciplinary Approaches to Sources, Sinks and Health Sustainable Solutions)

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21 pages, 8690 KB

Open AccessArticle

Occurrence, Ecological Risk, and Human Exposure of Rubber Additives and Transformation Products in Surface Waters of Kaifeng, China

by Xing Chen, Chenyang Sun, Lingnan Du, Xinding Yao, Haifeng Wang, Zongwu Wang, Jiapu Ji and Jinting Huang

Toxics 2026, 14(6), 521; https://doi.org/10.3390/toxics14060521 - 15 Jun 2026

Viewed by 680

Abstract

This study investigated rubber additives and relevant transformation products (RARTPs) in surface waters of Kaifeng, a city linking the Yellow River and Huaihe River basins. Seven of fifteen target analytes were detected in >10% of samples. The hydrolysis product 4-hydroxydiphenylamine (4OH) showed the [...] Read more.

This study investigated rubber additives and relevant transformation products (RARTPs) in surface waters of Kaifeng, a city linking the Yellow River and Huaihe River basins. Seven of fifteen target analytes were detected in >10% of samples. The hydrolysis product 4-hydroxydiphenylamine (4OH) showed the highest detection frequency (70%), followed by 1,2-Dihydro-2,2,4-trimethylquinoline (TMQ, 57%) and N-(1,3-Dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD, 27%). TMQ had the highest average concentration (6.16 ± 4.17 ng·L⁻¹). Urban rivers (14.20 ± 4.72 ng·L⁻¹) were contamination hotspots, driven by management practices (e.g., dredging of urban lakes). Although detected at lower levels (0.09 ± 0.21 ng·L⁻¹), 6PPD-quinone (6PPD-Q) was associated with elevated risk (risk quotient, RQ ≥ 1) at 19% of sites. The chronic daily intake assessment showed that drinking water ingestion contributed 66.7% of total exposure in daily use, whereas dermal absorption dominated during swimming. Children, especially girls, were the most vulnerable subgroup. Although estimated chronic daily intakes (CDIs) from surface water accounted for only a negligible proportion of the daily urinary excretion of p-phenylenediamine antioxidants (PPDs) reported in a Chinese population, the ecological risk of 6PPD-Q warrants continued attention. These findings highlight the need for improved management of water bodies receiving urban runoff and aquaculture inputs, and further health risk assessment of RARTPs. 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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30 pages, 3165 KB

Open AccessArticle

Assessing the Water Quality of a Stream and Its Relationship with Climate Change Using Water Quality Index and Multivariate Statistical Methods

by Aslıhan Katip and Elif Demiralp

Toxics 2026, 14(6), 520; https://doi.org/10.3390/toxics14060520 - 15 Jun 2026

Viewed by 947

Abstract

Industrial and domestic wastewaters, nonpoint pollution sources, and climate change affect stream ecosystems, water quantity, and quality. Within the scope of this study, the water quality of Nilüfer Stream was evaluated using the Water Quality Index (WQI), One-Way ANOVA, the Kruskal–Wallis Test, and [...] Read more.

Industrial and domestic wastewaters, nonpoint pollution sources, and climate change affect stream ecosystems, water quantity, and quality. Within the scope of this study, the water quality of Nilüfer Stream was evaluated using the Water Quality Index (WQI), One-Way ANOVA, the Kruskal–Wallis Test, and Principal Component Analysis (PCA). In the study, 4686 water quality data from seven sampling stations between 2008 and 2024 were used. WQI results showed a distinct decrease in water quality from the upstream to the downstream of the Stream. Average WQI values for the stations were found to be between 140.83 and 487.83. The lowest WQI value was found at Station 1 and the highest WQI value was found at Station 7. According to WQI, the ranking of the stations by magnitude was St7 > St4 > St5 > St6 > St2 > St3 > St1. A statistically significant difference was observed between the stations in terms of WQI, ANOVA, and Kruskal–Wallis Test (p < 0.05), and water quality was found to be seasonally diverse. Generally, at stations (except for two stations), the seasonal WQI values ranked by magnitude were autumn > summer > winter > spring. The PCA showed that relationships among parameters originating from industrial wastewater associated with the textile, automotive, and metal industries were stronger (component loadings > 0.75), whereas the groups identified in the upstream basin indicated domestic pollution and agricultural pollution from fertilizers and pesticides. PCA conducted between meteorological parameters and the WQI values of the stations showed that climate change could be effective at only two stations. It was determined that the region located before the wastewater treatment plant (St4) was associated with precipitation, humidity, and evaporation, while the downstream region (St7) was related to wind speed. It was observed that water quality was more influenced by industrial, urban, and agricultural pollution sources than by climate change. Full article

