Risk Of Pneumoconiosis Research Articles

Exploring the relationship between sarcopenia and 11 respiratory diseases: a comprehensive mendelian randomization analysis

BackgroundSarcopenia (SP) is an aging-related loss of muscle mass and function, affecting the respiratory system. However, the causality of the association between sarcopenia on lung diseases remains elusive.MethodsThe bidirectional univariate Mendelian randomization (UVMR), multivariate MR (MVMR) analysis, and mediation MR were utilized to systematically investigate the genetic causal relationship of SP and 11 respiratory diseases. Independent genomic variants related to sarcopenia or respiratory diseases were identified as instrumental variables (IVs), and the summary level data of genome-wide associated studies (GWAS) were obtained from the UK biobank and FinnGen. MVMR analysis was conducted to explore the mediation effects of body mass index (BMI), Alcohol Use Disorders Identification Test (AUDIT), smoking, education attainment (EA), physical activity, and Type 2 Diabetes Mellitus (T2DM).ResultsForward UVMR analysis based on the primary method revealed that pneumoconiosis was associated with a higher risk of appendicular lean mass (ALM) (OR = 1.01, p = 0.03), and BMI (10.65%), smoking (10.65%), and physical activity (17.70%) had a mediating role in the effect of pneumoconiosis on ALM. In reverse MR analysis, we found that genetically predicted ALM was significantly associated with an increased risk of pulmonary embolism (PE) (OR = 1.24, p = 7.21E-05). Chronic obstructive pulmonary disease (COPD) (OR = 0.98, p = 0.002) and sarcoidosis (OR = 1.01, p = 0.004) were identified to increase the loss of left-hand grip strength (HGS). Conversely, the increase in left- HGS presented a protective effect on chronic bronchitis (CB) (OR = 0.35, p = 0.03), (OR = 0.80, p = 0.02), and asthma (OR = 0.78, p = 0.04). Similarly, the loss of the right-HGS elevated the risk of low respiratory tract infection (LRTI) (OR = 0.97, p = 0.02) and bronchiectasis (OR = 1.01, p = 0.03), which is also an independent protective factor for LRTI and asthma. In the aspects of low HGS, the risk of LRTI was increased after MVMR analysis, and the risk of sarcoidosis and pneumoconiosis was elevated in the reverse analysis. Lastly, asthma was found to be related to the loss of the usual walking pace, and the reverse MR analysis suggested a causal relationship between the usual walking pace and LRTI (OR = 0.32, p = 2.79 × 10−5), asthma (OR = 0.24, p = 2.09 × 10−6), COPD (OR = 0.22, p = 6.64 × 10−4), and PE(OR = 0.35, p = 0.03).ConclusionsThis data-driven MR analysis revealed SP was bidirectional causally associated with lung diseases, providing genetic evidence for further mechanistic and clinical studies to understand the crosstalk between SP and lung diseases.

Fine mapping-based multi-omics analysis interprets the gut-lung axis function of SGLT2 inhibitors.

Currently, Sodium-glucose cotransporter 2 (SGLT2) inhibitors demonstrate additional effects beyond glucose control on the gut microbiota and circulating metabolites. The gut microbiota and metabolites have been found to be useful in elucidating potential biological mechanisms of pulmonary diseases. Therefore, our study aims to investigate the effects of gut microbiota and metabolites mediating SGLT2 inhibition in 10 pulmonary diseases through Mendelian randomization (MR) research. We conducted a two-sample, two-step MR study to assess the association between SGLT2 inhibition and 10 pulmonary diseases and to investigate the mediating effects of gut microbiota and metabolite. Gene-fine mapping and annotation of mediators by FUMA and Magma analyses were performed, and causal associations of mapped genes with diseases were assessed by muti-omics MR analyses. Possible side effects of SGLT2 inhibition were assessed by PheWAS analysis. SGLT2 inhibition was linked to a reduced risk of T2DM, Interstitial lung disease (ILD), Pneumoconiosis, Pulmonary tuberculosis, and Asthma(OR=0.457, 0.054, 0.002, 0.280, 0.706). The family Enterobacteriaceae and order Enterobacteriales were associated with SGLT2 inhibition and ILD(95% CI:0.079-0.138). The family Alcaligenaceae and X-12719 were linked to pneumoconiosis (95% CI: 0.042-0.120, 0.050-0.099). The genus Phascolarctobacterium was connected to pulmonary tuberculosis (95% CI: 0.236-0.703).The degree of unsaturation (Fatty Acids), ratio of docosahexaenoic acid to total fatty acids, and 4-androsten-3beta,17beta-diol disulfate 2, were associated with asthma(95% CI: 0.042-0.119, 0.039-0.101, 0.181-0.473). Furthermore, Fuma and Magma analyses identified target genes for the four diseases, and proteomic MR analysis revealed six overlapping target genes in asthma. PheWAS analysis also highlighted potential side effects of SGLT2 inhibition. This comprehensive study strongly supports a multi-omics association between SGLT2 inhibition and reduced risk of interstitial lung disease, tuberculosis, pneumoconiosis, and asthma. Four identified gut microbiota, four metabolites, sixteen metabolic pathways, and six target genes appear to play a potential role in this association. The results of the comprehensive phenome-wide association analysis also identified the full effect of SGLT2 inhibitors.

