某市企业矽尘总粉尘与呼吸性粉尘浓度关系分析

目的 了解矽尘总粉尘和呼吸性粉尘的危害程度及其相关关系,为确定粉尘治理、评价治理效果提供依据。 方法 对中山市存在矽尘危害企业的矽尘总粉尘和呼吸性粉尘浓度进行检测和分析。 结果 共采集矽尘总粉尘和呼吸性粉尘有效数据58对,总粉尘的超标率与呼吸性粉尘的超标率分别为77.5%和68.9%,两者比较,差异无统计学意义(χ2=3.155,P>0.05)。总粉尘和呼尘浓度比值(T/R)范围1.15~21.58。某运动用品厂的总粉尘和呼吸性粉尘浓度存在线性相关关系,采用24对数据,得到线性方程为Y=0.175 X+0.654(r=0.816,P<0.05)。 结论 所调查企业粉尘危害不容忽视,总粉尘浓度反映的危害程度与呼吸性粉尘基本一致;但部分岗位总粉尘和呼吸性粉尘浓度差别较大,不能确定多行业总粉尘和呼吸性粉尘换算关系。应尽量排除各种因素的影响干扰,确定两者的关系,指导日常工作。     

2011—2014年天津市东丽区矽肺动态监测结果

目的采用重点职业病哨点监测的方法了解天津市东丽区矽尘的职业危害现状,为预防和控制矽肺病的发生提供科学依据。方法按照《重点职业病监测技术方案》的要求,对天津市东丽区7家矽尘哨点企业进行了矽尘中游离二氧化硅含量、矽尘浓度的检测,对接尘劳动者进行了粉尘作业的职业健康检查。结果该区7家哨点企业积尘中游离二氧化硅的平均含量为53.7%,2011—2014年矽尘总粉尘浓度总超标率为37.3%,呼吸性粉尘浓度总超标率为35.8%,2014与2011年相比,矽尘总粉尘浓度和呼吸性粉尘浓度的差异有统计学意义(P0.05);4年来共检出疑似尘肺病32例,达到健康检查总人数的1.2%。结论天津市东丽区矽尘哨点企业矽尘总粉尘浓度和呼吸性粉尘浓度总超标率偏高,粉尘浓度超标会导致尘肺病的发生,采取行之有效的预防控制措施,防止尘肺病的发生刻不容缓。     

地质勘探工人历年接触矽尘的评价

目的对接触矽尘的地质勘探工人的接尘水平进行定量评价.方法收集9个省地质矿产勘查局所属队(厂、矿)50年代以来各工种历年的矽尘监测资料30000个,还收集历史的和近期的其他矽尘监测资料,以及1627个研究对象的工作史.利用上述资料按队(厂、矿)、工种和年段建立了矽尘接触水平,并用呼吸性矽尘量、全肺的矽尘量和总粉尘中矽尘含量估算矽尘的接触量.结果呼吸性粉尘接触浓度平均值是3mg/m3;总粉尘浓度平均值是14mg/m3,早年是29mg/m3,近年是3mg/m3;粉尘中游离二氧化硅含量平均值是(28.0±8.2)%.结合每个研究对象的工作史和矽尘接触水平分别计算出不同的矽尘接触指数.结论这种大规模矽尘接触评价方法对历年接触矽尘的估算可为剂量-反应关系评价提供依据.     

地质勘探行业呼吸性粉尘浓度与总粉尘浓度的关系

为探讨地质勘探行业呼吸性粉尘浓度与总粉尘浓度的关系,为利用历史总粉尘测定资料进行呼吸性粉尘浓度的估算提供参考依据,本文用３种采样器对地质勘探行为９个省（自治区）地质勘查局地勘接尘作业的呼吸性粉尘浓度与总粉尘浓度进行测定分析。结果表明,我国地质勘探行业接尘作业呼吸性粉尘浓度与总粉尘浓度的比值为１：４．６￣４．８。     

钢铁行业总粉尘与呼吸性粉尘浓度比值的研究

[目的]为探讨总粉尘与呼吸性粉尘浓度比值的关系。[方法]对某钢铁公司所属炼铁和采矿分公司的1504名接尘工人进行调查研究,通过进行矽肺病流行病学调查分析,把40年来的总粉尘浓度换算成呼吸性粉尘浓度。[结果]表明T/R比值在不同作业场所结果不一,配料和掘进两个工种呼吸性粉尘浓度较其他工种高,且患病率也高于其他工种。[结论]说明粉尘的生物学作用与呼吸性粉尘联系密切,进一步说明了呼吸性粉尘浓度比总粉尘浓度更能反映工人接尘的实际危害程度。     

