Epidemiological data on US coal miners'' pneumoconiosis, 1960 to 1988.

OBJECTIVES. Statistics on prevalence of pneumoconiosis among working underground coal miners based on epidemiologic data collected between 1960 and 1988 are presented. The main intent was to examine the time-related trend in prevalence, particularly after 1969, when substantially lower dust levels were mandated by federal act. METHODS. Data from studies undertaken between 1960 and 1968 were collected and compared. Information for the period 1969 to 1988 was extracted from a large ongoing national epidemiologic study. Tenure-specific prevalence rates and summary statistics derived from the latter data for four consecutive time intervals within the 19-year period were calculated and compared. RESULTS. The results indicate a reduction in pneumoconiosis over time. The trend is similar to that seen in a large radiologic surveillance program of underground miners operated concurrently. CONCLUSIONS. Although such factors as x-ray reader variation, changes in x-ray standards, and worker self-selection for examination may have influenced the findings to some extent, adjusted summary rates reveal a reduction in prevalence concurrent with reductions in coal mine dust levels mandated by federal act in 1969.     

British data on coal miners'' pneumoconiosis and relevance to US conditions.

OBJECTIVES. The current primary federal dust standard for US underground coal miners of 2 mg/m3 respirable dust is based on British epidemiological information on exposure-response derived in 1969. Since then, much new information has become available. This paper reviews and compares the available information as it relates to the US mining situation. METHODS. Recent exposure-response information on pneumoconiosis and dust exposure derived by British researchers was employed to estimate working-life risks of pneumoconiosis for miners exposed to 2 mg/m3. RESULTS. It is estimated that close to 9% of underground coal miners who work for 40 years in a 2 mg/m3 environment would develop pneumoconiosis (category 1 or greater). Progressive massive fibrosis would develop in 0.7%. CONCLUSIONS. There are unresolved questions relating to the validity of extrapolating findings on British mines and miners to the US and also in predicting disease levels at the low end of the dust exposure spectrum. Given the data available, current information suggests miners who are employed for a working life-time at the current federal dust limit of 2 mg/m3 are still at risk of developing pneumoconiosis.     

采煤工尘肺的流行病学研究

本文时八个煤矿采煤工尘肺进行了流行病学调查,发现各煤矿间尘肺发病情况极不平衡(0.4～23.2%)。其原因较为复杂,不能用单一因素解释,其中煤尘浓度的高低、接尘工龄的长短和煤尘中SiO_2含量的多少是主要原因。煤的变质程度、煤尘中元素含量、煤尘分散度等也影响采煤工尘肺的发生和发展。在含碳量高、含水量少的无烟煤矿及某些地质条件复杂的烟煤矿,应加强监测及采取强有力的措施,以控制尘肺的发生和发展。     

某地乡镇煤矿煤工尘肺发病调查

对本地乡镇煤矿尘肺发病的程度及特点进行流行病学调查,结果其煤工尘肺罹患高于国营煤矿,但作业环境监测结果与国营煤矿相差不大。     

Histocompatibility antigens in coal miners with pneumoconiosis.

Twenty-five histocompatibility antigens have been measured in 100 coal miners with pneumoconiosis attending a pneumoconiosis medical panel and the results compared with a panel of 200 normal volunteers not exposed to dust. Chest radiographs were read independently by three readers according to the ILO U/C classification. On a combined score, 40 men were thought to have simple pneumoconiosis and 60 men complicated pneumoconiosis. The number of antigens tested and associations between antigens caused difficulties in assessing the statistical significance of differences in prevalence of antigens between groups of men. Using stringent criteria for statistical significance, no significant differences were found in antigen prevalences between miners and controls, or miners with simple or complicated pneumoconiosis. When a less stringent statistical approach was applied, three antigens appeared to have abnormal prevalences in these 100 miners by comparison with the normal volunteers. More detailed examination of these antigen prevalences in relation to radiographic category of pneumoconiosis did not provide any supportive evidence that these slight associations were of statistical or clinical significance. Reports on histocompatibility antigens in miners with pneumoconiosis are reviewed briefly and the results compared. There is no good evidence that any of the histocompatibility antigens so far tested are associated with a clinically important altered risk of simple or complicated pneumoconiosis when dust is inhaled.     

Presence of stable coal radicals in autopsied coal miners' lungs and its possible correlation to coal workers' pneumoconiosis.