Improvement of the model for calculating the protection coefficient of filtering respirators from harmful aerosol

Research objective. Improvement of the model for calculating the protection coefficient of filtering respirators from harmful solid aerosol. Materials and methods. For the experimental determination of the protection coefficient of the filtering respirator according to the standard DSTU EN 149:2017 «Personal respiratory protective devices. Filtering half masks to protect against aerosols. Requirements, testing, marking» and the application of the method DSTU EN 13274-1:2005 «Personal respiratory protective devices. Methods of testing. Part 1. Determination of the penetration coefficient and the overall penetration coefficient», lightweight filtering half masks of «Standard» FFP2 type were used on volunteers. Results. The protection coefficient of the filtering respirators used on volunteers in laboratory conditions was calculated at the specified concentration of test aerosol in the ambient air by the standard testing method described in DSTU EN 13274-1:2005 «Personal respiratory protective devices. Methods of testing. Part 1. Determination of the penetration coefficient and the overall penetration coefficient» and takes into account the measurement error from the instruments not exceeding 10%. A comparison of the obtained indicators of the protection coefficient of filtering respirators in laboratory conditions and with the developed theoretical model, taking into account particle deposition in the sampling probe and submask space during the exhalation process, showed a good agreement of the indicators by the Student's t-test criterion. Scientific novelty. The scientific novelty lies in the development of a model for calculating the protection coefficient of filtering respirators based on the assessed mass distribution function of aerosol particles in the breathing zone; penetration function through the gap between the face and the half mask, taking into account the inhalation and exhalation process, as well as particle deposition in the sampling probe. Practical significance of the work lies in the development of a formula for the theoretical determination of the protection coefficient of filtering respirators, which is used to calculate the professional risk of pneumoconiosis among users

Identification of high-risk population of pneumoconiosis using deep learning segmentation of lung 3D images and radiomics texture analysis

ObjectionThe aim of this study is to develop an early-warning model for identifying high-risk populations of pneumoconiosis by combining lung 3D images and radiomics lung texture features. MethodsA retrospective study was conducted, including 600 dust-exposed workers and 300 confirmed pneumoconiosis patients. Chest computed tomography (CT) images were divided into a training set and a test set in a 2:1 ratio. Whole-lung segmentation was performed using deep learning models for feature extraction of radiomics. Two feature selection algorithms and five classification models were used. The optimal model was selected using a 10-fold cross-validation strategy, and the calibration curve and decision curve were evaluated. To verify the applicability of the model, the diagnostic efficiency and accuracy between the model and human interpretation were compared. Additionally, the risk probabilities for different risk groups defined by the model were compared at different time intervals. ResultsFour radiomics features were ultimately used to construct the predictive model. The logistic regression model was the most stable in both the training set and testing set, with an area under curve (AUC) of 0.964 (95 % confidence interval [CI], 0.950–0.976) and 0.947 (95 %CI, 0.925–0.964). In the training and testing sets, the Brier scores were 0.092 and 0.14, respectively, with threshold probability ranges of 2 %-99 % and 2 %-85 %. These results indicate that the model exhibits good calibration and clinical benefit. The comparison between the model and human interpretation showed that the model was not inferior in terms of diagnostic efficiency and accuracy. Additionally, the high-risk population identified by the model was diagnosed as pneumoconiosis two years later. ConclusionThis study provides a meticulous and quantifiable method for detecting and assessing the risk of pneumoconiosis, building upon accurate diagnosis. Employing risk scoring and probability estimation, not only enhances the efficiency of diagnostic physicians but also provides a valuable reference for controlling the occurrence of pneumoconiosis.

