铁路隧道现场粉尘容许浓度的估算探讨

目的：估算铁路隧道现场粉尘容许浓度。方法：对铁路工程部门9个局的隧道工5482名进行回顾性调查，收集从接尘开始到1998年12月底为止各隧道工人接尘史、粉尘浓度、分散度、接尘时间等，用直线回归法、寿命表法、呼吸粉尘值推算法、肺内石英粉尘负荷量估算法、肺内粉尘存留量反推法等5种方法，计算现场粉尘容许浓度。结果：平均粉尘浓度为20.51mg/m^3，如果把患病率控制在1％时，其容许浓度为1.47-4.75mg/m^3。结论：5种方法计算的参与因素不同，结果也不同。同时发现累积接尘量与矽肺患病率之间呈非线性关系。     

江西主要钨矿防尘效果的卫生学评价

自1958年综合防尘后，对江西钨矿的防尘效果进行卫生学评价。多数矿山矽肺患病率低于1％；个别矿山至1983年矽肺患病率为1．95％。以该矿资料，预测接尘30年的工人累积发病概率可达7．5％。据此，建议粉尘二氧化矽含量高于70％的矿山，粉尘最高允许浓度以1．0mg/m^3为宜。     

铁路隧道工矽尘接触与矽肺危险度评价

目的：对铁道隧道工进行矽肺危险度评价。方法：对9个铁路工程局铁道工5482人进行接尘史的回顾性调查，并调集各局卫生防疫站历年施工隧道粉尘监测资料，用SAS软件进行统计分析。结果：用样条函数建立隧道工矽尘危险度评价模型，与各单位的粉尘几何平均浓度有良好的剂量－效应关系，实际现场患病率和模型计算的患病率差异无显著性。结论：用评价模型可对现场的隧道工进行患病率的预测，并可根据隧道内粉尘浓度提出整改方案。同时，评价模型可供其他粉尘行业参考使用。     

锡矿工人接尘与矽肺危险度评价

目的探讨粉尘暴露与矽肺危险度之间的接触效应关系。方法选择广西４个锡矿１９６０～１９６５年间工作１年以上的３０１０名接尘工人进行队列研究。用生存分析法统计累积粉尘接触量和矽肺出现的关系。结果追访到１９９４年底,检出矽肺１０１５例（３３．７％）。矽肺平均潜伏期２１．３年。总粉尘浓度７．５ｍｇ／ｍ３（ＴＷＡ）。拟合生存分析模型表明：矽肺发病危险度与累积接尘量的关系适合Ｗｅｉｂｕｌ分布。累积总粉尘接触量低于１０ｍｇ·ｍ－３·ａ－１时,矽肺危险小于１％;累积总粉尘接触量超过２０ｍｇ·ｍ－３·ａ－１时,矽肺累积危险度升高加快;累积总粉尘接触量达１５０ｍｇ·ｍ－３·ａ－１时,矽肺危险超过６８％。接尘时间与接尘量和矽肺危险度呈正相关。结论矽肺危险度与累积接尘量之间存在接触效应关系。     

钨矿接尘工矽肺危险度

目的　探讨钨矿接尘工矽肺危险度并对其防治措施进行评价。方法　采用职业流行病学队列研究方法 ,按接尘水平进行定量分析和定性分析 ,估算钨矿接尘工矽肺危险度。结果　①接尘工累积接总粉尘不到 10mg/(m3 ·a) ,就有 45例矽肺发病 ,发病率为 0 7% ;②累积接总粉尘量与观察期矽肺发生差异有显著性 (P <0 .0 5 ) ;③钨矿矿尘空气中最高容许水平是 2mg/m3 ,相当累积呼吸性游离二氧化硅尘 0 0 41mg/(m3 ·a) ,此值在钨矿仍有病例发生。结论　我国当前采用的粉尘卫生标准在钨矿不是最低危害作用水平。同时也说明各类接尘厂矿的接触限值是有区别的。     

铁路隧道施工现场粉尘容许浓度的估算

为估算铁路隧道作业现场的最高容许浓度提供参考依据，利用肺内粉尘存留量反推法（检测一法）和以累积接尘时间为权重调整的阈限值法（检测二法）估算铁路隧道粉尘作业的粉尘容许浓度，结果表明，预期接尘工龄为30年，控制患病率分别为0．5％，和1％水平的隧道施工现场粉尘容许浓度的估计值，检测一法：0．8，1．2mg/m^3，检测二法：2．0，4．0mg/m^3。     

