瓷厂和钨矿生产性粉尘生物学效应的研究

目的 通过体外细胞实验测定瓷厂和钨矿作业点生产性粉尘的毒性等生物学效应,为评价粉尘的危害作用提供依据.方法 以豚鼠的肺泡巨噬细胞(AM)为作用细胞,以标准石英作为对照,应用肺泡灌洗的方法获得AM后,加入15、30、60、120μg/106个细胞浓度标准石英、瓷厂及钨矿作业点的呼吸性粉尘颗粒培养,测定细胞的乳酸脱氢酶(LDH)活力、细胞活力(MTT)、活性氧释放量和肿瘤坏死因子-α(TNF-α)的释放量.结果 瓷厂和钨矿的生产性粉尘均能诱导豚鼠AM培养液中LDH活力升高,诱导豚鼠AM释放活性氧和TNF-α量升高,并随粉尘浓度升高呈现明显的剂量一反应关系.瓷厂和钨矿粉尘与豚鼠AM共培养后导致AM活力下降,随着生产性粉尘的浓度增加而降低.钨矿粉尘引起LDH活力升高以及诱导豚鼠AM释放TNF-α能力强于瓷厂粉尘,在120μg/106个细胞浓度组,赣州钨矿粉尘诱导的TNF-α水平为(5.2±2.0)ng/ml,景德镇瓷厂粉尘诱导的TNF-α水平为(3.3±1.6)ng/ml,均高于标准石英(2.8±0.5)ng/ml.与钨矿尘肺患病和死亡率均高于瓷厂相印证.结论 不同来源的生产性粉尘具有不同的生物学效应结果,实验测定粉尘的生物学效应为区分生产性粉尘危害作用提供了基础数据.     

瓷厂及钨矿生产性粉尘对血管内皮细胞的损伤效应

目的 评价瓷厂和钨矿生产性粉尘对血管内皮细胞的直接损伤作用,探讨粉尘引发心血管疾病的机制.方法 以人脐静脉内皮细胞(HUVEC)株HUV-EC-C为作用细胞,以瓷厂、钨矿作业点收集的生产性粉尘为实验粉尘,以中国标准石英为对照,将粉尘配制成25、50、100、200、400μg/ml浓度与HUVEC共培养24 h,测定细胞乳酸脱氢酶(LDH)活力、细胞的活力噻唑蓝(MTT)、一氧化氮(NO)和肿瘤坏死因子-α(TNF-α)的释放量.结果 瓷厂和钨矿作业点的生产性粉尘均能使HUVEC细胞培养液中LDH活力升高,释放NO及TNF-α水平升高,并随粉尘浓度升高呈现明确的剂量-反应关系.瓷厂和钨矿作业点生产性粉尘均能导致HUVEC细胞活力下降,呈剂量-反应关系.石英粉尘诱导HUVEC培养液中LDH活力升高的能力明显高于瓷厂和钨矿的生产性粉尘,差异有统计学意义(P＜0.05).瓷厂和钨矿生产性粉尘诱导HUVEC细胞活力下降及释放NO的能力相近且与标准石英相当.在较低剂量组(25、50、100μg/ml)时,瓷厂和钨矿生产性粉尘诱导TNF-α的释放量与标准石英相当,差异无统计学意义(P＞0.05),而在较高剂量组(200、400 μg/ml)时,标准石英诱导TNF-α的释放量明显高于瓷厂和钨矿生产性粉尘,差异有统计学意义(P＜0.05).结论 不同来源的生产性粉尘及标准石英均能损伤血管内皮细胞,诱导TNF-α释放,引起不同程度的生物学效应.     

金属矿山和瓷厂的粉尘及有害因素

本文为研究金属矿工和瓷厂作业工人的肺癌病因,对4类金属矿(钨、锡,铜、铁)和9个瓷厂作业环境的粉尘,30种化学元素、放射性氡子体、γ射线和17种多环芳烃(PAH)等有害因素作了现场测定,并对各厂矿的历史测尘资料进行了整理分析。结果发现粉尘浓度早期以钨矿为最高。自70年代开始,钨矿降为最低。但游离SiO_2含量以钨矿最高,瓷厂次之,铁矿最低。瓷厂粉尘分散度比矿尘低。元素结果表明,砷、镉以锡矿最高:铁、镍以铁矿最高,这些被认为致癌物和可疑致癌物元素,可能成为矿工的致癌因素之一。井下氡子体仅铜矿超标,故铜矿工肺癌高发可能受氡暴露的影响。PAH 以井下使用柴油铲运机的锡矿、铜矿、铁矿为最高。但因其接触时间不长,其致癌作用还需进一步观察。     