Numerical simulation of the effect of a wind-assisted spraying device during continuous mining

The continuous mining face is the main dust-producing area in a coal mine. The dust produced endangers the physical and mental health of underground workers and increases their risk of pneumoconiosis. To improve the lack of spraying in the middle part of the continuous mining machine and the poor dust reduction effect, we developed a wind-assisted spraying device placed in the middle of the continuous mining machine. Spraying experiments have shown that a round nozzle with a 2.4-mm aperture containing an X-shaped guide core has a longer effective range and wider atomization angle. Numerical simulations have shown that when the spray pressure is 7 MPa, a dust reduction spray field with uniform droplet size distribution can be formed. After applying the spray parameters obtained in the coal mine field and using the dust removal device, the total dust concentration in the driver's area of the continuous mining machine was significantly reduced.

Analysis of dust and noise exposure levels in the mining industry from the national surveillance program in 2019

Objective: To understand the exposure level of dust and noise in the mining industry and provide data support for revising policy for the prevention and control of occupational diseases. Methods: In May 2022, Data was collected through the National Surveillance Program for Occupational Hazards in the Workplace. Descriptive analysis was conducted for dust and noise levels by industry type and enterprise size from 7, 679 enterprises in the mining industry among 29 provincial regions nationwide. Results: The enterprises in the mining industry included in the National Surveillance Program for Occupational Hazards in the Workplace are mainly small and micro, accounting for 47.97% (3684/7679) and 30.00% (230/7679) respectively. The industry is mainly compred of employers in the non-metallic ming and beneficiation industry, accounting for 50.25% (3859/7679). Among the enterprises with silica dust, coal dust, and noise hazards, the proportion of enterprises where total dust concentration and noise intensity exceed the standard is higher than 50%. 30% of the posts are with an exposure level of silica dust, coal dust, and noise that exceeds the standard. The exceedance rate and the median of the time-weighted average concentration of total coal dust among large and medium-sized enterprises are higher than those among small and micro-sized enterprises (P<0.05) . Conclusion: The dust and noise hazards in the mining industry are lower than in the past in China, but more than 25% of workers are still at a high risk of occupational pneumoconiosis and noise deafness. Therefore, intervention and surveillance strategies should be strengthened in the future.

Incidence and influencing factors of occupational pneumoconiosis: a systematic review and meta-analysis

ObjectivesTo determine the incidence of pneumoconiosis worldwide and its influencing factors.DesignSystematic review and meta-analysis.SettingCohort studies on occupational pneumoconiosis.ParticipantsPubMed, Embase, the Cochrane Library and Web of Science were searched until November...

Pneumoconiosis prevention and personal protective equipment

Inhalation of mineral dust increases the risk of pneumoconiosis which is an incurable and irreversible occupational disease. If the concentration of fibrogenic dust significantly exceeds the occupational exposure limit (OEL), the risk of pneumoconiosis becomes unacceptably high. The disease prevention involves the use of the collective prevention equipment and medical control. If these measures are insufficient, the respiratory protective devices are used. But respirators lack reliability. For example, pneumoconiosis (the initial stages of the disease) was found in a miner who had worked in the mine for only about six months. The miners cannot use respirators for a long time: they complicate communication during work and excessively impair gas exchange when breathing. The average concentration of carbon dioxide in the air inhaled from a respirator mask may exceed the maximal allowable concentration (MAC) set for the working space air by more than 2 times. The article provides a brief overview of improving respiratory protective equipment (RPE) in the United States: development of different Powered Air Purifying Respirators (PAPR); implementation of a personal dust monitor for measuring the dust concentration in real time. PAPR improve gas exchange during breathing and reduce the risk of unfiltered air leakage through gaps in facial contact areas. The effectiveness of the collective prevention equipment depends on many factors. It can be significantly increased via efficient monitoring of dust concentration in the breathing zone of a miner. Russian MAC on air dustiness create favorable conditions for the development of personal dust meters for determining dust concentration in real time. The article provides recommendations for improving dust protection of miners with regard to the international experience.The study was carried out without support. The authors declare no conflicts of interests.

