Understanding the pathogenesis of occupational coal and silica dust-associated lung disease

Occupational exposure to silica and risk of gastrointestinal cancers: a systematic review and meta-analysis of cohort studies

BACKGROUND

Although silica is a proven lung carcinogen, there is no convincing evidence linking crystalline silica to gastrointestinal malignancies.

METHODS

We detailedly searched studies on the link between gastrointestinal malignancies and occupational silica exposure. Studies published between 1987 and 2023 were found by searching PubMed, Scopus, Cochrane Library, and Web of Science databases. Further studies were included from reference searching. We conducted a meta-analysis of the incidence and mortality of gastrointestinal malignancies and occupational silica exposure. We computed pooled-risk estimates using random effects models. Egger's regression asymmetry test and a funnel plot were used to identify publication bias. Moreover, sensitivity analysis and subgroup analysis were out.

RESULTS

We identified 40 research with individuals from 13 different countries. The results indicate that occupational silica exposure raises the risk of gastric and esophageal cancer incidence, with pooled standardized incidence ratio of 1.35 (95% CI 1.21-1.51, p < 0.001), 1.31 (95% CI 1.04-1.65, p = 0.023), respectively, but there was a lack of statistically significant relationship between standardized mortality ratio. In addition, we found that silica exposure did not increase the risk of colorectal and pancreatic cancers. Occupational silica exposure was found to increase the risk of liver cancer, with pooled SIR and SMR of 1.19 (95% CI 1.04-1.35, p = 0.009), 1.24 (95% CI 1.03-1.49, p = 0.026), respectively.

CONCLUSIONS

We discovered a link between occupational silica exposure and gastrointestinal malignancies, with cancers of the liver, stomach, and esophagus being the most prevalent. Colorectal and pancreatic cancer were not linked to occupational silica exposure.

Structure-based multitargeted docking screening, pharmacokinetics, DFT, and dynamics simulation studies reveal mitoglitazone as a potent inhibitor of cellular survival and stress response proteins of lung cancer

Lung cancer is a disease in which lung cells grow abnormally and uncontrollably, and the cause of it is direct smoking, secondhand smoke, radon, asbestos, and certain chemicals. The worldwide leading cause of death is lung cancer, which is responsible for more than 1.8 million deaths yearly and is expected to rise to 2.2 million by 2030. The most common type of lung cancer is non-small cell lung cancer (NSCLC), which accounts for about 80% and small cell lung cancer (SCLC), which is more aggressive than NSCLC and is often diagnosed later and accounts for 20% of cases. The global concern for lung cancer demands efficient drugs with the slightest chance of developing resistance, and the idea of multitargeted drug designing came up with the solution. In this study, we have performed multitargeted molecular docking studies of Drug Bank compounds with HTVS, SP and XP algorithms followed by MM\GBSA against the four proteins of lung cancer cellular survival and stress responses, which revealed Mitoglitazone as a multitargeted inhibitor with a docking and MM\GBSA score ranging from - 5.784 to - 7.739 kcal/mol and - 25.81 to - 47.65kcal/mol, respectively. Moreover, we performed pharmacokinetics studies and QM-based DFT analysis, showing suitable candidate and interaction pattern analysis revealed the most count of interacting residues was 4GLY, 5PHE, 6ASP, 6GLU, 6LYS, and 6THR. Further, the results were validated with SPC water model-based MD simulation for 100ns in neutralised condition, showing the cumulative deviation and fluctuation < 2Å with many intermolecular interactions. The whole analysis has suggested that Mitoglitazone can be used as a multitargeted inhibitor against lung cancer-however, experimental studies are needed before human use.

Evaluation on the Sex-Specific Association Between Cigarette Smoke Exposure and Inflammation Markers-C-Reactive Protein and White Blood Cell Count

INTRODUCTION

Cigarette smoke increases peripheral white blood cell (WBC) count. However, the dose-dependent association between smoking and C-reactive protein (CRP), an important inflammatory marker, has been reported as inconsistent.

