Toxics最新文献

Excessive fluoride exposure induces developmental neurotoxicity, but effective preventive strategies are currently scarce. Melatonin (Mel), a lipophilic hormone secreted by the pineal gland, exerts antioxidant, anti-inflammatory, and neuroprotective properties. This study aimed to explore Mel's protective effect and mechanism against fluoride-induced developmental brain injury. We employed a network pharmacology approach to screen the common targets of Mel and fluoride-induced brain injury and performed enrichment analysis. A total of 189 common targets were identified, and these targets were mainly enriched in the HIF-1 signaling pathway and oxidative stress-related pathways. In vivo, Sprague Dawley rats were subjected to perinatal sodium fluoride (NaF) exposure with/without Mel; in vitro, HT22 cells were subjected to NaF and/or Mel. The results showed that Mel improved cognitive impairments and alleviated structural damage to hippocampal neurons and mitochondria. Furthermore, Mel upregulated SIRT3 and downregulated HIF-1α, thereby restoring mitochondrial oxidative phosphorylation and ATP content. This study demonstrates that Mel alleviates fluoride-induced developmental neurotoxicity by improving mitochondrial function through regulating the SIRT3/HIF-1α signaling pathway. This not only offers a novel perspective for elucidating the underlying molecular mechanisms of fluoride-induced developmental neurotoxicity but also provides a theoretical foundation for Mel as a potential protective candidate against fluoride exposure.

Soil ecosystems are seriously contaminated by microplastics of varying particle sizes, yet the ecological consequences across a broader size spectrum remain poorly understood. We conducted a 360-day field experiment to examine the effects of seven microplastic size fractions (ranging from 6.5 μm to 1000 μm) on the composition, trophic structure, temporal dynamics, complexity, and stability of soil nematode communities. Results showed that microplastics altered nematode community composition and structure, with impacts clearly dependent on both particle size and exposure time. Microplastics generally reduced the abundance, complexity, and stability of nematode communities, except for the 25 μm and 500 μm particles. Temporal analysis revealed an initial increase in nematode abundance, followed by a long-term decline across most treatments. Structural equation modeling indicated that microplastics regulated nematode diversity and stability through pathways that varied with particle size. We recommend that the environmental risk assessments for soil microplastics incorporate testing across a broad size spectrum and over extended timescales to capture their complex and dynamic impacts.

(1) Background: Energy-based transurethral resection of bladder tumor (TURBT) generates surgical smoke that may contain hazardous volatile organic compounds (VOCs), yet surgeon breathing-zone exposure during transurethral surgery remains insufficiently characterized. (2) Methods: We conducted a prospective paired-exposure study during 28 TURBT procedures over 10 operating days using personal sampling at the surgeon's breathing zone and simultaneous intraoperative background sampling at three predefined locations (~1.5 m from the surgeon). VOCs were measured by active sampling onto Tenax TA sorbent tubes followed by thermal desorption Gas Chromatography-Mass Spectrometry (GC-MS), and formaldehyde was measured by 2,4-dinitrophenylhydrazine (DNPH) cartridges with high-performance liquid chromatography/ultraviolet detection (HPLC/UV). Breathing-zone versus background contrasts were summarized as paired geometric mean ratios (GMRs), and a dose index was calculated as concentration × operative time (µg·h/m³). (3) Results: Breathing-zone concentrations consistently exceeded background levels, including total VOCs (GMR 4.31; 95% CI 2.92-6.38), ΣBTEXS (sum of benzene, toluene, ethylbenzene, xylenes, and styrene; GMR 2.10; 1.69-2.60), and styrene (GMR 8.51; 6.25-11.60); formaldehyde showed a smaller but significant elevation (GMR 1.20; 1.07-1.35). ΣBTEXS dose increased with operative time (Spearman ρ = 0.80, p < 0.001) and resection mass where available (ρ = 0.62, p = 0.0038; n = 20) and scaled with operative time (β = 0.86; R² = 0.69; n = 28). (4) Conclusions: TURBT is associated with marked enrichment of aromatic VOCs in the surgeon's breathing zone, supporting routine implementation of effective source-level smoke evacuation and filtration to reduce occupational exposure.