铁路隧道施工现场粉尘阈限值的估算探讨

目的估算铁路隧道施工现场粉尘阈限值,为有关行政管理部门采取措施,控制现场粉尘浓度提供依据。方法调查铁道部某3个工程局2851名隧道工1963~1998年共35 a的接尘史和相应的施工隧道粉尘监测资料,应用Kaplan-Meier法结合3次样条函数拟合的方法,建立隧道工累积接尘量与矽肺累积患病率关系的方程式,并由此估算铁路隧道施工现场粉尘阈限值。结果作业30 a不患矽肺的现场粉尘最高容许浓度为1.17 mg/m3;矽肺患病率控制为0.5%时,现场粉尘阈限值为3.23 mg/m3;患病率控制为1%时,现场粉尘阈限值为5.30 mg/m3。结论得到的阈限值可为有关行政管理部门采取措施降低现场粉尘浓度,保护工人身体健康提供科学依据。     

中小型钨锡矿山粉尘容许浓度的探讨

本文对该矿历年来的粉尘浓度和矽肺发病情况进行了初步调查, 用寿命表直线回归法对矽肺发病趋势进行了预测,并同时计算了累积患病率,求出接尘量与累积患病率的直线相关回归方程,推算出如控制矽肺患病率10‰、连续作业30年时,粉尘容许浓度估计值为1.45mg/m~3。建议中矽量(31～80%)的小型钨锡矿山,粉尘容许浓度以1.5mg/m~3为宜。     

定群寿命表在矽肺流行病学中的应用

应用定群寿命表的方法,推算出大厂矿务局接尘工人矽肺的预期发病年限为23.6年,矽肺病人脱尘30年累积存活率为51.61%,稳定率为37%,矽尘容许浓度建议值为1.98mg/m~3。     

某县办金属矿矽肺发病调查分析

本文对某县办金属矿1958—1986年矽肺发病情况进行了回顾性调查分析。结果表明:1.该矿自1970年开始采取防尘措施以来,粉尘年平均浓度为5.6～20.9mg/m~3;游离SiO_2含量平均为30％。2.矽肺患病率:接尘工人572名,历年检出矽肺123例,粗患病率为22.5％;工龄累积患病率,接尘25～年为85.4％,接尘15～年为54.4％,接尘7～年为9.0％。按1970年前后进矿接尘分别统计,粗患病率为53.3％和5.1％;工龄累积患病率,接尘15～     

关于修订车间空气中三硝基甲苯卫生标准的探讨

目的 对我国现行车间空气中三硝基甲苯卫生标准进行修订。方法 根据现场劳动卫生学调查、流行病学调查、动物实验及剂量－反应关系资料，并参考国外接触限值对三硝基甲苯卫生标准进行修订。结果 我国现行的车间空气中三硝基甲苯卫生标准，最高容许浓度为1.0mg/m^3（皮），职业危害严重，不能有效地保护作业人员的健康。结论 建议将车间空气中TNT的最高容许浓度（MAC）修订为0.5mg/m^3（皮），并制订时间加权平均容许浓度（TWA）为0.2mg/m^3(皮）。     

玛瑙尘引起急进型矽肺——附15例分析

目的　检测接触玛瑙尘作业工人生产环境与矽肺病发病状况。方法　测定广州某珠宝加工厂33名玛瑙尘接触工人作业环境玛瑙尘的总尘浓度、分散度和游离SiO     

Chronic obstructive pulmonary disease and occupational exposure to silica

Prolonged exposure to high levels of silica has long been known to cause silicosis This paper evaluates the evidence for an increased risk of chronic obstructive pulmonary disease (COPD) in occupations and industries in which exposure to crystalline silica is the primary exposure, with a focus on the magnitude of risks and levels of exposure causing disabling health effects. The literature suggests consistently elevated risks of developing COPD associated with silica exposure in several occupations, including the construction industry; tunneling; cement industry; brick manufacturing; pottery and ceramic work; silica sand, granite and diatomaceous earth industries; gold mining; and iron and steel founding, with risk estimates being high in some, even after taking into account the effect of confounders like smoking. Average dust levels vary from about 0.5 mg.m3 to over 10 mg.m3 and average silica levels from 0.04 to over 5 mg.m3, often well above occupational standards. Factors influencing the variation from industry to industry in risks associated with exposure to silica-containing dusts include (a) the presence of other minerals in the dust, particularly when associated with clay minerals; (b) the size of the particles and percentage of quartz; (c) the physicochemical characteristics, such as whether the dust is freshly fractured. Longitudinal studies suggest that loss of lung function occurs with exposure to silica dust at concentrations of between 0.1 and 0.2 mg.m3, and that the effect of cumulative silica dust exposure on airflow obstruction is independent of silicosis. Nevertheless, a disabling loss of lung function in the absence of silicosis would not occur until between 30 and 40 years exposure.     