AIMS AND METHODS

Here, we evaluated the associations between smoking and CRP using both smoking questionnaires and urine cotinine as exposure markers. The Korea National Health and Nutrition Examination Survey data were used for analyzing the associations. Multiple regression analyses were performed to examine the associations between cigarette smoke exposure, as assessed by questionnaires and urine cotinine, and health effects, as measured by CRP and WBC count, controlling for potential confounders. The confounders, including age, sex, body mass index, blood pressure, cholesterol, glucose, alanine aminotransferase, and uric acid, were selected a priori based on the literature.

RESULTS

A total of 11 435 participants were included for analysis. For the exposure-response relationship, the results indicated a significant increase in CRP levels in male smokers compared to male nonsmokers (p = .002), whereas no significant increase was found in female smokers compared to female nonsmokers (p = .680). For the dose-response relationship, a significant positive association was observed between urine cotinine and CRP in male smokers (p = .018), whereas no significant association was found in female smokers (p = .508). WBC count consistently showed significant exposure-response and dose-response relationships in both sexes.

CONCLUSIONS

WBC count was found to be a consistent effect marker of cigarette smoke exposure, while the association between CRP level and smoking was inconsistent and varied by sex. The sex-specific response to cigarette smoke exposure warrants further exploration in future studies.

IMPLICATIONS

Cigarette smoke exposure is known to increase inflammation and has been thought to increase CRP, a significant inflammation marker. However, recent studies have reported conflicting results regarding the dose-dependent association between cigarette smoke exposure and CRP. This study found that the association between smoking and CRP is inconsistent and varies by sex, showing significant exposure response in men but not in women. Furthermore, the study suggests that WBC count is a more consistent marker for cigarette smoke exposure.

The Impact of Occupational Exposures on the Risk of Idiopathic Pulmonary Fibrosis: A Systematic Review and Meta-Analysis

Rationale: Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic pulmonary disorder of unknown etiology that is characterized by a usual interstitial pneumonia pattern. Previous meta-analyses have reported associations between occupational exposures and IPF, but higher-quality studies have been published in recent years, doubling the number of studied patients. Objectives: To provide a contemporary and comprehensive assessment of the relationship between occupational exposures and IPF. Methods: We searched PubMed, Embase, and Web of Science through July 2023 to identify all publications on occupational exposure and IPF. We conducted a meta-analysis of the occupational burden, odds ratio (OR), and population attributable fraction (PAF) of exposures. Five exposure categories were analyzed: vapors, gas, dust, and fumes (VGDF); metal dust; wood dust; silica dust; and agricultural dust. A comprehensive bias assessment was performed. The study protocol was registered in the International Prospective Register of Systematic Reviews (identifier CRD42021267808). Results: Our search identified 23,942 publications. Sixteen publications contained relative risks needed to calculate pooled ORs and PAFs, and 12 additional publications reported an occupational burden within a case series. The proportion of cases with occupational exposures to VGDF was 44% (95% confidence interval [CI], 36-53%), with a range of 8-17% within more specific exposure categories. The pooled OR was increased for VGDF at 1.8 (95% CI, 1.3-2.4), with a pooled PAF of 21% (95% CI, 15-28%). ORs and PAFs, respectively, were found to be 1.6 and 7% for metal dust, 1.6 and 3% for wood dust, 1.8 and 14% for agricultural dust, and 1.8 and 4% for silica dust. The pooled ORs and PAFs within specific exposure categories ranged from 1.6 to 1.8 and from 4% to 14%, respectively. We identified some publication bias, but it was not sufficient to diminish the association between occupational exposures and IPF based on sensitivity analysis and bias assessment. Conclusions: Our findings indicate that 21% of IPF cases (or approximately one in five) could be prevented by removal of occupational exposure (alongside a pooled OR of 1.8). Additionally, 44% of patients with IPF report occupational exposure to VGDF. This meta-analysis suggests that a considerable number of cases of IPF are attributable to inhaled occupational exposures and warrant increased consideration in the clinical care of patients and future prevention efforts.

