Journal of Toxicology and Environmental Health-Part A-Current Issues最新文献

Sex ratio at birth (SRB) is a simple, noninvasive way to monitor the reproductive health of a population. Sex ratio at birth tends to vary across regions and time periods and has been declining globally over the last 50 years possibly due to exposure to environmental toxins, including endocrine-disrupting chemicals (EDCs) and other pollutants. The findings of few studies that assessed the relationship between ambient air pollution and SRBs have been inconsistent. The aim of this study was to investigate the possible association between long-term exposure to ambient PM_2.5 and number of SRBs across 66 municipalities in Taiwan. Our data on annual numbers of male and female births were obtained from Taiwan's Department of Household Registration, Ministry of Interior Affairs, while PM_2.5 data were obtained from Taiwan's Environmental Protection Administration (TEPA). Mean PM_2.5 levels and number of SRBs were calculated for each municipality from 2010 to 2023. The municipalities were categorized into PM_2.5 tertiles (low, medium, and high levels) and the relationship assessed between these tertile levels and number of SRB using a linear logistic regression model. Compared to the lowest PM_2.5 level, the adjusted ORs for the middle and the highest tertile of PM_2.5 levels were 1.015 (1.006-1.024) and 1.018 (1.008-1.029), respectively, noting a significant trend linking increased number of SRBs with higher PM_2.5 levels. This finding is inconsistent with the known fact that male fetuses are more susceptible to environmental threats compared to female fetuses.

Inhalation of emissions from dimensional (3D) printing with polycarbonate feedstock generated particulate and volatile chemicals as well as respirable bisphenol A (BPA). BPA is a known endocrine disruptor that affects both reproductive and metabolic endocrine functions. The goal of this study was to determine whether exposure to emissions generated by 3D-printing with PC stock disrupted endocrine function in a male Sprague Dawley rat model. In the current study, inhalation of 3D emissions (3DE) at an average 2.5 mg/m³/day increased circulating estradiol levels after 15 and 30 days' exposure, and elevated testosterone levels after 15 days 3DE exposure. Changes also occurred in circulating concentrations of the anterior pituitary hormone and thyroid stimulating hormone (TSH) following 30 days' exposure to 3DE. These alterations in circulating steroid hormones were associated with changes in gonadotropin and thyroid stimulating hormone (Tsh) transcript levels in pituitary and estradiol receptor as well as in transcripts for inflammatory factors in olfactory bulb and gonadotropin releasing hormone transcript levels in the hypothalamus. Data are in agreement with studies demonstrating that exposure to BPA results in endocrine disruption. These findings are also consistent with the hypothesis that inhalation of 3DE may constitute another route of exposure that needs to be considered taking into account the endocrine disrupting effects generated by inhalation of 3DE.

Engineered stone (ES) fabrication generates respirable dust containing crystalline silica (CS), linked to accelerated silicosis outbreaks. Mechanisms underlying this toxicity, particularly the role of particle aging, remain unclear. In the occupational setting, workers are exposed to engineered stone dust (ESD) upon generation by cutting and grinding ES; however, ESD-initiated toxicity is frequently studied in labs using aged particles. This study aimed to compare radical generation and in vitro cytotoxicity of fresh versus aged ESD. Three different respirable ES types (ES A: 60% CS; B: 20%; C: 0%), granite (30%), and Min-u-Sil 5 (MS5, 99.5%) were generated using an automated cutting system and analyzed either freshly stored under N₂ at -80°C or after aging in air at room temperature for 2 weeks. RAW 264.7 macrophages were exposed to particles (10 µg/well, 100 µg/ml, 31.25 µg/cm², 24 hr), and viability, apoptosis, necrosis, and intracellular reactive oxygen species (ROS) were measured. Fresh ESD/granite exhibited significantly higher electron paramagnetic resonance (EPR) radical signals than aged counterparts and MS5. Fresh ES/granite reduced macrophage viability, while aged materials/MS5 did not. Apoptosis increased with all particles where fresh/aged difference occurred only in ES B. Necrosis rose markedly with fresh ES A. Intracellular ROS was elevated by some materials, but N-acetylcysteine (NAC) antioxidant failed to prevent cytotoxicity induced by fresh particles. In conclusion, freshly generated ESD displayed greater radical-generating capacity and distinct cytotoxic effects compared to aged ESD, influenced by factors beyond CS content. ROS-independent mechanisms appear crucial for acute cytotoxicity. These findings indicate particle aging as a critical factor in ESD toxicological assessment.