金属矿和瓷厂粉尘浓度及二氧化硅含量比较

为了研究呼吸性粉尘和总粉尘浓度的比例关系，以及积尘与呼吸性粉尘游离二氧化硅（ＳｉＯ２）含量的差异，按我国规定的测尘方法，对１８个金属矿和９个瓷厂作业场所的呼吸性粉尘和总粉尘及游离ＳｉＯ２含量进行了测定比较。发现两种粉尘浓度有一定的比例关系，其比值金属矿为１３．２３，瓷厂为１３．７６，均有显著相关。这为原有总粉尘资料推算呼吸性粉尘浓度与尘肺的发病关系提供了依据。同一采样地点的积尘与呼吸性粉尘的游离ＳｉＯ２含量差异非常显著。表明积尘ＳｉＯ２含量难以代表呼吸性粉尘中的ＳｉＯ２含量。因此，早日进行呼吸性粉尘浓度及其ＳｉＯ２含量的测定是非常必要的。     

我国矽尘防治中对矽尘表面性质重视的必要性

矽尘是我国煤炭、采矿、橡胶、陶瓷、耐火材料、玻璃、冶金、铸造、石雕等多种行业的主要职业病危害因素之一.已报道的与接触矽尘有关的疾病包括矽肺、肺癌、慢性肾病、肺部感染、慢性阻塞性肺病、自身免疫性疾病、肺泡蛋白沉积症和肝细胞癌等.矽尘中游离二氧化硅百分含量的致矽肺作用已为世人公认,但同济医学院近20年来对4类接尘工人的研究发现：（1）54 651名钨矿、锡矿和瓷厂接尘工人中的10 053名矽肺患者,在吸入的粉尘量及其游离二氧化硅百分含量大致相等的情况下,钨矿工人发病率分别为锡矿工人和瓷厂工人的1.87及3.66倍;（2）接触低于国家容许浓度的铁矿尘（游离二氧化硅百分含量未超过10%）,工人的尘肺发病率居高不下,与锡矿工人发病差异不大.这些研究提示除游离二氧化硅百分含量外,势必存在其他对矽尘致病作用有重大影响的因素.近20年来国内外研究较多的是矽尘表面性质对矽尘致病的影响.大量实验室资料表明,矽尘的表面性质可影响其毒性机制中的多个关键环节如自由基的形成,肺泡巨噬细胞的活化及凋亡等.国外一些学者已建议政府应重视矽尘的表面性质对矽尘毒性的影响.这一部分的研究在我国起步较晚,研究资料较少,为了探索矽尘表面性质在我国防治矽尘危害工作中的应用,本文汇总了1996～2005年矽尘表面性质对其毒性的影响以及影响矽尘表面性质的因素,包括实验室资料和流行病学资料,并介绍了矽尘表面性质的检测技术.     

锡矿粉尘生物学活性与致病能力的关系

目的 通过体外细胞实验评价锡矿含石英粉尘的生物特性和毒性,并与接尘工人尘肺和肺癌等疾病发生进行比较.方法 选择鼠肺巨噬细胞为靶细胞,分别测定4个锡矿的呼吸性粉尘样本作用于靶细胞后,葡萄糖苷酸酶、乳酸脱氢酶、过氧化氢以及活性氧自由基（ROS）和肿瘤坏死因子-α（TNF-α）的释放.以标准石英（DQ12）和氧化铝作为对照.矿工人群流行病学研究为回顾前瞻性队列研究.结果 流行病学研究显示,锡矿接尘工人的尘肺标化死亡比（SMR）高达49.7（95%CI：39.5～61.8）,肿瘤（SMR=1.58,95%CI：1.39～1.76）和肺癌死亡率（SMR=3.17,95%CI：2.59～3.76）高于全国平均水平.锡矿粉尘的细胞毒性与细胞功能损伤作用高于氧化铝而低于石英,其诱导的ROS水平明显高于氧化铝和石英,此外,粉尘样本还导致TNF-α分泌升高,超过或接近纯石英粉尘的作用.结论 现场粉尘体外细胞实验结果能较好地解释人群流行病学调查的趋势,粉尘的体外毒性测定可能具有筛检现场粉尘危害的作用.     

