Incidence Of Silicosis Research Articles

Exploring Silico-tuberculosis: A Detailed Investigation of 45 Cases in Occupational Settings

Objective: Silicosis is a lung disease caused by inhaling crystalline silica dust, leading to inflammation and scarring of lung tissue. This retrospective study investigates the association between silicosis and tuberculosis (TB) in occupational settings, analyzing 45 male silicosis patients at Ibn Rochd University Hospital in Casablanca from June 2003 to December 2023. Cases: The average duration of occupational exposure was 18 years, primarily in well-digging, stone crushing, mining, and masonry. Clinical symptoms included dyspnea (89%), persistent bronchial syndrome (83%), and hemoptysis (54%). Imaging typically revealed pseudo-tumoral opacities, often with associated mediastinal lymphadenopathy and micronodular or excavated opacities. TB diagnosis was confirmed by GeneXpert (23% in sputum, 70% in bronchial aspirate fluid) and culture (7%). Conclusion: Anti-tuberculous treatment led to clinical improvement in most cases, but there were two deaths from acute respiratory failure and one case of TB relapse. The findings underscore the importance of screening and chemoprophylaxis for TB in managing silicosis. Preventive measures and worker health protections are crucial to reduce the incidence of silicosis and its complications.

A cross-national perspective on silicosis: incidence, occupational settings, and trends

Abstract Background: Historically, silicosis is a disease of miners, but the last decade witnessed outbreaks in occupational settings not traditionally associated with silica exposure. Evidence from other countries may ground awareness and control of re-emergent risks. Methods: Incident cases of occupational diseases, ranking and trends were analysed within 2012-2016, respectively within 2007-2016 for silicosis using a cross-national comparative study. Labor force profile and occupation were additional data used to identify similarities and differences between Romania and Israel. The incidence rates for silicosis extracted from the Global Burden of Disease Study 2017 were compared to national, continental, and global level. Results: Between the two countries, the ratio was 1:1.5 for musculoscheletal disorders, 1:3 for respiratory diseases, 1:4 for noise-induced hearing loss, and 1:10 for silicosis. Regarding silicosis, three major diffences were found, namely: the burden of disease, the trend of incidence (ascending in Israel; descending in Romania), and the occupational setting (coal miner in Romania; artificial stone worker in Israel). Globally, Romania was among countries with high incidence of silicosis in 2017. Conclusion: Silicosis was a national issue of concern at the time, but vigilance should continue, given the severity of this disease and the occurrence of other silica-related diseases.

Analyzing the incidence of silicosis across various industries in Taiwan: a study of occupational disease surveillance by linking national-based workers’ and medicoadministrative databases

ObjectivesThis study aimed to establish an occupational disease surveillance system by identifying high-risk industries for silicosis in Taiwan using a national database linkage approach. MethodsThe study was based on a comprehensive analysis of benefit claims from the National Labor Insurance Research Database and medical records from the National Health Insurance Research Database between 2004 and 2020, providing coverage for more than 88.5% of the workforce and 99.9% of citizens. Silicosis was defined as having received compensation for labor insurance benefits or having received a diagnosis of silicosis (International Classification of Diseases, 10th Revision: J62 or International Classification of Diseases, Ninth Revision: 502). The study used the International Standard Industrial Classification of All Economic Activities for industry-specific classification. Cox proportional hazard models were used to compare the silicosis incidence and risk among each industry and identify high-risk industries for silicosis. ResultsThis study analyzed 1466 cases of silicosis between 2004 and 2020 and found that 28 industries had incidence rates of over 40 cases per 100,000 workers, indicating more than double the risk of developing silicosis. Of these industries, 14 were considered high risk (relative risk of over four times). Among these, this study identified industries rarely mentioned in the past, such as wholesale of brick, sand, cement, and products, artistic creation, landscape construction, and materials recovery. Stratification by years of work experience reveals those industries such as quarrying of stone, sand, clay, and other mining, construction of buildings, landscape construction, site preparation, foundation and structure construction, building completion and finishing, manufacture of ships, boats, and floating structures, and plumbing, heat, and air conditioning installation display higher hazard ratios for individuals with <10 years of work experience. ConclusionsThe current surveillance system has identified certain industries that are at a higher risk of developing silicosis, which could be used for future occupational epidemiological surveys and targeted preventive measures in these sectors.