Tetrandrine Alleviates Silica-induced Pulmonary Fibrosis Through PI3K/AKT Pathway: Network Pharmacology Investigation and Experimental Validation

Tetrandrine (TET) is a bisbenzylisoquinoline alkaloid derived from Stephania tetrandra S. Moor, known for its potential use in attenuating the progression of silicosis. However, the precise effects and underlying mechanisms of TET remain controversial. In this study, we aimed to elucidate the pharmacological mechanism of TET using a network pharmacology approach, while also evaluating its effect on silica-induced lung fibrosis in mice and TGF-β1-stimulated pulmonary fibroblasts in vitro. We employed network pharmacology to unravel the biological mechanisms through which TET may exert its therapeutic effects on pulmonary fibrosis and silicosis. In a silica-induced mouse model of lung fibrosis, TET was administered orally either during the early or late stage of fibrotic progression. Additionally, we examined the effects of TET on fibroblasts stimulated by TGF-β1 in vitro. Through the analysis, we identified a total of 101 targets of TET, 7,851 genes associated with pulmonary fibrosis, and 80 overlapping genes. These genes were primarily associated with key pathways such as epidermal growth factor receptor tyrosine kinase inhibitor resistance, the vascular endothelial growth factor signaling pathway, and the phosphatidylinositol 3 kinase (PI3K)-protein kinase B (PKB or AKT) signaling pathway. Furthermore, molecular docking analysis revealed the binding of TET to AKT1, the catalytic subunit of phosphatidylinositol-3 kinase, and KDR. In vivo experiments demonstrated that TET significantly alleviated silica-induced pulmonary fibrosis and reduced the expression of fibrotic markers. Moreover, TET exhibited inhibitory effects on the migration, proliferation, and differentiation of TGF-β1-induced lung fibroblasts in vitro. Notably, TET mitigated silica-induced pulmonary fibrosis by suppressing the PI3K/AKT pathway. In conclusion, our findings suggest that TET possesses the ability to suppress silica-induced pulmonary fibrosis by targeting the PI3K/AKT signaling pathway. These results provide valuable insights into the therapeutic potential of TET in the treatment of pulmonary fibrosis and silicosis.

Delineated 3-1-BenCarMethInYlPro-Phosphonic Acid's Adroit Activity against Lung Cancer through Multitargeted Docking, MM\GBSA, QM-DFT and Multiscale Simulations

Lung cancer is a pervasive and challenging disease with limited treatment options, with global health challenges often present with complex molecular profiles necessitating the exploration of innovative therapeutic strategies. Single-target drugs have shown limited success due to the heterogeneity of this disease. Multitargeted drug designing is imperative to combat this complexity by simultaneously targeting multiple target proteins and pathways, which can enhance treatment efficacy and overcome resistance by addressing the dynamic nature of the disease and stopping tumour growth and spread. In this study, we performed the molecular docking studies of Drug Bank compounds with a multitargeted approach against crucial proteins of lung cancer such as heat shock protein 5 (BIP/GRP78) ATPase, myosin 9B RhoGAP, EYA2 phosphatase inhibitor, RSK4 N-terminal kinase, and collapsin response mediator protein-1 (CRMP-1) using HTVS, SP with XP algorithms, and poses were filtered using MM\GBSA which identified [3-(1-Benzyl-3-Carbamoylmethyl-2-Methyl-1h-Indol-5-Yloxy)-Propyl-]-Phosphonic Acid (3-1-BenCarMethIn YlPro-Phosphonic Acid) (DB02504) as multitargeted drug candidate with docking and MM\GBSA score ranges from -5.83 to -10.66 and -7.56 to -50.14 Kcal/mol, respectively. Further, the pharmacokinetic and QM-based DFT studies have shown complete acceptance results, and interaction fingerprinting reveals that ILE, GLY, VAL, TYR, LEU, and GLN were among the most interacting residues. The 100 ns MD simulation in the SPC water model with NPT ensemble showed stable performance with deviation and fluctuations <2 Å with huge interactions, making it a promising multitargeted drug candidate; however, experimental studies are needed before use.

