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Toxics, Volume 12, Issue 8 (August 2024) – 92 articles

Cover Story (view full-size image): Trace metal contamination in urban atmospheres has become a significant global concern. Two synanthropic bird species, the feral pigeon (Columba livia f. domestica) and the rook (Corvus frugilegus), can act as bioindicators for urban atmospheric trace metal pollution. Through high-resolution continuum source graphite furnace atomic absorption spectrometry, the concentrations of Ni, Pb, Cd, Co, Cr, and Cu were detected in the various organs, muscles, and bones of these two bird species. The order of the trace metal concentrations in the tissues of the two bird species was similar (Cu > Pb > Ni > Cd > Cr > Co), and element concentrations were higher in the rook samples. Pb concentrations in the PM10 fraction of atmospheric particles positively correlated with the Pb concentrations in rook kidney samples. View this paper
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25 pages, 2798 KiB  
Review
Unveiling the Mysteries of Contrast-Induced Acute Kidney Injury: New Horizons in Pathogenesis and Prevention
by Zhong Wang, Qiuhan Wang and Xuezhong Gong
Toxics 2024, 12(8), 620; https://doi.org/10.3390/toxics12080620 - 22 Aug 2024
Cited by 1 | Viewed by 2052
Abstract
The utilization of contrast media (CM) in clinical diagnostic imaging and interventional procedures has escalated, leading to a gradual increase in the incidence of contrast-induced acute kidney injury (CI-AKI). Presently, the scarcity of effective pharmacological treatments for CI-AKI poses significant challenges to clinical [...] Read more.
The utilization of contrast media (CM) in clinical diagnostic imaging and interventional procedures has escalated, leading to a gradual increase in the incidence of contrast-induced acute kidney injury (CI-AKI). Presently, the scarcity of effective pharmacological treatments for CI-AKI poses significant challenges to clinical management. Firstly, we explore the pathogenesis of CI-AKI in this review. Beyond renal medullary ischemia and hypoxia, oxidative stress, cellular apoptosis, and inflammation, emerging mechanisms such as ferroptosis, release of neutrophil extracellular traps (NETs), and nitrosative stress, which offer promising avenues for the management of CI-AKI, are identified. Secondly, a comprehensive strategy for the early prevention of CI-AKI is introduced. Investigating the risk factors associated with CI-AKI is essential for the timely identification of high-risk groups. Additionally, exploring early sensitive biomarkers is crucial for early diagnosis. A synergistic approach that combines these sensitive biomarkers, CI-AKI risk factors, and disease risk prediction models enhances both the accuracy and efficiency of early diagnostic processes. Finally, we explore recent pharmacological and non-pharmacological interventions for the management of Cl-AKI. Beyond the traditional focus on the antioxidant N-acetylcysteine (NAC), we look at active compounds from traditional Chinese medicine, including tetramethylpyrazine (TMP), salvianolic acid B (Sal B), as well as emerging preventive medications like N-acetylcysteine amide (NACA), alprostadil, and others, which all showed potential benefits in animal and clinical studies for CI-AKI prevention. Furthermore, innovative strategies such as calorie restriction (CR), enhanced external counterpulsation (EECP), and mesenchymal stem cell therapy are highlighted as providing fresh insights into Cl-AKI prevention and management. Full article
(This article belongs to the Special Issue Nephrotoxicity Induced by Drugs and Chemicals in the Environment)
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16 pages, 7015 KiB  
Article
Degradation Characteristics of Nicosulfuron in Water and Soil by MnO2 Nano-Immobilized Laccase
by Wanlei Yue, Xin Wang, Jiale Zhang, Jia Bao and Mengqin Yao
Toxics 2024, 12(8), 619; https://doi.org/10.3390/toxics12080619 - 21 Aug 2024
Viewed by 771
Abstract
As a typical sulfonylurea herbicide, nicosulfuron is mainly used to control grass weeds and some broadleaf weeds in corn fields. However, as the amount of use continues to increase, it accumulates in the environment and eventually becomes harmful to the ecosystem. In the [...] Read more.
As a typical sulfonylurea herbicide, nicosulfuron is mainly used to control grass weeds and some broadleaf weeds in corn fields. However, as the amount of use continues to increase, it accumulates in the environment and eventually becomes harmful to the ecosystem. In the present study, a new metallic nanomaterial, δ-MnO2, was prepared, which not only has a similar catalytic mechanism as laccase but also has a significant effect on pesticide degradation. Therefore, the bicatalytic property of MnO2 can be utilized to improve the remediation of nicosulfuron contamination. Firstly, MnO2 nanomaterials were prepared by controlling the hydrothermal reaction conditions, and immobilized laccase was prepared by the adsorption method. Next, we investigate the effects of different influencing factors on the effect of immobilized laccase, MnO2, and free laccase on the degradation of nicosulfuron in water and soil. In addition, we also analyze the metabolic pathway of nicosulfuron degradation in immobilized laccase and the bicatalytic mechanism of MnO2. The results demonstrated that the degradation rate of nicosulfuron in water by immobilized laccase was 88.7%, and the optimal conditions were 50 mg/L, 25 h, 50 °C, and pH 5. For nicosulfuron in soil, the optimal conditions for the degradation by immobilized laccase were found to be 151.1 mg/kg, 46 °C, and pH 5.9; under these conditions, a degradation rate of 90.1% was attained. The findings of this study provide a theoretical reference for the immobilized laccase treatment of sulfonylurea herbicide contamination in water and soil. Full article
(This article belongs to the Section Toxicity Reduction and Environmental Remediation)
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12 pages, 2042 KiB  
Article
Characterization of Neonicotinoid Metabolites by Cytochrome P450-Mediated Metabolism in Poultry
by Adisorn Dam-on, Collins Nimako, Sittinee Kulprasertsri, Yoshinori Ikenaka, Yared B. Yohannes, Shouta M. M. Nakayama, Mayumi Ishizuka, Saranya Poapolathep, Amnart Poapolathep and Kraisiri Khidkhan
Toxics 2024, 12(8), 618; https://doi.org/10.3390/toxics12080618 - 21 Aug 2024
Viewed by 1003
Abstract
Neonicotinoids, a neuro-effective class of insecticides, are heavily applied in agricultural activities worldwide. Poultry can be exposed to neonicotinoids by several routes, but the knowledge of neonicotinoid’s metabolism in poultry and its associated interspecies differences is highly limited. Hence, this study aims to [...] Read more.
Neonicotinoids, a neuro-effective class of insecticides, are heavily applied in agricultural activities worldwide. Poultry can be exposed to neonicotinoids by several routes, but the knowledge of neonicotinoid’s metabolism in poultry and its associated interspecies differences is highly limited. Hence, this study aims to investigate the species differences in metabolite formations, as well as cytochrome P450 (CYP)-dependent metabolism of four major neonicotinoid compounds, acetamiprid, imidacloprid, clothianidin, and thiamethoxam, in poultry. In vitro biotransformation assays using hepatic microsomes of chicken, ducks, geese, quails, and rats were conducted. Metabolites of neonicotinoids were then screened by LC/Q-TOF and quantified by LC/MS/MS. The results revealed an existence of interspecies differences in the formations of N-[(6-chloro-3-pyridyl) methyl] -N-methyl acetamidine (IM-1-5) of acetamiprid and dm-clothianidin of clothianidin between chicken and other species. In addition, the greatest CYP activities in the metabolism of most neonicotinoid substrates, such as acetamiprid to dm-acetamiprid, imidacloprid to hydroxylated-imidacloprid and imidacloprid-olefin, clothianidin to dm-clothianidin, and thiamethoxam to clothianidin, were found in chicken. These results suggested that the CYPs in chicken may have a greater capacity for metabolism of neonicotinoids compared to other poultry. This study further revealed that the maximum intrinsic clearance of dn-imidacloprid and dn-clothianidin in ducks may be superintended by CYP-mediated nitro-reductions of imidacloprid and clothianidin. Further studies employing CYP recombinant enzymes may be required to elucidate the specific CYP isoforms that may be involved in neonicotinoid metabolism in avian species. Full article
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16 pages, 4045 KiB  
Article
Impacts of Environmental Concentrations of Nanoplastics on Zebrafish Neurobehavior and Reproductive Toxicity
by Ziqing Sun, Baihui Wu, Jia Yi, Haiyang Yu, Jiaxuan He, Fei Teng, Tong Xi, Jinlong Zhao, Jing Ruan, Peiye Xu, Runchao Tao, Liushuo Jia and Hao Ji
Toxics 2024, 12(8), 617; https://doi.org/10.3390/toxics12080617 - 21 Aug 2024
Viewed by 1168
Abstract
Nanoplastics, as emerging environmental pollutants, can transport contaminants across marine environments, polluting pristine ecosystems and being ingested by marine organisms. This transfer poses a severe threat to global aquatic ecosystems and potentially impacts human health through the food chain. Neurobehavioral and reproductive toxicity [...] Read more.
