Pneumoconiosis and advanced occupational lung disease among surface coal miners--16 states, 2010-2011

Coal workers' pneumoconiosis (CWP) is a chronic occupational lung disease caused by long-term inhalation of dust, which triggers inflammation of the alveoli, eventually resulting in irreversible lung damage. CWP ranges in severity from simple to advanced; the most severe form is progressive massive fibrosis (PMF). Advanced CWP is debilitating and often fatal. To prevent CWP, the Coal Mine Health and Safety Act of 1969 established the current federal exposure limit for respirable dust in underground and surface coal mines. The Act also established a surveillance system for assessing prevalence of pneumoconiosis among underground coal miners, but this surveillance does not extend to surface coal miners. With enforcement of the exposure limit, the prevalence of CWP among underground coal miners declined from 11.2% during 1970-1974 to 2.0% during 1995-1999, before increasing unexpectedly in the last decade, particularly in Central Appalachia. Exposure to respirable dust is thought to be less in surface than underground coal miners. Although they comprise 48% of the coal mining workforce, surface coal miners have not been studied since 2002. To assess the prevalence, severity, and geographic distribution of pneumoconiosis among current surface coal miners, CDC obtained chest radiographs of 2,328 miners during 2010-2011 through the Coal Workers' Health Surveillance Program of the National Institute for Occupational Safety and Health (NIOSH). Forty-six (2.0%) of 2,257 miners with >1 year of surface mining experience had CWP, including 37 who had never worked underground. Twelve (0.5%) had PMF, including nine who had never worked underground. A high proportion of the radiographs suggested silicosis, a disease caused by inhalation of crystalline silica. Surface coal mine operators should monitor worker exposures closely to ensure that both respirable dust and silica are below recommended levels to prevent CWP. Clinicians should be aware of the risk for advanced pneumoconiosis among surface coal miners, in addition to underground coal miners, to facilitate prompt disease identification and intervention.     

Rapidly progressive coal workers' pneumoconiosis in the United States: geographic clustering and other factors

Background: Despite significant progress made in reducing dust exposures in underground coal miners in the United States, severe cases of coal workers'' pneumoconiosis (CWP), including progressive massive fibrosis (PMF), continue to occur among coal miners. Aims: To identify US miners with rapidly progressive CWP and to describe their geographic distribution and associated risk factors. Methods: Radiographic evidence of disease progression was evaluated for underground coal miners examined through US federal chest radiograph surveillance programmes from 1996 to 2002. A case of rapidly progressive CWP was defined as the development of PMF and/or an increase in small opacity profusion greater than one subcategory over five years. County based prevalences were derived for both CWP and rapidly progressive cases. Results: A total of 886 cases of CWP were identified among 29 521 miners examined from 1996 to 2002. Among the subset of 783 miners with CWP for whom progression could be evaluated, 277 (35.4%) were cases of rapidly progressive CWP, including 41 with PMF. Miners with rapidly progressive CWP were younger than miners without rapid progression, were more likely to have worked in smaller mines (<50 employees), and also reported longer mean tenure in jobs involving work at the face of the mine (in contrast to other underground mining jobs), but did not differ with respect to mean underground tenure. There was a clear tendency for the proportion of cases of rapidly progressive CWP to be higher in eastern Kentucky, and western Virginia. Conclusions: Cases of rapidly progressive CWP can be regarded as sentinel health events, indicating inadequate prevention measures in specific regions. Such events should prompt investigations to identify causal factors and initiate appropriate additional measures to prevent further disease.     

Pneumoconiosis prevalence among working coal miners examined in federal chest radiograph surveillance programs--United States, 1996-2002

Coal workers' pneumoconiosis (CWP) is a chronic lung disease caused by inhalation of coal mine dust. To characterize the prevalence of CWP, the National Institute for Occupational Safety and Health (NIOSH) analyzed recent radiographic information from the U.S. National Coal Workers' X-ray Surveillance Program (CWXSP). Established under the Federal Coal Mine Health and Safety Act of 1969, CWXSP is administered by NIOSH under federal regulations. NIOSH is responsible for approving coal miner examination plans, submitted approximately every 5 years by companies that operate underground coal mines. This report summarizes the results of the analysis, which indicate that the overall prevalence of CWP among participating miners continues to decline; however, new cases are occurring among miners who have worked exclusively under current dust exposure limits. An evaluation of the mining conditions that have resulted in these cases is underway.     