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20 pages, 3841 KB

Open AccessArticle

Material-Dependent Toxic Mechanisms of Different Types of Particulate Emerging Contaminants Toward Chlorella vulgaris

by Xiaona Li, Xiangjun Hou, Yu Kong, Ning Liu and Zhenyu Wang

Toxics 2026, 14(6), 519; https://doi.org/10.3390/toxics14060519 - 15 Jun 2026

Viewed by 759

Abstract

Particulate emerging contaminants (PECs) pose increasing ecological risks due to their widespread occurrence and complex environmental behaviors, yet their heterogeneous toxic mechanisms remain poorly understood, especially under environmentally relevant conditions and concentration gradients. Here, Chlorella vulgaris was used as a model organism to [...] Read more.

Particulate emerging contaminants (PECs) pose increasing ecological risks due to their widespread occurrence and complex environmental behaviors, yet their heterogeneous toxic mechanisms remain poorly understood, especially under environmentally relevant conditions and concentration gradients. Here, Chlorella vulgaris was used as a model organism to systematically compare the effects of polystyrene nanoparticles (PSNPs), silver nanoparticles (AgNPs), and titanium dioxide nanoparticles (TiO₂NPs) across environmentally relevant and elevated concentrations (100 μg/L and 10 mg/L). Distinct toxicity pathways were identified among PEC types. PSNPs primarily induced chronic interference via particle–cell interactions, heteroaggregation, sedimentation-driven shading, and extracellular polymeric substance (EPS) regulation, rather than ROS-dominated toxicity. In contrast, AgNPs exhibited transformation-driven toxicity, undergoing intracellular speciation into Ag₂S, AgCl, and Ag⁺, which triggered oxidative stress, membrane damage, and lipid peroxidation. TiO₂NPs showed relatively high bioavailability and persistent oxidative stress effects. These results demonstrate that PEC toxicity evolves with particle type and concentration. Importantly, oxidative stress alone is insufficient to capture PEC ecotoxicity, which also involves the long-term impacts on algal behavior, sedimentation dynamics, and energy metabolism. This study provides mechanistic insights into PEC-induced algal toxicity and supports the source-oriented management of particulate pollutants in aquatic environments, particularly in hotspot scenarios such as wastewater discharge and sediment resuspension. Full article

(This article belongs to the Special Issue Fate and Transport of Emerging Contaminants in Soil)

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18 pages, 1639 KB

Open AccessArticle

Analysis and Evaluation of Groundwater Pollution for Coastal Agricultural Waste Landfills

by Deyue Sun, Panshu Ma, Tong Qi, Wei Chen, Qingjia Meng, Ruizhi Liu and Wenwen Li

Toxics 2026, 14(6), 518; https://doi.org/10.3390/toxics14060518 - 12 Jun 2026

Viewed by 718

Abstract

With the rapid urbanization of China, environmental risks posed by informal landfills, particularly those dominated by agricultural waste, are an urgent yet understudied concern. This study systematically monitored groundwater quality surrounding five typical informal agricultural waste landfills in a coastal Chinese city. Eight [...] Read more.

With the rapid urbanization of China, environmental risks posed by informal landfills, particularly those dominated by agricultural waste, are an urgent yet understudied concern. This study systematically monitored groundwater quality surrounding five typical informal agricultural waste landfills in a coastal Chinese city. Eight major pollutants were analyzed using pollution index evaluation, the health risk model and multivariate statistical methods. The results indicate one landfill as a high-priority concern, exhibiting a combined multi-index pollution pattern with an exceedance rate of 87.5%, where NO₃⁻-N, F⁻, COD_Mn, and total hardness are the dominant indicators. Another landfill showed high background levels and anthropogenic impacts. Total non-carcinogenic risk of all landfills is below 1 (negligible). Children face approximately twice the health risk of adults. The exposure risk through drinking water ingestion is three orders of magnitude higher than that from dermal contact, with NO₃⁻-N contributing >90% of the total risk. Groundwater deterioration is primarily affected by geological conditions and seawater intrusion (52.31%), followed by agricultural activities and soil characteristics. Given these findings, priority attention should be directed to nitrogen-driven landfill and multi-index composite pollution landfill, with reinforced source tracing and control of NO₃⁻-N, alongside long-term monitoring for regional groundwater protection. Full article