Nanoplastics, as emerging environmental pollutants, can transport contaminants across marine environments, polluting pristine ecosystems and being ingested by marine organisms. This transfer poses a severe threat to global aquatic ecosystems and potentially impacts human health through the food chain. Neurobehavioral and reproductive toxicity are critical areas of concern because they directly affect the survival, health, and population dynamics of aquatic species, which can have cascading effects on the entire ecosystem. Using zebrafish as a model organism, we investigated the toxic effects of environmental concentrations of polystyrene nanoplastics (PS-NPs). Behavioral assessments, including the novel tank test and open field test, demonstrated significant neurobehavioral changes, indicating increased anxiety and depressive behaviors. A pathological analysis of brain and gonadal tissues, along with evaluations of neurobehavioral and reproductive toxicity biomarkers, revealed that exposure to PS-NPs leads to brain tissue lesions, inflammatory responses, oxidative stress activation, hormone level disruptions, and gonadal damage. Real-time quantitative PCR studies of reproductive gene expression further showed that PS-NPs disrupt the endocrine regulation pathways of the brain-pituitary-gonadal (BPG) axis, causing reproductive toxicity with sex-specific differences. These findings provide crucial insights into the impacts of nanoplastics on aquatic organisms and their ecological risks, offering theoretical support for future environmental protection and pollutant management efforts. Full article
(This article belongs to the Special Issue Reproductive and Neurobehavioral Effects of Microplastics on Fish)
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16 pages, 301 KiB  
Article
Limitations and Modifications of Skin Sensitization NAMs for Testing Inorganic Nanomaterials
by Britta Wareing, Ayse Aktalay Hippchen, Susanne N. Kolle, Barbara Birk, Dorothee Funk-Weyer and Robert Landsiedel
Toxics 2024, 12(8), 616; https://doi.org/10.3390/toxics12080616 - 21 Aug 2024
Viewed by 1114
Abstract
Since 2020, the REACh regulation requires toxicological data on nanoforms of materials, including the assessment of their skin-sensitizing properties. Small molecules’ skin sensitization potential can be assessed by new approach methodologies (NAMs) addressing three key events (KE: protein interaction, activation of dendritic cells, [...] Read more.
Since 2020, the REACh regulation requires toxicological data on nanoforms of materials, including the assessment of their skin-sensitizing properties. Small molecules’ skin sensitization potential can be assessed by new approach methodologies (NAMs) addressing three key events (KE: protein interaction, activation of dendritic cells, and activation of keratinocytes) combined in a defined approach (DA) described in the OECD guideline 497. In the present study, the applicability of three NAMs (DPRA, LuSens, and h-CLAT) to nine materials (eight inorganic nanomaterials (NM) consisting of CeO2, BaSO4, TiO2 or SiO2, and quartz) was evaluated. The NAMs were technically applicable to NM using a specific sample preparation (NANOGENOTOX dispersion protocol) and method modifications to reduce interaction of NM with the photometric and flowcytometric read-outs. The results of the three assays were combined according to the defined approach described in the OECD guideline No. 497; two of the inorganic NM were identified as skin sensitizers. However, data from animal studies (for ZnO, also human data) indicate no skin sensitization potential. The remaining seven test substances were assessed as “inconclusive” because all inorganic NM were outside the domain of the DPRA, and the achievable test concentrations were not sufficiently high according to the current test guidelines of all three NAMs. The use of these NAMs for (inorganic) NM and the relevance of the results in general are challenged in three ways: (i) NAMs need modification to be applicable to insoluble, inorganic matter; (ii) current test guidelines lack adequate concentration metrics and top concentrations achievable for NM; and (iii) NM may not cause skin sensitization by the same molecular and cellular key events as small organic molecules do; in fact, T-cell-mediated hypersensitivity may not be the most relevant reaction of the immune system to NM. We conclude that the NAMs adopted by OECD test guidelines are currently not a good fit for testing inorganic NM. Full article
(This article belongs to the Special Issue Skin Sensitization Testing Using New Approach Methodologies)
10 pages, 1424 KiB  
Communication
Deltamethrin’s Effect on Nitrogen-Fixing Nodules in Medicago truncatula
by Rosario De Fazio, Cristian Piras and Domenico Britti
Toxics 2024, 12(8), 615; https://doi.org/10.3390/toxics12080615 - 21 Aug 2024
Viewed by 709
Abstract
Deltamethrin is used against plant pests (e.g., mites and ants) and, in farm animals, against biting insects because of its acaricidal and repellent effects against ticks, thus protecting the sheep and cattle from the transmission of pathogens. However, its impact on the environment [...] Read more.
Deltamethrin is used against plant pests (e.g., mites and ants) and, in farm animals, against biting insects because of its acaricidal and repellent effects against ticks, thus protecting the sheep and cattle from the transmission of pathogens. However, its impact on the environment still needs to be fully evaluated. This study evaluates the impact of this pyrethroid on the nitrogen-fixing nodules in Medicago truncatula, a model legume. This research compares nodular biomass and root weight between a deltamethrin-treated section and an untreated control section of this legume. Our results indicate a significant reduction in the biomass of nitrogen-fixing nodules in the treated grove, suggesting that deltamethrin negatively affects the symbiotic relationship between M. truncatula and nitrogen-fixing bacteria. This reduction in nodule formation can impair soil fertility and plant growth, highlighting an ecological risk associated with pyrethroid’s use in livestock farming. These findings underscore the need for a shift towards Green Veterinary Pharmacology (GVP), which promotes environmentally sustainable practices in managing livestock health. By minimizing our reliance on harmful chemical treatments, GVP offers viable solutions to protect and enhance ecosystem services such as biological nitrogen fixation that are essential for maintaining soil health and agricultural productivity. Full article
(This article belongs to the Special Issue Ecotoxicity Induced by Pesticides Exposure Volume II)
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17 pages, 1819 KiB  
Article
Bioelectroremediation of a Real Industrial Wastewater: The Role of Electroactive Biofilm and Planktonic Cells through Enzymatic Activities
by Laura Katherin Chaparro Díaz, Antonio Berná and Karina Boltes
Toxics 2024, 12(8), 614; https://doi.org/10.3390/toxics12080614 - 20 Aug 2024
Viewed by 990
Abstract
Bioelectrochemical processes are emerging as one of the most efficient and sustainable technologies for wastewater treatment. Their application for industrial wastewater treatment is still low due to the high toxicity and difficulty of biological treatment for industrial effluents. This is especially relevant in [...] Read more.
Bioelectrochemical processes are emerging as one of the most efficient and sustainable technologies for wastewater treatment. Their application for industrial wastewater treatment is still low due to the high toxicity and difficulty of biological treatment for industrial effluents. This is especially relevant in pharmaceutical industries, where different solvents, active pharma ingredients (APIs), extreme pH, and salinity usually form a lethal cocktail for the bacterial community in bioreactors. This work evaluates the impact of the anode architecture on the detoxification performance and analyzes, for the first time, the profile of some key bioremediation enzymes (catalase and esterase) and reactive oxygen species (ROS) during the operation of microbial electrochemical cells treating real pharmaceutical wastewater. Our results show the existence of oxidative stress and loss of cell viability in planktonic cells, while the electrogenic bacteria that form the biofilm maintain their biochemical machinery intact, as observed in the bioelectrochemical response. Monitorization of electrical current flowing in the bioelectrochemical system showed how electroactive biofilm, after a short adaptation period, started to degrade the pharma effluent. The electroactive biofilms are responsible for the detoxification of this type of industrial wastewater. Full article
(This article belongs to the Section Toxicity Reduction and Environmental Remediation)
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13 pages, 2047 KiB  
Article
Perfluoroalkyl and Polyfluoroalkyl Substances in Relation to the Participant-Reported Total Pregnancy and Live Birth Numbers among Reproductive-Aged Women in the United States
by Guangtong Huang, Jiehao Li, Lixin Zhou, Tiantian Duan, Langjing Deng, Pan Yang and Yajie Gong
Toxics 2024, 12(8), 613; https://doi.org/10.3390/toxics12080613 - 20 Aug 2024
Viewed by 1260
Abstract
Perfluoroalkyl and polyfluoroalkyl substances (PFASs), widely utilized in various industries, may pose potential reproductive well-being risks. However, the research on the impact of PFAS exposures on pregnancy and live birth rates remains scarce. To address this gap, we conducted a cross-sectional study using [...] Read more.
