钨钼制品企业粉尘作业工人肺通气功能结果分析

了解钨钼粉尘对作业工人肺通气功能的影响,以某钨钼制品企业在岗期间参加职业健康检查的47名粉尘工人为接尘组,另选47名非接尘工人作为对照组进行肺通气功能测试,对结果进行统计学分析。结果显示,47名钨钼粉尘作业工人肺通气功能异常率为17.0%,不同接尘工龄组FVC、FEV1、FEV1/FVC 3项肺通气功能指标比较,差异均无统计学意义;接尘组和对照组工人肺通气功能异常率比较,差异无统计学意义(P=0.344,P0.05);接尘组吸烟者的肺通气功能异常率(28.6%)高于不吸烟者(7.7%),但二者差异无统计学意义;在不同烟龄和吸烟量组别中,接尘组工人的肺通气功能异常率均高于对照组,在吸烟量为1~10支/d组中二者差异有统计学意义(P=0.026,P0.05),其余差异无统计学意义。提示,该企业应加大戒烟宣传力度,保证钨钼粉尘作业工人的健康。     

陶瓷企业接尘工人肺功能研究

目的 探讨陶瓷粉尘作业工人肺功能损伤的特征。 方法 采用美能(日本) AS507型肺功能仪,测定某陶瓷厂"无尘肺"的967名接尘工人(接尘组)和197名非接尘健康工人(对照组)的肺通气功能。 结果 陶瓷粉尘总尘浓度为0.10~2.95 mg/m3,总尘浓度超标率为14.29%,呼吸性粉尘浓度超标率为3.57%;粉尘中游离SiO₂含量为21.3%~43.0%。接尘组VC、FVC、FEV 1、FEV 1%、FEF 25%和FEF 50%的数值均低于对照组,差异有统计学意义(P<0.05或P<0.01)。接尘组肺通气功能损伤和小气道损伤的发生率均高于对照组,差异有统计学意义(P<0.05)。接尘的吸烟者VC、FEV1和FEV1%数值与非吸烟者相比,差异有统计学意义(P<0.01)。接尘工人肺通气功能损伤发生率为7.45%(72/967),其中轻度损伤者占98.61%(71/72),限制性肺通气功能损伤占97.22%(70/72)。 结论 陶瓷粉尘可引起接尘工人肺功能的损伤,其损伤程度以轻度为多,损伤类型以限制型损伤为主。肺功能损伤主要与粉尘、接尘工龄、工种和吸烟等因素有关。     

2009年郑州某铁路铸造厂作业工人肺通气功能变化分析

[目的]研究铸造工人的肺通气功能变化。[方法]2009年9月对郑州某铁路铸造厂工人作业场所进行环境检测,调查180名作业工人的防护情况和生活习惯,测试肺通气功能。选择与接尘组条件一致的同等劳动强度、不接触粉尘的某机床厂176名男性职工为对照组。[结果]粉尘浓度超过国家职业接触限值,接尘组与对照组肺通气功能指标FVC、FEV1.0和FEV1%、PEFR比较,差异均有统计学意义(P<0.05)。[结论]接尘及作业环境与肺通气功能损害有密切关系,且随着工龄的增加,损害逐步加大。     

济南市某厂石灰石粉尘作业场所粉尘及其对接尘工人肺功能损伤情况调查

[目的]了解石灰石粉尘对肺通气功能的危害,为制订防护措施提供科学依据。[方法]2007年,在济南市市属某大型工厂石灰石生产车间,对360名作业场所进行空气中粉尘检测,对360名接尘工人进行肺通气功能测定与呼吸道症状罹患情况调查,并与360名对照人员比较。[结果]作业场所粉尘最高浓度,粉料仓库为7.4 mg/m3,其他工序均超过8 h时间加权平均浓度容许的最高浓度8 mg/m3。胸闷、气促、咳嗽、咳痰罹患率接尘组均高于对照组(P<0.01);肺通气功能的各项指标(VC、FVC、MVV、FEV1.0、FEV1.0%、MMEF)接尘组均低于对照组(P<0.01或<0.05)。[结论]长期从事石灰石作业可对肺功能造成损害。     