The role of mitochondrial dysfunction in macrophages on SiO2 -induced pulmonary fibrosis: A review

Several epidemiologic and toxicological studies have widely regarded that mitochondrial dysfunction is a popular molecular event in the process of silicosis from different perspectives, but the details have not been systematically summarized yet. Thus, it is necessary to investigate how silica dust leads to pulmonary fibrosis by damaging the mitochondria of macrophages. In this review, we first introduce the molecular mechanisms that silica dust induce mitochondrial morphological and functional abnormalities and then introduce the main molecular mechanisms that silica-damaged mitochondria induce pulmonary fibrosis. Finally, we conclude that the mitochondrial abnormalities of alveolar macrophages caused by silica dust are involved deeply in the pathogenesis of silicosis through these two sequential mechanisms. Therefore, reducing the silica-damaged mitochondria will prevent the potential occurrence and fatality of the disease in the future.

Global, Regional, and National Burden of COPD Attributable to Occupational Particulate Matter, Gases, and Fumes, 1990-2019: Findings from the Global Burden of Disease Study 2019

Background

A study aimed to estimate the burden of Chronic obstructive pulmonary disease (COPD) caused by occupational exposure to particulate matter, gases, and fumes in 204 countries from 1990 to 2019.

Methods

Data on the deaths number, age-standardized mortality rates (ASMR), and age-standardized disability-adjusted life years (DALYs) rates (ASDR) of COPD attributable to occupational particulate matter, gases, and fumes were collected from the GBD study 2019. We also investigated the association between the ASDR and SDI.

Results

There were 517.7 thousand deaths [95% UI: 413.9 to 634.5] in 2019. The number of deaths increased from 1990 to 2019. The ASMR and ASDR were 6.61 (5.24 to 8.17) and 143.02 (118.56 to 168.69) in 2019, respectively, representing a 46% and 44.5% decrease since 1990. China had the highest number of deaths [200,748.4 (151,897.6 to 260,703.9)], while Nepal had the highest ASMR [39 (27.7 to 50)] and ASDR [724.5 (549 to 894.2)]. Males and females 75-79 and 80-84 years old had the highest number of COPD deaths. A negative correlation was observed when SDI > 0.4, whereas a positive correlation was found when SDI < 0.4.

Conclusion

From 1990 to 2019, there was an increase in the number of deaths, but a decline in ASMR and ASDR globally. Besides, there was a heterogeneous burden of COPD attributable to occupational particulate matter, gases, and fumes across regions and countries. It is important to develop and implement strategies to prevent and reduce the burden of COPD attributable to occupational particulate matter, gases, and fumes.

8-hour performance of loose-fitting powered air-purifying respirators in simulated hospital and coal mine environments

Loose-fitting powered air-purifying respirators (LF-PAPRs) are increasingly used in hospitals and coal mines because of their high comfort and protection level, but the utilization faces the challenges of 8-hr continuous high protection requirements in the hospital environment and the coupling effects of high temperature, high humidity, high dust concentration in coal mines. Based on the self-developed powered air-purifying respirator simulation test system, this study explores the 8-hr changes of supplied airflow, the relative air pressure inside the inlet covering (ΔP), and total inward leakage (TIL) of four models of LF-PAPRs in simulated hospital and coal mine environments. Results show that: (1) In a simulated hospital environment, all four LF-PAPRs showed filter cartridge blockage within 5 ∼ 6 hr of continuous operation; while in the simulated coal mine, three models of LF-PAPRs showed filter cartridge blockage within 3 hr. (2) In both the hospital and coal mine environments, there are cases where the supplied airflow of LF-PAPRs dropped below 170 L/min within 3 hr. (3) In a simulated hospital environment, the ΔP of all LF-PAPRs maintained positive within 5-6 hr; while in the simulated coal mine, the ΔP of two LF-PAPRs, respectively, appeared negative after 1 hr and 1.6 hr operation. (4) The maximum TIL of the tested LF-PAPRs, respectively ranged from 0.5-0.9% and 1.4-3% in simulated hospital and coal mine environments. (5) In both hospital and coal mine environments, the supplied airflow and ΔP of each LF-PAPR showed a decreasing trend with increasing test duration, while the TIL significantly increased with testing time. (6) The supplied airflow, ΔP, and TIL of each LF-PAPR in the simulated hospital environment performed better than those in the coal mine. This study evaluated the performance of PAPR under the most severe operating conditions, and respirator performance may differ under in-situ conditions.