Perfluoroalkyl and polyfluoroalkyl substances (PFASs), widely utilized in various industries, may pose potential reproductive well-being risks. However, the research on the impact of PFAS exposures on pregnancy and live birth rates remains scarce. To address this gap, we conducted a cross-sectional study using the data from the United States National Health and Nutrition Examination Survey (NHANES) collected between 2013 and 2018. We focused on six PFAS compounds measured in the serum of women aged 20 to 50 years, employing the Poisson regression, Quantile G-composition (Qgcomp), and Weighted Quantile Sum (WQS) regression models. Adjusting for age, racial/ethnic origin, educational level, marital status, family income, body mass index (BMI), menarche age, birth control pill use, and other female hormone consumption, the Poisson regression identified significant negative associations between the individual PFAS exposures and pregnancy and live birth numbers (p < 0.05 for all 24 null hypotheses for which the slope of the trend line is zero). The Qgcomp analysis indicated that a one-quartile increase in the mixed PFAS exposures was associated with reductions of 0.09 (95% CI: −0.15, −0.03) in the pregnancy numbers and 0.12 (95% CI: −0.19, −0.05) in the live birth numbers. Similarly, the WQS analysis revealed that a unit increase in the WQS index corresponded to decreases of 0.14 (95% CI: −0.20, −0.07) in the pregnancy numbers and 0.14 (95% CI: −0.21, −0.06) in the live birth numbers. Among the six specific PFAS compounds we studied, perfluorononanoic acid (PFNA) had the most negative association with the pregnancy and live birth numbers. In conclusion, our findings suggest that PFAS exposures are associated with lower pregnancy and live birth numbers among women of reproductive age. Full article
(This article belongs to the Section Human Toxicology and Epidemiology)
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14 pages, 2014 KiB  
Article
Occurrence, Bioaccumulation, and Risk Assessment of Organophosphate Esters in Rivers Receiving Different Effluents
by Shuyan Da and Jun Wang
Toxics 2024, 12(8), 612; https://doi.org/10.3390/toxics12080612 - 20 Aug 2024
Viewed by 871
Abstract
Organophosphate esters (OPEs), as alternatives to brominated flame retardants, are extensively used in both production and daily life, with their environmental contamination and toxic effects being a concern. This study investigated the concentration levels, bioaccumulation, and ecological effects of OPEs in five different [...] Read more.
Organophosphate esters (OPEs), as alternatives to brominated flame retardants, are extensively used in both production and daily life, with their environmental contamination and toxic effects being a concern. This study investigated the concentration levels, bioaccumulation, and ecological effects of OPEs in five different effluent-receiving rivers. The results demonstrate that the concentration range of Σ13OPEs across the five rivers was between 142.23 and 304.56 ng/L (mean: 193.50 ng/L). The highest pollution levels of OPEs were found in rivers receiving airport and industrial wastewater, followed by agricultural wastewater, mixed wastewater, and domestic wastewater. Tris(2-chloroisopropyl) phosphate (TCPP), triethyl phosphate (TEP), and tricresyl phosphate (TCrP) were identified as the main pollutants. The accumulation concentrations of OPEs in fish ranged from 54.0 to 1080.88 ng/g dw, with the highest bioaccumulation found in Pelteobagrus fulvidraco, followed by Carassius auratus and Misgurnus anguillicaudatus. The brain was the primary organ of accumulation, followed by the liver, gills, intestine, and muscle. Tri-n-propyl phosphate (TPeP) and TEP exhibited the highest bioconcentration, with log BAF values exceeding three. The bioaccumulation of OPEs was influenced by pollutant concentration levels, hydrophobic properties, and biological metabolism. Ecological risk assessment revealed that the cumulative risk values of Σ13OPEs ranged from 0.025 to 16.76, with TCrP being the major contributor. It posed a medium–low risk to algae but a high risk to crustaceans and fish. Full article
(This article belongs to the Special Issue Environmental Risk Assessment and Control of Emerging Contaminants)
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17 pages, 3467 KiB  
Article
Toxicity of Moxifloxacin on the Growth, Photosynthesis, Antioxidant System, and Metabolism of Microcystis aeruginosa at Different Phosphorus Levels
by Liang Wan, Yan Zhou, Rong Huang, Yiying Jiao and Jian Gao
Toxics 2024, 12(8), 611; https://doi.org/10.3390/toxics12080611 - 20 Aug 2024
Cited by 1 | Viewed by 983
Abstract
Moxifloxacin (MOX), a widely used novel antibiotic, may pose ecological risks at its actual environmental concentrations, as has been detected in aquatic systems. However, its ecotoxicity to aquatic organisms and regulatory mechanisms of phosphorus in eutrophic aqueous environments are still limited. This study [...] Read more.
Moxifloxacin (MOX), a widely used novel antibiotic, may pose ecological risks at its actual environmental concentrations, as has been detected in aquatic systems. However, its ecotoxicity to aquatic organisms and regulatory mechanisms of phosphorus in eutrophic aqueous environments are still limited. This study aimed to analyze its physiological and biochemical parameters, including cellular growth, chlorophyll fluorescence, photosynthetic pigments, oxidative stress biomarkers, and metabolomics to elucidate the toxicity induced by environmental concentrations of MOX in Microcystis aeruginosa at different phosphorus levels. The results revealed that the EC50 values of MOX on M. aeruginosa at different phosphorus concentrations were 8.03, 7.84, and 6.91 μg/L, respectively, indicating MOX toxicity was exacerbated with increasing phosphorus levels. High phosphorus intensified the suppression of chlorophyll fluorescence and photosynthetic pigments, while activating the antioxidant enzyme, indicating severe peroxidation damage. Metabolomic analysis showed MOX induced different discriminating metabolites under different phosphorus levels, and perturbed more biological pathways at higher phosphorus concentrations, such as starch and sucrose metabolism, pyrimidine metabolism, and glycerolipid metabolism. This indicates that phosphorus plays an important role in regulating metabolism in M. aeruginosa exposed to MOX. The findings provide valuable information on the mechanisms involved in cyanobacteria responses to antibiotic stress, and offer a theoretical basis for accurately assessing antibiotic toxicity in eutrophic aqueous environments. Full article
(This article belongs to the Section Ecotoxicology)
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27 pages, 7305 KiB  
Perspective
Current Challenges in Monitoring Low Contaminant Levels of Per- and Polyfluoroalkyl Substances in Water Matrices in the Field
by Hector Medina and Carson Farmer
Toxics 2024, 12(8), 610; https://doi.org/10.3390/toxics12080610 - 20 Aug 2024
Viewed by 1103
Abstract
The Environmental Protection Agency (EPA) of the United States recently released the first-ever federal regulation on per- and polyfluoroalkyl substances (PFASs) for drinking water. While this represents an important landmark, it also brings about compliance challenges to the stakeholders in the drinking water [...] Read more.
