Inhalation Toxicology最新文献

Rivers State, Niger Delta, Nigeria often referred to as the 'treasure bed of the nation' is the seat of crude oil production activities with the accompanying environmental degradation. The severity of the environmental pollution and contaminated air quality took a new turn for the worse in November 2016, when the residents of Port Harcourt city, Rivers State, a major oil producing State experienced for the first time, aerosol deposition of plumes of black soot. This systematic review paper is aimed at quantifying the severity of this public health challenge. Using appropriate search words, the following databases SCOPUS, PUBMED, Google Scholar, and AJOL were searched from 1990 to 2022 to enable comparative analyses of data before and after the emergence of black soot deposition. Air-related morbidities and mortalities such as cerebrospinal meningitis (CSM), chronic bronchitis, measles, pertussis, hemoptysis, cough, pulmonary tuberculosis, pneumonia, and upper respiratory tract infection (URTI), pneumonia, eye irritation, conjunctivitis, traumatic skin outgrowth, cancers, cardiovascular diseases, and child deformities were compared with levels of air pollutants and particulate matter. The results showed that Port Harcourt city's ambient air quality data were above the standard National Ambient Air Quality data and that of other regulatory agencies having higher levels of both inorganic and organic pollutants. There were significant relationships between air pollutants concentration with morbidities. These correlations were significant in the period covering 2016-2022. Consequently, it is concluded that the black soot emissions in Port Harcourt city, Nigeria has worsened the public health situation in the city.

Important differences in health that are closely linked with social disadvantage exist within and between countries. According to the World Health Organization, life expectancy and good health continue to increase in many parts of the world, but fail to improve in other parts of the world, indicating that differences in life expectancy and health arise due to the circumstances in which people grow, live, work, and age, and the systems put in place to deal with illness. Marginalized communities experience higher rates of certain diseases and more deaths compared to the general population, indicating a profound disparity in health status. Although several factors place marginalized communities at high risk for poor health outcomes, one important factor is exposure to air pollutants. Marginalized communities and minorities are exposed to higher levels of air pollutants than the majority population. Interestingly, a link exists between air pollutant exposure and adverse reproductive outcomes, suggesting that marginalized communities may have increased reproductive disorders due to increased exposure to air pollutants compared to the general population. This review summarizes different studies showing that marginalized communities have higher exposure to air pollutants, the types of air pollutants present in our environment, and the associations between air pollution and adverse reproductive outcomes, focusing on marginalized communities.

Sugarcane is the most widely cultivated crop in the world, with equatorial developing nations performing most of this agriculture. Burning sugarcane is a common practice to facilitate harvest, producing extremely high volumes of respirable particulate matter in the process. These emissions are known to have deleterious effects on agricultural workers and nearby communities, but the extent of this exposure and potential toxicity remain poorly characterized. As the epidemicof chronic kidney disease of an unknown etiology (CKDu) and its associated mortality continue to increase along with respiratory distress, there is an urgent need to investigate the causes, determine viable interventions to mitigate disease andimprove outcomes for groups experiencing disproportionate impact. The goal of this review is to establish the state of available literature, summarize what is known in terms of human health risk, and provide recommendations for what areas should be prioritized in research.

Objective: Our work is focused on tungsten, considered as an emerging contaminant. Its environmental dispersion is partly due to mining and military activities. Exposure scenario can also be occupational, in areas such as the hard metal industry and specific nuclear facilities. Our study investigated the cerebral effects induced by the inhalation of tungsten particles.

Methods: Inhalation exposure campaigns were carried out at two different concentrations (5 and 80 mg/m³) in single and repeated modes (4 consecutive days) in adult rats within a nose-only inhalation chamber. Processes involved in brain toxicity were investigated 24 h after exposure.