陶瓷厂和钨矿生产性粉尘中11种元素比较分析

目的探讨陶瓷厂和钨矿生产性粉尘中多种元素含量的差异以及其对粉尘毒性和致病作用的可能影响。方法收集厂矿粉尘各50g，用火焰原子吸收光谱法检测陶瓷厂和钨矿粉尘样品中铜、锌、铅、镉、镍、铁、锰、钙、镁9种元素的含量，用石墨炉原子吸收光谱法检测样品中铝元素的含量，用原子荧光光谱法检测样品中砷元素的含量。结果陶瓷厂和钨矿粉尘样品中铝、砷、镉、铁、锰、铅元素含量的差异有统计学意义（P〈0．05），陶瓷厂粉尘中铝元素的平均含量为104688．71μg/g，大于钨矿粉尘中的平均含量64883．17μg／g；陶瓷厂粉尘中砷、镉、铁、锰、铅元素的平均含量分别为31．04、2．27、4473．23、369．67、96．86μg/g，而钨矿的分别为80．32、20．64、28619．06、1596．93、333．02μg／g，均高于陶瓷厂。结论陶瓷厂和钨矿粉尘中多种元素的含量有明显的差异，元素含量的不同，可能会影响粉尘的生物学效应活性，对粉尘的致病作用有一定的影响。     

钨矿呼吸性粉尘浓度与总粉尘浓度关系的研究

钨矿呼吸性粉尘浓度与总粉尘浓度关系的研究张天园，葛春元，胡招娣，盛莉云，涂英娥，邓俊峰笔者采用ＬＷ─Ⅰ型呼吸性粉尘采样头［１］与ＦＣ─Ⅱ型总粉尘采样头（下分别简称ＬＷ─Ⅰ型采样头和ＦＣ─Ⅱ型采样头）平行测定江西３个钨矿的采场和平巷空气中总粉尘浓度和呼...     

多功能呼吸同步采样仪现场应用评价

目的：评价多功能呼吸同步采样仪的实际应用价值。方法：使用多功能呼吸同步（尘、毒）采样仪,常规定点粉尘采样仪,个体粉尘采样仪以及肺通气量仪,对某市27个工厂的95个粉尘作业工种（岗位）进行采样,试点测试3工厂,扩大测试完共获得有效样品692个进行统计分析。结果：（1）多功能呼吸同步采样仪测出的粉尘浓度稍高于常规定点粉尘采样仪和个体粉尘采样仪的测定结果,经显著性检验差异无显著意义（P＞0．05）。（2）多功能呼吸同步采样仪测得的分散度与个体粉尘测尘仪测定结果差异无显著意义（P＞0．05）。（3）根据多功能呼吸同步采样仪与定点粉尘采样仪的测定结果所进行的粉尘危害程度分级,其结果大体一致。（4）根据多功能呼吸同步采样仪与YA－Ⅱ-Pt型肺通气量仪测得的肺通气量进行的工人体力劳动强度分级,其结果基本一致,结论：多功能呼吸同步采样仪具有轻便,易操作,用呼吸作动力和同时测得粉尘浓度,肺通气量等优点,有较大的应用前景。     

广西锡矿矿尘致矽肺的危险度评价

目的　探索锡矿矿尘的致病强度和最低无害作用水平。方法　选择广西锡矿 1 960～1 974年期间接触矿尘至少 1年的男性矿工 4 471名建立回顾性接尘队列 ,并用以同一方法建立的瓷厂接尘队列与其进行比较 ;采用SAS中的生存检验分析软件进行非参数估算 ,评价锡矿矿尘致矽肺的危险度。结果　随访到 1 994年底 ,锡矿队列工人矽肺发病 971例 (2 1 .7% ) ,其中 81 %的病例为 1 958年前接尘对象 ,累积接触总粉尘量 (CTD)与矽肺危险度明显相关 :当CTD <50mg·m- 3·年 - 1 时 ,矽肺危险度为 0 .0 1 2 ;CTD >40 0mg·m- 3·年 - 1 时 ,矽肺危险度上升到 0 .971。瓷厂接尘工人CTD >40 0mg·m- 3·年 - 1 时 ,矽肺危险度仅为 0 .369。结论　锡矿接触矿尘工人的矽肺发病与CTD明显相关 ;锡矿矿尘导致矽肺的危险性远比瓷厂的陶瓷尘严重     

Risk of silicosis in cohorts of Chinese tin and tungsten miners and pottery workers (II): Workplace-specific silica particle surface composition