Prevalence and associations between occupational diseases, emotional exhaustion, and dust mask anxiety among coal miners in Northern China

This study examined the prevalence and associations between occupational-related diseases, emotional exhaustion, and dust mask anxiety among coal miners in Northern China. The study sampled 506 miners from two coal mines in Northern China. Descriptive (frequency, percentages, and chi-square tests) and inferential (complementary log-log logistic regression) analyses were carried out to assess prevalence and associations. The prevalence of coal mining-related pulmonary diseases was 94%, with 40% and 37% reporting pneumoconiosis and bronchitis respectively. Emphysema and tuberculosis were less prevalent with a total prevalence of 5% while 12% of the miners reported two, three, or four of these diseases. For cardiovascular diseases, 66% of the miners reported 3H (hypertension, hyperlipemia, and hyperglycemia) while heart disease and cerebral infarction were reported by 6% and 2% of the miners respectively. Also, 5% and 2% of the miners reported two or all three of 3H, heart condition, and cerebral infarction. The overall prevalence of cardiovascular diseases was 81% while 82% and 63% of the miners reported experiencing some frequency of emotional exhaustion and dust mask anxiety respectively. The study also identified associations between mining-related diseases, emotional exhaustion, dust mask anxiety, and other demographic, personal habits and work-related factors. Miners with pulmonary diseases were more likely to experience emotional exhaustion and dust mask anxiety. Contrariwise, miners with cardiovascular diseases were less likely to experience dust mask anxiety. Factors such as age, engaging in physical exercises, rhinitis, source of pressure and shift system were also associated with emotional exhaustion and dust mask anxiety. These findings highlight the prevalence of occupational diseases, emotional exhaustion, and dust mask anxiety among coal miners in China. The study emphasizes the need for interventions to address health risks, improve work conditions, and support miners' well-being in the coal mining industry.

Environmental Causes of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF), the most common and severe of the idiopathic interstitial pneumonias, is a chronic and relentlessly progressive disease, which occurs mostly in middle-aged and elderly males. Although IPF is by definition "idiopathic", multiple factors have been reported to increase disease risk, aging being the most prominent one. Several occupational and environmental exposures, including metal dust, wood dust and air pollution, as well as various lifestyle variables, including smoking and diet, have also been associated with an increased risk of IPF, probably through interaction with genetic factors. Many of the predisposing factors appear to act also as trigger for acute exacerbations of the disease, which herald a poor prognosis. The more recent literature on inhalation injuries has focused on the first responders in the World Trade Center attacks and military exposure. In this review, we present an overview of the environmental and occupational causes of IPF and its pathogenesis. While our list is not comprehensive, we have selected specific exposures to highlight based on their overall disease burden.

Emerging trends in silicosis research: a scientometric review

Silicosis is a global disease whose prevention efforts cannot be ignored today. Although numerous silicosis-related data have been published recently, emphasizing the characteristics and nature of silicosis, a summary of the developmental laws of research is lacking, especially in the visual analysis of the literature. We aim to address this issue through a scientometric review. The Web of Science Core Collection and the All Databases were searched with "silicosis" as the topic, excluding unrelated publications, and obtained data from 9802 and 1613 publications, respectively. The data was then analyzed using the Web of Science's online scientometric analysis function and CiteSpace's visual analysis functionality, including publication volume analysis, co-occurrence analysis, co-citation analysis, cluster analysis, and explosive detection. The results identify the "respiratory system" as the most influential area over a century. Furthermore, the publication's number was correlated with the gross domestic product. We ranked countries and institutions based on the frequency of publications and discovered that Europe, the USA, and China are the leading regions for silicosis research, with the USA and Europe having a stronger influence. Many reports related to artificial stone and denim jean production have been studied through citation analysis, indicating new epidemic trends in silicosis. Besides, silicosis-related diseases and the pathogenesis of silicosis were the research hotspots of silicosis through co-occurrence keyword analysis and outbreak detection. Furthermore, related diseases include coal workers' pneumoconiosis and tuberculosis, while the mechanism of silicosis includes studies on inflammation and fibrosis, oxidative stress, alveolar macrophages, apoptosis, and pathways.