(This article belongs to the Special Issue Environmental Fate, Toxicity, Risk Assessment and Remediation of Contaminants Associated with Mining and Industrial Activities)

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21 pages, 6926 KB

Open AccessArticle

Neonatal Exposure to Di(2-ethylhexyl) Phthalate Is Associated with Lung Injury in a Rat Model of Chronic Lung Disease of Prematurity

by Shahana Perveen, Li Lou, Sohini Alim, Abigail Akselrod, Chunfang Zhao, Namita Sen, Clifford S. Deutschman and Annemarie Stroustrup

Toxics 2026, 14(6), 517; https://doi.org/10.3390/toxics14060517 - 12 Jun 2026

Viewed by 1143

Abstract

Chronic lung disease of prematurity (CLD) is a common complication of preterm birth with a complex pathology. Recent epidemiologic studies have identified a link between neonatal exposure to di(2-ethylhexyl) phthalate (DEHP), frequently used in medical equipment, and the development of CLD. We hypothesize [...] Read more.

Chronic lung disease of prematurity (CLD) is a common complication of preterm birth with a complex pathology. Recent epidemiologic studies have identified a link between neonatal exposure to di(2-ethylhexyl) phthalate (DEHP), frequently used in medical equipment, and the development of CLD. We hypothesize that DEHP exposure in the early neonatal period contributes to lung injury in newborn rats. Newborn rat pups were raised in one of the following environments: room air (RA), RA + DEHP, hyperoxia (60% oxygen), and hyperoxia + DEHP. Ambient DEHP was inhaled at a dose of 25 mg/m³ for 6 h daily for 14 days. Lung tissue and blood samples were collected on the 14th day of life. Independent exposure to DEHP and hyperoxia resulted in thicker pulmonary septal walls, fewer alveoli, increased pulmonary polymorphonuclear leukocytes and myeloperoxidase (MPO) activity and decreased expression of CD31 on endothelial cells in lung tissue. Additionally, DEHP-exposed rats showed higher serum malondialdehyde (MDA) levels and reduced vascular endothelial growth factor (VEGF) mRNA and protein levels compared to controls. Our experiments demonstrate that inhaled DEHP, with or without hyperoxia, resulted in a similar pattern of morphological lung injury and inflammation characteristic of CLD, suggesting an association with CLD of prematurity. Full article

(This article belongs to the Special Issue Phthalates: Environmental Distribution, Human Exposure, and Health Risks)

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23 pages, 6016 KB

Open AccessEditor’s ChoiceArticle

Hybrid Biochar from Corn Stover and Sewage Sludge for VOCs Adsorption: A Sustainable Waste Utilization Approach

by Zhen Zhang, Ninglu Zhang, Xiaohui Pan, Bingchao Zhao, Jun Liu, Shujian Tian, Liyu Hao and Zihao Zhao

Toxics 2026, 14(6), 516; https://doi.org/10.3390/toxics14060516 - 12 Jun 2026

Viewed by 724

Abstract

Volatile organic compounds (VOCs) are major contributors to air pollution and pose significant risks to both environmental quality and human health. Biochar-based adsorption technology is an efficient and sustainable approach to VOCs removal. Herein, hybrid biochar was prepared from corn stover and municipal [...] Read more.