金属粉尘对男性作业工人呼吸系统影响的调查

为了探讨金属粉尘作业工人的呼吸系统症状阳性率和肺通气功能状况,我们选择129名接触金属粉尘的作业工人作为接触组,126名非接触粉尘的作业工人作为对照组,采用美国胸科协会制订的标准化呼吸系统症状询问表和用力肺活量测试方法进行了调查。结果显示,咳嗽、咯痰、气短、喘息等呼吸系统症状阳性率和慢性支气管炎患病率,接触组中吸烟者(27.13%,20.15%,17.83%,19.38%,16.93%)和非吸烟者(14.73%,10.85%,15.50,10.85%,8.13%)高于对照组中吸烟者(13.49%,9.52%,8.73%,11.11%,8.97%)和非吸烟者(7.93%,7.14%,8.73%,4.76%,4.05%),差异均有统计学意义(P<0.05),且以接触组中吸烟者发生率最高。肺通气功能指标FVC,FEV1.0,FEV1.0%的实测值占预计值百分比,接触组中吸烟者(83.23±18.03,84.42±21.36,89.50±13.31)和非吸烟者(86.83±15.61,85.59±17.16,90.67±18.13)低于对照组中吸烟者(93.44±12.49,88.75±12.56,93.97±17.13)和非吸烟者(94.86±11.19,90.63±12.27,94.73±16.02),差异均有统计学意义(P<0.05)。接触组中吸烟者和非吸烟者FVC,FEV1.0,FEV1.0%的实测值占预计值百分比随着接尘工龄的延长而呈递减趋势,尤其吸烟者和非吸烟者接尘工龄≤5 a组分别与接尘工龄≥11 a组比较,差异均有统计学意义(P<0.05)。说明金属粉尘与作业工人呼吸系统功能的变化有直接关系;吸烟是金属粉尘作业工人发生呼吸系统功能损伤的危险因素;且随着接尘工龄的延长有加重的趋势。     

耐火陶瓷纤维对作业工人肺通气功能的影响

[目的]探讨耐火陶瓷纤维对作业工人肺通气功能的影响. [方法]选择从事耐火陶瓷纤维生产和加工的265名作业工人作为接触组,273名仅接触噪声的作业工人作为对照组,进行肺通气功能检查,指标为用力肺活量(FVC)、第一秒用力呼气量(FEV 1.0)、一秒率(第一秒用力呼气量占用力肺活量百分率,FEV 1.0/FVC),均以实测值占预计值的百分比(FVC％、FEV1.0％、FEV1.0/FVC％)表示.接触组分别按纤维计数浓度＜0.1、0.1～0.5、＞0.5 f/mL,按总粉尘质量浓度＜1、1～5、＞5 mg/m3分为低、中、高水平.低纤维低总尘亚组81人、中纤维中总尘亚组123人、中纤维高总尘亚组30人、高纤维高总尘亚组31人. [结果]接触组作业工人FVC％、FEV1.0％和FEV 1.0/FVC％的均数均低于对照组(P＜0.05);高纤维高总尘亚组作业工人FVC％和FEV1.0％的下降较其他3个亚组更为明显(P＜0.05),不同接触工龄亚组间各指标差异均无统计学意义(P＞0.05).接触组限制性、阻塞性和混合性肺通气功能障碍检出率为58.9％、4.5％和3.8％,与对照组的检出率10.9％、5.1％和4.0％比较,仅限制性肺通气功能障碍检出率的差别有统计学意义(P＜0.05).限制性肺通气功能障碍与纤维计数浓度、接触工龄具有关联性(P＜0.05),与总粉尘质量浓度、是否吸烟无关联性(P＞0.05). [结论]接触耐火陶瓷纤维可导致以限制性通气功能障碍为主的肺通气功能损害,限制性通气功能障碍检出率与纤维累计接触水平存在正相关关系,与纤维计数浓度的关联性优于总粉尘质量浓度.     

水泥粉尘对工人肺功能影响的研究分析

目的了解水泥作业工人的肺通气功能情况,探讨接触水泥粉尘对作业者大气道及小气道通气功能的不同影响。方法设立观察组(生料组和熟料组)与对照组,测定反映肺通气功能的各项指标(VC、FVC、FEV1、FEV1/FVC、PEFR、V50、V25),并对接尘组与对照组肺功能进行比较,同时测定历年来作业场所空气中粉尘浓度。结果FEV1、PEFR、V50生料组比对照组降低,差异有统计学意义(P<0.05);PEFR、V50熟料组比对照组降低,差异有统计学意义(P<0.05);而生料组与熟料组之间肺功能各项指标比较差异无统计学意义(P>0.05);接尘组的小气道功能指标中V50/H、PEFR、V50/V25、比对照组均有明显降低,差异有统计学意义(P<0.05),V25/H差异无统计学意义(P>0.05);接尘工人中肺功能改变随工龄增长而明显,其中V50、FEV1出现异常时间较早,大约5年~7年,而PEFR改变则稍晚些,大约11年~13年。结论接触水泥粉尘可对作业者的肺功能产生影响,且随作业工龄的增长而增强,尤其对小气道影响明显。     