Exploring the Impact of Silicosis Incidence on Tuberculosis Mortality and Morbidity: A Multi-Country Study.

There are several risk factors attributed to tuberculosis (TB) mortality and morbidity. There are few studies and systematic reviews showing the association of silicosis and tuberculosis at a country level. Very limited studies have been conducted using multi-country data in studying the association of incidence of silicosis with TB mortality and morbidity. Hence, the aim of this research was to explore the association of incidence of silicosis and other important risk factors with TB mortality and morbidity using multi-country data. Data from 217 WHO region countries were utilized, sourcing TB-related statistics from the Institute of Health Metrics and Evaluation and additional risk factors from the Demographic and Health Survey, Global Burden of Disease, and World Bank for 2019. Regression analysis was conducted to examine the association between silicosis incidence and TB outcomes. The study found an average silicosis incidence of 121.92 per 100,000 population. Additionally, 62.69% of the sample population are exposed to air pollution from solid fuel cooking. Sanitation access stands at an average of 59.67%. Regression outcomes indicate that while alcohol consumption's influence on TB is not statistically significant, a unit increase in silicosis incidence significantly elevates TB deaths (235.9, p = 0.005), YLL (9399.3, p = 0.011), and YLD (910.8, p = 0.002). The burden of silicosis is found to be one of the important determinants of deaths, YLL, and YLD due to tuberculosis. Country-specific strategies to prevent and control silicosis is a need of the hour.

Potential Effect of Combined Exposure of Crystalline Silica Dust and Cigarette Smoking on the Incidence of Silicosis among Chinese Male Stone Processing Workers: A Cross-Sectional Study.

Background: Silicosis is a progressive and irreversible disease primarily caused by exposure to crystalline silica dust and, to a lesser extent, cigarette smoking. However, further research is needed to validate the potential combined effect of these risk factors on the increased incidence of the disease. Methods: A total of 1688 male workers employed at a Chinese stone processing plant between 1 January 1999 and 31 December 2019, were included in the study. Cumulative exposure to industrial crystalline silica dust and packyears of smoking were collected through health surveillance, and odds ratios (ORs) with 95% confidence intervals (CIs) for silicotic changes due to industrial silica exposure and cigarette smoking were estimated using logistic regression models. Results: Among all participants, a significant exposure-response relationship was observed between long-term exposure to industrial silica dust and radiographic findings resembling silicosis (OR 1.74, 95% CI 1.25 to 2.41). However, among middle-aged workers, a weak and statistically insignificant relationship was found between prolonged cigarette smoking and X-ray evidence of lung silicosis (OR 1.59, 95% CI 1.00 to 2.53). Furthermore, significant combined effects, exceeding the additive models, were identified in each age group and employment sector (relative risk due to interaction 0.51, 95% CI 0.08 to 3.42). Conclusions: It is critically important to implement effective dust removal measures and tobacco control strategies in order to enhance respiratory health among employees across all age groups in the stone processing industry.

Nine human epidemiological studies on synthetic amorphous silica and respiratory health