煤尘职业接触者和早期煤工尘肺BAL液中表面活性物质研究

目的 探讨煤尘职业接触者和早期煤工尘肺患者BAL液中表面活性物质含量改变特点及其意义。方法 采煤工人23人,按X线诊断煤工尘肺期别分为0期（煤尘接触者）组7人、0^ 组8人和I期组8人,并取健康农民7人为对照组。经纤维支气管肺泡灌洗（BAL）收集BAL液,测定表面活性蛋白A(SP－A）和磷脂（PL）及其组分含量。结果 0期组BAL液中SP－A含量、SP－A／PL和PG／PI明显高于对照组（P＜0．01）,且随煤工尘肺期别增加而有降低趋势。结论 BAL液中SP－A含量、SP－A／PL和PG／PI升高可能是煤尘接触的早期效应指标。     

煤矿粉尘接触和人群脂质过氧化水平的观察

目的 为了解煤矿粉尘接触和人群脂质过氧化水平。方法 检测煤矿粉尘接触量和人群脂质过氧化水平。结果 矿井巷道和采煤面粉尘浓度低于国家标准装渣,放炮作业和各工种一次最高浓度均超国标。除矿井出风口外,地面各监测点可吸入粉尘均在容许范围,粉尘接触人群ＳＯＤ活性降低,井下工人ＭＤＡ增加,吸烟者更显著,煤工尘肺患者两项指标同时提高,结论 提示煤尘接触引起人群脂质过氧化代谢紊乱,紊乱程度和粉尘接触量有关,吸烟是     

An investigation into the relationship between coal workers' pneumoconiosis and dust exposure in U.S. coal miners.

The National Study of Coal Workers' Pneumoconiosis (NSCWP) is a large, continuing epidemiologic study of the respiratory health of U.S. coal miners. By using information from the study, prevalence of coal workers' pneumoconiosis (CWP) was related to indexes of dust exposure obtained from research and compliance sampling data. Clear relationships between prevalences of both simple CWP and progressive massive fibrosis (PMF) and estimated dust exposure were seen. Additional effects independently associated with coal rank (% carbon) and age were also seen. Logistic model fitting indicated that between 2% and 12% of miners exposed to a 2-mg/m3 dust environment in bituminous coal mines would be expected to have Category 2 or greater CWP after a 40-yr working life; PMF would be expected for between 1.3% and 6.7%. The risks for anthracite miners appeared to be greater. There was a suggestion of a background level of abnormality, not associated with dust exposure, but increasing with age. Although there are certain weaknesses in the data used to derive these exposure estimates, the results are in general agreement with, but somewhat greater than, some recent findings for British coal miners.     

煤工尘肺患病率、人年患病率和预期发病工龄分析——烟煤矿时期患(发)病调查

本文报道了烟煤煤矿井下工人22年追踪观察的职业流行病学调查研究结果。在全面收集资料的基础上,统一诊断标准,规定统计工种内容,患病率采用同一时期(1958～1985)全部接尘工人为基数;人年患病率以1958年以来逐年出入煤矿工人的实际暴露人年为分母;预期发病工龄按寿命表程序计算。探讨了烟煤影响下的煤工尘肺患病情况及发病趋势。     

Airways obstruction, coal mining, and disability.

It has recently been suggested that the inhalation of coal in the absence of complicated coal workers' pneumoconiosis (CWP) or smoking can lead to disabling airways obstruction. The cause of such obstruction has been variously attributed to emphysema or bronchitis. The frequency of significant airways obstruction in a group of United States coal miners seeking compensation for occupationally induced pulmonary impairment was therefore determined. In a sample of 611 "Black Lung" claimants there was only one subject who was a non-smoker and who in the absence of other non-occupationally related diseases,--for example, asthma and bronchiectasis--had sufficient airways obstruction to render it difficult for him to carry out hard labour. An alternative explanation for his reduced ventilatory capacity other than coal dust or smoking may be available. If the inhalation of coal dust in the absence of smoking and complicated CWP ever induces sufficient ventilatory impairment to preclude a miner from working, it is indeed rare.     

