Lung function, blood gases, pH and serum electrolytes of small-scale miners exposed to chrome ore dust on the Great Dyke in Zimbabwe

We measured and compared lung function indices and some blood parameters (gases, electrolytes, glucose, pH, red cell indices) of 54 male small-scale miners (SSM) chronically exposed to chrome ore dust to those of 50 nonmining control subjects (NMC) and 46 large-scale chrome miners (LSM) who had taken internationally recommended precautionary measures (secondary control). The respirable dust level in the SSM environment (6.0 +/- 0.5 mg/m3) was significantly higher (P < 0.001) than in the NMC and LSM environments (0.3 +/- 0.1 mg/m3 and 0.5 +/- 0.3 mg/m3, respectively). There were no significant differences in neither dust levels nor lung function status between NMC and LSM environments. The values of FVC, FEV1, PEFR and FEV1% of the SSM were 3.5 +/- 0.09 l, 2.61 +/- 0. 09 l, 6.07 +/- 0.36 l/second and 76.19 +/- 2.36%, respectively. These values were significantly lower than those of NMC (P < 0.01, respectively). However, the blood parameters of the SSM and NMC were not significantly different. The results are indicative of both restrictive and obstructive ventilatory defects in the SSM which may be attributed exposure to chrome ore dust in the environment. Associated risk factors appear to be advancing age, prolonged exposure to chrome ore dust and acid base disturbance.     

Genetic polymorphisms in alveolar macrophage response-related genes, and risk of silicosis and pulmonary tuberculosis in Chinese iron miners

Alveolar macrophages (AMs) play a prominent role in influencing the development of lung inflammation and injury. The aim of this study is to investigate the roles of AMs response-related genes TNF-alpha, iNOS, and NRAMP1 (SLC11A1) in susceptibility to silicosis and pulmonary tuberculosis (PTB), and to analyze the interaction of dust exposure and genetic susceptibility to silicosis, interactions of TNF-alpha-308 and Natural Resistance-associated Macrophage Protein 1 (NRAMP1) INT4, D543N polymorphisms to PTB. Several epidemiological designs were used: retrospective investigations on dust exposure, case-control studies of 184 silicosis cases and 111 miners occupationally exposed to silica dust, and 1:2 matched case-control studies of 61 PTB cases and 122 PTB-free miners. The miners and controls were recruited from an iron mining operation in Anhui province, China. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was applied to detect single nucleotide polymorphisms. Despite the recruitment of high dust exposure among the controls, silicosis patients still had significantly higher dust exposure than controls (242.6 +/- 98.8 vs. 217.6 +/- 100.7 mg a/m(3)). The mutation of iNOS Ser608Leu is associated with protection against silicosis and against severity of silicosis in the miners. There is a 0.47-fold (95% CI: 0.28-0.79) decrease in risk of silicosis for individuals with C/T, T/T genotype compared with the wild-type homozygous (C/C) individuals after adjustment for occupational exposure, smoking, and drinking. The protection effect of the iNOS polymorphism was particularly detected in the > or = 150 mg a/m(3) exposure group (OR: 0.44, 95% CI: 0.22-0.91). However, no interaction of dust exposure with the iNOS polymorphism was observed. Furthermore, the variant NRAMP1 INT4 genotype is significantly associated with PTB in miners. No association of other polymorphisms (NRAMP1 D543N, TNF-alpha-308) and susceptibility to silicosis or PTB in Chinese miners was found. Our data showed a 3.26-fold (95% CI: 1.47-7.23) increased risk of PTB for miners carrying both the NRAMP1 D543N G/G and NRAMP1 INT4 G/C+C/C genotypes. Additionally, in miners with TNF-alpha-308 G/G genotype, the risk of PTB increased 2.38-fold if they carry the NRAMP1 INT4 G/C+C/C genotype (95% CI: 1.14-4.98). In conclusion, the C>T mutation of iNOS Ser608Leu may be an important protective factor to miners. On the other hand, the variant NRAMP1 INT4 may play a role in the development of PTB in Chinese miners. Therefore, the novel information can be used as guideline for further mechanistic investigations and for strengthening specific protection protocols for workers.     