水泥粉尘对作业工人鼻腔的损伤作用

目的: 探讨水泥粉尘对作业工人鼻腔的损伤作用。方法: 检查609例水泥粉尘作业工人、416 例矽尘作业工人、及287 例非接尘工人鼻腔疾病患病率及鼻腔粘膜的病理改变。结果: 水泥粉尘接触工人鼻腔疾病患病率明显高于矽尘作业工人及非接尘工人 (P< 0.05)。而且与接触粉尘的浓度、接尘工龄存在接触水平-反应关系。水泥粉尘所致鼻腔疾病主要表现为干燥性鼻炎, 鼻前庭炎, 鼻窦炎, 鼻中隔糜烂、溃疡与矽尘组比较有显著性差异(P< 0.05)。鼻粘膜细胞涂片检查, 水泥尘组鼻粘膜细胞损害较矽尘组、非接尘组严重。结论: 水泥粉尘对作业工人鼻腔有较强的损伤作用     

地质勘探作业呼吸性粉尘与尘肺的剂量-反应关系

目的研究地质勘探作业呼吸性粉尘浓度接触阈限值.方法用寿命表法分析地质勘探坑探掘进接尘工人呼吸性粉尘吸入量与尘肺发病的剂量-反应关系.结果地质勘探坑探掘进接尘工人的呼吸性粉尘接触浓度与环境中粉尘浓度的比值为1∶4.6,粉尘中游离二氧化硅含量的平均值为(48±9)%,剂量-反应关系回归方程为Y=3.2506lgX-1.0607.结论地质勘探作业呼吸性粉尘(含游离二氧化硅48%)浓度接触阈限值为0.4696mg/m3.     

地质勘探行业工人粉尘暴露水平的调查

目的　确定地质勘探行业粉尘危害程度。方法　对地质勘探行业接触粉尘工种 ,采用国产个体呼吸性粉尘采样器采集、测定呼吸性粉尘浓度、总粉尘浓度和粉尘中游离二氧化硅 (FSiO2 )含量 ,并与历年接尘点的呼吸性粉尘浓度测定结果进行比较。结果　 9个省 (自治区 )地质勘探行业的765个接触矽尘作业点中 ,呼吸性粉尘浓度超标率为 47.95 % ;呼吸性粉尘浓度最高的作业和工种是从事地质勘探作业的刻槽取样工种 ,1 996～ 2 0 0 0年其呼吸性粉尘浓度为 (6 .1 5± 3 .2 1 )mg/m3;地质勘探行业工人接触的呼吸性粉尘占总粉尘的比例高 ,粉尘中FSiO2 含量高。结论　地质勘探行业某些工种呼吸性粉尘暴露水平明显高于国家卫生标准 ,尤其是刻槽取样工和凿岩工。     

连云港市硅产品生产和使用企业矽尘危害状况调查

目的了解连云港市生产和使用硅产品企业矽尘危害现状,分析不同岗位工人健康损害情况,探讨硅产品生产和使用企业矽肺病防治对策和建议。方法采用现场询问,调查员填写问卷的方法对连云港市生产和使用硅产品的6家企业的基本情况进行调查;收集1 005名矽尘作业工人的职业健康检查资料;收集矽尘危害企业和矽尘作业工人基本情况资料;对矽尘作业岗位粉尘浓度和游离二氧化硅含量进行测定。结果建材行业矽尘作业工人胸片异常率(87.6%)高于电子行业(3.6%);矽尘作业岗位总尘合格率为3.8%,呼吸性粉尘合格率为7.8%;职业健康检查胸片异常率为45.5%,肺功能异常率为32.3%,疑似尘肺病检出率为0.7%;矽尘作业场所中粉尘浓度较高的岗位有球磨、破碎、振动筛、称量、粉料包装、分拣、成品混合、拣砂、喷砂、装料、倒角等岗位,时间加权平均浓度(CTWA)超标倍数4.5的岗位工人胸片异常率明显高于CTWA超标倍数≤4.5组;疑似尘肺病患者所在岗位粉尘浓度及岗位CTWA高于其他接尘人员所在岗位。结论应重点加强硅产品生产企业矽尘危害防治工作,加强对重点岗位的粉尘治理和职业健康监护工作。     

重庆市渝北区四家页岩砖厂粉尘危害状况调查

分析渝北区页岩砖厂的粉尘现状及接尘岗位的粉尘暴露水平，提出防护措施及日常监管的要求。对渝北区4家页岩砖厂进行职业卫生现场调查，收集职业健康检查和职业病诊断资料，同时对部分岗位进行粉尘采样并检测。结果显示，渝北页岩砖厂均为小型私营企业，接尘岗位缺乏粉尘防护设施，接尘劳动者防尘口罩佩戴情况不佳。其中一页岩砖厂曾在2020年出现矽肺病例。2021年接尘工人胸片异常改变以肺纹理增多、胸膜增厚人数最多，肺功能以限制性通气障碍为主。页岩砖厂的粉尘类型均为矽尘，岗位矽尘（呼吸性粉尘）总体合格率为27.78%。提示渝北区页岩砖厂矽尘危害严重，亟需进行相应整改。企业应落实主体责任，设置防尘设施、改善作业环境，培训和督促劳动者正确使用个人防护用品，同时加强职业健康监护。行政部门应加强宣传教育和监管，多措并举，避免及减少这类企业发生粉尘健康危害。     

Relation between exposure to respirable silica dust and silicosis in a tungsten mine in China.

