Environmental analysis, health and toxicology最新文献

Petroleum-powered generators are commonly used in many developing countries as an alternative to meet utility demands. Generator exhaust emission significantly contributes to air pollution, which remains a constant threat to human health due to the presence of aromatic hydrocarbons and other harmful gases. This study assessed oxidative stress parameters in response to exhaust emission from gasoline generator engine in adult male wistar rats. Forty-eight (48) adult wistar rats weighing between 180-200g were randomly allocated to four (4) groups (A-D) of twelve (12) rats each. After the acclimatization period, the control group (A) were kept unexposed, whereas rats in groups (C-D) were exposed daily at 2, 4, and 8-hour intervals for 4, 8, and 12 weeks, respectively. Tissue samples were obtained at four weeks intervals. Fresh lung tissues weighing 1g were rinsed twice in phosphate-buffered saline (PBS, pH 8.0), homogenized and centrifuged at 3000 revolutions per minute for 20 min at 4°C. Supernatant levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST), reduced glutathione (GSH), nitric oxide (NO), hydrogen peroxide (H2O2), catalase (CAT), and total antioxidant status (TAS) were determined using standard protocols. The findings revealed elevated oxidant levels of MDA, NO, and H2O2, whereas SOD, GPX, GST, GSH, CAT, and TAS were significantly reduced across the exposure time points compared to the unexposed control rats (p < 0.05). The research findings revealed that exposure to emissions from gasoline generators induced oxidative stress in the exposed rats, with the extent of disruption to their oxidative balance dependent on the duration and length of exposure time.

Boric acid (BA) is a weak acid and the simplest compound resulting from the dissolution of boron in water. There is great competition to determine whether boron is an essential or nonessential nutrient. Date molasses is a potent type of sweetener with valuable components, such as flavonoids and phenolics, and has significant health benefits. This study investigated the neuro-essentiality and neurotoxicity of boric acid boron in adult male albino rat cortex and cerebellum brain areas and the impact of date molasses treatment. Animals were grouped into the following groups: control, low and high boric acid doses, 10 and 500 mg/kg, respectively, with or without 250 mg/kg date molasses. The results revealed the ability of BAs to cross the blood-brain barrier and accumulate in the cerebellum and cortex, revealing the ability of date molasses to decrease BA accumulation at different time intervals. Additionally, the results varied between a nonsignificant increase or decrease in calcium ion content, monoamines (norepinephrine, dopamine, and serotonin), glucose, adenosine triphosphate, malondialdehyde and glutathione, depending on the BA dose. Moreover, date molasses mitigated any unwanted BA results. In conclusion, boric acid, which is within a permissible limit, could be essential and have a neuroprotective effect, whereas at a sublethal level, it could have a neurotoxic effect. Additionally, Date molasses can have neuroprotective effects and antagonize the neurotoxic effects of boric acid through its antioxidant and scavenging effects.

Snakebite by a cobra is considered neurotoxic as the cause of neuromuscular paralysis mediated by low molecular weight toxins, which are major toxin components of cobra. However, these toxins represent a problem in generating antibodies owing to their low immunogenicity. Developing complementary strategies to improve the antibody response could be a useful approach to creating better therapeutic antivenoms with higher neutralizing potencies. To develop simple immunization strategies for more potent antivenoms by studying the effects of combining crude cobra venom and toxin fraction in a complementary way. The evaluation of specific cell immunology and cytokine mediators for relevant immune responses will be measured in a rabbit model using four simple immunization strategies. Flow cytometry will be used to quantify the number of B and T cells, and qRT-PCR will be used to ascertain the cytokine genes expressed. B cells with anti-CD20 were seen on D14, and a booster dose was insufficient to maximize the antibodies. Conversely, anti-CD5 for T cells decreased periodically but remained stable. Using a mixture of crude cobra venom and its <10 kDa fraction, peak expression of pro-inflammatory cytokine genes was seen in D42 or D58, with a rise of 4 and 6 folds. Similarly, gene expression of pro-inflammatory cytokines was greater than that of anti-inflammatory cytokines (IL-4 and IL-10), which were up-regulated after D42. Thus, immunization with both the crude and its <10 kDa fraction of cobra venom seems to have synergistic effects that boost cytokines, activate the immune system, and cause lymphocyte differentiation.