Analysis of dust hazard characteristics in 59 ferrous metal foundry enterprises in Ningbo City

Objective: To analyze the post distribution of dust concentration in ferrous metal foundry enterprises and evaluate the occupational health risks, and provide basis for policies of the formulation of pneumoconiosis prevention and control. Methods: From August to September in 2020, the basic information, dust hazard information and occupational health management information of 59 ferrous metal casting enterprises were investigated, the dust concentration distribution was analyzed, and the risk assessment was carried out by using the quantitative assignment model. The dust concentration is tested by LSD method after logarithmic treatment. The 3 times time weighted average allowable exposure concentration of dust is taken as the peak concentration limit of dust; The time weighted average allowable exposure concentration of dust converted by exposure time is taken as the time weighted average exposure concentration limit of dust, and whether the time weighted average exposure concentration and peak concentration of dust at the same post exceed the limit is taken as the basis for exceeding the limit of dust post concentration to calculate the post exceeding the limit rate. Results: The dust hazards were mainly distributed in the posts of sand treatment, molding, sand falling, sand cleaning and cutting and grinding. Dust exposure time weighted average concentration was 0.44 (0.03, 5.11) mg/m(3), peak exposure concentration was 1.30 (0.18, 10.94) mg/m(3), and the over standard rate of Posts was 38.92% (79/203) . Weighted average exposure concentration of other dust (total dust) in the cutting and grinding post is 1.50 (0.15, 7.40) mg/m(3), peak exposure concentration is 0.90 (0.07, 12.48) mg/m(3), and the post exceedance rate is 4.88% (2/41) . Weighted average exposure concentration of silica dust (exhaling dust) in dust operation posts of investment casting enterprises is 0.43 (0.05, 6.35) mg/m(3), peak exposure concentration is 0.90 (0.12, 8.28) mg/m(3), and the post over standard rate is 35.77% (49/137) ; Weighted average exposure concentration of other dust (total dust) at the cutting and grinding post is 2.00 (11.00, 21.00) mg/m(3), and the post exceedance rate is 2.50% (2/80) . There was no significant difference in the concentration of respirable dust between sand casting and investment casting (P>0.05) . The concentration of respirable dust in sand casting was higher than that in sand treatment, molding and sand cleaning posts (P<0.05) . The concentration of silica dust in investment casting was higher than that in sand treatment and molding posts, and that in sand cleaning posts was higher than that in sand treatment posts (P<0.05) . 98.48% (454/461) of the dust operation posts have an occupational health risk value greater than or equal to 400, and 1.52% (7/461) of the dust operation posts have an occupational health risk value of 200~399. Conclusion: there is a high rate of exceeding the standard in the dust work posts in the ferrous metal foundry enterprises in Ningbo, and the workers have a high occupational health risk of pneumoconiosis or metal and its compound pneumoconiosis. Targeted measures should be taken to reduce the occupational health risk.

Genetic susceptibility in pneumoconiosis in China: a systematic review.

Pneumoconiosis, encompassing coal workers' pneumoconiosis (CWP), silicosis and asbestosis, is one of the most common occupational diseases in China. Previous studies revealed significant associations between genetic variations and pneumoconiosis risk among individuals in different countries. With the known variability of genetic makeup between ethnicities, susceptibility to pneumoconiosis due to genetic differences is likely to be ethnicity-specific. The present review aimed at providing a comprehensive overview on the association between genetic polymorphisms and susceptibility of pneumoconiosis, specifically among people in China. The literature search was performed in seven English and Chinese databases using keywords related to the review aim. An appraisal of the methodological quality of the included studies was conducted using the assessment tool derived from the Strengthening the Reporting of Genetic Association Studies (STREGA) statement. Forty-five studies were included in this review. Genotypes of specific genes which are associated with the risk of CWP, silicosis and asbestosis were reported. Our findings showed that genes encoding inflammatory cytokines have been examined extensively, and they demonstrated an association between these genes and pneumoconiosis risk. Gene-environment interactions in pneumoconiosis susceptibility were also reported by a number of studies. This review summarised the evidence demonstrating the association between genetic polymorphisms and pneumoconiosis susceptibility among people in China, and that various genotypes could modify their risk to develop pneumoconiosis. The findings prompt that identification of individuals at high pneumoconiosis risk through genetic screening and strategies limiting their exposure to dust could be a potential strategy for the control of this occupational disease in China.