Intrapulmonary lymph nodes in South African miners--an autopsy survey

BACKGROUND: Knowledge on intrapulmonary lymph nodes (IPLNs) is still limited. Progress in imaging techniques has enabled easier, more frequent visualization of IPLNs so that a more comprehensive understanding of these nodes is necessary. METHODS: Microscopic slides of lung tissue from 2,337 dust-exposed South African miners autopsied in 1975 were reviewed to identify IPLNs. The prevalence of IPLNs was calculated and histopathological changes in IPLNs and the surrounding lung parenchyma were described. Pathological changes of IPLNs were correlated with those of the surrounding pulmonary parenchyma. RESULTS: IPLNs were found in 86 of the miners (3.7%). Silicotic nodules were seen in IPLNs in 32 of the 86 cases (37.2%), in the majority of which (21/32; 65.6%) the surrounding lung parenchyma was almost normal. CONCLUSION: IPLNs are not uncommon among dust-exposed individuals. Silicotic fibrosis of IPLNs appears to precede pulmonary parenchymal disease.     

鲁南地区煤矿工人血清25-OH-D水平检测及相关因素分析

目的对鲁南地区煤矿工人维生素D营养状况进行综合评价,为其健康宣教提供依据。方法以鲁南地区290例从事井下工作10 a以上的男性煤矿职工（观察组）及60例同期健康查体者（对照组）为研究对象,均抽取清晨空腹静脉血,用酶联免疫定量法检测血清25-羟基维生素D（25-OH-D）水平,并以Spearman等级相关法分析其相关性。结果观察组和对照组血清25-OH-D水平分别为（44.64±32.65）、（51.21±21.59）nmol/L（P〈0.05）,观察组并2型糖尿病（T2DM）和非T2DM者分别为（39.95±20.33）、（44.57±31.72）nmol/L,T2DM者显著低于非T2DM者和对照组（P均〈0.05）;观察组血清25-OH-D水平与年龄、工龄及是否伴有T2DM等有关,但与吸烟、饮酒及骨折史等无明显相关性。结论鲁南地区煤矿工人血清维生素D水平偏低,尤以年龄大、工龄长及伴T2DM者为著;此类人群应注重多参加户外活动,接受适当日光照射,并适量补充维生素D。     

2008年弥渡县部分个体私营小煤矿在岗工人健康状况调查

[目的]了解在岗煤矿作业工人的健康状况。[方法]2008年8～9月,对弥渡县11家个体私营小煤矿的720名作业工人进行健康检查。[结果]检查720名职工,发现异常者234人,异常检出率为32．50％。其中,心血管系统异常率为21.39％（其中高血压检出率为12．36％）,肝功能异常率为9．17％,泌尿系统异常率为1．94％。异常率,采煤工种为37．85％,管理、安检工种为6．93％,其他工种为20．93％（P〈0．01）。[结论]将近1／3的在岗煤矿作业工人处于亚健康或有病状态,高血压等心血管疾病严重危害职工身体健康。     

Metal and non-metal miners' exposure to crystalline silica, 1998-2002

BACKGROUND: Crystalline silica is well known to cause silicosis and other diseases. Exposure is common in the mining industry and consequently, the US Mine Safety and Health Administration (MSHA) evaluates miners exposure to silica to determine compliance with its exposure limit. METHODS: MSHA exposure measurements were obtained for the 5-year period from 1998 to 2002 and average exposure was calculated classified by occupation and by mine. Evaluation criteria were whether average values exceeded MSHA's permissible exposure limit or the limit recommended by the National Institute for Occupational Safety and Health (NIOSH), whether there was a risk of exposure to freshly fractured silica, and whether there was a risk of a high rate of exposure to silica. RESULTS: Miners in certain jobs are exposed to silica above permissible and recommended exposure limits. Some miners may also be exposed at a high rate or to freshly fractured silica. CONCLUSIONS: Known dust control methods should be implemented and regular medical surveillance should be provided.     