The Environmental Protection Agency (EPA) of the United States recently released the first-ever federal regulation on per- and polyfluoroalkyl substances (PFASs) for drinking water. While this represents an important landmark, it also brings about compliance challenges to the stakeholders in the drinking water industry as well as concerns to the general public. In this work, we address some of the most important challenges associated with measuring low concentrations of PFASs in drinking water in the field in real drinking water matrices. First, we review the “continuous monitoring for compliance” process laid out by the EPA and some of the associated hurdles. The process requires measuring, with some frequency, low concentrations (e.g., below 2 ppt or 2 ng/L) of targeted PFASs, in the presence of many other co-contaminants and in various conditions. Currently, this task can only (and it is expected to) be accomplished using specific protocols that rely on expensive, specialized, and laboratory-scale instrumentation, which adds time and increases cost. To potentially reduce the burden, portable, high-fidelity, low-cost, real-time PFAS sensors are desirable; however, the path to commercialization of some of the most promising technologies is confronted with many challenges, as well, and they are still at infant stages. Here, we provide insights related to those challenges based on results from ab initio and machine learning studies. These challenges are mainly due to the large amount and diversity of PFAS molecules and their multifunctional behaviors that depend strongly on the conditions of the media. The impetus of this work is to present relevant and timely insights to researchers and developers to accelerate the development of suitable PFAS monitoring systems. In addition, this work attempts to provide water system stakeholders, technicians, and even regulators guidelines to improve their strategies, which could ultimately translate in better services to the public. Full article
(This article belongs to the Section Emerging Contaminants)
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15 pages, 3055 KiB  
Article
Toxicity Evaluation and Transcriptome Analysis of Yellowstripe Goby (Mugilogobius chulae) in Response to 2,7-Dibromocarbazole Exposure during Early Development
by Caixia Gao, Suqun Lai, Jin Zeng, Ying Peng and Jianjun Li
Toxics 2024, 12(8), 609; https://doi.org/10.3390/toxics12080609 - 20 Aug 2024
Viewed by 745
Abstract
Polyhalogenated carbazoles (PHCZs) are a class of nitrogen-containing heterocyclic compounds that are widely distributed throughout the marine environment and sediment. These compounds share structural and toxicity similarities with dioxins. However, our understanding of the toxicological effects of PHCZs on marine organisms and their [...] Read more.
Polyhalogenated carbazoles (PHCZs) are a class of nitrogen-containing heterocyclic compounds that are widely distributed throughout the marine environment and sediment. These compounds share structural and toxicity similarities with dioxins. However, our understanding of the toxicological effects of PHCZs on marine organisms and their underlying molecular mechanisms remains limited. In this study, we employed the marine model organism Mugilogobius chulae as the experimental subject and selected 2,7-dibromocarbazole (2,7-DBCZ), a compound known for its high toxicity and detection frequency, to conduct both an acute toxicity test and transcriptome analysis on M. chulae embryos. Our findings revealed that the 96 h median lethal concentration (LC50) of 2,7-DBCZ for M. chulae embryos was 174 μg/L, with a median effective concentration (EC50) resulting in pericardial edema deformity of 88.82 μg/L. Transcriptome analysis revealed significant impacts on various systems in M. chulae embryos following exposure to 2,7-DBCZ, including the sensory, cardiovascular, immune, and endocrine systems. Furthermore, this compound perturbed signaling pathways such as phototransduction, protein folding and processing, amino acid metabolism, lipid transport, and exogenous compound metabolism. Notably, transcript abundance of the CYP1A gene associated with the activation of the AhR signaling pathway, similar to dioxin-like compounds, was 18.18 times higher than that in the control group. This observation suggests that M. chulae embryos mount a stress response when exposed to PHCZs. In summary, this study contributes to our understanding of the toxicological implications of PHCZ in marine fish and offers a theoretical foundation for risk assessment and regulatory frameworks for PHCZs in the marine environment. Full article
(This article belongs to the Section Exposome Analysis and Risk Assessment)
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16 pages, 3279 KiB  
Article
Short-Term Chronic Toxicity of Copper to Hyalella azteca: Contrast in Terms of Equilibrating Diet, Diet Type, and Organic Matter Source
by Nafis Fuad, Rebecca Williams and Timothy M. Vadas
Toxics 2024, 12(8), 608; https://doi.org/10.3390/toxics12080608 - 20 Aug 2024
Viewed by 806
Abstract
The most up-to-date regulatory guidelines for establishing acute and chronic numeric limits for copper in freshwaters are based on a biotic ligand model for various species, but the model for Cu lacks data on dietary uptake. In addition, some common macroinvertebrate toxicity assay [...] Read more.
The most up-to-date regulatory guidelines for establishing acute and chronic numeric limits for copper in freshwaters are based on a biotic ligand model for various species, but the model for Cu lacks data on dietary uptake. In addition, some common macroinvertebrate toxicity assay parameters are less representative of the ecosystem. We investigated the effects of diet and its type in the experimental setup and as an exposure pathway to an established amphipod (crustacean) Hyalella azteca (H. azteca) for Cu toxicity assays. We also investigated another overlooked aspect, the organic matter (OM) source. Our experiments compared the toxicity of pre-equilibrated and unequilibrated natural diets and a laboratory-favored diet in effluent and stormwater sources of organic matter adjusted to standard water characteristics. The experiments indicated a more toxic effect of the pre-equilibrated diet and natural dietary sources, and less toxic effects in the presence of effluent OM compared with stormwater OM, shifting LC50 or EC20 values by as much as 67% compared with the controls. The use of a pre-equilibrated natural diet in toxicity assays provides the advantage of producing toxicity data more representative of field conditions. Considering organic matter type, especially in dietary exposures, will better predict toxicity, accounting for copper complexation with OM from different sources and partitioning to the food supply. Adapting these ecologically relevant parameters in whole effluent toxicity testing or other assays will also provide safer regulatory oversite of discharges to surface waters. Full article
(This article belongs to the Section Ecotoxicology)
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13 pages, 4224 KiB  
Article
Evaluation of THP-1 and Jurkat Cell Lines Coculture for the In Vitro Assessment of the Effects of Immunosuppressive Substances
by Nina Franko and Marija Sollner Dolenc
Toxics 2024, 12(8), 607; https://doi.org/10.3390/toxics12080607 - 19 Aug 2024
Viewed by 1044
Abstract
The strong appeal to reduce animal testing calls for the development and validation of in vitro, in chemico and in silico models that would replace the need for in vivo testing and ex vivo materials. A category that requires such new approach methods [...] Read more.
The strong appeal to reduce animal testing calls for the development and validation of in vitro, in chemico and in silico models that would replace the need for in vivo testing and ex vivo materials. A category that requires such new approach methods is the assessment of immunosuppression that can be induced by chemicals including environmental pollutants. To assess the immunosuppressive action on monocytes and lymphocytes, we mimicked the whole-blood cytokine-release assay by preparing an in vitro coculture of THP-1 and Jurkat cell lines. We optimised its activation and investigated the effects of known immunosuppressive drugs with different mechanisms of action on the release of proinflammatory cytokines. Decreased secretion of IL-8 was achieved by several immunosuppressive mechanisms and was therefore selected as an appropriate marker of immunosuppression. A set of environmentally occurring bisphenols, BPA, BPAP, BPP, BPZ, BPE, TCBPA and BPS-MAE, were then applied to the model and BPP and BPZ were found to act as potent immunosuppressants at micromolar concentrations. Full article
(This article belongs to the Special Issue Feature Papers in the Novel Methods in Toxicology Research)
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24 pages, 1825 KiB  
Article
Removal of the Highly Toxic Anticoccidial Monensin Using Six Different Low-Cost Bio-Adsorbents
by Samiha Hamdi, Manel Issaoui, Sonia Hammami, Ainoa Míguez-González, Raquel Cela-Dablanca, Ana Barreiro, Avelino Núñez-Delgado, Esperanza Álvarez-Rodríguez and María J. Fernández-Sanjurjo
Toxics 2024, 12(8), 606; https://doi.org/10.3390/toxics12080606 - 19 Aug 2024
Viewed by 1326
Abstract
The anticoccidial monensin (MON) is a high-concern emerging pollutant. This research focused on six low-cost bio-adsorbents (alfa, cactus, and palm fibers, and acacia, eucalyptus, and zean oak barks), assessing their potential for MON removal. Batch adsorption/desorption tests were carried out, and the results [...] Read more.