Polycyclic aromatic hydrocarbons are pervasive in the atmosphere, originating from sources like vehicle emissions and incomplete combustion. Exposure to PAHs occurs through diet, tobacco smoke, and air pollutants, and they are recognized as carcinogens. This study, conducted from July to October 2021 in Seoul, Gyeonggi, and Ulsan regions, focused on taxi drivers, a group with elevated PAH exposure due to prolonged vehicle use. The study involved 19 male taxi drivers and 46 control participants (18 male, 28 female). LC-MS/MS analysis was employed to quantify urinary levels of 18 hydroxy-PAHs, oxidative damage markers (MDA, 8-OHdG), and cotinine. The detection rates of OH-PAHs were 1-naphthol (96.9 %), 2-naphthol (90.8 %), 2-hydroxyfluorene (86.2 %), and 1-hydroxypyrene (80.0 %). Compared to the male controls, taxi drivers showed higher median concentrations of 2-OH-Na (1.698 ng/mL), 1-OH-Na (0.666 ng/mL), 2-OH-Flu (0.067 ng/mL), and 1-OHP (0.045 ng/mL). Similarly, significant differences were observed between taxi drivers and female controls for 1-OH-Na, 2-OH-Na, 2-OH-Flu, 3-OH-Phe, and 1-OHP. MDA and 8-OHdG were detected in over 90% of all groups, with significant differences between taxi drivers. Strong positive correlations were revealed between urinary OH-PAHs, MDA, and 8-OHdG (r ranging from 0.589 to 0.770, p<0.01). The findings suggest that taxi drivers, due to prolonged exposure to traffic-related air pollutants, have elevated levels of PAH metabolites and oxidative stress, especially among smokers. Further studies with larger sample sizes are recommended to validate these results and explore the long-term health implications of occupational PAH exposure in urban transportation workers..

In November 2021, a bridge was constructed over Yeongrang Lake by placing large cement blocks on the lakebed, leading to ecological consequences. Thus, this study assessed the distribution of metals to evaluate the risk in the aquatic environment of the lake. Ten metals were monitored in water, sediment, and fish samples across four seasons. The samples were analyzed using inductively coupled plasma-optical emission spectrometry (ICP-OES) after treatment with nitric acid. During the sampling period, the distribution of metals in water followed the order of Fe > Cu > Al > Zn > Mn > Pb > Ni > Cr > Cd > V, while in sediment, it was Fe > Al > Mn > Zn > V > Pb > Cu > Cr > Ni > Cd. Cu and Cd levels exceeded the criteria and threshold effect levels set by the U.S. Environmental Protection Agency. Although no significant seasonal variations were observed, the ecological risk was considered significant. Situated near the East Sea, the lake has shown signs of salinization after the construction of the bridge. Cu, Mn, and Zn exhibited the highest bioconcentration factors in both benthic and floating fish. Nevertheless, an improved sampling strategy is necessary to verify the bioconcentration of metals in fish in future studies. The hazard index exceeded 1 in a human risk assessment related to fish consumption. However, the actual risk is anticipated to be lower, considering the fish consumption pattern. This study highlights the importance of management actions in reducing ecological risks.

The evaluation of respiratory chemical substances has been mostly performed in animal tests (OECD TG 403, TG 412, TG 413, etc.). However, there have been ongoing discussions about the limited use of these inhalation toxicity tests due to differences in the anatomical structure of the respiratory tract, difficulty in exposure, laborious processes, and ethical reasons. Alternative animal testing methods that mimic in vivo testing are required. Therefore, in this study, we established a co-culture system composed of differentiated epithelial cells under an air-liquid interface (ALI) system in the apical part and fibroblasts in the basal part. This system was designed to mimic the wound-healing mechanism in the respiratory system. In addition, we developed a multi-analysis system that simultaneously performs toxicological and functional evaluations. Several individual assays were used sequentially in a multi-analysis model for pulmonary toxicity. Briefly, cytokine analysis, histology, and cilia motility were measured in the apical part, and cell migration and gel contraction assay were performed by exposing MRC-5 cells to the basal culture. First, human airway epithelial cells from bronchial (hAECB) were cultured under air-liquid interface (ALI) system conditions and validated pseudostratified epithelium by detecting differentiation-related epithelial markers using Transepithelial Electrical Resistance (TEER) measurement, Hematoxylin and Eosin (H&E) staining, and immunocytochemistry (ICC) staining. Afterward, the co-culture cells exposed to Transforming growth factor-beta 1 (TGF-β1), a key mediator of pulmonary fibrosis, induced significant toxicological responses such as cytotoxicity, cell migration, and gel contraction, which are wound-healing markers. In addition, cilia motility in epithelial cells was significantly decreased compared to control. Therefore, the multi-analysis model with a 3D epithelial-fibroblast co-culture system is expected to be useful in predicting pulmonary toxicity as a simple and efficient high-throughput screening method and as an alternative to animal testing.

Magnetite nanoparticles have attracted the attention of researchers for biomedical uses, but their impacts on the reproductive system did not report. Here, we have studied the possible attenuation efficiency of quercetin against magnetite nanoparticles-induced apoptosis in ovarian. Forty female rats were divided equally into control, quercetin (100 mg/kg), magnetite nanoparticles (50 mg/kg), and magnetite nanoparticles+quercetin, where all rats received their doses for four weeks. Compared with the control, magnetite nanoparticles significantly reduced the serum hormonal levels (follicle-stimulating hormone, luteinizing hormone, estrogen, and progesterone) along with glutathione and superoxide dismutase in ovarian tissues. Moreover, magnetite nanoparticles markedly increased the ovarian malondialdehyde, and apoptotic gene expressions (Bax and caspase-3), and induced many histopathological changes. Significantly, co-treatment with quercetin markedly alleviated the hormonal profile, antioxidant disturbance, and ovarian apoptotic pathway of magnetite nanoparticles. Furthermore, our docking study revealed that quercetin could act as a caspase-3 inhibitor and allosteric agonist to follicle-stimulating hormone (Met520 and Val53), luteinizing hormone (Met517, Ala589, Ser604, and Lys595), estrogen (Met421, Phe425, and Ala350), and progesterone (Met759 and Met909) receptors. Those records reveal that the antioxidants and antiapoptotic characteristics are acceptable pointers for female infertility defenders of quercetin, especially during nanoparticle exposure.