The respiratory health effects of Synthetic Amorphous Silica (SAS) have been studied in human epidemiological research. This article presents a historical overview and review of nine occupational worker studies that have been conducted so far on this topic. The combined study population of all of these studies included 1172 employees, and exposure concentrations ranged from < 1 mg/m3 to 100 mg/m3. In two studies with a total of 293 workers, the incidence of silicosis was investigated after long-term exposure to precipitated SAS, and no cases of silicosis were found (Plunkett and Dewitt, 1962; Volk, 1960). In another study, the spirometry results of 40 workers were normal (Vitums et al., 1977). In a study of 28 workers, 4 cases of silicosis were identified, but it is possible that contamination with cristobalite occurred and detailed information about the amorphous silica origin was not provided (Mohrmann and Kahn, 1985). Ferch et al. (1987) found that lung impairment was associated with confounding factors (smoking) but not with exposure to precipitated SAS in a study of 143 workers. Choudat et al. (1990) reported a reduction in forced expiratory flow in a group exposed to precipitated SAS compared to a control group. Still, they found no correlation between the extent of exposure and pulmonary function was found in a study of 131 workers. Wilson et al. (1979) also failed to show a significant association between the degree of exposure to precipitated SAS and annual changes in lung function in a study of 165 workers. In the most recent and most extensive study (Taeger et al., 2016; Yong et al., 2022) in Germany, involving 462 factory workers, no association between inhalable or respirable SAS dust exposure and respiratory health was reported. Based on the available data, there is no evidence-base to support a relationship between SAS and respiratory health in humans.

Silicosis, asbestosis, and pulmonary fibrosis in Ontario, Canada from 1996 to 2019.

Silicosis is a fibrotic lung disease caused by exposure to respirable crystalline silica. Historically, silicosis was common among miners and other professions in the 20th century, and in recent decades has re-emerged in coal mining and appeared in new workplaces, including the manufacture of distressed jeans and artificial stone countertops. Physician billing data for the province of Ontario between 1992 and 2019 were analyzed across six time-periods (1993-1995, 1996-2000, 2001-2005, 2006-2010, 2011-2015, and 2016-2019). The case definition was two or more billing records within 24 months with a silicosis diagnosis code (ICD-9 502, ICD-10 J62). Cases from 1993 to 1995 were excluded as prevalent cases. Crude incidence rates per 100,000 persons were calculated by time-period, age, sex, and region. Analyses were repeated in parallel for pulmonary fibrosis (PF) (ICD-9 515, ICD-10 J84) and asbestosis (ICD-9 501; ICD-10 J61). From 1996 to 2019, 444 cases of silicosis, 2719 cases of asbestosis and 59,228 cases of PF were identified. Silicosis rates decreased from 0.42 cases per 100,000 in 1996-2000 to 0.06 per 100,000 people in 2016-2019. A similar trend was observed for asbestosis (1.66 to 0.51 per 100,000 persons) but the incidence rate of PF increased from 11.6 to 33.9 per 100,000 persons. Incidence rates for all outcomes were higher among men and older adults. A decreasing incidence of silicosis was observed in this analysis. However, the incidence of PF increased, consistent with findings from other jurisdictions. While cases of silicosis have been recorded among artificial stone workers in Ontario these cases do not seem to have impacted the population rates thus far. Ongoing, periodic surveillance of occupational diseases is helpful for tracking population-level trends over time.

66 A New Raman Spectroscopy Approach for the Measurement of Respirable Crystalline Silica Aerosols Collected onto Filters: Practical Considerations and Advantages

Abstract It is estimated that 560,000 workers in the United Kingdom are potentially exposed to respirable crystalline silica (RCS), which can cause disabling diseases such as silicosis and cancer. The incidence of silicosis in exposed workers can occur at levels below current workplace exposure limits and sensitive analytical techniques are needed to measure low RCS concentrations. The analytical performance of a new Raman spectroscopy method was compared with current X-ray diffraction (XRD) methods. The study investigated limits of detection, measurement uncertainty and measured samples collected from inside respirators. In total, 119 respirable, thoracic, and samples from the Sioutas impactor (PM10 to PM2.5) were also collected from cutting and polishing of engineered and natural stones and analysed for RCS. The LOD for Raman of 0.26 µg is lower than those published for current XRD or infrared methods (5 to 10 µg). The coefficients of determination were between 0.97 and 0.94. The Raman response is as stable as XRD when measuring samples with different median particle sizes (from 0.5 to 7 µm). Raman measurements were significantly different at the 95 % confidence level for the respirable samples (slope = 1.11) but not for thoracic samples (slope = 1.03). Raman spectroscopy has an advantage when measuring quartz in the presence of some minerals that cause interferences with XRD such as zircon. Raman spectroscopy is a promising alternative to XRD for RCS measurements. It has a low LOD and few modifications of current protocols would be necessary to adopt a Raman analysis approach. 2022© Crown copyright

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...