The anticoccidial monensin (MON) is a high-concern emerging pollutant. This research focused on six low-cost bio-adsorbents (alfa, cactus, and palm fibers, and acacia, eucalyptus, and zean oak barks), assessing their potential for MON removal. Batch adsorption/desorption tests were carried out, and the results were fitted to the Freundlich, Langmuir, Linear, Sips, and Temkin models. The concentrations adsorbed by the six materials were very similar when low doses of antibiotic were added, while they differed when adding MON concentrations higher than 20 µmol L−1 (adsorption ranging 256.98–1123.98 μmol kg−1). The highest adsorption corresponded to the sorbents with the most acidic pH (<5.5) and the highest organic matter and effective cation exchange capacity values (eucalyptus bark and acacia bark, reaching 92.3% and 87.8%), whereas cactus and palm fibers showed the lowest values (18.3% and 10.17%). MON desorption was below 8.5%, except for cactus and palm fibers. Temkin was the model showing the best adjustment to the experimental data, followed by the Langmuir and the Sips models. The overall results indicate that eucalyptus bark, alfa fiber, and acacia bark are efficient bio-adsorbents with potential for MON removal, retaining it when spread in environmental compartments, reducing related risks for human and environmental health. Full article
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3 pages, 165 KiB  
Editorial
Understanding PFAS: Occurrence, Fate, Removal, and Effects
by Chang-Gui Pan and Run-Xia Sun
Toxics 2024, 12(8), 605; https://doi.org/10.3390/toxics12080605 - 19 Aug 2024
Viewed by 1679
Abstract
Per- and polyfluoroalkyl substances (PFASs) have emerged as one of the most pressing environmental and public health concerns of the 21st century [...] Full article
20 pages, 4171 KiB  
Article
Neuroinflammation and Neurometabolomic Profiling in Fentanyl Overdose Mouse Model Treated with Novel β-Lactam, MC-100093, and Ceftriaxone
by Mohammed S. Alasmari, Fawaz Alasmari, Shakir D. Alsharari, Abdullah F. Alasmari, Nemat Ali, Syed Rizwan Ahamad, Abdullah M. Alghamdi, Aban A. Kadi, Alaa M. Hammad, Yousif S. Mohamed Ali, Wayne E. Childers, Magid Abou-Gharbia and Youssef Sari
Toxics 2024, 12(8), 604; https://doi.org/10.3390/toxics12080604 - 19 Aug 2024
Viewed by 887
Abstract
Opioid-related deaths are attributed to overdoses, and fentanyl overdose has been on the rise in many parts of the world, including the USA. Glutamate transporter 1 (GLT-1) has been identified as a therapeutic target in several preclinical models of substance use disorders, and [...] Read more.
Opioid-related deaths are attributed to overdoses, and fentanyl overdose has been on the rise in many parts of the world, including the USA. Glutamate transporter 1 (GLT-1) has been identified as a therapeutic target in several preclinical models of substance use disorders, and β-lactams effectively enhance its expression and function. In the current study, we characterized the metabolomic profile of the nucleus accumbens (NAc) in fentanyl-overdose mouse models, and we evaluated the protective effects of the functional enhancement of GLT-1 using β-lactams, ceftriaxone, and MC-100093. BALB/c mice were divided into four groups: control, fentanyl, fentanyl/ceftriaxone, and fentanyl/MC-100093. While the control group was intraperitoneally (i.p.) injected with normal saline simultaneously with other groups, all fentanyl groups were i.p. injected with 1 mg/kg of fentanyl as an overdose after habituation with four repetitive non-consecutive moderate doses (0.05 mg/kg) of fentanyl for a period of seven days. MC-100093 (50 mg/kg) and ceftriaxone (200 mg/kg) were i.p. injected from days 5 to 9. Gas chromatography–mass spectrometry (GC-MS) was used for metabolomics, and Western blotting was performed to determine the expression of target proteins. Y-maze spontaneous alternation performance and the open field activity monitoring system were used to measure behavioral manifestations. Fentanyl overdose altered the abundance of about 30 metabolites, reduced the expression of GLT-1, and induced the expression of inflammatory mediators IL-6 and TLR-4 in the NAc. MC-100093 and ceftriaxone attenuated the effects of fentanyl-induced downregulation of GLT-1 and upregulation of IL-6; however, only ceftriaxone attenuated fentanyl-induced upregulation of TRL4 expression. Both of the β-lactams attenuated the effects of fentanyl overdose on locomotor activities but did not induce significant changes in the overall metabolomic profile. Our findings revealed that the exposure to a high dose of fentanyl causes alterations in key metabolic pathways in the NAc. Pretreatment with ceftriaxone and MC-100093 normalized fentanyl-induced downregulation of GLT-1 expression with subsequent attenuation of neuroinflammation as well as the hyperactivity, indicating that β-lactams may be promising drugs for treating fentanyl use disorder. Full article
(This article belongs to the Special Issue Toxicity of Central Nervous System (CNS) Modulators)
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11 pages, 478 KiB  
Article
Association between Serum 6:2 Chlorinated Polyfluorinated Ether Sulfonate Concentrations and Lung Cancer
by Weili Mao, Jianli Qu, Ruyue Guo, Yuanchen Chen, Hangbiao Jin and Jingyan Xu
Toxics 2024, 12(8), 603; https://doi.org/10.3390/toxics12080603 - 19 Aug 2024
Viewed by 806
Abstract
6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA) exhibits pronounced estrogenic effects, potentially influencing the etiology of lung cancer. This study assessed the potential associations between serum concentrations of 6:2 Cl-PFESA and lung cancer risk at the population level. Odds ratios (ORs) for lung [...] Read more.
6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA) exhibits pronounced estrogenic effects, potentially influencing the etiology of lung cancer. This study assessed the potential associations between serum concentrations of 6:2 Cl-PFESA and lung cancer risk at the population level. Odds ratios (ORs) for lung cancer across serum 6:2 Cl-PFESA quartiles were assessed using conditional logistic regression. Additionally, we investigated potential effect modification by various confounding factors. Elevated serum levels of 6:2 Cl-PFESA were consistently associated with an increased risk of lung cancer in both the crude model (OR = 1.62, 95% CI: 1.08–2.42, p = 0.018) and the adjusted model (OR = 1.59, 95% CI: 1.06–2.39, p = 0.026). Stratified analyses revealed that elevated serum levels of 6:2 Cl-PFESA were associated with increased risk estimates of lung cancer among males (adjusted OR = 2.04, 95% CI: 1.19–3.51, p = 0.006), smokers (adjusted OR = 2.48, 95% CI: 1.25–4.89, p = 0.003), and drinkers (adjusted OR = 2.20, 95% CI: 0.94–5.16, p = 0.049). The results of this study imply that exposure to 6:2 Cl-PFESA at levels considered environmentally relevant may be linked to an elevated risk of developing lung cancer. Full article
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23 pages, 5631 KiB  
Article
Changes in the Aggregation Behaviour of Zinc Oxide Nanoparticles Influenced by Perfluorooctanoic Acid, Salts, and Humic Acid in Simulated Waters
by Anwar Ul Haq Khan, Yanju Liu, Ravi Naidu, Cheng Fang, Ho Kyong Shon, Huiming Zhang and Rajarathnam Dharmarajan
Toxics 2024, 12(8), 602; https://doi.org/10.3390/toxics12080602 - 18 Aug 2024
Viewed by 1097
Abstract
The increasing utilization of zinc oxide nanoparticles (ZnO-NPs) in many consumer products is of concern due to their eventual release into the natural environment and induction of potentially adverse impacts. The behaviour and environmental impacts of ZnO-NPs could be altered through their interactions [...] Read more.