Solid waste disposal generates leachate, a mixture of deleterious chemical, physical and microbial contaminants, which poses risk to human and wildlife health. Leachate toxicity on relative organ weight and histopathology of important viscera in mammalian body is scarce. Leachate induced toxic effects on organosomatic indices and histopathology of vital mammalian organs were investigated. Wister rats were orally exposed to 1 - 25 % of raw and simulated leachates from Aba-Eku and Olusosun landfills for 30 days. At post-exposure, organosomatic index and histoarchitectural assessment of major viscera (heart, spleen, thymus and lungs) were conducted. The physico-chemical and organic compositions of the leachates were analysed using standard protocol. The tested leachates decreased weekly and terminal body weights, and altered organosomatic index of examined viscera in rats. The histoarchitecture of the investigated viscera revealed pathologies that ranged from mild to severe degeneration, cellular infiltration, haemorrhage, congestion, necrosis, disorganization of tissues and vacuolations. Others include increased histiocytes within the bronchial associated lymphoid, lymphoid depletions, haemosiderin deposits and apoptosis were observed in the examined viscera. Physico-chemical analysis of the leachates showed different concentrations of toxic metals, PAHs and PCBs that were higher than national and international permissible limits allowed in wastewaters. The physico-chemical compositions of the leachates are capable of eliciting the observed alterations in organosomatic indices and histopathological lesions in mammalian viscera. Xenobiotic components of the leachates possibly generated free radicals and/or directly disrupted the organ architectures. These findings suggest health risk to wildlife and human population exposed to emissions from waste landfills.

In Nigeria, limited research has been conducted on Microplastics (MPs) in inland rivers, necessitating a comprehensive assessment to understand the extent of contamination. This study aimed to assess the abundance, distribution, and composition of MPs in fishes, sediment, and water from inland rivers across Nigeria's six geopolitical zones. Samples were collected from selected rivers in each geopolitical zone (Rivers Yauri, Benue, Argungu, Jamare, Ogun, Ethiope and Orashi). MPs were isolated using a combination of filtration, density separation, and visual identification. MPs abundance, distribution, shapes, colors, and chemical composition were determined using microscopy and Fourier-transform infrared spectroscopy. The study presents the first report of MPs in six in land rivers in Nigeria and found that MPs were present in all the fishes, sediments and river waters studied across all the rivers. The abundance and composition of MPs varied among the different sample types, with fibers being the most abundant shape in both water and fish samples. PET, PP, and PE were the most prevalent types of plastics found in fish samples, while PE/PA/Nylon, PVA, and PVC were predominant in water samples. PA/Nylon, PUR, PVC, and PET were the most common in sediment samples. Source analysis by Principal component analysis (PCA) and Hierarchical Cluster Analysis (HCA) indicated that the presence of MPs was mainly influenced by local anthropogenic activities. However, estimated daily intakes are generally low, indicating that daily consumption of the samples is not likely to be harmful. The widespread presence of MPs in inland rivers across Nigeria highlights the urgent need for effective waste management strategies and environmental conservation efforts to mitigate plastic pollution.

Microplastics and nanoplastics (MNPs) represent a pervasive environmental pollutant, raising significant concerns about potential health effects on humans. These tiny plastic particles have been detected across various environmental matrices, including air, water, soil, and food sources. While the adverse impacts of MNPs on wildlife and ecosystems are well-documented, understanding their effects on human health is still in its infancy. This study aims to comprehensively review existing case reports documenting adverse health outcomes associated with MNPs exposure. Through an extensive literature search, relevant articles were identified and analyzed. MNPs exposure primarily occurs through ingestion and inhalation routes. Health effects on the digestive system include oxidative stress, inflammation, dysbiosis, and metabolic disorders, with cases linking MNPs exposure to gastrointestinal injury and liver dysfunction. Respiratory system impacts include asthma exacerbation and hypersensitivity pneumonitis, particularly in industries involving plastic production. MNPs exposure has also been associated with nervous system conditions, reproductive toxicity, skeletal system interference, excretory system disruption, and cardiovascular morbidity and mortality. Despite limited case reports, the widespread presence of MNPs warrants further investigation into their potential health risks. This study underscores the urgency of understanding and mitigating the adverse health effects posed by MNPs exposure. Further research is imperative in order to comprehensively assess and address the dangers associated with MNPs contamination in the environment.