The temporal characteristics of the disruption of gut microbiota, serum metabolome, and cytokines by silica exposure in wistar rats

Silicosis is one of the most frequent, rapidly developing, and lethal types of pneumoconiosis. However, our understanding of the underlying mechanisms of its pathogenesis and progress remains unclear. We investigated the fundamental processes of silicosis incidence and progression using a combination of lung function testing, histopathology, 16 S rRNA, untargeted metabolomics, and cytokine chips at different exposure times (4 or 8 weeks). The results show that silica exposure damages lung tissue reduces lung function, and increases with time. Cytokines with time-specific properties were found in lung lavage fluid: IFN-γ (4 weeks; P＜0.05), TNF-α, M-CSF, GM-CSF (8 weeks; P＜0.01). In addition, silica exposure for different periods interferes to varying degrees with the metabolism of lipids. The composition of the intestinal microbiota changed with increasing exposure time and there were time-specific: Allobaculum, Turicibacter、Jeotgalicoccu、Coprococcus 1 (4 weeks; P＜0.05), Ruminococcaceae NK4A214 group、Ruminiclostridium 5 (8 weeks; P＜0.05). We found strong associations between cytokines, gut microbiota changes, and metabolic disturbances at different exposure times. These results suggest that time-specific changes in crosstalk among cytokines, the gut microbiota, and metabolites may be a potential mechanism for silica-induced lung injury.

Lipid dysregulation associated with progression of silica-induced pulmonary fibrosis.

Silicosis is an irreversible, progressive, fibrotic lung disease caused by long-term exposure to dust-containing silica particles at the workplace. Despite the precautions enforced, the rising incidence of silicosis continues to occur globally, particularly in developing countries. A better understanding of the disease progression and potential metabolic reprogramming of silicosis is warranted. The low- or high-dose silica-induced pulmonary fibrosis in mice was constructed to mimic chronic or accelerated silicosis. Silica-induced mice lung fibrosis was analyzed by histology, lung function, and computed tomography scans. Non-targeted metabolomics of the lung tissues was conducted by ultra-high-performance liquid chromatography-mass spectrometry to show the temporal metabolic trajectory. The low-dose silica-induced silicosis characterized inflammation for up to 42 days, with the onset of cellular silicon nodules. Conversely, the high-dose silica-induced silicosis characterized inflammation for up to 14 days, after which the disease developed rapidly, with a large volume of collagen deposition, presenting progressive massive fibrosis. Both low- and high silica-induced fibrosis had aberrant lipid metabolism. Combined with the RNA-Seq data, this multiomics study demonstrated alterations in the enzymes involved in sphingolipid metabolism. Time-dependent metabolic reprogramming revealing abnormal glycerophospholipid metabolism was intimately associated with the process of inflammation, whereas sphingolipid metabolism was crucial during lung fibrosis. These findings suggest that lipid dysregulation, especially sphingolipid metabolism, was involved in the process of silicosis.

Epidemiology of occupational diseases in Romania and Israel: silicosis as a national concern

Abstract Background: Historically, silicosis is a disease of miners, but the last decade witnessed outbreaks in occupational settings not traditionally associated with silica exposure. Evidence from other countries may ground awareness and control of re-emergent risks. Methods: Incident cases of occupational diseases, ranking and trends were analysed within the period 2005-2016 using a cross-national comparative study. Labor force profile and occupation were additional data used to identify similarities and differences between Romania and Israel. The incidence rates for silicosis extracted from the Global Burden of Disease Study 2017 were compared to national, continental, and global level. Results: Between the two countries, the ratio was 1:1 for silicosis, musculoscheletal disorders, hearing loss, and chronic bronchitis. Regarding silicosis, two major diffences were found, namely: the trend of incidence (ascending in Israel; descending in Romania) and the occupational setting (coal miner in Romania; artificial stone worker in Israel). Globally, Romania was among countries with high incidence of silicosis in 2017. Conclusion: Silicosis was a national issue of concern at the time, but vigilance should continue, given the severity of this disease and the occurrence of other silica-related diseases.