Antithetical effect of tumor necrosis factor-alphagene polymorphism on coal workers' pneumoconiosis (CWP)

BACKGROUND: Inter-individual variation in the severity of pneumoconiosis has been described, even with the same environmental exposure. We hypothesized that TNF-alpha promoter polymorphisms associate with lung responses to environmental exposure in coal worker's pneumoconiosis (CWP) patients. METHODS: We examined polymorphisms at -238, -308, and -376 in 124 patients with CWP who had similar dust exposure history and in 122 non-exposed controls. CWP patients were divided into two groups: (1) nodular CWP (n = 84); (2) progressive massive fibrosis (PMF) (n = 44). RESULTS: The -308 A allele frequency was higher in patients with CWP compared to controls (6.35% and 2.05%, P < 0.01). It was also higher in patients with nodular CWP compared to PMF (P < 0.05). Logistic regression analysis revealed that patients with the -308 A allele were 3.8 times (P = 0.036) and those with smoking habit were 2.3 times (P < 0.002) more likely to have nodular CWP than PMF. CONCLUSION: TNF-alpha-308 A allele might interact with smoking to enhance susceptibility to nodular CWP.     

Neopterin as a marker for immune system activation in coal workers' pneumoconiosis

Coal workers' pneumoconiosis (CWP) is an occupational pulmonary disease that occurs by chronic inhalation of coal dust. Coal workers' pneumoconiosis is divided into two categories depending on the extent of the disease as simple pneumoconiosis (SP) and progressive massive fibrosis (PMF). Development of CWP is associated with the activation of the immune system. Neopterin is a predictive biochemical marker of cell-mediated immune activation and elevated levels of neopterin are detected in body fluids of patients with immune-related diseases. The present study was aimed to investigate whether increased serum, urine and bronchoalveolar lavage (BAL) fluid levels of neopterin is associated with the development and/or severity of CWP. Mean serum neopterin levels in SP and PMF patients (10.72 +/- 0.98 nmol/L; 14.08 +/- 3.86 nmol/L, respectively) were significantly higher than those of control group (5.30 +/- 0.47 nmol/L) (P < 0.05). Although urinary neopterin levels were also increased in SP and PMF patients (235.17 +/- 7.40 micromol/mol creatinine; 256.05 +/- 9.43 micromol/mol creatinine, respectively) as compared with the control group (140.00 +/- 5.43 micromol/mol creatinine) (P < 0.01), they were within the normal concentration range. No significant difference was observed between serum and urinary neopterin levels of SP and PMF patients. A correlation was observed between serum and urinary neopterin levels of all subjects (r = 0.525, P < 0.01). Bronchoalveolar lavage fluid neopterin levels were significantly higher in patients with SP and PMF (22.67 +/- 2.9 nmol/L; 41.67 +/- 8.68 nmol/L, respectively) compared with control subjects (6.264 +/- 1.74 nmol/L) (P < 0.05, P < 0.01, respectively). The levels of neopterin in BAL fluid were also significantly higher in patients with PMF than in those with SP (P < 0.05). These findings indicate that elevated serum and BAL levels of neopterin may be considered as a suitable biomarker for the assessment of CWP.     