徐州铁路分局电焊作业场所卫生状况调查

[目的]探讨电焊尘对作业工人肺通气功能的影响。[方法]2004年4月，对徐州铁路分局电焊作业现场进行了劳动卫生学调查，对电焊工进行了肺通气功能测定。[结果]作业场所电焊烟尘浓度较高。检测238名电焊工人，肺活量（VC）、用力肺活量（FVC）、第一秒用力肺活量（FEV1.0）、FEV1.0％（FEV1．0／FVC百分比）均低于506名非接尘的对照组（P〈0．01）。肺通气功能异常率接尘组为32．77%，对照组为8．50％（P〈0．01），2组均有随着工龄的增加异常率增高的趋势（P〈0．01）。[结论]电焊烟尘可引起电焊工的肺通气功能损伤，接尘工龄与肺通气功能损伤有密切关系。     

某市乡镇铸造行业粉尘危害的调查分析

目的 :了解乡镇铸造行业粉尘危害的情况。方法 :对某市 114家黑色铸造厂和车间所产生的铸工粉尘进行了监测 ,并对 12 3 5名铸造工人进行了肺通气功能的测定。结果 :在主要工种作业场所中 ,粉尘浓度的几何均值从高到低依次为 :混砂 >清砂 >筛砂 >造型 ,且各工种的几何均值间的差异均有非常显著性 (P<0 .0 1)。接尘组与对照组工人的 5项肺通气功能间的差异均有极显著性 (P<0 .0 1) ,接尘组的异常率明显高于对照组。结论 :该镇应加强对铸造粉尘的卫生管理及监督     

某市灯饰加工工业接尘工人肺功能测定分析

目的了解某市灯饰加工工业接尘工人的肺功能损害情况。方法对某市某镇15家灯饰加工厂接尘工龄1年以上的300名男工进行肺功能测定,另选择该镇的150名非接尘男工作为对照组;并对灯饰加工厂进行粉尘测定。结果15家灯饰加工厂铝尘、矽尘浓度超标率分别为53.33%和86.67%,最高超标分别为2.2倍和16.0倍。矽尘中游离SiO2含量平均96.44%。接尘组肺通气功能的异常率显著高于对照组(P<0.01),用力肺活量(FVC)、第1秒用力肺活量(FEV1.0)、第1秒用力肺活量与用力肺活量之比(FEV1.0/FVC)、肺活量(VC)、最大呼气中期流速(FEF25-75)、最大呼气25%、50%、75%肺活量时流量(FEF25、FEF50、FEF75)均明显低于对照组(P<0.01)。肺通气功能随着接尘工龄的延长而降低(P<0.01)。结论灯饰加工工业粉尘可致接尘工人肺功能一定程度的损伤,应做好预防工作。     

Loss of lung function associated with exposure to silica dust and with smoking and its relation to disability and mortality in South African gold miners.

The data from a lung function study on 2209 white 45-54 year old South African gold miners in 1968-71 and at a five year follow up examination, were analysed to establish the actual loss of lung function associated with exposure to silica dust and with smoking. Ex-smokers were excluded from the analysis. Of the remaining 1625 subjects, 1249 had the five year follow up test of lung function. The estimated excess loss of lung function for a 50 year old gold miner, associated with 24 years of underground dust exposure of an average respirable dust concentration of 0.30 mg m-3 (14.4 ghm-3) was 236 ml of FEV1 (95% confidence interval (95% CI 134-337) and 217 ml of FVC (95% CI 110-324). By comparison, the effect of smoking one packet of cigarettes a day over 30 years was associated with an estimated loss of 552 ml of FEV1 (95% CI 461-644) and 335 ml of FVC (95% CI 170-500). The cumulative dust exposure was not associated with the longitudinal loss of FEV1 or FVC when the initial FEV1 and FVC were adjusted in the models. According to the predicted values, however, gold miners appear to have a greater loss of lung function from 50 to 55 years of age than that predicted for a general population.     

Loss of lung function associated with exposure to silica dust and with smoking and its relation to disability and mortality in South African gold miners.