Short- and ultra-short per- and polyfluoroalkyl substances (PFAS) such as perfluorobutanoic acid (PFBA, 4C), perfluorobutane sulfonic acid (PFBS, 4C), trifluoroacetic acid (TFA, 2C) and trifluoromethane sulfonic acid (TFMS, 1C) were detected in various environmental matrices, but studies addressing the effects attributed to exposure are still scarce. This study aimed to (1) investigate acute toxicity of these emerging PFAS using Daphnia magna (immobility, mortality, reproduction, and body size) and Hydra vulgaris (morphological changes and reproduction) and (2) assess the sub-chronic/chronic toxicity of TFA in both species. Glutathione S-transferase (GST) activity was also assessed in both species after long-term exposure to TFA. Chemical analysis confirmed presence and stability of the 4 PFAS in exposure media. For all tested PFAS, endpoints examined after acute tests were not markedly affected by exposure and LC₅₀ values were > 1000 mg/L. However, this toxicity was significantly affected by media acidification induced by the tested chemicals (LC₅₀ = 316 and 31,6 mg/L for D. magna and H. vulgaris, respectively). Long-term exposure to TFA did not significantly induce any effect on both species and GST levels were not altered. Overall, results suggest lower toxicity of ultra/short-chain PFAS to these species under selected exposure conditions. However, additional studies investigating multigenerational effects of these PFAS using realistic environmental concentrations are needed to overcome the significant gaps in our understanding of short/ultra-short PFAS-induced toxicity.

Glyphosate is the most widely used herbicide worldwide; however, most toxicity studies utilizing plants have been conducted in aqueous solutions, thus overlooking the role of soil properties in modulating herbicidal effects. The aim of this study was to examine the phyto-, cyto-, and genotoxic responses following Allium cepa exposure to glyphosate-contaminated soil. This would thus address a critical knowledge gap regarding herbicide-initiated toxicity under realistic environmental conditions. Glyphosate concentrations were tested in a geometric series with a 2× ratio, ranging from 1 to 1024 mg a.i./kg of soil, based upon levels found in agricultural environments. The parameters examined included germination rate, root length, cell viability, mitotic index, and frequency of chromosomal alterations. Glyphosate concentrations ranging from 16 to 1024 mg a.i./kg inhibited root growth and damaged cell membrane integrity, whereas levels from 1, 4, and 128 mg a.i./kg increased cell division associated with reduced mitotic index at 512 mg a.i./kg. Genotoxic effects were observed from 4 to 1024 mg a.i./kg. While low and intermediate concentrations primarily triggered genotoxic effects, the highest concentrations (256 to 1024 mg a.i./kg) promoted marked cytotoxicity. These findings provide novel evidence that glyphosate in soil might induce biphasic and multiparametric responses in A. cepa, reinforcing the importance of using soil-based bioassays for environmental risk assessment.

The aim of this study was to investigate oxidative stress, biotransformation and bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) in tropical estuarine food webs including fish (Chrysicthys nigrodigitatus), fiddler crab (Uca tangeri), blue crab (Calinectis amnicola), prawn (Macrobrachium vollenhovenii), periwinkle (Tympanotonus fuscatus) and sediment samples at three sites, Adiabo (control site), Obutong and Nsidung representing different degrees of anthropogenic contamination along Cross River Estuary, Nigeria. Hepatic oxidative stress and biotransformation enzyme activities glutathione peroxidase (Gpx), glutathione reductase (Gr), glutathione S-transferase (Gst), uridine diphosphate glucuronosyltranferease (Udpgt), 7-ethoxy-, methoxy-, pentoxy-, and benzyloxyresorufin O-deethylase (EROD, MROD, PROD and BROD) and PAHs levels were determined. Data demonstrated species- and site-specific mediated toxicological effects in oxidative stress, biotransformation responses, and PAHs bioaccumulation in biota and sediments from contaminated sites (Obutong and Nsidung), compared to control (Adiabo). The EROD, MROD, BROD, PROD activities and GPx, Gr, Gst, Udpgt exhibited significant increase in biota collected from contaminated sites at Obutong and Nsidung compared with control Adiabo. These biomarker response observations paralleled PAHs accumulation at Obutong and Nsidung suggesting PAHs exposure induced oxidative and biotransformation biomarker responses. Principal component analysis (PCA) produced significant associations between variables indicating sites were major factors determining contaminants uptake and biomarker responses in biota (fish, crabs, prawn and periwinkle). Data demonstrated site and species-specific occurrence and concentrations of PAHs in sediment and tropical estuarine food webs with corresponding biotransformation and oxidative stress responses on resident biota. Concentrations of PAHs detected in these tropical food webs indicate serious human food safety and environmental health concerns.

Industrial effluents may contain a wide range of contaminants capable of producing adverse environmental effects even after conventional treatment. This study aimed to assess the phytotoxic potential of effluents derived from a waste treatment company located in a rural area of Minas Gerais, Brazil, by integrating physicochemical analyses and terrestrial plant bioassays. Samples were collected from raw and treated effluents, as well as nearby surface waters, and tested using four plant species: Lactuca sativa, Phaseolus vulgaris, Cenchrus americanus, and Zea mays. Biological endpoints included germination percentage (%G), germination speed index (GSI), fresh biomass, and seedling growth parameters. The treated effluent exhibited elevated levels of biochemical oxygen demand (BOD), nickel, and surfactants, which exceeded environmental regulatory limits. Among the tested species, L. sativa demonstrated the highest sensitivity across all endpoints, displaying an average inhibition of 31.59% and the highest Integrated Biological Response (IBR) value. The combination of sensitivity indices and IBR confirmed the toxic potential of treated effluent, emphasizing the relevance of bioassays as complementary tools to traditional physicochemical assessments. These findings indicate the limitations of current treatment processes and reinforce the need for ecotoxicological monitoring using multiple plant models to detect sublethal and potentially genotoxic effects of effluent discharge on terrestrial and aquatic ecosystems.