Study on dust-gas coupling pollution law and selection of optimal purification distance of air duct during tunneling process.

During the excavation of high gas mine, gas and dust often exist at the same time. In order to ensure that the gas concentration remains within a safe range and minimize the risk of workers' pneumoconiosis, we simulated the interaction mechanism of airflow, gas, and dust, explored the pollution law of gas and dust, and obtained the optimal purification distance (Lp) by the CFD method. The reliability of the numerical simulation was verified by field measurements. Firstly, the properties of the gas and dust affected the structure of the airflow field. At the same time, the change in the airflow field affected the concentration distributions of the gas and dust. During the diffusion process, some high-risk regions in which the gas or dust concentrations exceeded 0.80% or 200 mg/m3, respectively, were discovered. Moreover, we have found that the airflow velocity in the top region of the tunnel and at the intersection corner between the cutting face and tunnel wall was the main factor affecting the purification effects. When Lp = 5-8 m, the gas concentration remained below 0.50%. When Lp = 6 m, the dust concentration reached a minimum of 287.5 mg/m3. Therefore, the optimal purification distance was determined to be 6 m; in which case, the gas and dust concentrations decreased by 32.84% and 47.02%, respectively.

Demonstrating the protective effect of a 70-year-old occupational exposure limit against pneumoconiosis caused by mica.

Workers involved in crushing, milling, screening, and bagging of mica scrap are at increased risk to develop pneumoconiosis, a progressive material overloading of the lung that can lead to fibrosis and, in the later stages, to dyspnea. Pneumoconiosis is only seen after 10–20 years of respiratory mica exposure, and it can have a latency period of up to 40 years—today’s cases date back to exposures during the second half of the 20th century. An occupational lifetime exposure level of 3 mg/m3 respirable mica dust has been considered to present no risk of pneumoconiosis since 1951 when the American Conference of Governmental Industrial Hygienists (ACGIH) established a 20 million particles per cubic foot (mppcf) (3.5 mg/m3 respirable particles) exposure limit. As a result, numbers of unspecified and other pneumoconioses in the United States have steadily declined since the early 1970s. Data from the National Institute for Occupational Safety and Health documents a 91% decrease between 1972 and 2014 (i.e., the peak of documented cases and the latest reported data) for combined cases of aluminosis, berylliosis, stannosis, siderosis, and fibrosis from production and use of bauxite, graphite fibers, wollastonite, cadmium, Portland cement, emery, kaolin, antimony, and mica. Ample evidence indicates that the 70-year-old occupational lifetime exposure level of 3 mg/m3 respirable mica dust is protective of workers’ health.

Heterozygous Ins/Del genotype of the CASP8 rs3834129 polymorphism significantly decreases the risk of coal workers' pneumoconiosis in a Chinese Han population: a case-control study.