BACKGROUND: It is hypothesized that surface occlusion by alumino-silicate affects the toxic activity of silica particles in respirable dust. In conjunction with an epidemiological investigation of silicosis disease risk in Chinese tin and tungsten mine and pottery workplaces, we analyzed respirable silica dusts using a multiple-voltage scanning electron microscopy-energy dispersive X-ray spectroscopy (MVSEM-EDS). METHODS: Forty-seven samples of respirable sized dust were collected on filters from 13 worksites and were analyzed by MVSEM-EDS using high (20 keV) and low (5 keV) electron beam accelerating voltages. Changes in the silicon-to-aluminum X-ray line intensity ratio between the two voltages are compared particle-by-particle with the 90th percentile value of the same measurements for a ground glass homogeneous control sample. This provides an index that distinguishes a silica particle that is homogeneously aluminum-contaminated from a clay-coated silica particle. RESULTS: The average sample percentages of respirable-sized silica particles alumino-silicate occlusion were: 45% for potteries, 18% for tin mines, and 13% for tungsten mines. The difference between the pottery and the metal mine worksites accounted for one third of an overall chi-square statistic for differences in change in measured silicon fraction between the samples. CONCLUSION: The companion epidemiological study found lower silicosis risk per unit cumulative respirable silica dust exposure for pottery workers compared to metal miners. Using these surface analysis results resolves differences in risk when exposure is normalized to cumulative respirable surface-available silica dust.     

Risk of silicosis in cohorts of Chinese tin and tungsten miners, and pottery workers (I): an epidemiological study

BACKGROUND: Epidemiological evaluations of the risk of silicosis in relation to exposure to crystalline silica have raised the question of whether different types of silica dust exposures vary with respect to their ability to cause silicosis. The aim of this study is to compare the risk of silicosis among cohorts of silica dust-exposed Chinese tin miners, tungsten miners, and pottery workers and to assess whether gravimetric measurements of respirable silica dust sufficiently determine the risk of silicosis or whether other factors of exposure may play a significant role. METHODS: Cohorts were selected from 20 Chinese mines and potteries. Inclusion criteria were starting employment after January 1, 1950 and being employed for at least 1 year during 1960-1974 in one of the selected workplaces. Radiological follow-up for silicosis onset was from January 1, 1950 through December 31, 1994. Silicosis was assessed according to the Chinese radiological criteria for diagnosis of pneumoconiosis (as suspect, Stage I, II, or III). Exposure-response relationships were estimated for silicosis of Stage I or higher. Silica dust exposure was estimated in terms of cumulative total dust exposure, calculated from a workplace, job title, and calendar year exposure matrix, and individual occupational histories. Cumulative total dust exposure was converted in two steps into cumulative respirable dust exposure and cumulative respirable silica dust exposure using conversion factors estimated from side-by-side measurements conducted in 1988-89. RESULTS: The male cohorts included 4,028 tin miners, 14,427 tungsten miners, and 4,547 pottery workers who had similar onset of employment and duration of follow-up. For a given exposure level, the risk of silicosis was higher for the tin and tungsten than the pottery workers. CONCLUSION: The observed differences in the risk of silicosis among the three cohorts suggest that silica dust characteristics, in addition to cumulative respirable silica dust exposure, may affect the risk of silicosis.     

A nested case-control study of lung cancer among silica exposed workers in China.

In an attempt to assess whether silica induces lung cancer, a nested case-control study of 316 male lung cancer cases and 1352 controls was carried out among pottery workers and tungsten, copper-iron, and tin miners from five provinces in south central China. Exposure to dust and silica for each study subject was evaluated quantitatively by cumulative exposure measures based on historical industrial hygiene records. Measurements on confounders such as inorganic arsenic, polycyclic aromatic hydrocarbons (PAHs), and radon were also collected from the worksites. Information on cigarette smoking was obtained by interviews of the subjects or their next of kin. A significant trend of increasing risk of lung cancer with exposure to silica was found for tin miners, but not for miners working in tungsten or copper-iron mines. Concomitant and highly correlated exposures to arsenic and PAHs among tin miners were also found. Risk of lung cancer among pottery workers was related to exposure to silica, although the dose-response gradient was not significant. Risks of lung cancer were significantly increased among silicotic subjects in iron-copper and tin mines, but not in pottery factories or tungsten mines. The results of this study provide only limited support for an aetiological association between silica and lung cancer.     

A nested case-control study of lung cancer among silica exposed workers in China.