The data from a lung function study on 2209 white 45-54 year old South African gold miners in 1968-71 and at a five year follow up examination, were analysed to establish the actual loss of lung function associated with exposure to silica dust and with smoking. Ex-smokers were excluded from the analysis. Of the remaining 1625 subjects, 1249 had the five year follow up test of lung function. The estimated excess loss of lung function for a 50 year old gold miner, associated with 24 years of underground dust exposure of an average respirable dust concentration of 0.30 mg m-3 (14.4 ghm-3) was 236 ml of FEV1 (95% confidence interval (95% CI 134-337) and 217 ml of FVC (95% CI 110-324). By comparison, the effect of smoking one packet of cigarettes a day over 30 years was associated with an estimated loss of 552 ml of FEV1 (95% CI 461-644) and 335 ml of FVC (95% CI 170-500). The cumulative dust exposure was not associated with the longitudinal loss of FEV1 or FVC when the initial FEV1 and FVC were adjusted in the models. According to the predicted values, however, gold miners appear to have a greater loss of lung function from 50 to 55 years of age than that predicted for a general population.     

Relation between dust exposure and lung function in miners and ex-miners

A sample of men working in the British coal industry in the 1950s has been followed up and examined 22 years later. The relations between lung function and individual cumulative exposure to respirable dust have been studied in 1867 men who were still working in the industry at the time of follow up and 2192 men who had left. Levels of forced expired volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio at follow up were found to be inversely related to exposure to respirable dust after allowing for other factors, even in men without pneumoconiosis. The magnitude of this estimated effect was equivalent to a loss of 228 ml FEV1 in response to an exposure of 300 gh/m3, a moderately high exposure for this group. Ex-miners aged under 65 had worse lung function than miners on average, suggesting that ill health had encouraged some of these men to leave the industry. Whereas a more severe response to dust exposure among ex-miners under 65 was suggested, this difference could easily have arisen by chance. The presence of symptoms of chronic bronchitis was associated with reduced levels of lung function, however, and, additionally, ex-miners under 65 with chronic bronchitis showed a more severe response of the FVC to dust exposure than miners without these symptoms. Among these ex-miners with chronic bronchitis a small group of men who had taken other jobs showed a much more severe effect of dust exposure on their lung function than the average, likely in heavily exposed men to contribute importantly to disability. Men in this group who had given up smoking showed and even more severe effect of dust exposure, equivalent to a loss of 940 ml FEV1 in response to an exposure of 300 gh/m3. These results indicate that exposure to respirable dust can occasionally cause severe respiratory impairment in the absence of progressive massive fibrosis. Dust exposure was related to a parallel reduction of FEV1 and FVC, implying that the pathology of dust induced lung damage differs form that induced by smoking. This pattern of abnormality was shown by some non-smokers, whereas smokers and ex-smokers apparently severely affected by dust showed a classic obstructive pattern of abnormality with pronounced reduction of the FEV1/FVC ratio.     

Relation between dust exposure and lung function in miners and ex-miners.

A sample of men working in the British coal industry in the 1950s has been followed up and examined 22 years later. The relations between lung function and individual cumulative exposure to respirable dust have been studied in 1867 men who were still working in the industry at the time of follow up and 2192 men who had left. Levels of forced expired volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio at follow up were found to be inversely related to exposure to respirable dust after allowing for other factors, even in men without pneumoconiosis. The magnitude of this estimated effect was equivalent to a loss of 228 ml FEV1 in response to an exposure of 300 gh/m3, a moderately high exposure for this group. Ex-miners aged under 65 had worse lung function than miners on average, suggesting that ill health had encouraged some of these men to leave the industry. Whereas a more severe response to dust exposure among ex-miners under 65 was suggested, this difference could easily have arisen by chance. The presence of symptoms of chronic bronchitis was associated with reduced levels of lung function, however, and, additionally, ex-miners under 65 with chronic bronchitis showed a more severe response of the FVC to dust exposure than miners without these symptoms. Among these ex-miners with chronic bronchitis a small group of men who had taken other jobs showed a much more severe effect of dust exposure on their lung function than the average, likely in heavily exposed men to contribute importantly to disability. Men in this group who had given up smoking showed and even more severe effect of dust exposure, equivalent to a loss of 940 ml FEV1 in response to an exposure of 300 gh/m3. These results indicate that exposure to respirable dust can occasionally cause severe respiratory impairment in the absence of progressive massive fibrosis. Dust exposure was related to a parallel reduction of FEV1 and FVC, implying that the pathology of dust induced lung damage differs form that induced by smoking. This pattern of abnormality was shown by some non-smokers, whereas smokers and ex-smokers apparently severely affected by dust showed a classic obstructive pattern of abnormality with pronounced reduction of the FEV1/FVC ratio.     