Coal workers' pneumoconiosis (CWP) is a chronic inflammatory and fibrotic pulmonary disease that involves a complex interaction of multiple environmental and genetic factors. Polymorphism, as a genetic factor, may affect the onset of the disease in susceptible populations. The present study investigated the association between the polymorphisms of six genes and CWP risk in a Chinese Han population. Six polymorphisms (CASP8 rs3834129, IL1A rs1800587, IL6 rs1800796, IL4 rs2070874, TNFA rs361525, and NLRP3 rs1539019) were examined in 222 CWP subjects and 247 dust-exposed control subjects. The CASP8 rs3834129 Ins/Del genotype significantly decreased CWP risk (p=0.040; adjusted odds ratio [OR] = 0.586; 95% confidence interval [CI] 0.367-0.935) compared with the Ins/Ins genotype. Stratification analyses revealed a significant interaction between the heterozygous Ins/Del genotype and age. Compared with the Ins/Ins + Del/Del genotype, this was particularly evident among subjects aged 41-60 (p<0.001; adjusted OR = 0.054; 95% CI 0.007-0.420) and those with an exposure time of 20-29 years (p=0.014; adjusted OR = 0.392; 95% CI 0.183-0.842). This decreased risk was also found in the group with former smokers (p=0.012; adjusted OR = 0.448; 95% CI 0.238-0.844). Findings revealed that the heterozygous Ins/Del genotype of CASP8 rs3834129 was related to a significantly decreased risk of stage I CWP (p=0.045; adjusted OR = 0.592; 95% CI 0.353-0.992), but not stage II or III CWP. Our study indicated that the heterozygous Ins/Del genotype of CASP8 rs3834129 significantly decreased CWP risk in a Chinese Han population.

Early signs of pneumoconiosis in a dental technician in Italy: a case report

BackgroundDental technicians are at high risk of pneumoconiosis, usually driven by inhalation of mixed dusts, including metals. An etiological diagnosis is not easy to be performed, particularly in advanced stages.Case presentationWe describe the case of an early pneumoconiosis occurring in a 47-year-old dental technician who developed respiratory symptoms shortly after beginning work. She described the work environment as dusty and lacking relevant primary prevention tools. A chest CT showed multiple peripheral pseudonodular lesions in both lower lobes; bronchoalveolar lavage and bronchial aspirate evidenced numerous macrophages with reflective metal bodies included into the cytoplasm, that at scanning electron microscopy coupled to Energy Dispersive X-Ray Analysis resulted Zirconium and Aluminum, whereas Tungsten (W) was localized outside cells. End of shift urinary concentrations of W were substantially raised as compared to pre-shift (1.1 vs. 0.2 µg/L).ConclusionsWe concluded for diagnosis of early work-related pneumoconiosis due to abnormal occupational exposure to metals. The case demonstrates the need also for dental professionals to comply with industrial hygiene standards and to be monitored by occupational health physicians.

Mortality in the cohort of talc miners and millers from Val Chisone, Northern Italy: 74 years of follow-up

ObjectiveTo update the analysis of mortality of a cohort of talc miners and millers in Northern Italy. MethodsWe analyzed overall mortality and mortality from specific causes of death during 1946–2020 of 1749 male workers in a talc mine where asbestos was not detected (1184 miners and 565 millers) employed during 1946–1995. ResultsThe overall standardized mortality ratio (SMR) was 1.21 (95 % confidence interval [CI] 1.14–1.28); no deaths were observed from pleural cancer. Mortality from lung cancer was not increased (SMR = 1.02 95 % CI 0.82–1.27), while mortality from pneumoconiosis was (SMR 9.55; 95 % CI 7.43–12.08), especially among miners (SMR 12.74; 95 % CI 9.79–16.31). There was a trend in risk of pneumoconiosis with increasing duration of employment in the overall cohort, and the SMR for 25+ years of employment was 15.12 (95 % CI 10.89–20.43). ConclusionsThis uniquely long-term follow up confirms the results of previous analyses, namely the lack of association between exposure to talc with no detectable level of asbestos and lung cancer and mesothelioma. Increased mortality from pneumoconiosis among miners is related to past exposure to silica.

The effectiveness of the miners’ respirators

Introduction. Dust is one of the main harmful factors in underground coal mining. The dust concentration in the coal mines remains high due to the imperfection of the used technologies, increasing the pneumoconiosis risk in miners. Respirators are the last means of protection, but information about their effectiveness is contradictory. Aim. Assess the effectiveness of individual respiratory protective devices in the coal mines. Material and methods. The protection factor (PF), the ratio of the dust concentration outside the mask to the concentration under the mask) is used to assess respirators’ effectiveness. We measured the PFs in the laboratory and the workplaces. We also measured the time the miners did not use respirators. The measurements’ results were used as input data for mathematical modeling to reduce dust load reduction. Results. The concentration of dust under the mask exceeded the Occupational Exposure Limit (OEL) in most cases. Information about the high efficiency of the negative pressure half-mask respirators (in case of continuous use) was not confirmed. The PFs measured under laboratory conditions reached 6.2, and in the workplace were from 5 to 31. The miners did not use respirators from 10 to 45% of the shift duration (15 measurements). The measurements and information on the concentration of dust in 5 mines were used to simulate the impact of the respirators’ usage on the dust load. Calculations performed by different methods, and using various programs, gave the same result. The negative pressure half-mask respirators cannot reduce the dust’s concentration in the inhaled air to the OEL even with continuous use. Conclusion. The results showed that the respirators’ usage could not prevent developing incurable pneumoconiosis in miners.