The increasing utilization of zinc oxide nanoparticles (ZnO-NPs) in many consumer products is of concern due to their eventual release into the natural environment and induction of potentially adverse impacts. The behaviour and environmental impacts of ZnO-NPs could be altered through their interactions with environmentally coexisting substances. This study investigated the changes in the behaviour of ZnO-NPs in the presence of coexisting organic pollutants (such as perfluorooctanoic acid [PFOA]), natural organic substances (i.e., humic acid [HA]), and electrolytes (i.e., NaCl and CaCl2) in simulated waters. The size, shape, purity, crystallinity, and surface charge of the ZnO-NPs in simulated water after different interaction intervals (such as 1 day, 1 week, 2 weeks, and 3 weeks) at a controlled pH of 7 were examined using various characterization techniques. The results indicated alterations in the size (such as 162.4 nm, 1 day interaction to >10 µm, 3 weeks interaction) and zeta potential (such as −47.2 mV, 1 day interaction to −0.2 mV, 3 weeks interaction) of the ZnO-NPs alone and when PFOA, electrolytes, and HA were present in the suspension. Different influences on the size and surface charge of the nanoparticles were observed for fixed concentrations (5 mM) of the different electrolytes. The presence of HA-dispersed ZnO-NPs affected the zeta potential. Such dispersal effects were also observed in the presence of both PFOA and salts due to their large aliphatic carbon content and complex structure. Cation bridging effects, hydrophobic interactions, hydrogen bonding, electrostatic interactions, and van der Waals forces could be potential interaction forces responsible for the adsorption of PFOA. The presence of organic pollutants (PFOA) and natural organic substances (HA) can transform the surface characteristics and fate of ZnO-NPs in natural and sea waters. Full article
(This article belongs to the Special Issue Environmental Transport and Transformation of Pollutants)
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16 pages, 4797 KiB  
Article
Pollution Characteristics of Heavy Metals in PM1 and Source-Specific Health Risks in the Tianjin Airport Community, China
by Jingbo Zhao, Jingcheng Xu, Yanhong Xu and Yaqin Ji
Toxics 2024, 12(8), 601; https://doi.org/10.3390/toxics12080601 - 18 Aug 2024
Viewed by 983
Abstract
The airport and its surrounding areas are home to a variety of pollution sources, and air pollution is a recognized health concern for local populated regions. Submicron particulate matter (PM1 with an aerodynamic diameter of <1 mm) is a typical pollutant at [...] Read more.
The airport and its surrounding areas are home to a variety of pollution sources, and air pollution is a recognized health concern for local populated regions. Submicron particulate matter (PM1 with an aerodynamic diameter of <1 mm) is a typical pollutant at airports, and the enrichment of heavy metals (HMs) in PM1 poses a great threat to human health. To comprehensively assess the source-specific health effects of PM1-bound HMs in an airport community, PM1 filter samples were collected around the Tianjin Binhai International Airport for 12 h during the daytime and nighttime, both in the spring and summer, and 10 selected HMs (V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, and Pb) were analyzed. The indicatory elements of aircraft emissions were certified as Zn and Pb, which accounted for more than 60% of the sum concentration of detected HMs. The health risks assessment showed that the total non-cancer risks (TNCRs) of PM1-bound HMs were 0.28 in the spring and 0.23 in the summer, which are lower than the safety level determined by the USEPA, and the total cancer risk (TCR) was 2.37 × 10−5 in the spring and 2.42 × 10−5 in the summer, implying that there were non-negligible cancer risks in the Tianjin Airport Community. After source apportionment with EF values and PMF model, four factors have been determined in both seasons. Consequently, the source-specific health risks were also evaluated by combining the PMF model with the health risk assessment model. For non-cancer risk, industrial sources containing high concentrations of Mn were the top contributors in both spring (50.4%) and summer (44.2%), while coal combustion with high loads of As and Cd posed the highest cancer risk in both seasons. From the perspective of health risk management, targeted management and control strategies should be adopted for industrial emissions and coal combustion in the Tianjin Airport Community. Full article
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14 pages, 664 KiB  
Article
Associations between Glyphosate Exposure and Glycemic Disorders: A Focus on the Modifying Effect of Sex Hormones
by Yu Dong, Yuan Li, Liwen Ma, Shuge Shu, Jiawen Ren, Xiangyu Yu, Dan Luo, Zhizhou Duan and Yongquan Yu
Toxics 2024, 12(8), 600; https://doi.org/10.3390/toxics12080600 - 18 Aug 2024
Viewed by 1122
Abstract
Widespread glyphosate contamination in the environment and its endocrine-disrupting potential are concerning. However, evidence of glyphosate’s effects on glycemic health is limited. To examine the association between glyphosate and glucose homeostasis in the general US population, a total of 3038 individuals were enrolled [...] Read more.
Widespread glyphosate contamination in the environment and its endocrine-disrupting potential are concerning. However, evidence of glyphosate’s effects on glycemic health is limited. To examine the association between glyphosate and glucose homeostasis in the general US population, a total of 3038 individuals were enrolled from the 2013-2016 cycles of the National Health and Nutrition Examination Survey (NHANES). Survey-weighted linear regression and restricted cubic spline curves were used to detect the associations between glyphosate and glycemic disorders. The effects of interactions between sex hormones and glyphosate on glycemic outcomes were evaluated. The results showed that glyphosate was significantly linked to increased glycated hemoglobin A1c (HbA1c) levels (β = 0.01; 95%CI, 0.01 to 0.02; p = 0.001) and the compromised homeostatic model assessment of beta-cell function (HOMA-beta) scores (β = −0.09; 95%CI, −0.17 to −0.01; p = 0.024). More importantly, these “glyphosate–glycemic disorder” associations were significantly modified by sex hormone-binding globulin (SHBG; P for interaction < 0.05), with more pronounced relationships being identified in individuals with low SHBG levels. Our findings indicate that glyphosate is correlated with glucose dyshomeostasis. Individuals with low SHBG levels exhibited susceptibility to glyphosate-related glycemic toxicity; therefore, it might be prudent to determine glycemic health in those subjects with glyphosate exposure. Full article
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20 pages, 15410 KiB  
Article
Mercury Dynamics and Bioaccumulation Risk Assessment in Three Gold Mining-Impacted Amazon River Basins
by Vitor Sousa Domingues, Carlos Colmenero, Maria Vinograd, Marcelo Oliveira-da-Costa and Rodrigo Balbueno
Toxics 2024, 12(8), 599; https://doi.org/10.3390/toxics12080599 - 18 Aug 2024
Viewed by 1312
Abstract
Mercury contamination from gold mining in the Amazon poses significant environmental and health threats to the biome and its local populations. The recent expansion of non-industrial mining areas has severely impacted territories occupied by traditional communities. To address the lack of sampling data [...] Read more.
Mercury contamination from gold mining in the Amazon poses significant environmental and health threats to the biome and its local populations. The recent expansion of non-industrial mining areas has severely impacted territories occupied by traditional communities. To address the lack of sampling data in the region and better understand mercury dynamics, this study used the probabilistic model SERAFM to estimate the mercury distribution and bioaccumulation in fish. The analysis covered 8,259 sub-basins across three major Amazonian basins: the Branco, Tapajós and Xingu rivers. The findings revealed increasing downstream mercury levels, with notable accumulations in the main watercourses influenced by methylation processes and mining releases. The projected concentrations showed that an average of 27.47% of the sub-basins might not comply with Brazilian regulations, rising to 52.38% in the Branco and Tapajós river basins separately. The risk assessment of fish consumption based on the projections highlighted high mercury exposure levels among traditional communities, particularly indigenous populations, with an average of 49.79% facing an extremely high risk in the Branco and Tapajós river basins. This study demonstrated SERAFM’s capacity to fill information gaps in the Amazon while underscoring the need for enhanced data collection, culturally sensitive interventions and regulatory updates to mitigate mercury contamination in gold mining-affected areas. Full article
(This article belongs to the Special Issue Mercury Cycling and Health Effects)
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17 pages, 3057 KiB  
Article
Green Tea Polyphenol Nanoparticles Reduce Anxiety Caused by Tobacco Smoking Withdrawal in Rats by Suppressing Neuroinflammation
by Alaa M. Hammad, Lujain F. Alzaghari, Malek Alfaraj, Vanessa Lux and Suhair Sunoqrot
Toxics 2024, 12(8), 598; https://doi.org/10.3390/toxics12080598 - 18 Aug 2024
Viewed by 857
Abstract
Repeated exposure to tobacco smoke causes neuroinflammation and neuroplasticity, which correlates with smoking withdrawal-induced anxiety. The purpose of this study was to investigate the anticipated involvement of antioxidant-rich nanoparticles (NPs) prepared by oxidation-triggered polymerization of green tea catechins in impacting these effects in [...] Read more.