Sex ratio at birth (SRB) is a simple, noninvasive way to monitor population reproductive health. Some metals might function as endocrine-disrupting chemicals (EDCs) with known estrogenic or androgenic effects and were reported to potentially influence SRBs. The metal arsenic (As) is a major risk factor for blackfoot disease (BFD), a peripheral vascular disease, endemic to southwest Taiwan for more than 50 years attributed to residents' consumption of local artesian well water, which contained high levels of this metal. In the early 1960s, a tap water supply system was implemented in BFD-endemic areas. By the mid-1970s, individuals residing in the areas had stopped using artesian well water for drinking or cooking. The aim of this study was to investigate the effects of long-term exposure to As in drinking water on the SRBs. Annual numbers of male and female births were obtained from Taiwan's Department of Household Registration, Ministry of Interior Affairs. Sex ratios at birth were calculated for BFD-endemic areas for the years from 1947 to 2024. Compared to the entire Taiwan, the BFE-endemic area displayed an odds ratio (OR) of 0.9966 (95% CI = 0.9804-1.013) for producing a male child between 1947 and 1980. However, from 1980 onwards, the OR for having a boy was significantly increased in the areas (OR = 1.0311, 95% CI = 1.0114-1.0512) compared to the time residents imbibed water from artesian well water containing high amounts of As (1947-1980). These findings provide increasing evidence that As exposure produced changes in SRBs in Taiwan.

Tobacco consumption remains one of the leading causes of preventable diseases and deaths worldwide. Among its major constituents, nicotine (NIC) and tobacco-specific nitrosamines (TSNAs) stand out attributed to their toxicological and carcinogenic potential. While NIC is primarily recognized for its addictive properties, TSNAs such as N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are well-established procarcinogens derived from nicotine metabolism. Although the genotoxic and mutagenic effects of NNN and NNK have been extensively documented, the impact of their combined exposure with NIC remains poorly understood. This study investigated the mutagenic and recombinogenic activities of NIC in association with NNN and NNK in vivo using the Drosophila melanogaster wing somatic mutation and recombination test (SMART). Two experimental designs were applied: the standard cross, with basal levels of cytochrome P450-dependent metabolic activity, and the high bioactivation cross, characterized by elevated P450 levels essential for metabolic activation of procarcinogens and promutagens. Data demonstrated that NIC, NNN, and NNK tested individually did not significantly alter mutant clone frequencies. However, combined treatment of NNN 0.001 mg/ml and NNK 0.001 mg/ml in the high bioactivation cross induced a significant rise in total frequency of mutant spots. Further analysis revealed that 73.5% of induced genetic alterations were attributable to somatic recombination events. These findings demonstrate the genotoxic potential of combined TSNAs, suggesting that simultaneous exposure may potentiate genetic damage primarily through recombination mechanisms, emphasizing an important risk factor for tobacco-related health outcomes.

Hexavalent chromium (Cr(VI)) contamination poses persistent risks to aquatic ecosystems and human health, requiring the development of adsorbents that combine rapid uptake, high capacity, and easy magnetic recovery. The aim of this study was to synthesize a novel graphene oxide/nickel ferrite nanocomposite (GO/NiFe₂O₄) utilizing a hydrothermal route to integrate the surface functionality of GO with ferrimagnetic properties of NiFe₂O₄ for efficient Cr(VI) removal. The hybrid material was characterized by SEM-EDS, XRD, FT-IR, Raman spectroscopy, and vibrating sample magnetometry, confirming ferrimagnetic behavior at room temperature and retention of GO's oxygenated functional groups that serve as high-affinity binding sites. Batch adsorption experiments (40-300 mg/L) in an acidic medium revealed rapid kinetics and short equilibrium times. Nonlinear modeling identified the Elovich model as the best fit, indicating heterogeneous surface energies and multistage mass transfer. Equilibrium data (20-40 °C) fitted the Sips isotherm, confirming heterogeneous multilayer adsorption. Thermodynamic parameters (ΔG⁰ < 0; ΔH⁰ < 0) indicated a spontaneous and exothermic process. Regeneration tests using HCl demonstrated efficient desorption and reusability. The proposed mechanism involves electrostatic attraction of Cr(VI) oxyanions, interfacial reduction to Cr(III), coordination to ferrite and oxygenated sites, and post-reduction cation-π stabilization acting synergistically. These results demonstrate the novelty of this study-the first systematic integration of Elovich and Sips modeling to correlate kinetic and equilibrium behaviors in a GO/NiFe₂O₄ system-providing mechanistic insight and confirming the material's high performance and reusability for scalable Cr(VI) remediation.