Volatile organic compounds (VOCs) are major contributors to air pollution and pose significant risks to both environmental quality and human health. Biochar-based adsorption technology is an efficient and sustainable approach to VOCs removal. Herein, hybrid biochar was prepared from corn stover and municipal sewage sludge using the water vapor activation method, and its physicochemical characteristics and adsorption mechanisms for typical volatile organic compounds commonly produced during biomass-derived energy generation—such as methylbenzene, isopentane, and ethylene—were systematically investigated. The results show that hybrid biochar significantly outperformed single-source biochar, with its ability to adsorb methylbenzene, isopentane, and ethylene exceeding that of pure sludge biochar by 112.21%, 74.53%, and 66.72%, respectively, and surpassing pure corn stover biochar by 74.25%, 62.98%, and 55.25%, respectively. Competitive adsorption analysis indicated that the interaction strength between VOC molecules and the steam-treated hybrid carbon material was associated with their boiling points; compounds with higher boiling points tended to exhibit stronger affinity. This work provides an integrated waste utilization and pollution control strategy for VOCs removal. Full article

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

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33 pages, 8274 KB

Open AccessEditor’s ChoiceReview

Implications of Endocrine-Disrupting Chemicals for Human Health and Effective Methods for Prevention and Reduction

by Codruța-Claudia Gherman-Lencu, Teodora-Gabriela Alexescu, Cristian Mureșanu, Cezara Andreea Gerdanovics, Mircea-Vasile Milaciu and Dana-Monica Iancu

Toxics 2026, 14(6), 515; https://doi.org/10.3390/toxics14060515 - 12 Jun 2026

Cited by 2 | Viewed by 2144

Abstract

Endocrine-disrupting chemicals (EDCs) are a heterogeneous group of exogenous compounds capable of interfering with hormonal homeostasis and endocrine-regulated physiological processes. Their widespread occurrence in food, water, air, consumer products and industrial materials has raised increasing concern regarding their contribution to chronic disease burden. [...] Read more.

Endocrine-disrupting chemicals (EDCs) are a heterogeneous group of exogenous compounds capable of interfering with hormonal homeostasis and endocrine-regulated physiological processes. Their widespread occurrence in food, water, air, consumer products and industrial materials has raised increasing concern regarding their contribution to chronic disease burden. This review synthesizes current evidence on the exposure characteristics, molecular mechanisms, health effects, and prevention strategies related to major EDC classes, including bisphenol A and phthalates, dioxins and polychlorinated biphenyls, per- and polyfluoroalkyl substances, pesticides, and brominated flame retardants. Evidence indicates that EDCs may act through receptor-mediated signaling, altered hormone synthesis and metabolism, oxidative stress, mitochondrial dysfunction, immune modulation, and epigenetic mechanisms, with effects that may vary according to dose, timing, sex, age, and developmental susceptibility. Reported health outcomes include metabolic and cardiovascular disorders, reproductive dysfunction, hormone-dependent cancers, thyroid disruption, immune dysregulation, and adverse developmental effects. Although complete avoidance is unrealistic, exposure reduction and risk mitigation can be achieved through coordinated individual, clinical, environmental, and regulatory interventions. A life-course approach is essential to limit the health burden associated with endocrine disruption. Full article

(This article belongs to the Special Issue Exposure and Effects of Endocrine Disrupting Chemicals)

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27 pages, 906 KB

Open AccessEditor’s ChoiceReview

Microplastics in Foods Intended for Health Purposes: From Dietary Supplements to Clinical Nutrition Products

by Kornelia Kadac-Czapska, Justyna Ośko, Katarzyna Jażdżewska and Małgorzata Grembecka

Toxics 2026, 14(6), 514; https://doi.org/10.3390/toxics14060514 - 12 Jun 2026

Viewed by 1359

Abstract

Microplastics (MPs) are pervasive contaminants that have been detected throughout the food chain. Their presence raises concerns in foods intended for health-related purposes, as these products are often consumed by vulnerable populations such as infants, older adults, and patients requiring clinical nutrition support. [...] Read more.

Microplastics (MPs) are pervasive contaminants that have been detected throughout the food chain. Their presence raises concerns in foods intended for health-related purposes, as these products are often consumed by vulnerable populations such as infants, older adults, and patients requiring clinical nutrition support. These groups may be more susceptible to contaminant exposure and may rely heavily on specialized foods. Therefore, understanding the occurrence and potential risks of MPs in such products is important. This review summarizes the current state of knowledge regarding the presence, sources, and health implications of plastic particles in several categories of health-oriented foods, including dietary supplements, medicinal herbs, plant-based beverages, honey, infant formulas, and clinical nutrition products, including enteral and parenteral formulations. Microplastics have been reported across these matrices. Fibers and fragments dominate, and common polymers include polyamide, polyethylene, polypropylene, and poly(ethylene terephthalate). These particles can originate from polluted water, soil, and air, as well as from production processes, packaging wear, and clinical delivery systems. Current evidence suggests that improving methodological consistency and expanding targeted toxicological research relevant to vulnerable populations will be crucial for strengthening risk assessment. Full article