Stable coal radicals (SCRs) were detected by electron spin resonance (ESR) spectroscopy in the lung tissue of autopsied coal miners. The SCR concentrations were measured in the lung tissues from 98 coal miners with and without (a) coal workers' pneumoconiosis (CWP), (b) cancer, and (c) a history of cigarette smoking. Concentrations of SCRs were also determined in the lungs of nonminer controls. The SCR concentration was related to longer mining tenure, CWP disease severity, lung cancer, and cigarette smoking. The mean concentration of SCRs in the lung tissues of miners with 30 +/- 1.4 y of coal mining exposure was 5.3 +/- 1.3 x 10(17) spins/g versus controls who had a nondetectable level (less than 10(15) spins/g). An increase in disease severity was accompanied by a progressive increase in SCR concentration. A SCR concentration of 4.8 +/- 0.7 x 10(17) spins/g was found for simple CWP (with moderate coal macules) versus 7.8 +/- 4.6 spins/g lung tissue for complicated CWP (with progressive massive fibrosis). Significantly higher (i.e., 10 x 10(17] concentrations of SCR in the coal miners' lung tissues were associated with an exposure history in the anthracite regions of northeastern Pennsylvania. These results indicate a possible role for SCRs in the disease process. Furthermore, ESR appears to be an adequate methodology for the quantitation of coal dust retained in the lung and for distinguishing exposures to anthracite and/or bituminous coal.     

Progression on the prevention of coal workers' pneumoconiosis

通过收集、分析国内、外相关的文献资料,了解煤工尘肺的预防及治疗进展.我国煤工尘肺职业病防治形势严峻.煤工尘肺防治技术还需提高.必须提高煤工尘肺预防与治疗技术水平,增强用人单位及劳动者的防护意识,达到降低煤矿职业病发病率、提高煤工尘肺患者生存质量目的.     

Ectopic pregnancy in the United States, 1970-1986

In 1986, both the rate of hospitalizations due to ectopic pregnancy and the number of hospitalizations decreased from those reported in the previous year, although the decreases were not statistically significant. If this leveling off of previous yearly increases becomes a continuing trend, possible explanatory hypotheses include a leveling off of disease occurrence, and an increasing use of outpatient management. The case-fatality rate rose slightly in 1986, to 4.9 deaths per 10,000 ectopic pregnancies, although this rate still represents an 86% decline from the 35.5 deaths per 10,000 ectopic pregnancies reported in 1970. In 1986, ectopic pregnancy accounted for only 1.4% of all pregnancies but was associated with over 13% of maternal deaths. Compared with white women, women of black and other minority races had a 1.6 times greater risk of ectopic pregnancy. Ectopic pregnancy remains one of the leading causes of maternal death in the United States and continues to be an important public health problem.     

Surveillance of occupational lead exposure in New Jersey: 1986 to 1989.

Between January 1986 and June 1989, 1916 New Jersey workers were identified through a surveillance system for occupational lead exposure. The average annual proportion of workers with a blood lead level above 2.42 mumol/L was 12%. Industries with the highest proportion of workers with blood lead levels above 2.42 mumol/L were special trade construction (35%) and industries dealing with scrap and waste materials (27%).     

Presence of acute phase response in coal workers' pneumoconiosis.

To evaluate the role of personal factors in pneumoconiosis, several acute phase proteins were studied in 62 coal miners without acute illnesses and classified as having no pneumoconiosis (n = 19), simple pneumoconiosis (n = 23), or complicated pneumoconiosis with progressive massive fibrosis (n = 20). Groups were similar for age, years of work at high risk jobs, chronic bronchitis, and forced expiratory volume in one second (FEV1). C-reactive protein concentration was significantly higher in the simple and complicated pneumoconiosis groups in comparison with the no pneumoconiosis group. The C-reactive protein concentration was above the upper normal value in 12 (27.9%) out of 43 cases with simple and complicated pneumoconiosis. On the other hand only one case of no pneumoconiosis was above the upper normal range (5.3%), a significant difference taking into account a stratified analysis for chronic bronchitis. Fibrinogen concentration was significantly increased in the simple pneumoconiosis group compared with the no pneumoconiosis group. The value of fibrinogen was above the upper normal limit in 17 out of the 43 cases with pneumoconiosis (39.5%) by contrast with two cases in the no pneumoconiosis group (10.5%). No significant differences in alpha 1-antitrypsin and ceruloplasmin concentrations were found between groups. In conclusion, an alteration in some acute phase proteins related to pneumoconiosis was found in miners. This could be used as a marker of disease activity and personal response against the pathogenic agent.     