Driven by factors such as meteorology, topography, and industrial structure, the concentrations of volatile organic compounds (VOCs) exhibit significant spatial heterogeneity. Investigating the characteristics and sources of VOCs in different regions is therefore crucial for formulating targeted strategies to mitigate their contributions to fine particulate matter (PM_2.5) and ozone (O₃) pollution. This study comprehensively investigated-for the first time-the concentration characteristics, sources, and contributions to secondary organic aerosol (SOA) and O₃ formation of VOCs at an urban background site in Ganzhou, a southern Chinese city, based on hourly observations of VOCs during 2023. Analyses included ozone formation potential (OFP), secondary organic aerosol formation potential (SOAFP), and positive matrix factorization (PMF) source apportionment. The influence of photochemical loss was assessed using a photochemical age parameterization method. The results showed an annual average total VOC concentration of 22.6 ± 13.17 ppbv, with higher levels in winter and lower in summer. Alkanes were the dominant species (45.76%). After correcting for photochemical loss, the initial concentration of VOCs (IC-VOCs) was approximately 60% higher than the observed concentration of VOCs (OC-VOCs), with alkenes becoming the dominant group in IC-VOCs (≈72%). OFP analysis indicated that the OFP calculated using initial VOC concentrations (IC-OFP) was substantially higher (by 320 μg/m³) than the values calculated using observed VOC concentrations (OC-OFP), primarily due to the increased contribution of alkenes. SOAFP was higher in spring and winter, and lower in summer and autumn, with aromatic hydrocarbons being the dominant contributors (>85%). PMF results based on month-case studies identified combustion and industrial process sources as the major contributors (>20%) in August, while combustion and vehicle exhaust dominated in January. Photochemical loss significantly influenced source apportionment, particularly leading to an underestimation of biogenic emissions during a warm month (August). These findings underscore the necessity of accounting for photochemical aging and offer a scientific basis for refining targeted VOC control measures in Ganzhou and similar regions.

The presence of trace and toxic elements in milk and dairy products is an important food safety issue, as contamination can occur along the dairy supply chain and may be influenced by animal species, production system, and processing conditions. This study aimed to investigate and compare the multi-elemental composition of milk and selected dairy products obtained from organic, conventional, and commercial production systems in north-western Romania. A total of 307 samples, including raw milk from different animal species (cow, goat, buffalo, donkey) as well as yogurt, cheese, and mozzarella, were collected from farms and retail outlets. Samples were subjected to standardized microwave-assisted acid digestion and analyzed for toxic and essential elements (Pb, Cd, Hg, As, Cr, Ni, Al, Sn, Cu, and Zn) using inductively coupled plasma mass spectrometry (ICP-MS), with quality assurance ensured through certified reference materials and proficiency testing. The results indicated low concentrations of toxic metals across all dairy matrices, with Pb ranging from 0.0047 to 0.0117 mg/kg, Cd from 0.0008 to 0.0011 mg/kg, and As from 0.0007 to 0.0664 mg/kg, depending on animal species and production system. Mercury was consistently below the limit of detection in all datasets (LCD = 100%). Essential and transition elements were systematically quantified, occurring within expected ranges (Al: 0.021-0.264 mg/kg; Cu: 0.078-0.270 mg/kg; Zn: 3.245-7.963 mg/kg; Sn ≈ 0.0030-0.0035 mg/kg). All toxic element concentrations were below the maximum limits established by European Union legislation. Variations in elemental profiles were observed between animal species and production systems, with organic cow milk showing the most homogeneous composition. All toxic element concentrations were below the maximum limits established by European Union legislation. Overall, the findings confirm the safety of the analyzed dairy products and emphasize the relevance of multi-elemental monitoring as a practical tool for dairy supply chain surveillance and risk assessment.

Atmospheric deposition of emerging contaminants, including toxic trace elements, remains a critical environmental and public health concern. Moss biomonitoring offers a sensitive and cost-effective tool for assessing airborne pollutants, yet traditional analyses rely on descriptive statistics and lack predictive and mechanistic insights. Here, we introduce Mosses ML, a machine-learning-enhanced framework that integrates moss biomonitoring with bulk and dry deposition measurements to improve detection, interpretation, and risk assessment of atmospheric contaminants. Using Hylocomium splendens transplants exposed for 90 days across industrial, urban, and rural sites in Upper Silesia (Poland), we combined trace element accumulation (Cd, Pb, Zn, Ni, Cr, Fe), relative accumulation factors (RAFs), PCA-derived gradients, and site-level metadata with Random Forest and Gradient Boosting models. ML algorithms achieved high predictive performance (R² up to 0.91), accurately estimating moss metal concentrations from deposition metrics and environmental variables. SHAP feature-importance analysis identified dry deposition load and co-occurring metal signals as the dominant predictors of contamination, confirming the primary role of particulate emissions in shaping moss chemistry. Compared with classical threshold-based classification, the ML approach improved high-risk site identification by 24-38%. Mosses ML combines biologically meaningful indicators with modern computational tools, strengthening the role of mosses as early-warning systems for atmospheric pollution. The framework is broadly applicable to bryophyte biomonitoring and supports regulatory decision-making for emerging contaminants.