To estimate the quantitative relation between exposure to respirable silica dust and risk of an attack of silicosis, 1151 workers exposed to silica dust and employed from 1958 to 1987 in a tungsten mine in China were investigated. The results showed that the ratio of respirable silica dust concentration to total silica dust concentration was 0.529. Then, the total silica dust concentration in historical surveillance and monitoring data was converted to respirable silica dust concentration. The free silica content in respirable dust determined by x ray diffraction averaged 24.7%. Multiple logistic regression was used for the dichotomous dependent variables (presence or absence of silicosis). The independent variables in the multiple logistic regression with presence of silicosis as the dependent variable were age when first exposed, tuberculosis (presence or absence), and cumulative exposure to respirable silica dust. The partial regression coefficient of individual cumulative exposure was estimated as 0.079. It implied a positive association between exposure to respirable silica dust and risk of an attack of silicosis. The exposure limit for respirable silica dust was estimated as 0.24 mg/m3 under given conditions.     

Relation between exposure to respirable silica dust and silicosis in a tungsten mine in China.

To estimate the quantitative relation between exposure to respirable silica dust and risk of an attack of silicosis, 1151 workers exposed to silica dust and employed from 1958 to 1987 in a tungsten mine in China were investigated. The results showed that the ratio of respirable silica dust concentration to total silica dust concentration was 0.529. Then, the total silica dust concentration in historical surveillance and monitoring data was converted to respirable silica dust concentration. The free silica content in respirable dust determined by x ray diffraction averaged 24.7%. Multiple logistic regression was used for the dichotomous dependent variables (presence or absence of silicosis). The independent variables in the multiple logistic regression with presence of silicosis as the dependent variable were age when first exposed, tuberculosis (presence or absence), and cumulative exposure to respirable silica dust. The partial regression coefficient of individual cumulative exposure was estimated as 0.079. It implied a positive association between exposure to respirable silica dust and risk of an attack of silicosis. The exposure limit for respirable silica dust was estimated as 0.24 mg/m3 under given conditions.     

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.     

Respiratory effects of exposure to low levels of concrete dust containing crystalline silica

BACKGROUND: Dusts containing crystalline silica are generated in mining, construction, glass, granite and concrete production industries. The association between exposure to low levels of concrete dust containing crystalline silica and reduction in lung function, was evaluated in a cross-sectional study. METHODS: The study was carried out among 144 concrete workers, from two factories, with exposure assessment of respirable dust and silica by personal samplers. Results of respiratory questionnaires and standardized measurements of lung function were compared with the results in a control population. Multiple linear regression analysis was used in selecting factors that predict (age and standing height standardized residual) lung function. RESULTS: The average concentration of respirable dust in both factories was 0.8 mg/m(3) and 0.06 mg/m(3) for respirable silica. The average silica content of the dust was 9%. The average cumulative dust exposure was 7.0 mg/m(3) year and cumulative silica exposure was 0.6 mg/m(3) year. Significant associations between exposure to concrete dust and a small lung function (FEV(1)/FVC ratio, MMEF) loss were found, independent of smoking habits and of a history of allergy. CONCLUSIONS: Our results indicate that, concrete workers with chronic obstructive pulmonary symptoms and/or work-related lower respiratory symptoms are at risk of having a reduction in lung function (FEV&(1)/FVC ratio) outside the 5th percentile of the external reference population, and therefore, of mild chronic obstructive pulmonary disease, at respirable concrete dust levels below 1 mg/m(3) with a respirable crystalline silica content of 10% (TWA, 8 hr).     