Results and discussion: Site-specific effects in terms of neuroanatomy and concentration-dependent changes in specific cellular actors were observed. Results obtained in the olfactory bulb suggest a potential early effect on the survival of microglial cells. Depending on the mode of exposure, these cells showed a decrease in density accompanied by an increase in an apoptotic marker. An abnormal phenotype of the nuclei of mature neurons, suggesting neuronal suffering, was also observed in the frontal cortex, and can be linked to the involvement of oxidative stress. The differential effects observed according to exposure patterns could involve two components: local (brain-specific) and/or systemic. Indeed, tungsten, in addition to being found in the lungs and kidneys, was present in the brain of animals exposed to the high concentration.

Conclusion: Our data question the perceived innocuity of tungsten relative to other metals and raise hypotheses regarding possible adaptive or neurotoxic mechanisms that could ultimately alter neuronal integrity.

Objective: The present work concentrated on validating whether sinomenine alleviates bleomycin (BLM)-induced pulmonary fibrosis, inflammation, and oxidative stress.

Methods: A rat model of pulmonary fibrosis was constructed through intratracheal injection with 5 mg/kg BLM, and the effects of 30 mg/kg sinomenine on pulmonary inflammation, fibrosis, apoptosis, and 4-hydroxynonenal density were evaluated by hematoxylin and eosin staining, Masson's trichrome staining, TUNEL staining, and immunohistochemistry. Hydroxyproline content and concentrations of inflammatory cytokines and oxidative stress markers were detected using corresponding kits. MRC-5 cells were treated with 10 ng/ml PDGF, and the effects of 1 mM sinomenine on cell proliferation were assessed by EdU assays. The mRNA expression of inflammatory cytokines and the protein levels of collagens, fibrosis markers, and key markers involved in the TLR4/NLRP3/TGFβ signaling were tested with RT-qPCR and immunoblotting analysis.

Results: Sinomenine attenuated pulmonary fibrosis and inflammation while reducing hydroxyproline content and the protein expression of collagens and fibrosis markers in BLM-induced pulmonary fibrosis rats. Sinomenine reduced apoptosis in lung samples of BLM-challenged rats by increasing Bcl-2 and reducing Bax and cleaved caspase-3 protein expression. In addition, sinomenine alleviated inflammatory response and oxidative stress in rats with pulmonary fibrosis induced by BLM. Moreover, sinomenine inhibited the TLR4/NLRP3/TGFβ signaling pathway in lung tissues of BLM-stimulated rats. Furthermore, TLR4 inhibitor, TAK-242, attenuated PDGF-induced fibroblast proliferation and collagen synthesis in MRC-5 cells.

Conclusion: Sinomenine attenuates BLM-caused pulmonary fibrosis, inflammation, and oxidative stress by inhibiting the TLR4/NLRP3/TGFβ signaling, indicating that sinomenine might become a therapeutic candidate to treat pulmonary fibrosis.

Objective: The purpose of these studies was to investigate the uptake of atrazine across the nasal mucosa to determine whether direct transport to the brain through the olfactory epithelium is likely to occur. These studies were undertaken to provide important new information about the potential for the enhanced neurotoxicity of herbicides following nasal inhalation.

Materials and methods: Transport of atrazine from aqueous solution and from commercial atrazine-containing herbicide products was assessed using excised nasal mucosal tissues. The permeation rate and the role of membrane transporters in the uptake of atrazine across the nasal mucosa were also investigated. Histological examination of the nasal tissues was conducted to assess the effects of commercial atrazine-containing products on nasal tissue morphology.

Results: Atrazine showed high flux across both nasal respiratory and olfactory tissues, and efflux transporters were found to play an essential role in limiting its uptake at low exposure concentrations. Commercial atrazine-containing herbicide products showed remarkably high transfer across the nasal tissues, and histological evaluation showed significant changes in the morphology of the nasal epithelium following exposure to the herbicide products.

Discussion: Lipophilic herbicides such as atrazine can freely permeate across the nasal mucosa despite the activity of efflux transporters. The adjuvant compounds in commercial herbicide products disrupt the nasal mucosa's epithelial barrier, resulting in even greater atrazine permeation across the tissues. The properties of the herbicide itself and those of the formulated products play crucial roles in the potential for the enhanced neurotoxicity of herbicides following nasal inhalation.