Assessment of pneumoconiosis in surface coal miners after implementation of a national radiographic surveillance program, United States, 2014-2019.

Pneumoconiosis can occur in surface coal miners. The Coal Workers' Health Surveillance Program (CWHSP) has only included surface coal miners as part of its regular disease surveillance since 2014. This analysis identifies the prevalence of pneumoconiosis among working surface coal miners participating in the CWHSP since their initial inclusion, through 2019. Working surface coal miners who had chest radiographs through the CWHSP from January 1, 2014 through December 31, 2019 were included in this analysis. Demographic information, mining tenure and occupation, and radiographic classifications according to the International Labour Office system were included from each miner's most recent encounter with the CWHSP. Prevalence ratios were calculated comparing the prevalence of the disease by region and occupation by log-binomial regression. Pneumoconiosis was present in 109 (1.6%) surface coal miners, including 12 miners with progressive massive fibrosis, the most severe form of the disease. After taking surface mining tenure into account, surface miners in Central Appalachia (prevalence ratio [PR], 3.2; 95% confidence interval [CI], 2.2-4.7) and surface miners who worked as a driller or blaster (PR, 2.1; 95% CI, 1.3-3.5) were at increased risk of pneumoconiosis. The occurrence of pneumoconiosis in surface coal miners supports including them within a systematic respiratory health surveillance program. The current surveillance findings are consistent with past findings of pneumoconiosis, particularly silicosis, in surface mining occupations such as drilling and blasting.

Association of occupational dust exposure with combined chronic obstructive pulmonary disease and pneumoconiosis: a cross-sectional study in China.

ObjectivesOccupational dust exposure may induce various lung diseases, including pneumoconiosis and chronic obstructive pulmonary disease (COPD). The features of combined COPD and pneumoconiosis have not been well described, and this may hamper the management. This study aimed to describe the prevalence and characteristics as well as the risk factors of the combined diseases.DesignA cross-sectional study.Setting and participants758 patients with pneumoconiosis were recruited at a single-medical centre. Of these, 675 patients with pneumoconiosis, including asbestosis, silicosis, coal workers’ pneumoconiosis and other pneumoconiosis, was eligible for analysis.Primary outcome measuresCOPD was diagnosed based on clinical features and/or history of exposure to risk factors and post bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio <0.7. Clinical data were collected from predesigned medical reports. The patients underwent both chest radiograph and high-resolution CT scans. Risk factors for combined COPD and pneumoconiosis were analysed using regression analysis.ResultsCOPD prevalence overall was 32.7% (221/675) and was the highest in silicosis (84/221) and coal workers’ pneumoconiosis (100/221). COPD prevalence increased with smoking pack-years, dust exposure duration and pneumoconiosis stage. Patients with combined diseases had lower body mass index, higher smoking index and worse pulmonary function. Risk factors for combined diseases included heavy smoking, silica or coal exposure and advanced pneumoconiosis. The interaction between dust exposure and smoking in COPD was also identified. The risk of combined COPD significantly increased with heavy smoking and silica or coal exposure (OR 5.49, 95% CI 3.04 to 9.93, p<0.001).ConclusionsCOPD is highly prevalent in patients with pneumoconiosis, especially patients with silicosis and coal workers’ pneumoconiosis. Occupational dust exposure as well as heavy smoking is associated with an increased risk of combined COPD and pneumoconiosis, which demands an effective preventive intervention.