Extracellular signal-regulated kinase signaling pathway and silicosis.

Silicosis is a scarring lung disease caused by inhaling fine particles of crystalline silica in the workplace of many industries. Due to the lack of effective treatment and management, the continued high incidence of silicosis remains a major public health concern worldwide, especially in the developing countries. Till now, related molecular mechanisms underlying silicosis are still not completely understood. Multiple pathways have been reported to be participated in the pathological process of silicosis, and more complex signaling pathways are receiving attention. The activated extracellular signal-regulated kinase (ERK) signaling pathway has been recognized to control some functions in the cell. Recent studies have identified that the ERK signaling pathway contributes to the formation and development of silicosis through regulating the processes of oxidative stress, inflammatory response, proliferation and activation of fibroblasts, epithelial-mesenchymal transformation, autophagy, and apoptosis of cells. In this review article, we summarize the latest findings on the role of ERK signaling pathway in silica-induced experimental models of silicosis, as well as clinical perspectives.

Sex-Related Differences in the Risk of Silicosis Among Chinese Pottery Workers: A Cohort Study.

To investigate the effect of sex on the risk of silicosis and to explore any interaction between cigarette smoking and sex in the development of silicosis. The cohort was selected from eight Chinese pottery factories. Diagnoses of silicosis were based on 1986 Chinese pneumoconiosis Roentgen diagnostic criteria. Data on cigarette smoking were collected by face-to-face interviews in 1989 and 2003. Eight thousand eight hundred and eighty seven dust-exposed workers were included. Men had a 77% higher incidence of silicosis than women. At lower pack-years of smoking, men were 72% more at risk than women. The latency period was found to be longest in female never-smokers and shortest in female ever-smokers. Men had a higher risk of developing silicosis than women. Cigarette smoking increased the risk in both sexes, more so in women.

Incidence of silicosis among excavation workers

Objective: To assess the incidence of silicosis among excavation workers in Suzhou city. Methods: In 2011-2016, we investigated the incidence of silicosis among 3190 excavation workers who participated in the mining operations from 1971 to 1974 in Suzhou city. To compare the general condition, complications, blood indexes and pulmonary function between different stages of silicosis patients. Results: Among all the participants, 144 cases were diagnosed as silicosis, and the incidence of silicosis was 4.51%, including 138 stage I cases (95.83%) , 4 stage II cases (2.78%) , and 2 stage III cases (1.39%) . Both systolic blood pressure (154.17±14.74 mmHg) and diastolic blood pressure (96.67±10.25 mmHg) of silicosis patients in stage II-III were significantly higher than that of patients in stage I (134.64±15.41 mmHg, 82.20±10.62 mmHg) (P<0.05) . Hypertension (54 cases, 37.50%) were the most commonly complication of silicosis patients, followed by abnormal electrocardiogram (38 cases, 26.39%) , diabetes (22 cases, 15.28%) , malignant tumor (10 cases, 6.94%) , hepatitis B (8 cases, 5.56%) and tuberculosis (8 cases, 5.56%) . The serum levels of red blood cell count (RBC) , hemoglobin (Hb) , albumin (ALB) , magnesium (Mg) and sodium (Na) in stage I silicosis patients were significantly higher than stage II-III patients (P<0.05) . While the serum levels of C-reactive protein (CRP) and carbohydrate antigen 199 (CA199) in stage I silicosis patients were significantly lower than stage II-III patients (P<0.05) . The proportions of normal pulmonary function, mild airflow limitation, moderate airflow limitation and severe airflow limitation in silicosis patients were 44.03% (59/134) , 18.66% (25/134) , 29.85% (40/134) and 7.46% (10/134) , respectively. Conclusion: Our data obviously show that the excavation workers has a high incidence of silicosis. It is necessary to strengthen the occupational health surveillance of silicosis patients, reduce complications and improve their quality of life.