铁法大隆矿煤工尘肺预防效果评价

目的评价40年来大隆矿煤工尘肺的预防效果,为进一步改善防尘降尘措施提供理论依据。方法采用"煤工尘肺调查表"和"接尘工人未患尘肺者调查表"对所有曾接尘的该矿工人进行个案调查,用单因素方差分析、寿命表法、Log-rank检验等统计学方法,分析了其中所有接尘工人的资料。结果大隆矿1959年前、1960～1964年、1965～1969年、1970～1979年不同年代接尘作业工人至2004年底尘肺累积发病率分别为:67.50%、15.07%、11.64%、0.00%,年平均发病率分别为:1.41%、0.36%、0.31%、0.00%。不同年代诊断的尘肺病人平均发病年龄与平均接尘工龄分别由80年代以前的40.94岁与16.11年,延长到80～90年代为49.04岁与22.04年,90年代进一步延长为63.30岁与27.70年。推行综合防尘措施后参加接尘作业矿工较之推行前,在相同观察周年内,累积发病率比较,差别有显著性(P<0.0001)。假设1980年后各年尘肺发病率与1980年前参加者相同,计算得预期发病人数为21人,而实际发病人数为0人。结论大隆矿煤工尘肺的发病情况逐渐减轻,1980年推行综合防尘降尘措施后发病情况减轻。     

Relations between occupational exposure to coal mine dusts,erythrocyte catalase and Cu++/Zn++ superoxide dismutase activities,and the severity of coal workers' pneumoconiosis

OBJECTIVES: To better understand the relations between occupational exposure, blood antioxidant enzyme activities, total plasma antioxidant concentration, and the severity of coal workers'' pneumoconiosis (CWP). METHODS: Blood samples were obtained from miners without CWP exposed to low dust concentrations for > or = 4 years at the time of the study (n = 105), or exposed to high dust concentrations for > or = 14 years at the time of the study (n = 58), and from retired miners with CWP (n = 19). Miners without CWP were classified into three subgroups according to their estimated cumulative exposure to dust. Chest x ray films were obtained for each miner. Miners were classified in five subgroups according to their International Labour Organisation (ILO) profusion grades. Univariate tests were completed by multiple linear regression analyses. RESULTS: The estimated cumulative exposure to dust was strongly positively related to erythrocyte catalase activity and strongly negatively related to Cu++/Zn++ SOD activity only in miners exposed to high dust concentrations for > or = 14 years at the time of the study (F tests p = 0.006 and p = 0.004 respectively). Moreover, catalase activity was strongly related to the severity of CWP expressed as five subgroups of ILO profusion grades (F test p = 0.003); the greatest difference in the mean values was found between the group of 1/1 to 1/2 ILO profusion grades and the group of 2/1 to 3/3 ILO profusion grades. CONCLUSION: These results are in good agreement with the hypothesis that production of reactive oxygen species may be an important event in the exposure to coal mine dusts and the severity of CWP. Erythrocyte catalase and Cu++/Zn++ SOD activities are more closely related to recent exposure to high dust concentrations than to cumulative exposure, and could be considered as biological markers of exposure rather than as markers of early adverse biological effect.       

Changing patterns of pneumoconiosis mortality--United States, 1968-2000

Pneumoconioses are caused by the inhalation and deposition of mineral dusts in the lungs, resulting in pulmonary fibrosis and other parenchymal changes. Many persons with early pneumoconiosis are asymptomatic, but advanced disease often is accompanied by disability and premature death. Known pneumoconioses include coal workers' pneumoconiosis (CWP), silicosis, asbestosis, mixed dust pneumoconiosis, graphitosis, and talcosis. No effective treatment for these diseases is available. This report describes the temporal patterns of pneumoconiosis mortality during 1968-2000, which indicates an overall decrease in pneumoconiosis mortality. However, asbestosis increased steadily and is now the most frequently recorded pneumoconiosis on death certificates. Increased awareness of this trend is needed among health-care providers, employers, workers, and public health agencies.     