Clinoptilolite is a zeolite with a microporous structure that enables ion exchange, molecular sieving, and adsorption, conferring detoxifying, antioxidant, and anti-inflammatory properties. These properties have applications in food, medicine, catalysis, and environmental remediation. This study evaluated the safety of the lab-made Clinoptilolite as a potential food ingredient through a 90-day repeated-dose toxicity study in male and female Sprague Dawley rats. The test substance was administered via oral gavage at doses of 0, 5, 10, and 15 mg/kg bw/day, followed by a 28-day recovery period. In addition, genotoxicity was assessed using the Ames test, in vitro chromosomal aberration assay, and an in vivo micronucleus test. All studies were conducted in accordance with OECD and FDA guidelines. Results showed no adverse systemic, genotoxic, or irreversible effects at any dose, with minor clinical variations being incidental and reversible. Genotoxicity tests confirmed no mutagenic or clastogenic potential. Overall, the lab-made Clinoptilolite evaluated in this investigation was well tolerated, non-toxic, and showed no evidence of treatment-related toxicity at the doses tested. These findings provide supportive evidence for its consideration toward a Generally Recognized as Safe (GRAS) determination.

Per- and polyfluoroalkyl substances (PFAS) are global pollutants, yet data from tropical freshwater ecosystems remain scarce. This study provides the first assessment of PFAS occurrence in the Rusizi delta (Burundi), from tributaries to Lake Tanganyika, by analyzing water, sediment, macrophytes, and fish, and by evaluating human health risks from fish consumption. In water, only PFOA (<0.60-7.80 ng/L) was detected and showed a uniform spatial distribution. Sediment concentrations were largely below quantification limits, likely reflecting unfavorable sorption conditions. Macrophytes were dominated by short-chain PFAS, particularly PFBS, without consistent species- or site-specific patterns, supporting their potential as biomonitors of cumulative PFAS exposure. Fish exhibited the highest PFAS diversity, with more diverse profiles in liver than muscle, although tissue-specific patterns were often absent. PFBS was dominant across fish species, and emerging PFAS (e.g., PFBS and NaDONA) were frequently detected. Human health risks from fish consumption were, except for children, mostly below EFSA tolerable weekly intake values for regulated PFAS, but potential concern for adolescents and adults emerged when PFAS were expressed as PFOA equivalents. This study provides essential baseline data for tropical freshwater systems and highlights the need for expanded PFAS monitoring and risk assessment in data-poor regions.

In this study, the gradient pressure enrichment method was first used to screen out an environmental bacterium with the degradation ability of typical petroleum hydrocarbons such as phenanthrene and n-hexadecane, identified as Pseudomonas and named TB-1, from soil samples collected from 9 crude oil-contaminated sites; then, enhanced degradation of mixed organic pollutants, including petroleum and chlorinated hydrocarbons which are commonly coexistent, was achieved by a dual-bacteria system, with the addition of a laboratory storage strain Pseudomonas BL5. The degradation rate of phenanthrene and n-hexadecane by the dual-bacteria system was lower compared with the single bacterium Pseudomonas TB-1 under the tested conditions: phenanthrene degradation decreased from 44.2% to 23.1%, and n-hexadecane degradation decreased from 77.9% to 54.7% at a pollutant concentration of 100 mg/L after 7 days of cultivation. In contrast, the degradation ability of the dual-bacteria system against the mixed pollutants composed of petroleum and chlorinated hydrocarbons was good, with a degradation rate of 82.2% for phenanthrene, 89.2% for n-hexadecane, 73.1% for p-chlorobenzene, and 95.7% for dichloroethane with each concentration of 100 mg/L after 7 days. These results indicate that, although the dual-bacteria system does not enhance degradation under single-hydrocarbon conditions, its performance under chemically complex co-contamination suggests a potential cooperative or complementary interaction between the two strains. Such interactions are proposed here as a working hypothesis rather than a confirmed mechanism. Overall, the defined dual-Pseudomonas system shows promising potential for the treatment of environments co-contaminated with petroleum and chlorinated hydrocarbons.

With the increasing detection of micro- and nanoplastics (MNPs) in marine environments and the expanding body of related research, their environmental behavior and ecological effects have become central topics in marine environmental science. This review addresses the growing concern over MNP pollution in the marine realm, encompassing their primary sources, spatial accumulation and distribution, environmental transport and transformation dynamics, and ecotoxicological effects on marine organisms and ecosystems, as well as the ecological risks they pose within key habitats such as seagrass beds and coral reefs. We synthesize evidence on the biological impacts of MNPs, including oxidative stress, tissue accumulation, metabolic disturbances, and immune impairment, as well as the heightened risk of pathogen transmission facilitated by the so-called "Plastisphere". Moreover, we explore the potential implications of MNP exposure on oceanic carbon cycling and net primary productivity. The reviewed literature suggests that MNPs are capable of long-range transport and progressive fragmentation into ultrafine particles, which are readily ingested and retained by a wide array of marine organisms, subsequently inducing toxicological effects and compromising both organismal health and ecological integrity. Such disturbances may undermine critical ecosystem services, including carbon sequestration capacity and food web stability. Finally, based on the current research landscape, we outline future research priorities: improving environmental detection and toxicological evaluation of MNPs, elucidating their long-term effects at the ecosystem scale, and investigating their interactions with co-occurring pollutants under complex, multi-stressor scenarios. These efforts are essential to support science-based assessment and effective management strategies for marine MNP pollution.