Mortality of Dutch coal miners in relation to pneumoconiosis, chronic obstructive pulmonary disease, and lung function.

OBJECTIVES: To analyse the mortality patterns of former Dutch coal miners, focusing on coal workers' pneumoconiosis (CWP) and chronic obstructive pulmonary diseases (COPD) in relation to pre-existing impairment of lung function. METHODS: 3790 selected miners, medically examined between 1952 and 1963, were followed up to the end of 1991 with the municipal population registries and the causes of death from the death certificates were ascertained and converted to the codes from the ninth revision of the international classification of diseases (ICD-9). Mortality comparisons were made with the male population in The Netherlands, resulting in standardised mortality ratios (SMRs). 3367 miners had radiological manifestation of CWP at medical examinations. RESULTS: 80% of the miners died during the follow up period. Excess mortalities from CWP (SMR 4523) and COPD (SMR 179) were found. Coal miners without CWP also showed an increased mortality from COPD (SMR 2913). A diminished lung function (forced expiratory volume in one second (FEV1), or FEV1/FVC (forced vital capacity) ratio) at medical examination resulted in a significantly increased SMR for COPD (322 and 212 respectively) whereas normal lung function yielded expected mortalities from COPD. A positive correlation also emerged between diminished lung function and the SMR due to CWP. The body mass index (BMI) at the moment of medical examination was correlated with the risk of dying of COPD and CWP: a decreasing BMI resulting in an increased SMR. CONCLUSIONS: Not only infectious diseases and CWP but also COPD is an important cause of occupational mortality in miners with extensive exposure to coal mine dust. No obvious connection between pre-existing CWP and the COPD mortality exists. Impaired FEV1 and FEV1/FVC ratios are predictors of an increased risk of COPD death. The BMI seems to indicate the severity of the COPD, resulting in premature death.     

Presence of acute phase response in coal workers' pneumoconiosis.

To evaluate the role of personal factors in pneumoconiosis, several acute phase proteins were studied in 62 coal miners without acute illnesses and classified as having no pneumoconiosis (n = 19), simple pneumoconiosis (n = 23), or complicated pneumoconiosis with progressive massive fibrosis (n = 20). Groups were similar for age, years of work at high risk jobs, chronic bronchitis, and forced expiratory volume in one second (FEV1). C-reactive protein concentration was significantly higher in the simple and complicated pneumoconiosis groups in comparison with the no pneumoconiosis group. The C-reactive protein concentration was above the upper normal value in 12 (27.9%) out of 43 cases with simple and complicated pneumoconiosis. On the other hand only one case of no pneumoconiosis was above the upper normal range (5.3%), a significant difference taking into account a stratified analysis for chronic bronchitis. Fibrinogen concentration was significantly increased in the simple pneumoconiosis group compared with the no pneumoconiosis group. The value of fibrinogen was above the upper normal limit in 17 out of the 43 cases with pneumoconiosis (39.5%) by contrast with two cases in the no pneumoconiosis group (10.5%). No significant differences in alpha 1-antitrypsin and ceruloplasmin concentrations were found between groups. In conclusion, an alteration in some acute phase proteins related to pneumoconiosis was found in miners. This could be used as a marker of disease activity and personal response against the pathogenic agent.     

Basic mechanisms leading to focal emphysema in coal workers' pneumoconiosis

Coal miners develop focal emphysema characterized by dilatation of second- and third-order respiratory bronchioles with coal mine dust-laden macrophages infiltrating the wall. A reticulin network with small amounts of collagen and atrophy of smooth muscle occurs. To evaluate the mechanisms of lung injury associated with this lesion, 17 long-term non- or ex-smoking West Virginia underground coal miners underwent bronchoalveolar lavage (BAL) and were compared to healthy nonsmoker and smoker controls. The coal miners had evidence of an alveolar macrophage-neutrophil alveolitis with a significant increase in neutrophils/microliter of epithelial lining fluid and an increased gallium lung scan index (206 +/- 26 units). Alveolar macrophages lavaged from coal miners spontaneously released exaggerated amounts of superoxide anion and hydrogen peroxide in vitro compared to nonsmoking controls. Coal workers had significantly elevated levels of neutrophil elastase in BAL fluid complexed with alpha 1-antitrypsin (P less than 0.01) and normal levels of alpha 1-antitrypsin. An accumulation of activated, dust-laden inflammatory cells with increased release of oxidants and elastase may contribute to the development of focal emphysema identified at postmortem in miners with coal workers' pneumoconiosis.     