Repeated exposure to tobacco smoke causes neuroinflammation and neuroplasticity, which correlates with smoking withdrawal-induced anxiety. The purpose of this study was to investigate the anticipated involvement of antioxidant-rich nanoparticles (NPs) prepared by oxidation-triggered polymerization of green tea catechins in impacting these effects in a rat model of tobacco smoke exposure. Exposure to tobacco smoke was carried out for 2 h a day, 5 days a week, for a total of 36 days. Weekly behavioral tests were conducted prior to recommencing the exposure. Following a 20-day exposure period, rats were administered either distilled water or green tea (GT) NPs (20 mg/kg, orally) for an additional 16 days. Our findings revealed that tobacco smoke exposure induced anxiety-like behavior indicative of withdrawal, and this effect was alleviated by GT NPs. Tobacco smoke exposure caused a marked increase in the relative mRNA and protein expression of nuclear factor-kappa B (NF-κB) and reduced the relative mRNA and protein expression of brain-derived neurotrophic factor (BDNF) in the hippocampus (HIP) and hypothalamus (HYP) brain subregions. The intervention of GT NPs effectively inhibited these effects. Our findings demonstrate the potent protective role of GT NPs in reducing withdrawal-induced anxiety-like behavior, neuroinflammation, and neuroplasticity triggered by tobacco smoke exposure. Full article
(This article belongs to the Special Issue Toxicity of Central Nervous System (CNS) Modulators)
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20 pages, 7534 KiB  
Article
QSTR Models in Dioxins and Dioxin-like Compounds Provide Insights into Gene Expression Dysregulation
by Elisa G. Eleazar, Andrei Raphael M. Carrera, Janus Isaiah R. Quiambao, Alvin R. Caparanga and Lemmuel L. Tayo
Toxics 2024, 12(8), 597; https://doi.org/10.3390/toxics12080597 - 17 Aug 2024
Viewed by 599
Abstract
Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-p-furans (PCDD/Fs) are a group of organic chemicals containing three-ring structures that can be substituted with one to eight chlorine atoms, leading to 75 dioxin and 135 furan congeners. As endocrine-disrupting chemicals (EDCs), they can alter physiological processes causing [...] Read more.
Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-p-furans (PCDD/Fs) are a group of organic chemicals containing three-ring structures that can be substituted with one to eight chlorine atoms, leading to 75 dioxin and 135 furan congeners. As endocrine-disrupting chemicals (EDCs), they can alter physiological processes causing a number of disorders. In this study, quantitative structure–toxicity relationship (QSTR) studies were used to determine the correlations between the PCDD/Fs’ molecular structures and various toxicity endpoints. Strong QSTR models, with the coefficients of determination (r2) values greater than 0.95 and ANOVA p-values less than 0.0001 were established between molecular descriptors and the endpoints of bioconcentration, fathead minnow LC50, and Daphnia magna LC50. The ability of PCDD/Fs to bind to several nuclear receptors was investigated via molecular docking studies. The results show comparable, and in some instances better, binding affinities of PCDD/Fs toward the receptors relative to their natural agonistic and antagonistic ligands, signifying possible interference with the receptors’ natural biological activities. These studies were accompanied by the molecular dynamics simulations of the top-binding PCDD/Fs to show changes in the receptor–ligand complexes during binding and provide insights into these compounds’ ability to interfere with transcription and thereby modify gene expression. This introspection of PCDD/Fs at the molecular level provides a deeper understanding of these compounds’ toxicity and opens avenues for future studies. Full article
(This article belongs to the Section Emerging Contaminants)
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16 pages, 6901 KiB  
Article
Hormesis in the Assessment of Toxicity Assessment by Luminescent Bacterial Methods
by Haoyu Si, Guoquan Zhou, Yu Luo, Zhuoxuan Wang, Xuejun Pan and Guohua Dao
Toxics 2024, 12(8), 596; https://doi.org/10.3390/toxics12080596 - 17 Aug 2024
Viewed by 714
Abstract
The threat posed by water pollutants to aquatic ecosystems and human health cannot be overlooked, and the assessment of the toxicity of these contaminants is paramount to understanding their risks and formulating effective control measures. Luminescent bacteria-based assays, as a vital tool in [...] Read more.
The threat posed by water pollutants to aquatic ecosystems and human health cannot be overlooked, and the assessment of the toxicity of these contaminants is paramount to understanding their risks and formulating effective control measures. Luminescent bacteria-based assays, as a vital tool in evaluating contaminant toxicity, encounter a challenge in ensuring accuracy due to the phenomenon of “Hormesis” exhibited by pollutants towards biological entities, which may skew toxicity assessments. This study elucidated the specific effects of pollutants on luminescent bacteria at different concentrations, used modeling to characterize the effects and predict their toxicity trends, and explored the applicable concentration ranges for different pollutants. Research revealed that six typical pollutants, namely PAHs, endocrine disruptors, antibiotics, pesticides, heavy metals, and phytosensory substances, could promote the luminescence intensity of luminescent bacteria at low concentrations, and the promotional effect increased and then decreased. However, when the concentration of the substances reached a certain threshold, the effect changed from promotional to inhibitory, and the rate of inhibition was directly proportional to the concentration. The EC50 values of six types of substances to luminescent bacteria is as follows: endocrine disruptors > pesticides > antibiotics > heavy metals > polycyclic aromatic hydrocarbons > chemosensory agents. The effect curves were further fitted using the model to analyze the maximum point of the promotion of luminescence intensity by different substances, the threshold concentration, and the tolerance of luminescent bacteria to different substances. The maximum promotion of bacterial luminescence intensity was 29% for Bisphenol A at 0.005 mg/L and the minimum threshold concentration of chromium was 0.004 mg/L, and the maximum bacterial tolerance to erythromycin is 6.74. In addition, most of the current environmental concentrations had a positive effect on luminescent bacteria and may still be in the range of concentrations that promote luminescence as the substances continue to accumulate. These findings will enhance the accuracy and comprehensiveness of toxicity assessments, thereby facilitating more informed and effective decision-making in the realms of environmental protection and pollution management. Full article
(This article belongs to the Section Hormesis in Toxicology)
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16 pages, 1761 KiB  
Article
Effects of Strawberry Tree Water Leaf Extract and Arbutin on Biochemical Markers and DNA Integrity in Brain Cells of Lewis Rats
by Vesna Benković, Dora Vuković, Iva Đelatić, Vanja Popović, Karlo Jurica, Fabijan Knežević, Irena Brčić Karačonji, Ana Lucić Vrdoljak and Nevenka Kopjar
Toxics 2024, 12(8), 595; https://doi.org/10.3390/toxics12080595 - 16 Aug 2024
Viewed by 708
Abstract
There is growing evidence that arbutin and plant extracts rich in arbutin, such as extracts of the strawberry tree (Arbutus unedo L.), exert a range of beneficial effects, including cyto- and genoprotective properties. This study evaluated the effects of strawberry tree water [...] Read more.
There is growing evidence that arbutin and plant extracts rich in arbutin, such as extracts of the strawberry tree (Arbutus unedo L.), exert a range of beneficial effects, including cyto- and genoprotective properties. This study evaluated the effects of strawberry tree water leaf extract (STE) and arbutin in the brain tissue of Lewis rats. STE or arbutin were administered per os to male and female rats at a dose of 200 mg/kg body weight/day for 14 or 28 days. Treatment outcomes were evaluated using biochemical markers (lipid peroxidation and the activities of the antioxidative enzymes catalase and superoxide dismutase). The effects of the tested substances on DNA integrity in brain cells were evaluated using the alkaline comet assay. The results suggest a high biocompatibility of both tested substances with rat brain tissue. No significant harmful disturbances were observed in the oxidative/antioxidative status or impairments of DNA integrity in the rat brain cells. Nearly all post-treatment values were within tolerable limits as compared to the matched control rats. Such encouraging findings support further research using other subtle biomarkers to clarify the safety aspects of arbutin and STE prior to the development of specific nutraceutical products. Full article
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14 pages, 8691 KiB  
Article
Stressful Effects of Individual and Combined Exposure to Low-Concentration Polylactic Acid Microplastics and Chromium on Marine Medaka Larvae (Oryzias melastigma)
by Yuan Yin, Yini Ma, Qiang Li, Nan Chen and Shaobai Wen
Toxics 2024, 12(8), 594; https://doi.org/10.3390/toxics12080594 - 16 Aug 2024
Viewed by 812
Abstract
Microplastics and heavy metal pollution frequently co-occur in the marine environment, raising concerns about their potentially harmful impacts on marine fish. This study undertook a comprehensive evaluation of the individual and combined stress effects of polylactide microplastics (PLA-MPs) and chromium (Cr) on marine [...] Read more.