Feasibility of conducting a lung-cancer chemoprevention trial among tin miners in Yunnan,P. R. China

Tin miners in Yunnan Province in southern China have an extremely high rate of lung cancer, more than one percent per year among those at high risk (40 + years old, with 10 + years of underground mining and/or smelting experience). The extraordinary lung cancer rates result from combined exposure to radon, arsenic, and tobacco smoking (cigarettes and/or bamboo water pipe). A study to determine the feasibility of conducting a large-scale, lung-cancer chemoprevention trial was conducted in 1986 among currently employed or retired miners from the Yunnan Tin Corporation in the city of Gejiu. The study was designed to answer four questions: (i) Could potentially eligible miners be identified and recruited? (ii) Could intervention agents be shipped successfully from the United States to the study area and be appropriately distributed? (iii) Would miners adequately adhere to the study protocol and comply with the intervention regimen? (iv) Could potential adverse effects be monitored and documented? The six-month feasibility study yielded affirmative answers to each of these questions. A roster of over 7,000 high-risk miners was compiled. Four agents (vitamin A, 25,000 IU; -carotene, 50 mg; vitamin E, 800 IU; and selenium, 400 g) were administered daily with placebos to 350 miners according to a 2⁴ factorial design. Adherence, assessed by pill counts and serum micronutrient levels, was approximately 90 percent. The findings from this preliminary study indicate that a full-scale, lung-cancer chemoprevention trial in this population is feasible.     

唐山煤矿工人幽门螺杆菌感染的影响因素调查

目的 了解煤矿工人幽门螺杆菌(Hp)感染情况及其影响因素。方法 采用多阶段分层随机整群抽样方法选取425名煤矿工人,进行问卷调查。同时行胃镜检查,采取胃黏膜标本用于菌培养和病理诊断;Hp感染的检测方法采用细菌培养法和ELISA法;全部调查资料采用X~2分析和分层分析。结果 煤矿工人Hp总的感染率为69.9％,井下工人的Hp感染率比井上工人的高,差异有显著性(P=0.004);大兴矿、鲍店矿、唐山矿工人Hp的感染率差别无显著性(P>0.05)。影响煤矿工人Hp感染的主要因素有年龄、未成年时月人均经济收入、未成年时住房形式、现家庭人口数等社会经济因素,个人嗜好中的饮酒状况。影响井下工人Hp感染还有家庭进餐形式。结论 井下工人Hp感染率比井上工人的高;影响因素有社会经济因素、个人嗜好、家庭进餐形式。     

Lung cancer mortality and airways obstruction among metal miners exposed to silica and low levels of radon daughters

Starting from a cross-sectional survey in 1973, the mortality of two cohorts of Sardinian metal miners was followed through December 31, 1988. In mine A, the quartz concentration in respirable dust ranged between 0.2% and 2.0% and the exposure to radon daughters averaged 0.13 working level (WL), with the highest estimated cumulative exposure around 80–120 WLM. In mine B, the silica content was much higher (6.5–29%), but exposure to radon daughters was significantly lower than in mine A. More than 98% of the overall work force in 1973 (1,741 miners) entered the cohort, providing 25,842.5 person-years. Smoking, occupational history, chest radiographs, and lung function tests were available for the cohort members at admission. Mortality for all causes was slightly lower than expected. A significant excess for nonmalignant chronic respiratory diseases was noticed in both mines. Twenty-four subjects died of lung cancer, 17 from mine A (SMR: 128; 95% confidence interval [CI]: 75–205) and 7 from mine B (SMR: 85; 95% CI: 34–175). The SMR for lung cancer was highest among the underground workers from mine A (SMR: 148; 95% CI: 74–265), with a significant upward trend by duration of employment in underground jobs. Mine B underground miners showed lung cancer SMRs close to 100 without a significant trend by duration of employment. Among underground miners with spirometric airways obstruction in 1973, those from mine A showed the highest risk (SMR: 316; 95% CI: 116–687). The relationship did not change after adjusting for age and smoking. Based on the present findings, crystalline silica per se does not appear to affect lung cancer mortality. A slight association between lung cancer mortality and exposure to radon daughters, though within relatively low levels, may be considered for underground miners from mine A. Impaired pulmonary function may be an independent predictor of lung cancer and an important risk factor enhancing the residence time of inhaled carcinogens, i.e., alpha particles or PAHs, by impairing their bronchial and alveolar clearance. © 1994 Wiley-Liss, Inc.