In an attempt to assess whether silica induces lung cancer, a nested case-control study of 316 male lung cancer cases and 1352 controls was carried out among pottery workers and tungsten, copper-iron, and tin miners from five provinces in south central China. Exposure to dust and silica for each study subject was evaluated quantitatively by cumulative exposure measures based on historical industrial hygiene records. Measurements on confounders such as inorganic arsenic, polycyclic aromatic hydrocarbons (PAHs), and radon were also collected from the worksites. Information on cigarette smoking was obtained by interviews of the subjects or their next of kin. A significant trend of increasing risk of lung cancer with exposure to silica was found for tin miners, but not for miners working in tungsten or copper-iron mines. Concomitant and highly correlated exposures to arsenic and PAHs among tin miners were also found. Risk of lung cancer among pottery workers was related to exposure to silica, although the dose-response gradient was not significant. Risks of lung cancer were significantly increased among silicotic subjects in iron-copper and tin mines, but not in pottery factories or tungsten mines. The results of this study provide only limited support for an aetiological association between silica and lung cancer.     

Estimating historical respirable crystalline silica exposures for Chinese pottery workers and iron/copper, tin, and tungsten miners.

Collaborative studies of Chinese workers, using over four decades of dust monitoring data, are being conducted by the National Institute for Occupational Safety and Health (NIOSH) and Tongji Medical University in China. The goal of these projects is to establish exposure-response relationships for the development of diseases such as silicosis or lung cancer in cohorts of pottery and mine workers. It is necessary to convert Chinese dust measurements to respirable silica measurements in order to make results from the Chinese data comparable to other results in the literature.This article describes the development of conversion factors and estimates of historical respirable crystalline silica exposure for Chinese workers. Ambient total dust concentrations (n>17000) and crystalline silica concentrations (n=347) in bulk dust were first gathered from historical industrial hygiene records. Analysis of the silica content in historical bulk samples revealed no trend from 1950 up to the present. During 1988-1989, side-by-side airborne dust samples (n=143 pairs) were collected using nylon cyclones and traditional Chinese samplers in 20 metal mines and nine pottery factories in China. These data were used to establish conversion factors between respirable crystalline silica concentrations and Chinese total dust concentrations. Based on the analysis of the available evidence, conversion factors derived from the 1988-1989 sampling campaign are assumed to apply to other time periods in this paper. The conversion factors were estimated to be 0.0143 for iron/copper, 0.0355 for pottery factories, 0.0429 for tin mines, and 0.0861 for tungsten mines. Conversion factors for individual facilities within each industry were also calculated. Analysis of variance revealed that mean conversion factors are significantly different among facilities within the iron/copper industry and within the pottery industry. The relative merits of using facility-specific conversion factors, industry-wide conversion factors, or a weighted average of the two are discussed. The exposure matrix of the historical Chinese total dust concentrations was multiplied by these conversion factors to obtain an exposure matrix of historical respirable crystalline silica concentrations.     

Lung cancer risk, silica exposure, and silicosis in Chinese mines and pottery factories: the modifying role of other workplace lung carcinogens.

BACKGROUND: Aims of our study were to explore whether and to what extent exposure to other lung carcinogens, or staging and clinical features of silicosis modify or confound the association between silica and lung cancer. METHODS: We used data from a nested case-control study, conducted in the late 1980s in 29 Chinese mines and potteries (10 tungsten mines, 6 copper and iron mines, 4 tin mines, 8 pottery factories, and 1 clay mine), that included 316 lung cancer cases and 1,356 controls, matched by decade of birth and facility type. The previous analysis of these data presented results by type of mine or factory. RESULTS: In our study, pooling all 29 Chinese work sites, lung cancer risk showed a modest association with silica exposure. Risk did not vary after excluding subjects with silicosis or adjusting the risk estimates by radiological staging of silicosis. Strong correlation among exposures prevented a detailed evaluation of the role of individual exposures. However, lung cancer risk was for the most part absent when concomitant exposure to other workplace lung carcinogens, such as polycyclic aromatic hydrocarbons (PAHs), nickel or radon-daughters, was considered. The cross classification of lung cancer risk by categories of exposure to respirable silica and total respirable dust did not show an independent effect of total respirable dust. Silicosis showed a modest association with lung cancer, which did not vary by severity of radiological staging, or by radiological evidence of disease progression, or by level of silica exposure. However, among silicotic subjects, lung cancer risk was significantly elevated only when exposure to cadmium and PAH had occurred. CONCLUSIONS: Our results suggest that, among silica-exposed Chinese workers, numerous occupational and non-occupational risk factors interact in a complex fashion to modify lung cancer risk. Future epidemiological studies on silica and lung cancer should incorporate detailed information on exposure to other workplace lung carcinogens, total respirable dust, and on surface size and age of silica particles to understand whether and to what extent they affect the carcinogenic potential of silica.