Characterization of Silica Exposure during Manufacturing of Artificial Stone Countertops.

Artificial stone is increasing in popularity in construction applications, including commercial and residential countertops. Eco-friendliness, durability, and resistance to staining, make artificial stone attractive to consumers. Health concerns have arisen during manufacturing of artificial stone due to increased incidence of silicosis after relatively short exposure. Three artificial stone samples (A, B, and C) and one natural granite sample were subjected to cutting and grinding in a controlled environment. Gravimetric analysis, X-Ray diffraction, and scanning electron microscopy with energy dispersive spectroscopy were employed to determine crystalline silica concentrations and particle morphology of bulk and respirable particles. Silica content of bulk dust from artificial samples A and B was 91%, sample C was <10%, while granite was 31%. Silica percent in the respirable fraction for samples A and B was 53% and 54%, respectively, while sample C was <5% and granite was 8%. Number concentrations for samples A and B were mainly in the nano-fraction, indicating potential for translocation of silica particles to other organs outside of the lungs. Respirable dust concentrations inside the chamber were well above Occupational Safety and Health Administration standards for all materials, indicating that confined-space exposures require ventilation to lower risks of acute silicosis regardless of the nature of the stone.

Can the South African Milestones for Reducing Exposure to Respirable Crystalline Silica and Silicosis be Achieved and Reliably Monitored?

Silicosis and other respirable crystalline silica-associated diseases, most notably tuberculosis, have long been substantial causes of morbidity and mortality in South Africa. For the mining and non-mining industries, silicosis elimination programmes have been developed with milestones regarding reduction of levels of exposure to respirable crystalline silica (RCS) and targets regarding the date of eradication. The present paper explores the feasibility of achieving these targets by investigating the evidence that levels of exposure and silicosis incidence rates have declined by an appraisal of the methods for data collection and reporting. In the mining industry the silicosis elimination programme is supported by the development and advocacy of leading practices to reduce the exposure. RCS exposure data are routinely collected according to a Code of Practice (CoP) and the results are reported to the Mine Health and Safety Inspectorate. As the CoP and the actual workplace practices have been demonstrated to have some flaws, there is some concern about the accuracy of the actual exposure data and the data interpretation. The annually reported levels of exposure suggest a decline, however, the actual levels of RCS as well as the number of exposed workers, were not reported over the last few years. With regard to the silicosis incidence rates, a steady decline of new cases is reported. However, there is a risk of under-diagnosis and- reporting especially in former miners. In the non-mining industries, a systematic baseline of RCS exposure levels and silicosis incidence is lacking. The reporting by industries on assigning of the workforce to exposure categories seems to be fragmented and incomplete. Consequently, any evidence of progress toward achieving the silicosis elimination target cannot be documented. Both the silicosis elimination target and the exposure milestone are aspirational but are unlikely to be achieved. Nevertheless, the formal mining industry may get close. Exposure control interventions, especially in the non-mining industries, should be developed and implemented and pragmatic methods need to be put in place to identify sources of new silicosis cases for targeted intervention.

Silicosis in finishing workers in quartz conglomerates processing.