Dose-response relationship between different respirable coal dust exposures and pneumoconiosis risk

Objective: To investigate the dose-response relationship between the cumulative dust exposures to anthracite, bituminous coal, and lignite and the cumulative prevalence rates of pneumoconiosis due to the exposures, respectively and provide a basis for scientific development of occupational health standards. Methods: Investigation on the exposure to coal dust and pneumoconiosis prevalence was conducted in 9 state-owned coal mines. The cumulative anthracite, bituminous coal, and lignite dust exposure specific cumulative prevalence rates of pneumoconiosis were calculated by life table method, respectively. The linear regression equations were used to control the unilateral interval to obtain the exposure concentration limits of the respirable coal dust, respectively. Results: A total of 21 000 coal miners in the 9 coal mines were included in the study. The detection rates of pneumoconiosis in coal miners in anthracite, bituminous coal and lignite mines were 11.27%, 21.32%, and 6.00%. The average lengths of exposure to coal dust at pneumoconiosis onset were 20.12 years, 22.88 years, and 25.21 years, respectively and the dose-response relationships between the cumulative respirable coal dust exposure and the cumulative prevalence rates were all linear regression equations, which are y=5.788x-16.043 (R(2)=0.949), y=5.679x-16.837 (R(2)=0.904), and y=6.465x-19.573 (R(2)=0.944), respectively. Supposing that the safety coefficient is 1.2, when the cumulative prevalence rate of pneumoconiosis after 30 years of exposure to dust is not higher than 1%, the exposure concentration limits of the three types of respirable coal dust are 1.7, 2.3, and 3.9 mg/m(3), respectively. Conclusions: The results of this study shows that the detection rate of pneumoconiosis, the average length of exposure to coal dust at pneumoconiosis onset, and the exposure concentration limits of the respirable coal dust varied with coal types. In the case of the same cumulative level of coal dust exposure, the lower the coal volatiles is (i.e. the higher the carbon content is), the higher the cumulative prevalence rate of pneumoconiosis is (anthracite>bituminous coal>lignite). It is suggested to develop national occupational health standards of coal dust exposure according to the grades of coal.

Dose-response relationship analysis between cumulative coal dust exposure and pneumoconiosis risk

Objective: To explore the dose-response relationship between the cumulative coal dust exposure and the cumulative prevalence rate of pneumoconiosis among the coal miners, and to provide a basis for the revision of exposure concentration limits standards of the respirable coal dust and the total dust. Methods: A retrospective cohort study was conducted to study the coal miners in 11 state-owned coal mines from January to August 2013. 21000 coal miners in the 9 coal mines were adopted in the furthre study after the bias treatment.The occupational health records of coal miners from the date of coal production to the end of 2012 in each coal mine were collected. Based on the cumulative dust exposure group of the respirable coal dust and that of the total dust, both the miner's cumulative prevalence rate of pneumoconiosis were calculated by the life table method respectively. The dose-response relationship between the cumulative coal dust exposure and pneumoconiosis risk was established (subject to logistic regression model) . Assuming the cumulative prevalence rate is not higher than 1% after 30 or 25 years of exposure to coal dust and the safety factor is 1.2, the exposure concentration limits of the respirable coal dust and the total dust were calculated by the logistic regression equations with one-sided interval statistical control. Results: There were 3224 pneumoconiosis patients (15.35%) altogether. The dose-response relationship between the cumulative respirable coal dust exposure and the cumulative prevalence rate of pneumoconiosis is a logistic regression equation logistic(r)=5.649lgDr-16.573 (R(2)=0.925) , and the legistic regression equation for the total dust, is logistic(t)=5.712lgDt-18.767 (R(2)=0.897) . When the prevalence rate of pneumoconiosis after 30 years of exposure to coal dust is not higher than 1%, the exposure concentration limits of the respirable coal dust and that of total dust contact are 2.2 mg/m(3) and 4.8 mg/m(3), which are similar to those of national occupational health standards of China (2.5 mg/m(3) and 4 mg/m(3)) . When the prevalence rate of pneumoconiosis after 25 years of exposure to coal dust is not higher than 1%, the exposure concentration limits of the respirable coal dust is 2.7 mg/m(3). Conclusion: It is recommended to strictly implement the current national occupational health standard and abolish the relevant safety production industry standard.