The impact of coal mine dust characteristics on pathways to respiratory harm: investigating the pneumoconiotic potency of coals

Exposure to dust from the mining environment has historically resulted in epidemic levels of mortality and morbidity from pneumoconiotic diseases such as silicosis, coal workers' pneumoconiosis (CWP), and asbestosis. Studies have shown that CWP remains a critical issue at collieries across the globe, with some countries facing resurgent patterns of the disease and additional pathologies from long-term exposure. Compliance measures to reduce dust exposure rely primarily on the assumption that all "fine" particles are equally toxic irrespective of source or chemical composition. For several ore types, but more specifically coal, such an assumption is not practical due to the complex and highly variable nature of the material. Additionally, several studies have identified possible mechanisms of pathogenesis from the minerals and deleterious metals in coal. The purpose of this review was to provide a reassessment of the perspectives and strategies used to evaluate the pneumoconiotic potency of coal mine dust. Emphasis is on the physicochemical characteristics of coal mine dust such as mineralogy/mineral chemistry, particle shape, size, specific surface area, and free surface area-all of which have been highlighted as contributing factors to the expression of pro-inflammatory responses in the lung. The review also highlights the potential opportunity for more holistic risk characterisation strategies for coal mine dust, which consider the mineralogical and physicochemical aspects of the dust as variables relevant to the current proposed mechanisms for CWP pathogenesis.

Malignant mesothelioma tumours: molecular pathogenesis, diagnosis, and therapies accompanying clinical studies

The pathetic malignant mesothelioma (MM) is a extremely uncommon and confrontational tumor that evolves in the mesothelium layer of the pleural cavities (inner lining- visceral pleura and outer lining- parietal pleura), peritoneum, pericardium, and tunica vaginalis and is highly resistant to standard treatments. In mesothelioma, the predominant pattern of lesions is a loss of genes that limit tumour growth. Despite the worldwide ban on the manufacture and supply of asbestos, the prevalence of mesothelioma continues to increase. Mesothelioma presents and behaves in a variety of ways, making diagnosis challenging. Most treatments available today for MM are ineffective, and the median life expectancy is between 10 and 12 months. However, in recent years, considerable progress has already been made in understanding the genetics and molecular pathophysiology of mesothelioma by addressing hippo signaling pathway. The development and progression of MM are related to many important genetic alterations. This is related to NF2 and/or LATS2 mutations that activate the transcriptional coactivator YAP. The X-rays, CT scans, MRIs, and PET scans are used to diagnose the MM. The MM are treated with surgery, chemotherapy, first-line combination chemotherapy, second-line treatment, radiation therapy, adoptive T-cell treatment, targeted therapy, and cancer vaccines. Recent clinical trials investigating the function of surgery have led to the development of innovative approaches to the treatment of associated pleural effusions as well as the introduction of targeted medications. An interdisciplinary collaborative approach is needed for the effective care of persons who have mesothelioma because of the rising intricacy of mesothelioma treatment. This article highlights the key findings in the molecular pathogenesis of mesothelioma, diagnosis with special emphasis on the management of mesothelioma.