2003至2008年某矿务集团煤工尘肺发病情况分析

目的 分析某煤矿2003至2008年尘肺病检出情况,探讨该矿尘肺发病特点,为尘肺病的防治提供科学依据.方法 收集1949年以来井下粉尘监测数据及2003至2008年的健康监护资料和尘肺诊断资料,分析尘肺发病情况,根据不同年代的粉尘接触水平结合工种和工龄推算安全总粉尘累积剂量.结果 2003至2008年该矿务集团在岗工人职业性健康监护率呈逐年提高趋势,共新检出煤工尘肺病例296例,总检出率为0.57%,平均年检出率为0.32%;Ⅰ期煤工尘肺268例,占全部病例的90.59%,87.20%(258例)的煤工尘肺患者为采掘工;新发病例的接尘工龄最短为3年,最长38年;每年总粉尘累积剂量为86.1～4926.0mg/m3.用百分位数法(第99%百分位数)推算煤矿井下工人每年安全总粉尘累积剂量为120.6 mg/m3.结论 尘肺病防治的重点工种是采掘工,在现有工作条件下井下采掘作业工龄不应超过13年.

Abstract：

Objective Analyzed associations among the incidence of coal workers' pneumoconiosis from 2003 to 2008, jobs, exposure years and cumulative total dust exposure levels(CTE ) and found the current characteristics of the mine incidence of pneumoconiosis disease. Methods collected the health care information of the new diagnosed pneumoconiosis of underground mine workers from 2003 to 2008 and the dust monitoring data of underground mine from 1949 and estimated the personnel cumulative total dust exposure levels (CTE); analyzed the incidence features of the new diagnosed pneumoconiosis. Results The rates of health surveillance of workers were gradually improved from 2003 to 2008 and 296 new coal workers pneumoconiosis were diagnosed. The total incidence was 0.57%, and the average annual rate was 0.32%. Among the new diagnosed cases, phase I accounted for 90.5% and the 87.2% from coal mine drillers. The shortest exposure period was 3 years and the longest was 38 years, and the cumulative total dose of dust was varied between 86. 1 and 4926 mg/m3 per year. The total dust accumulated limited dose was calculated by the percentile method to prevent 99% of miners from pneumoconiosis, which was 120.6 mg/m3 per year, so we suggested that the exposure years should be shorter than 13 years under the current working conditions. Conclusions Preventive coal workers' pneumoconiosis should be focused on mine drillers and their limited exposure years should be within 13 years.     

广西不同煤质煤矿尘肺流行病学比较分析

目的探讨不同煤质煤尘对尘肺患病的影响。方法用回顾性流行病学方法对广西3种不同煤质的12个煤矿进行尘肺患病率、历年粉尘浓度、粉尘游离二氧化硅含量情况进行调查分析。结果褐煤、烟煤、无烟煤作业场所历年平均粉尘浓度（mg／m^3）分别为68．75、24．01、17．18,游离二氧化硅含量（％）分别为11,07、59．77和13,78。褐煤、烟煤、无烟煤煤矿工人尘肺患病率（％）分别为0．15、6．70、1．58。褐煤矿接尘工人尘肺患病率明显低于烟煤、无烟煤矿工人（P〈0．001）。结论广西煤工尘肺患病率以烟煤矿最高,无烟煤矿次之,褐煤矿最低。不同煤质煤矿尘肺患病率差异除了与粉尘浓度和游离二氧化硅含量有关外,还可能有其它影响因素。研究结果提示,在今后修订煤尘卫生标准时,可能需要根据不同的煤质制订相应的卫生标准。     

The relationship between coal rank and the prevalence of pneumoconiosis.

As part of the Periodic X-ray Scheme of the National Coal Board (NCB), a comparison is made between the previous and new films of all miners who were face-workers on the former occasion, five years earlier. This assessment is made by distributing the films randomly to all the NCB readers. This paper compares the rank of coal mined in each colliery with each colliery's percentage prevalence of pneumoconiosis of at least ILO category 1 in the films of previous face-workers obtained during the third survey round (1969-73). Of the NCB's 291 collieries in Britain, information enabling a rank classification to be made was available for 250, employing 62 362 face-workers. In these 250 mines a progressive and five-fold increase in prevalence was observed from collieries mining low-rank (bituminous) coal to those mining coal of high ranks (anthracite and high-grade steam and coking coal). A possible reason for this is that, in the past, high-rank collieries may have had the highest mass-concentrations of respirable dust.