Microplastics and heavy metal pollution frequently co-occur in the marine environment, raising concerns about their potentially harmful impacts on marine fish. This study undertook a comprehensive evaluation of the individual and combined stress effects of polylactide microplastics (PLA-MPs) and chromium (Cr) on marine medaka larvae. Following a 14-day exposure to PLA-MPs (100 μg/L) and Cr (50 μg/L), both individually and in combination, significant increases in heart rate and body length were observed. Notably, the combined exposure to PLA-MPs and Cr caused marked histopathological alterations, including shedding, atrophy, and lysis of the intestinal tissues. Furthermore, both individual and combined exposure induced oxidative stress in fish larvae, leading to changes in various enzyme activity indices. Individual exposure to either PLA-MPs or Cr led to anxious behavior in the larvae, whereas combined exposure not only caused anxious behavior but also altered swimming patterns. These findings suggest that combined exposure to PLA-MPs and Cr can exacerbate the toxic effects on marine medaka larvae. Full article
(This article belongs to the Special Issue Hazardous Effects of Emerging Contaminants on Wildlife)
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24 pages, 1691 KiB  
Article
Trace Metal Bioaccumulation in Feral Pigeons (Columba livia f. domestica) and Rooks (Corvus frugilegus) Residing in the Urban Environment of Iasi City, Romania
by Diana Iacob, Emanuela Paduraru, Vicentiu-Robert Gabor, Carmen Gache, Iuliana Gabriela Breaban, Silviu Gurlui, Gabriel Plavan, Roxana Jijie and Mircea Nicoara
Toxics 2024, 12(8), 593; https://doi.org/10.3390/toxics12080593 - 16 Aug 2024
Viewed by 1501
Abstract
Nowadays, trace metal contamination within urban atmospheres is a significant and concerning global issue. In the present study, two synanthropic bird species, namely, the feral pigeon (Columba livia f. domestica) and the rook (Corvus frugilegus), were employed as [...] Read more.
Nowadays, trace metal contamination within urban atmospheres is a significant and concerning global issue. In the present study, two synanthropic bird species, namely, the feral pigeon (Columba livia f. domestica) and the rook (Corvus frugilegus), were employed as bioindicators to assess the atmospheric trace metal pollution in Iasi City, Romania. The concentrations of Ni, Pb, Cd, Co, Cr, and Cu were determined through high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF-AAS) of various tissues, including the liver, kidney, lung, heart, muscle, and bone, of feral pigeons and rooks collected in Iasi City. The order of trace metal concentrations in the tissues of feral pigeons and rooks in Iasi City was similar: Cu > Pb > Ni > Cd > Cr > Co. However, trace element values in most tissues were higher in the rook samples than in feral pigeon ones, except for Co, which had elevated levels in feral pigeon renal and cardiac tissues, and Cu, which registered the highest concentrations in feral pigeon liver and kidney tissues. While not statistically significant, Pb concentration values in the PM10 fraction of atmospheric particles positively correlated with Pb concentrations in rook kidney samples (p = 0.05). The concentration levels of Cd, Pb, and Ni in the PM10 fraction of air particles showed a positive correlation with Cd levels in the samples of pigeon heart and rook liver, kidney, and heart, Pb levels in the samples of pigeon kidney, heart, and muscle and rook liver and bone, and Ni levels in the samples of pigeon liver, kidney, and bone and rook liver, muscle, and bone, respectively. Full article
(This article belongs to the Section Metals and Radioactive Substances)
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20 pages, 4068 KiB  
Review
An Assessment of Polycyclic Aromatic Hydrocarbons Using Estimation Programs
by Oluwabunmi P. Femi-Oloye, Ryen T. Sutton, Heidi D. Gordon, Ayush Ain Das, Grace O. Morenikeji, Melissa K. Odorisio, Ovidiu D. Francestscu, Ryan L. Myers and Femi F. Oloye
Toxics 2024, 12(8), 592; https://doi.org/10.3390/toxics12080592 - 15 Aug 2024
Cited by 1 | Viewed by 1106
Abstract
In the environment, the class of chemicals known as polycyclic aromatic hydrocarbons (PAHs) behave somewhat differently. This review covers situations where PAHs can be ‘labile’ and where they can be persistent. The in-silico prediction of toxicity and the properties of selected 29 PAHs [...] Read more.
In the environment, the class of chemicals known as polycyclic aromatic hydrocarbons (PAHs) behave somewhat differently. This review covers situations where PAHs can be ‘labile’ and where they can be persistent. The in-silico prediction of toxicity and the properties of selected 29 PAHs were estimated using programs developed by the U.S. Environmental Protection Agency (EPA), such as the Estimation Programs Interface (E.P.I.) and the Toxicity Estimation Software Tool (version 5.1.2) (TEST), with online software such as SwissADME and SwissDock. TEST was used to estimate the LC50 of the fathead minnow (with a range of 14.53 mg/L for 1-indanone and 2.14 × 10−2 mg/L for cyclopenta[c,d]pyrene), the LC50 of Daphnia magna (with a range of 14.95 mg/L for 1-indanone and 7.53 × 10−2 mg/L for coronene), the IGC50 of Tetrahymena pyriformis (with a range of 66.14 mg/L for 1-indanone and 0.36 mg/L for coronene), the bioconcentration factor (8.36 for 1,2-acenaphthylenedione and 910.1 for coronene), the developmental toxicity (0.30 (−) for 1,2-acenaphthylenedione and 0.82 (+) for 4-hydroxy-9-fluorenone), and the mutagenicity (0.25 (−) for 2-methyl-9-fluorenone and 1.09 (+) for coronene). The carbon chain and molecular weight have a significant effect on the properties of PAHs. Overall, it was found that PAHs with a lower molecular weight (LMW) have a higher water solubility and LC50 value and a smaller LogKow value, whereas the opposite is true for heavier PAHs, with TEST predicting that PAHs with an MW of over 168.2 g/mol, with a few exceptions, are mutagenic. Hence, LMW PAHs have a higher potential to be in the environment but are less toxic. Full article
(This article belongs to the Section Novel Methods in Toxicology Research)
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16 pages, 3973 KiB  
Article
SOS! Hydrogen Sulfide Enhances the Flavonoid Early Warning System in Rice Plants to Cope with Thiocyanate Pollution
by Peng Tian, Yu-Xi Feng and Yan-Hong Li
Toxics 2024, 12(8), 591; https://doi.org/10.3390/toxics12080591 - 14 Aug 2024
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Abstract
The presence of thiocyanate (SCN) in irrigation water has adverse effects on both plant growth and crop output. Hydrogen sulfide (H2S) is an important gaseous signaling molecule that can alleviate SCN stress. Flavonoids are secondary compounds produced by [...] Read more.
The presence of thiocyanate (SCN) in irrigation water has adverse effects on both plant growth and crop output. Hydrogen sulfide (H2S) is an important gaseous signaling molecule that can alleviate SCN stress. Flavonoids are secondary compounds produced by plants and are ubiquitous in the plant kingdom. They play important roles in several physiological and biochemical processes. To investigate the effect of exogenous H2S on the growth of early rice plants under SCN stress, we carried out a hydroponic experiment focusing on the interaction of exogenous H2S with flavonoids. In this study, a hydroponic experiment was performed to investigate the behavior of SCN when subjected to varying effective doses (EC20: 24.0 mg/L; EC50: 96.0 mg/L; and EC75: 300.0 mg/L). The findings indicated that the relative growth rate (RGR) of the plants treated with H2S + SCN was greater than that of the plants treated with SCN alone. Higher amounts of flavonoids were detected in the shoots than in the roots, with more variability in the shoots. The early warning level results showed that most of the flavonoids were present at levels I and II, while quercetin was present at level IV. Genetic expression variation factor (GEVF) analyses revealed an increase in the quantity of “promoter genes” with increasing SCN concentration in both rice tissues. Furthermore, administering external H2S while exposing rice tissues to SCN resulted in a considerable decrease in the levels of reactive oxygen species. This study provides novel insights into the regulation of flavonoid levels in rice plants by exogenous H2S, facilitating enhanced resistance to SCN stress and promoting sustainable agriculture. Full article
(This article belongs to the Special Issue Insights into the Biology of Plants Affected by Toxic Chemicals)
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