(This article belongs to the Section Emerging Contaminants)

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21 pages, 4038 KB

Open AccessArticle

Combined Analysis of Network Toxicology and Metabolomics Uncovers the Potential Mechanisms Underlying Neodymium Oxide-Induced Pulmonary Fibrosis

by Kai Wu, Yi Zhang, Xi Chen, Yanhong Dong, Suhua Wang and Yanrong Gao

Toxics 2026, 14(6), 513; https://doi.org/10.3390/toxics14060513 - 12 Jun 2026

Viewed by 746

Abstract

Rare earth element-related occupational and environmental health risks have received increasing attention, but the molecular mechanisms underlying neodymium oxide (Nd₂O₃)-induced pulmonary fibrosis remain unclear. This study aimed to identify potential targets, metabolites, and pathways involved in fibrosis-related lung responses [...] Read more.

Rare earth element-related occupational and environmental health risks have received increasing attention, but the molecular mechanisms underlying neodymium oxide (Nd₂O₃)-induced pulmonary fibrosis remain unclear. This study aimed to identify potential targets, metabolites, and pathways involved in fibrosis-related lung responses after Nd₂O₃ exposure. An integrated network toxicology and metabolomics approach was combined with an in vivo mouse model of Nd₂O₃-induced pulmonary toxicity. Histopathological injury, collagen deposition, and fibrosis-related protein expression were evaluated by HE staining, Masson staining, and Western blotting, respectively. Candidate targets were identified from public databases, key pathways were analyzed through network construction, and selected genes were validated by RT-qPCR. Nd₂O₃ exposure caused evident lung injury, inflammatory cell infiltration, structural disruption, increased collagen deposition, and elevated fibrosis-related protein expression. A total of 162 overlapping targets related to Nd₂O₃ exposure and pulmonary fibrosis were identified. ESR1, PTGS2, HSP90AA1, and MMP9 emerged as key targets, while cAMP signaling, arachidonic acid metabolism, PI3K-Akt signaling, and efferocytosis-related processes were implicated. Metabolomics showed distinct separation between control and high-exposure groups, with differential metabolites mainly associated with lipid metabolism and inflammation. RT-qPCR further confirmed altered expression of key genes. These findings suggest that Nd₂O₃ may promote fibrosis-related lung responses through inflammatory signaling, lipid metabolic disturbance, and profibrotic pathway activation. Full article

(This article belongs to the Special Issue Integration of Animal Models and Omics Technologies for Exploring Toxicity Mechanisms)

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16 pages, 647 KB

Open AccessArticle

Occupational Exposure to Cooking-Generated Polycyclic Aromatic Hydrocarbons and Associated Oxidative Stress and DNA Damage Among Grill Restaurant Workers

by Sumed Yadoung, Peerapong Jeeno, Phannika Tongchai, Sakaewan Ounjaijean, Kongsak Boonyapranai, Saweang Kawichai, Hataichanok Chuljerm, Kanokwan Kulprachakarn, Anurak Wongta and Surat Hongsibsong

Toxics 2026, 14(6), 512; https://doi.org/10.3390/toxics14060512 - 12 Jun 2026

Viewed by 996

Abstract

Street-food grilling is a common occupation in Asia, yet the occupational health risks associated with cooking-generated polycyclic aromatic hydrocarbons (PAHs) exposure, occurring alongside plausible unmeasured co-exposures such as ambient heat and physical workload, remain under-researched. This study investigated the internal dose of PAH [...] Read more.