Effect of hollow bit local exhaust ventilation on respirable quartz dust concentrations during concrete drilling

Drilling large holes (e.g., 10–20?mm diameter) into concrete for structural upgrades to buildings, highways, bridges, and airport runways can produce concentrations of respirable silica dust well above the ACGIH^® Threshold Limit Value (TLV^® = 0.025?mg/m³). The aim of this study was to evaluate a new method of local exhaust ventilation, hollow bit dust extraction, and compare it to a standard shroud local exhaust ventilation and to no local exhaust ventilation. A test bench system was used to drill 19?mm diameter x 100?mm depth holes every minute for one hour under three test conditions: no local exhaust ventilation, shroud local exhaust ventilation, and hollow bit local exhaust ventilation. There were two trials for each condition. Respirable dust sampling equipment was placed on a “sampling” mannequin fixed behind the drill and analysis followed ISO and NIOSH methods. Without local exhaust ventilation, mean respirable dust concentration was 3.32 (±?0.65) mg/m³ with a quartz concentration of 16.8% by weight and respirable quartz dust concentration was 0.55 (±?0.05) mg/m³; 22 times the ACGIH TLV. For both LEV conditions, respirable dust concentrations were below the limits of detection. Applying the 16.8% quartz value, respirable quartz concentrations for both local exhaust ventilation conditions were below 0.007?mg/m³. There was no difference in respirable quartz dust concentrations between the hollow bit and the shroud local exhaust ventilation systems; both were below the limits of detection and well below the ACGIH TLV. Contractors should consider using either local exhaust ventilation method for controlling respirable silica dust while drilling into concrete.     

Comparison of foundry dust evaluation by various methods.

Matched sets of dust samples were collected in gray iron foundries for the purpose of comparing results obtained by four sampling techniques. Both respirable and total dust samples were collected. The results are compared on the basis of total concentration and on the basis of silica content. The problems in obtaining an adequate sample for silica analysis are considered. A proposal is made for using total respirable dust as an index of permissible dustiness in foundries.     

Respirable Dust and Respirable Silica Exposure in Ontario Gold Mines

A comprehensive survey of respirable dust and respirable silica in Ontario gold mines was conducted by the Ontario Ministry of Labor during 1978–1979. The aim was to assess the feasibility of introducing gravimetric sampling to replace the assessment method which used konimeters, a device which gave results in terms of number of particles per cubic centimeter (ppcc) of air. The study involved both laboratory and field assessments. The field assessment involved measurement of airborne respirable dust and respirable silica at all eight operating gold mines of the time. This article describes the details of the field assessment. A total of 288 long-term (7–8 hr) personal respirable dust air samples were collected from seven occupational categories in eight gold mines. The respirable silica (α-quartz) was determined by x-ray diffraction method. The results show that during 1978–1979, the industry wide mean respirable dust was about 1 mg/m³, and the mean respirable silica was 0.08 mg/m^3.The mean% silica in respirable dust was 7.5%. The data set would be useful in future epidemiological and health studies, as well as in assessment of workers’ compensation claims for occupational diseases such as silicosis, chronic obstructive pulmonary disease (COPD), and autoimmune diseases such as renal disease and rheumatoid arthritis.     

Regulatory implications of airborne respirable free silica variability in underground coal mines.

The respirable dust standard for respirable free crystalline silica in underground coal mines is expressed as milligrams per cubic meter (mg/m3) of respirable dust and is determined by the silica content of the dust. The Mine Safety and Health Administration (MSHA) regulates silica exposure by determining and enforcing compliance with the respirable dust standard for each active mine section. The MSHA strategy for regulation is examined in the context of respirable free crystalline silica and dust data. Deficiencies of the strategy include the same enforcement efforts regardless of compliance history, inappropriate treatment of data, and emphasis on short-term variability of silica content. These deficiencies result in inadequate enforcement in chronically dusty mines, "game playing" with optional samples, and an overall approach that does not focus on the long-term impact of silica exposure on lung health. Alternative approaches include enforcement efforts proportional to compliance history, use of a moving average silica content, and more statistically sound approaches to data interpretation.     

Silica exposure assessment in a mortality study of Vermont granite workers

A study of past silica and respirable dust exposures in the Vermont granite industry was conducted to develop a job exposure matrix (JEM) that used 5204 industrial hygiene measurements made from 1924-2004. The construction of the JEM involved data entry from several original sources into an Excel database that was reviewed later to ensure accuracy. Exposure measurements by job or location were grouped in two broad categories of quarry or shed and then into 22 job classes. Missing exposure data by time period were computed, taking into account improvements in dust control and periods of significant reduction in dustiness. Percent free silica (α-quartz) in respirable dust was estimated to be 11.0% based on previous published studies in Vermont and on data in the current database. About 60% of all measurement data (primarily from years prior to 1972) were obtained using the impinger and expressed in millions of particles per cubic foot (mppcf), which were converted to equivalent respirable free silica concentrations using the conversion of 10 mppcf = 0.1 mg/m(3) of respirable silica. For impinger data, respirable dust was calculated by multiplying respirable silica by a factor of 9.091 to reflect that the respirable silica was 11.0% respirable dust. This JEM has been used in a recent epidemiologic study to assess mortality in Vermont granite workers and to examine the relationships among mortality from silicosis, lung cancer, and other nonmalignant respiratory diseases.