某煤业集团煤工尘肺病人肺通气功能分析

目的了解某煤业集团煤工尘肺病人和接尘非煤工尘肺病人肺通气功能损伤情况,探讨煤工尘肺病人不同工种、工龄、分期之间肺通气功能损伤的差异。方法选取某煤业集团确诊的煤工尘肺病人555名。另外选取该煤业集团555名接尘的非煤工尘肺病人和207名非接尘工人作为对照。采用统一的体检表格,由专业医师进行统一体检,并逐一填写表格。肺功能测定仪器为北京产AS.507型肺量计,进行肺通气功能指标测定。运用卡方检验、单因素方差分析、相关分析进行统计学处理。结果尘肺病人组肺功能异常率高于接尘非尘肺病人组和不接尘健康工人组,差异有统计学意义(χ2=193.319,P<0.001);采用单因素方差分析,三组人群各指标的比较结果显示,尘肺病人组的FEV1.0相对值和FEV1.0%低于接尘非尘肺病人组和不接尘工人组,尘肺病人组和接尘非病人组的FVC相对值均低于不接尘工人组。555名尘肺病人包括不吸烟108人、戒烟427人和吸烟20人,其肺功能异常率分别是67.6%、74.5%和90.0%(χ2=4.381,P=0.036<0.05),不吸烟组和吸烟组的FVC相对值均低于戒烟组,戒烟组的FEV1.0%明显低于不吸烟组。FEV1.0相对值在各组之间差异无统计学意义。各工种之间FVC相对值、FEV1.0相对值,FEV1.0%比较,差异均无统计学意义;各工龄组之间差异亦无统计学意义。各期别尘肺病人FVC相对值、FEV1.0相对值比较,差异无统计学意义,但贰期、叁期尘肺病人FEV1.0%高于壹期尘肺病人。结论接尘非煤工尘肺病人与煤工尘肺病人肺通气功能均有损伤,煤工尘肺病人肺通气功能损伤重于接尘非煤工尘肺病人,说明肺通气功能可以作为监测煤工尘肺的早期敏感动态观察指标。吸烟是影响肺通气功能的一个重要因素,吸烟加剧煤工尘肺病人肺通气功能的损伤程度。     

The survival analyses of 2738 patients with simple pneumoconiosis.

OBJECTIVES: To explore whether the inhalation of coal mine dust increases the risk of premature death in miners, a survival analysis was conducted in a cohort of 2738 patients with simple pneumoconiosis in the Huai-Bei coal mine, in China. METHODS: Age specific mortalities were calculated by disease severity in terms of pneumoconiotic category with the life table method. The progressions from simple pneumoconiosis to death or progressive massive fibrosis (PMF) were analysed with the Cox's regression model with time as the dependent variable to identify risk factors. RESULTS: During a follow up period (mean 8 y) 3.2% of patients with simple pneumoconiosis developed PMF. The patients with development of PMF presented higher age specific mortalities than those remaining in a state of simple pneumoconiosis (SMR: 3.42; P < 0.01). After adjustment for tuberculosis and duration of work, the relative risk of premature death due to development of PMF was 2.4. Tuberculosis was found to be a main risk factor which not only facilitated premature death (relative risk (RR): 2.0; P < 0.01), but was also a strong facilitator for development of PMF (RR: 7.0; P < 0.01). Also, a long term of work underground and drilling as a main job were identified as risk factors for development of PMF. CONCLUSION: The results imply that patients with simple pneumoconiosis will have altered survival, and premature death among them is related to an increased risk of the development of PMF and the complication of tuberculosis.     

镇江东风煤矿煤工尘肺发病情况30年动态观察

为分析薄煤层小型煤矿煤工尘肺动态发病情况、规律及影响因素，按前瞻性调查方法对各作业点粉尘浓度、接尘工人Ｘ线胸片进行了３０年动态观察。结果３０年间全矿共发现煤工尘肺患者７５０例，患病率２５．０７％，病死率１１．８７％，现患率２２．７７％。动态观察表明随着作业场所防尘措施的不断改善，尘肺发病率明显下降。不同诊断年代的发病工龄、年龄及平均生存年限，随时间推移明显延长，经等极相关检验有非常显著性意义（Ｐ＜０．０５）。提示薄煤层小型矿只要能采取以湿式作业为主的综合防尘措施，就能预防和控制煤工尘肺的发生和发展。     

Genetic polymorphisms of MnSOD, GSTM1, GSTT1, and OGG1 in coal workers' pneumoconiosis

Little is known about the genetic susceptibility to coal workers' pneumoconiosis (CWP). We investigated the association between genetic polymorphisms of MnSOD, GSTM1, GSTT1, or OGG1 and susceptibility to CWP. The study population was composed of 259 Chinese retired coal miners who had similar dust exposure histories. Of these, there were 99 cases with International Labor Organization chest radiologic criteria for CWP and 160 controls (with no radiologic criteria for CWP). Individual dust exposure variables were estimated from work histories, and smoking information was obtained from interviews. Polymerase chain reaction-based techniques evaluated the genotypes of all study subjects. There were no differences in genotype frequency of MnSOD, GSTM1, GSTT1, and OGG1 between miners with CWP and miners without CWP, by logistic regression analysis. Cumulative dust exposures, but not genetic polymorphisms, were associated significantly with the presence of CWP. This study illustrates the complexity of factors that may contribute to the development of CWP.     