Street-food grilling is a common occupation in Asia, yet the occupational health risks associated with cooking-generated polycyclic aromatic hydrocarbons (PAHs) exposure, occurring alongside plausible unmeasured co-exposures such as ambient heat and physical workload, remain under-researched. This study investigated the internal dose of PAH exposure and its association with early biological effects and physiological strain among grill restaurant workers. A cross-sectional study was conducted involving grill workers and 20 age/BMI-matched controls. Urinary 1-hydroxypyrene (1-OHP) was utilized as the primary exposure biomarker. The study assessed early biological effects such as oxidative stress (8-OHdG, F₂-isoprostanes), lung epithelial integrity (CC16), and genotoxicity (BPDE-DNA adducts) via ELISA. Physiological parameters, including blood pressure and heart rate, were recorded to evaluate acute cardiovascular strain. Workers had significantly elevated urinary 1-OHP levels compared to controls (Hodges–Lehmann ratio = 3.66, 95% CI: 1.68–7.12, representing a 3.7-fold median increase), with exposure levels increasing proportionally to smoke proximity. Notably, workers demonstrated a significantly higher median resting heart rate (HL ratio = 1.13, 95% CI: 1.05–1.23; +12.9%) and systolic blood pressure (HL ratio = 1.09, 95% CI: 1.00–1.18; +8.9%) compared to their office-based peers. Although strong correlations were observed among biological effect biomarkers (r_s = 0.42–0.63), there were no significant differences between groups for 8-OHdG, CC16, or BPDE-DNA adducts, suggesting that cardiovascular parameters reflect acute short-term responses, while genomic damage markers may require higher cumulative exposure thresholds to become detectable. The study revealed that grill restaurant workers face substantial internal PAH exposure and significant cardiovascular strain, occurring alongside plausible unmeasured co-exposures including ambient heat and physical workload. The prevalence of chronic cough and elevated heart rate is a critical early warning sign for occupational health. Our findings indicate that current general ventilation is inadequate, highlighting an urgent need for localized engineering controls and comprehensive health surveillance, including cardiovascular monitoring in the service sector. Full article

(This article belongs to the Special Issue Environmental Exposure to Persistent Organic Pollutants: Determination and Implications for Food Safety and Public Health)

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Open AccessEditor’s ChoiceArticle

Validation of the Electrophilic Allergen Screening Assay for Detection of Key Event 1 of the Skin Sensitization Adverse Outcome Pathway

by Emily N. Reinke, Elijah J. Petersen, John D. Gordon, Rick Uhl, Valerie H. Adams, Diego Rua, Victor J. Johnson, Gary R. Burleson, Judy Strickland, Robert Gutierrez, Catherine S. Sprankle, Tripp LaPratt, David M. Lehmann, Dori R. Germolec and Nicole C. Kleinstreuer

Toxics 2026, 14(6), 511; https://doi.org/10.3390/toxics14060511 - 11 Jun 2026

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Abstract

The electrophilic allergen screening assay (EASA) uses small-molecule probes as surrogates for skin proteins to measure hapten protein carrier complex formation, Key Event (KE) 1 in the adverse outcome pathway for skin sensitization. Although multiple assays are accepted for this purpose, the EASA [...] Read more.

The electrophilic allergen screening assay (EASA) uses small-molecule probes as surrogates for skin proteins to measure hapten protein carrier complex formation, Key Event (KE) 1 in the adverse outcome pathway for skin sensitization. Although multiple assays are accepted for this purpose, the EASA has higher throughput and needs less specialized equipment than other commonly used KE1 assays. This validation study assessed transferability of the EASA to naïve laboratories and within- and between-laboratory reproducibility. The predictive capacity of the assay in relation to reference data both from the murine local lymph node assay (LLNA) and, where available, human predictive patch tests, was estimated. The validation study was conducted using performance standards developed for methods that are under evaluation for inclusion in relevant test guidelines. The within- and between-laboratory reproducibility were cumulatively 96% and 85%, respectively. These scores exceeded the performance standard thresholds of 80%. Compared to reference LLNA data, the cumulative EASA results from the four laboratories had an overall sensitivity of 87%, specificity of 76%, and accuracy of 83%. The consensus results among the four laboratories had an overall sensitivity of 85%, specificity of 80%, and accuracy of 83%. For human reference data, the cumulative EASA results had an overall sensitivity of 81%, specificity of 76%, and accuracy of 70%. The EASA predicted sensitizers very well, although it had a slightly higher rate of misclassifying some negative test chemicals as positive with a specificity below the performance standards criterion of 80%. Our findings support further exploring use of the EASA in defined approaches to identify potential skin sensitizers. Full article

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

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Toxics, Volume 14, Issue 6 (June 2026) – 88 articles

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