The therapeutic effect of exosomal lncRNA MSTRG.91634.7 on mitochondrial dysfunction during SiO2-induced lung fibrosis

Long-term silica (SiO₂) exposure led to irreversible lung fibrosis, in which epithelial-mesenchymal transition (EMT) played an essential role. A novel lncRNA MSTRG.91634.7 in the peripheral exosomes of silicosis patients was reported in our previous study, which could remold the pathological process of silicosis. However, whether its regulatory role on the development of silicosis was related to EMT process is unclear, and its mechanism remains to be further studied. In this study, up-regulating lncRNA MSTRG91634.7 restricted SiO₂-activated EMT and restored mitochondrial homeostasis binding to PINK1 in vitro. Moreover, overexpressing PINK1 could inhibit SiO₂-activated EMT in pulmonary inflammation and fibrosis in mice. Meanwhile, PINK1 contributed to restoring the SiO₂-induced mitochondrial dysfunction in mice lung. Our results revealed that exosomal lncRNA MSTRG.91634.7 from macrophages could restore mitochondrial homeostasis to restrict the SiO₂-activated EMT by binding to PINK1 during pulmonary inflammation and fibrosis due to SiO₂ exposure.

Development and Characterization of a 96-Well Exposure System for Safety Assessment of Nanomaterials

In this study, a 96-well exposure system for safety assessment of nanomaterials is developed and characterized using an air-liquid interface lung epithelial model. This system is designed for sequential nebulization. Distribution studies verify the reproducible distribution over all 96 wells, with lower insert-to-insert variability compared to non-sequential application. With a first set of chemicals (TritonX), drugs (Bortezomib), and nanomaterials (silver nanoparticles and (non-)fluorescent crystalline nanocellulose), sequential exposure studies are performed with human lung epithelial cells followed by quantification of the deposited mass and of cell viability. The developed exposure system offers for the first time the possibility of exposing an air-liquid interface model in a 96-well format, resulting in high-throughput rates, combined with the feature for sequential dosing. This exposure system allows the possibility of creating dose-response curves resulting in the generation of more reliable cell-based assay data for many types of applications, such as safety analysis. In addition to chemicals and drugs, nanomaterials with spherical shapes, but also morphologically more complex nanostructures can be exposed sequentially with high efficiency. This allows new perspectives on in vivo-like and animal-free approaches for chemical and pharmaceutical safety assessment, in line with the 3R principle of replacing and reducing animal experiments.

Global evolutional trend of safety in coal mining industry: a bibliometric analysis

Mining safety is recognized as one of the factors influencing the mining industry's long-term viability. Therefore, we did a bibliometric analysis to take stock of safety management in the coal mining industry. This study suggests a three-step strategy, comprising literature extraction and screening, bibliometric analysis, and discussion, to provide an in-depth understanding of the present state and development trend of mine safety research. The findings raise additional concerns which include the following: (i) Coal dust pollution has a direct and indirect impact on the environment. (ii) Most research projects have prioritized technology innovation and development over safety norms. (iii) Most works have come from advanced countries such as China, the USA, the UK, and Australia to the neglect of developing nations, leaving a significant vacuum in the literature. (iv) There are more major safety principles in the food business than in the mining industry, indicating a weak safety culture in the mining industry. Additionally, future research goals are provided, such as creating safer policy guidelines to support technological advancements, constructing effective safety mines, and creating solutions to dust pollution and human errors.

Effects of occupational exposures on respiratory health in steel factory workers

Background

The steel factory work environment contains various chemical exposures that can affect indoor air quality and have impact on respiratory health of the workers.

Aims

The objective of this study was to assess potential effects of occupational exposures in steel factory workers in Iran on the respiratory symptoms, occurrence and the lung function levels.

Method

This was a cross-sectional study of 133 men working in a steel factory forming the exposed group and 133 male office workers forming the reference group from a steel company in Iran. The participants filled in a questionnaire and underwent spirometry. Work history was used both as dichotomous (exposed/reference) and a quantitative measure of exposure, the latter measured as duration of exposure in the specified work (in years) for the exposed group and zero for the reference group.

Results

Multiple linear regression and Poisson regression were used to adjust for confounding. In Poisson regression analyses, an increased prevalence ratio (PR) of all respiratory symptoms was observed in the exposed group. Lung function parameters were significantly reduced in the exposed group (p < 0.001). There was a dose-response relation between duration of occupational exposures and reduction in the predicted value of FEV1/FVC level (0.177, 95% CI -0.198 to -0.156) in all models.