Respiratory Status of Surface Coal Miners in the United States

The United States Public Health Service examined 1,438 surface coal miners to determine the prevalence of coal worker’s pneumoconiosis (CWP), chronic bronchitis, and ventilatory impairment among them. Four percent (fifty-nine individuals) showed some roentgenographic evidence of pneumoconiosis, but only seven miners had films interpreted as CWP of category2 or greater (according to the UlCC/Cincinnati classification system). Moreover, most of the affected miners had worked in underground coal mines for prolonged periods. Significant decrements in pulmonary function to increasing exposure to surface mine dust were demonstrated only in the forced vital capacity of smokers. Increased prevalence of chronic bronchitis with increasing exposure was found in all smoking categories. However, significant airway obstruction was an uncommon finding (6.6%) in nonsmoking miners. Employment in surface mining was not likely to cause either the development of CWP or clinically significant respiratory impairment.     

Serum Levels of TGF-β1 and MCP-1 as Biomarkers for Progressive Coal Workers’ Pneumoconiosis in Retired Coal Workers: A Three-year Follow-up Study

Various cytokines activated by the inhalation of coal dust may mediate inflammation and lead to tissue damage. Objective of this study was to examine the relationships between coal workers’ pneumoconiosis (CWP) progression over a 3 yr period and the serum levels of cytokines in 85 retired coal workers. To investigate the relevance of serum cytokines in CWP, serum levels of interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-α), transforming growth factor–beta1 (TGF-β1), and monocyte chemotactic protein-1 (MCP-1) as progressive CWP biomarkers were studied in relation to the progression of pneumoconiosis over a 3 yr period in 85 patients with CWP. CWP progression was evaluated through paired comparisons of chest radiographs. Median levels of TGF-β1 and MCP-1 were significantly higher in subjects with progressive CWP than in those without CWP progression. The area under the ROC curve for TGF-β1 (0.693) and MCP-1 (0.653) indicated that these cytokines could serve as biomarkers for the progression of CWP. Serum TGF-β1 levels were related to the progression of CWP (β=0.247, p=0.016). The results suggest that high serum levels of TGF-β1 and MCP-1 are associated with the progression of CWP.     

煤工尘肺患者血清白细胞介素-9和可溶性细胞间黏附分子-1水平变化及意义

目的探讨煤工尘肺患者(CWP)血清白细胞介素-9(IL-9)和可溶性细胞间黏附分子-1(sICAM-1)水平变化及意义。方法用双抗体夹心酶联免疫吸附法检测106名CWP患者(CWP组)、55名具有与CWP组相同接尘条件的0+煤矿工人(0+组)、62名具有相同接尘史但未患CWP的煤矿工人(接尘对照组)及47名非接尘井上健康工人(正常对照组)血清IL-9和sICAM-1水平。结果与正常对照组比较,接尘对照组和0+组IL-9水平明显升高,差异均具有统计学意义(P均<0.05),而CWP组则轻度升高(P>0.05);接尘对照、0+及CWP三组sICAM-1水平均明显降低,差异均具有统计学意义(P<0.05和P<0.01)。CWP组IL-9水平明显低于接尘对照组和0+组,差异均具有统计学意义(P均<0.05),接尘对照组和0+组比较无明显变化(P>0.05)。sICAM-1水平在接尘对照、0+和CWP三组中均无明显改变(P均>0.05)。IL-9和sICAM-1水平在Ⅰ期CWP和Ⅱ期+Ⅲ期CWP以及不同接尘时间中均无显著变化(P均>0.05)。CWP组IL-9和sICAM-1无明显相关性(r=0.024,P>0.05)...