Pulmonary alveolar proteinosis induced by silica dust?

Abstract Pulmonary alveolar proteinosis (PAP) is a rare disease, with several aetiologies. This study reports the first Finnish case of PAP with possible induction by silica dust. A 58-year-old male patient had a documented history of heavy exposure to silica dust over a long period, although he himself considered the exposure to be low. The patient's cumulative exposure to silica dust was approximately 10 mg m(-3) years according to the workplace measurements. The patient developed classical symptoms and signs of PAP that closely mimicked those of acute silicosis, but he did not have any signs of classic silicosis. We conclude that significant chronic exposure to silica favours the diagnosis of PAP rather than acute silicosis in this case. PAP should be taken into account when patients exposed to silica dust complain of respiratory symptoms. A patient's assessment of his/her exposure to silica may not always be reliable.     

陶工尘肺危险度及其防制措施评价

８个陶瓷厂矿队列研究（１９６０．１．１￣１９７４．１２．３１）１３４７６人,追访至１９９４年底。其中接尘工１０３３１人,尘肺发病１１７９例,发病率０．４５％。１９６０年前进厂的接尘工尘肺发病率是０．６０％,１９５９年后进厂者为０．２４％,说明５０年代末期所推行的防尘措施有一定成效,但由于各厂降尘设备不完善,尘肺发病下降远不如金属钨矿和锡矿工人明显。本研究采用了定量分析,结果表明：①接尘工累积接总粉     

Association between lymph node silicosis and lung silicosis in 4,384 German uranium miners with lung cancer

This study investigates the association between lymph node-only and lung silicosis in uranium miners with lung cancer and exposure to quartz dust. Tissue slides of 4,384 German uranium miners with lung cancer were retrieved from an autopsy archive and reviewed by 3 pathologists regarding silicosis in the lungs and lymph nodes. Cumulative exposure to quartz dust was assessed with a quantitative job-exposure matrix. The occurrence of silicosis by site was investigated with regression models for exposure to quartz dust. Miners with lung silicosis had highest cumulative quartz exposure, followed by lymph node-only silicosis and no silicosis. At a cumulative quartz exposure of 40 mg/m(3) × years, the probability of lung silicosis was above 90% and the likelihood of lymph node-only silicosis and no silicosis do not differ anymore. The results support that lymph node silicosis can precede lung silicosis, at least in a proportion of subjects developing silicosis, and that lung silicosis strongly depends on the cumulative quartz dose.     

Change of exposure response over time and long-term risk of silicosis among a cohort of Chinese pottery workers

An analysis was conducted on a cohort of Chinese pottery workers to estimate the exposure-response relationship between respirable crystalline silica dust exposure and the incidence of radiographically diagnosed silicosis, and to estimate the long-term risk of developing silicosis until the age of 65. The cohort comprised 3,250 employees with a median follow-up duration of around 37 years. Incident cases of silicosis were identified via silicosis registries (Chinese X-ray stage I, similar to International Labor Organisation classification scheme profusion category 1/1). Individual exposure to respirable crystalline silica dust was estimated based on over 100,000 historical dust measurements. The association between dust exposure, incidence and long-time risk of silicosis was quantified by Poisson regression analysis adjusted for age and smoking. The risk of silicosis depended not only on the cumulative respirable crystalline silica dust exposures, but also on the time-dependent respirable crystalline silica dust exposure pattern (long-term average concentration, highest annual concentration ever experienced and time since first exposure). A long-term "excess" risk of silicosis of approximately 1.5/1,000 was estimated among workers with all annual respirable crystalline silica dust concentration estimates less than 0.1 mg/m(3), using the German measurement strategy. This study indicates the importance of proper consideration of exposure information in risk quantification in epidemiological studies.