Introduction:Outbreaks of silicosis have bene recently reported in artificial stone workers.Aim:To describe the features of silicosis in quartz conglomerate workers in North-Eastern Italy.Methods:Active search of pneumoconiosis was performed in 11 companies of North-Eastern Italy involved in the fabrication of quartz conglomerate countertops. Occupational history, lung function tests, chest X-ray and high resolution computed tomography (HRCT) were performed. In selected cases, trans-bronchial biopsies were taken for histological evaluation and identification of silica crystals in the tissue. Cumulative exposure to crystalline silica was estimated.Results:We recruited 45 workers and 24 cases of silicosis were diagnosed. Mean age at diagnosis was 43 years and duration of exposure to quartz conglomerate dust was 3.5 to 20 years. The average silica cumulative exposure was 4.3 mg/m3/y. Abnormal findings were detected in 42% of chest X-rays, in 33% of spirometry and 50% of carbon monoxide lung diffusion (DLco). HRCTs were abnormal in all cases showing well-defined rounded opacities, irregular/linear intralobular opacities and bilateral enlarged mediastinal lymph-nodes. Histological findings consistent with silicosis were observed in 24 cases. Numerous silica particles (diameter 0.1-5 μm) were identified in lung tissue.Conclusions:We reported an unexpected high incidence of silicosis in Italian workers exposed to quartz conglomerate dust. The results suggest that chest HRCT is indicated for screening of workers with high exposure to silica and DLco should be added to spirometry in health surveillance. More rigorous application of safety regulations and more effective preventive interventions at work are necessary.

Silicosis in rhinestone-manufacturing workers in South China.

Silicosis is caused by long-term exposure to silica dust. Crystal rhinestone workers can be exposed to high levels of silica dust and are at risk of silicosis. To explore silicosis cases, silica dust exposure and control measures in a rhinestone factory in South China. We extracted and analysed data on new silicosis cases reported to China's occupational disease and occupational health information monitoring system between 2006 and 2012 from a rhinestone factory in South China. We measured the quartz content of bulk dust, static total and respirable dust samples. Ninety-eight silicosis cases were reported between 2006 and 2012. The mean duration of silica dust exposure was 9.2 years (range 3-16). Drilling and polishing workers accounted for 96 (98%) of cases. We collected 1479 static samples including 690 total dust and 789 respirable dust samples. Mean dust levels for drilling were 1.01 mg/m3 (range 0.20-3.80) for total dust and 0.51 mg/m3 (range 0.04-1.70) for respirable dust. Mean dust levels for polishing were 0.59 mg/m3 (range 0.20-2.10) for total dust and 0.28 mg/m3 (range 0.08-0.71) for respirable dust. Over a third [289/789 (37%)] of total dust samples and 129/690 (19%) respirable dust samples exceeded the national permissible exposure limit. Exposure to silica dust, ineffective dust control measures and inefficient health surveillance may have contributed to the incidence of silicosis in the factory we studied. Identification of silica dust exposure and effective dust control measures would reduce the risk of silicosis in rhinestone workers.

The epidemiological characteristics of silicosis cases in Tianjin from 2001 to 2015

Objective: To provide scientific evidence for the prevention and control measures of silicosis by analyzing the epidemiological characteristics of silicosis cases reported in Tianjin city during 2001-2015. Methods: The database of silicosis cases reported in Tianjin from 2001 to 2015 was established and analyzed by SPSS 24.0 software. Results: 2 213 cases of silicosis were reported during 2001~2015 in Tianjin, 2015 of them were new cases, and fewer reports of promoting stage cases and death cases, which were129 and 69 cases. The new cases were increasing by years, mainly stage I silicosis accounting for 99.2%, the years of dust exposure were concentrated from 1970 to 1989, accounting for 69.58%. From 2001 to 2015, the median length of service at the onset of silicosis was 19.30 years, the age of the onset of silicosis is decreasing. The median of onset age in new cases of silicosis was 53.28 years, and increased year by year. There were significant differences in indirect dust working age and diagnostic age in different reporting years. Most cases were distributed in non-mental mineral product industry, and ferrous metal smelting and rolling processing industry. The work types of these cases are various. Conclusion: The increasing incidence of silicosis and the shortening of dust-exposed working years suggest that the form of silicosis hazards is still severe in Tianjin. According to the epidemic characteristics of silicosis, we should strengthen the supervision and management of key industries and special investigation, carry out silicosis census and silicosis screening of dust-removal workers, and take pertinent measures to prevent and control the occurrence of silicosis.