Ventilatory function after exposure to various respirable hazards in a population of former coal miners

The ventilatory function of 406 male former coal miners who had presented at the Cook County Hospital occupational medicine clinic between January 1976 and April 1987 was studied to determine whether subsequent exposure to respiratory hazards after leaving the coal mines adversely affected lung function. The miners were divided into five exposure groups based on their exposure to respirable hazards. These were coal dust only, coal dust plus asbestos dust, coal dust plus silica dust, coal dust plus another respirable hazard and coal dust plus two other respirable dust exposures. Duration of employment in coal mines, race, smoking history, and mean age were not significantly different between the various exposure groups. No significant difference was found in the per cent of predicted forced expiratory volume in one second (FEV1), per cent of predicted forced vital capacity (FVC), and FEV1/FVC when the coal dust only group was compared with each of the other four exposure groups using ANOVA. Among former coal miners who present for a respiratory disability determination, therefore, exposure to respirable hazards subsequent to employment in coal mines is not associated with a statistically significant deterioration in ventilatory function.     

Ventilatory function after exposure to various respirable hazards in a population of former coal miners.

The ventilatory function of 406 male former coal miners who had presented at the Cook County Hospital occupational medicine clinic between January 1976 and April 1987 was studied to determine whether subsequent exposure to respiratory hazards after leaving the coal mines adversely affected lung function. The miners were divided into five exposure groups based on their exposure to respirable hazards. These were coal dust only, coal dust plus asbestos dust, coal dust plus silica dust, coal dust plus another respirable hazard and coal dust plus two other respirable dust exposures. Duration of employment in coal mines, race, smoking history, and mean age were not significantly different between the various exposure groups. No significant difference was found in the per cent of predicted forced expiratory volume in one second (FEV1), per cent of predicted forced vital capacity (FVC), and FEV1/FVC when the coal dust only group was compared with each of the other four exposure groups using ANOVA. Among former coal miners who present for a respiratory disability determination, therefore, exposure to respirable hazards subsequent to employment in coal mines is not associated with a statistically significant deterioration in ventilatory function.     

Exposure-response relationships for coal mine dust and obstructive lung disease following enactment of the Federal Coal Mine Health and Safety Act of 1969.

Underground U.S. coal miners were studied cross-sectionally for the association of respirable coal mine dust exposure with pulmonary function and symptoms of airways obstruction. The study group included 1,185 miners participating in Round 4 of the National Study of Coal Workers' Pneumoconiosis who had started mining in or after 1970 when comprehensive exposure regulations first came into effect. Quantitative estimates of cumulative exposure, derived using respirable dust measurements taken by the Mine Safety and Health Administration over the entire study period, were used in linear and logistic regression models on indicators of pulmonary function and chest symptoms while controlling for smoking status, pack-years, and other potential confounders. Statistically significant associations between log cumulative exposure and decrements in FVC, FEV1, and FEV1/FVC were observed. In logistic models, statistically significant associations of cumulative exposure with increasing prevalence of FEV1 and FEV1/FVC less than 80% predicted and symptoms including chronic phlegm, chronic bronchitis, breathlessness, wheeze, and wheeze with shortness of breath were found. It is concluded that exposures to respirable coal mine dust present in U.S. mines since 1970 continue to affect respiratory health in underground miners.     

Work related decrement in pulmonary function in silicon carbide production workers.