Conclusion

The results of these analyses showed that occupational exposures in steel factory work increase the prevalence of respiratory symptoms and reduce lung function. Safety training and workplace conditions were found to need improvement. In addition, use of proper personal protective equipment is recommended.

Nicotinamide Mononucleotide Ameliorates Silica-Induced Lung Injury through the Nrf2-Regulated Glutathione Metabolism Pathway in Mice

Nicotinamide mononucleotide (NMN) is a natural antioxidant approved as a nutritional supplement and food ingredient, but its protective role in silicosis characterized by oxidative damage remains unknown. In this study, we generated a silicosis model by intratracheal instillation of silica, and then performed histopathological, biochemical, and transcriptomic analysis to evaluate the role of NMN in silicosis. We found that NMN mitigated lung damage at 7 and 28 days, manifested as a decreasing coefficient of lung weight and histological changes, and alleviated oxidative damage by reducing levels of reactive oxygen species and increasing glutathione. Meanwhile, NMN treatment also reduced the recruitment of inflammatory cells and inflammatory infiltration in lung tissue. Transcriptomic analysis showed that NMN treatment mainly regulated immune response and glutathione metabolism pathways. Additionally, NMN upregulated the expression of antioxidant genes Gstm1, Gstm2, and Mgst1 by promoting the expression and nuclear translocation of nuclear factor-erythroid 2 related factor 2 (Nrf2). Gene interaction analysis showed that Nrf2 interacted with Gstm1 and Mgst1 through Gtsm2. Promisingly, oxidative damage mediated by these genes occurred mainly in fibroblasts. In summary, NMN alleviates silica-induced oxidative stress and lung injury by regulating the endogenous glutathione metabolism pathways. This study reveals that NMN supplementation might be a promising strategy for mitigating oxidative stress and inflammation in silicosis.

Global disease burden and trends of leukemia attributable to occupational risk from 1990 to 2019: An observational trend study

Background

Leukemia caused by occupational risk is a problem that needs more attention and remains to be solved urgently, especially for acute lymphoid leukemia (ALL), acute myeloid leukemia (AML), and chronic lymphoid leukemia (CLL). However, there is a paucity of literature on this issue. We aimed to assess the global burden and trends of leukemia attributable to occupational risk from 1990 to 2019.

Methods

This observational trend study was based on the Global Burden of Disease (GBD) 2019 database, the global deaths, and disability-adjusted life years (DALYs), which were calculated to quantify the changing trend of leukemia attributable to occupational risk, were analyzed by age, year, geographical location, and socio-demographic index (SDI), and the corresponding estimated annual percentage change (EAPC) values were calculated.

Results

Global age-standardized DALYs and death rates of leukemia attributable to occupational risk presented significantly decline trends with EAPC [-0.38% (95% CI: -0.58 to -0.18%) for DALYs and -0.30% (95% CI: -0.45 to -0.146%) for death]. However, it was significantly increased in people aged 65-69 years [0.42% (95% CI: 0.30-0.55%) for DALYs and 0.38% (95% CI: 0.26-0.51%) for death]. At the same time, the age-standardized DALYs and death rates of ALL, AML, and CLL were presented a significantly increased trend with EAPCs [0.78% (95% CI: 0.65-0.91%), 0.87% (95% CI: 0.81-0.93%), and 0.66% (95% CI: 0.51-0.81%) for DALYs, respectively, and 0.75% (95% CI: 0.68-0.82%), 0.96% (95% CI: 0.91-1.01%), and 0.55% (95% CI: 0.43-0.68%) for death], respectively. The ALL, AML, and CLL were shown an upward trend in almost all age groups.

Conclusion

We observed a substantial reduction in leukemia due to occupational risks between 1990 and 2019. However, the people aged 65-69 years and burdens of ALL, AML, and CLL had a significantly increased trend in almost all age groups. Thus, there remains an urgent need to accelerate efforts to reduce leukemia attributable to occupational risk-related death burden in this population and specific causes.