The relation between pulmonary function, cigarette smoking, and exposure to mixed respirable dust containing silicon carbide (SiC), hydrocarbons, and small quantities of quartz, cristobalite, and graphite was evaluated in 156SiC production workers using linear regression models on the difference between measured and predicted FEV1 and FVC. Workers had an average of 16 (range 2-41) years of employment and 9.5 (range 0.6-39.7) mg-year/m3 cumulative respirable dust exposure; average dust exposure while employed was 0.63 (range 0.18-1.42) mg/m3. Occasional, low level (less than or equal to 1.5 ppm) sulphur dioxide (SO2) exposure also occurred. Significant decrements in FEV1 (8.2 ml; p less than 0.03) and FVC (9.4 ml; p less than 0.01) were related to each year of employment for the entire group. Never smokers lost 17.8 ml (p less than 0.02) of FEV1 and 17.0 (p less than 0.05) of FVC a year, whereas corresponding decrements of 9.1 ml (p = 0.12) in FEV1 and 14.4 ml (p less than 0.02) in FVC were found in current smokers. Similar losses in FEV1 and FVC were related to each mg-year/m3 of cumulative dust exposure for 138 workers with complete exposure information; these findings, however, were generally not significant owing to the smaller cohort and greater variability in this exposure measure. Never smokers had large decrements in FEV1 (40.7 ml; p less than 0.02) and FVC (32.9 ml; p = 0.08) per mg-year/m3 of cumulative dust exposure and non-significant decrements were found in current smokers (FEV1: -7.1 ml; FVC: -11.7 ml). A non-significant decrement in lung function was also related to average dust exposure while employed. No changes were associated with SO(2) exposure or and SO(2) dust interaction. These findings suggest that employment in SiC production is associated with an excessive decrement in pulmonary function and that current permissible exposure limits for dusts occurring in this industry may not adequately protect workers from developing chronic pulmonary disease.     

Work related decrement in pulmonary function in silicon carbide production workers

The relation between pulmonary function, cigarette smoking, and exposure to mixed respirable dust containing silicon carbide (SiC), hydrocarbons, and small quantities of quartz, cristobalite, and graphite was evaluated in 156SiC production workers using linear regression models on the difference between measured and predicted FEV1 and FVC. Workers had an average of 16 (range 2-41) years of employment and 9.5 (range 0.6-39.7) mg-year/m3 cumulative respirable dust exposure; average dust exposure while employed was 0.63 (range 0.18-1.42) mg/m3. Occasional, low level (less than or equal to 1.5 ppm) sulphur dioxide (SO2) exposure also occurred. Significant decrements in FEV1 (8.2 ml; p less than 0.03) and FVC (9.4 ml; p less than 0.01) were related to each year of employment for the entire group. Never smokers lost 17.8 ml (p less than 0.02) of FEV1 and 17.0 (p less than 0.05) of FVC a year, whereas corresponding decrements of 9.1 ml (p = 0.12) in FEV1 and 14.4 ml (p less than 0.02) in FVC were found in current smokers. Similar losses in FEV1 and FVC were related to each mg-year/m3 of cumulative dust exposure for 138 workers with complete exposure information; these findings, however, were generally not significant owing to the smaller cohort and greater variability in this exposure measure. Never smokers had large decrements in FEV1 (40.7 ml; p less than 0.02) and FVC (32.9 ml; p = 0.08) per mg-year/m3 of cumulative dust exposure and non-significant decrements were found in current smokers (FEV1: -7.1 ml; FVC: -11.7 ml). A non-significant decrement in lung function was also related to average dust exposure while employed. No changes were associated with SO(2) exposure or and SO(2) dust interaction. These findings suggest that employment in SiC production is associated with an excessive decrement in pulmonary function and that current permissible exposure limits for dusts occurring in this industry may not adequately protect workers from developing chronic pulmonary disease.     

Longitudinal and cross sectional analyses of exposure to coal mine dust and pulmonary function in new miners.

The association between exposure to dust and pulmonary function was studied by longitudinal and cross sectional analyses in a group of United States underground coal miners beginning work in or after 1970. Quantitative estimates of exposure to respirable coal mine dust were derived from air samples taken periodically over the entire study period. The cohort included 977 miners examined both in round 2 (R2) (1972-5) and round 4 (R4) (1985-8) of the National Study of Coal Workers' Pneumoconiosis. Multiple linear regression models were developed for both cross sectional (pulmonary function at R2 and R4) and longitudinal (change in pulmonary function between R2 and R4) analyses with exposure partitioned into pre-R2 and post-R2 periods and controlled for covariates including smoking history. The results indicate a rapid initial (at R2) loss of FVC and FEV1 in association with cumulative exposure of the order of 30 ml per mg/m3-years. Between R2 and R4 (about 13 years) no additional loss of function related to dust exposure was detected although the percentage of predicted FVC and FEV1 did decline over the period. After some 15 years since first exposure (at R4), a statistically significant association of cumulative exposure with FEV1 of about -5.9 ml per mg/m3-years was found. These results indicate a significant non-linear effect of exposure to dust on pulmonary function at dust concentrations present after regulations took effect. The initial responses in both the FVC and FEV1 are consistent with inflammation of the small airways in response to exposure to dust.