Obstructive pulmonary function defects among Taiwanese firebrick workers in a 2-year follow-up study.

The purpose of the study was to follow up an earlier observation of pulmonary function among workers employed in firebrick-manufacturing factories. A 2-year follow-up study of pulmonary function among 442 workers in 30 firebrick-manufacturing factories was designed. Excluding 79 workers with a history of other occupational dust exposure, changes in pulmonary function of 291 firebrick workers were compared with pulmonary function in 72 control subjects over a period of 2 years. Baseline pulmonary function values (i.e., forced expiratory volume in 1 second [FEV1]/forced vital capacity [FVC] and forced expiratory flow after 50% of vital capacity has been expelled [FEF50%] in smoking firebrick workers, and FEV1/FVC and FEF75% in nonsmoking firebrick workers) were significantly lower than those in the comparison group. The statistical method for repeated measurements was used for comparison of the difference between follow-up and baseline lung function. There was no significant difference in FVC and FEV1 changes between firebrick workers and those in the comparison group during the 2-year follow-up period. The decreases in FEV1/FVC, peak expiratory flow rate, maximal midexpiratory flow, and FEF50% in the firebrick workers were significantly greater than in the comparison group, after adjustment for smoking status. The FEV1, maximal midexpiratory flow, FEF50%, and FEF75% also showed a dose-response relationship with job titles. The decrement of pulmonary function in the 2-year follow-up period was the worst in burning work, followed by crushing and molding. The results show that workers in firebrick-manufacturing factories with exposure to silica-containing dusts may contract obstructive pulmonary function defects.     

Spirometric indices after bronchodilator test in obstructive lung disease

Bronchial responsiveness to bronchodilator medications is usually tested to establish reversibility of airflow obstruction. Among the various tests to establish bronchodilator response, FEV1, FEF(25-75%) or FEF50%, and FVC are the most widely used. In a cross-sectional study, we assessed spirometric responses after administration of bronchodilator in 187 workers with obstructive pattern in spirometry. Considering responsiveness to bronchodilator (200 cc and 12% increase in FEV1 or FVC), the study cases were divided into responsive or non-responsive groups, and the average increase in spirometric indices were measured and compared between two groups. 35.8% of cases were responsive to bronchodilator. Among responsive cases, FEV1 was the most frequent index increased significantly; And PEF and FVC were the least frequent ones. The highest mean increase from baseline after administration of bronchodilator was observed in FEF75%. Increases in all indices were significantly higher in responsive group. The increase in FEV1% predicted was inversely correlated with baseline FEV1. In conclusion, we consider that FEV1 is the most reliable spirometric index for assessing bronchodilator response. And Bronchial reversibility has an inverse relationship with baseline measures.     

陶瓷作业工人肺功能测试结果分析

目的了解陶瓷作业工人肺功能损害的情况,为预防尘肺病发生提供依据。方法选择某陶瓷厂200名接尘工人,平均年龄为（32.31±8.25）岁,另选取非接尘工人50名为对照组,平均年龄为（34.88±9.75）岁,采用意大利的spirolabII型的肺功能仪,测试的项目包括肺活量（VC）、用力呼吸肺活量（FVC）、第1s用力呼气量（FEV1）、一秒率（FEV1%）、最大呼气中段流速（FEF25-75）、最大呼气25%、50%、75%肺活量时流量（FEF25%、FEF50%、FEF75%）;应用SPSS13.0统计软件统计分析。结果接尘组的肺功能指标FEV1、FEV1%、FEF25-75、FEF50%、FEF75%明显低于对照组,差异有统计学意义（P〈0.05）;接尘工龄在10年～、15年～、20年～组的工人肺功能指标中VC、FVC、FEF25-75、FEF50%、FEF75%的测试均值明显低于接尘工龄〈5年组,差异有统计学意义（P〈0.05）。结论陶瓷粉尘对作业工人的肺功能有损害作用,且随着接尘工龄的增加肺功能受损害程度增加。     

小气道功能测定在粉尘作业人员职业健康监护及风险评估中的应用

[目的]了解粉尘作业对员工呼吸功能的影响,探讨小气道功能测定在粉尘作业人员职业健康监护及尘肺风险评估中的应用。[方法]2009年对某机械制造企业粉尘作业车间进行生产环境调查、粉尘浓度检测,对216名粉尘作业人员进行肺功能测定等职业健康检查及问卷调查。[结果]粉尘作业人员用力呼气75％肺活量的瞬间流量（forcedexpiratoryflowat75％offorcedvitalcapacity,FEF75％）的中位数为79％,低于正常值,用力肺活量（forcedvitalcapacity,FVC）、第1秒用力呼气容积（forcedexpiratoryvolumeinonesecond,FEV1）、1秒率（FEVl／FVC）、最高呼气流量（peakexpiratoryflow,PEF）、用力呼气25％肺活量的瞬间流量（forcedexpiratoryflowat25％FVC,FEF25％）、用力呼气50％肺活量的瞬间流量（forcedexpiratoryflowat50％ofFVC,FEF50％）的均数或中位数都在正常范围内,PEF、FEF25％、FEF50％和FEF75％异常的人员比例明显增高,分别为21．30％、BO．56％、45．37％和50．00％,而且这些参数异常人员接尘工龄较短,中位数分别为3．5年、4年、5年和5年。FVC、FEV1、FEV1／FVC、PEF、FEF25％、FEF50％、FEF75％异常人员的胸片检查异常比例分别为55．56％、60％．00、0、21．74％、15．15％、23．47％、25．00％。将胸片异常组与正常组的肺功能进行比较,胸片正常组的PEF、FEF25％、FEF50％的参数值低于异常组,差异有统计学意义（P〈0．05）。工龄10年以上的粉尘作业人员FEV1、FEF25％和FEF75％异常比例高于工龄较短组（P〈0．05）。[结论]粉尘作业人员存在气流受限、小气道功能障碍。随着接尘工龄的增加,FEV1、FEF25％和FEF75％异常人员有增多的趋势。该人群肺功能检查结果与胸片表现并不同步。在职业健康监护工作中,应对粉尘作业人员的肺功能尤其是小气道功能进行重点观察和动态对比分析,并将其作为尘肺风险评估的指标之一。建议在职业健康检查中将FEF25％、FEF50％、FEF75％等反映小气道功能的参数增设为监测指标。     

Spirometric function in non-smoking workers exposed to aluminum

BACKGROUND: Exposure to aluminum (Al) causes the onset of respiratory disorders. This study is aimed at providing further information on how occupational exposure to Al affects the respiratory apparatus in healthy non-smokers, with particular attention to respiratory function. METHODS: A group of 50 male shipyard workers who were exposed to Al underwent medical examination, standard chest X-rays and spirometry in accordance with the C.E.C.A. protocol. The data were compared with those of a homogeneous group of controls, all with blood aluminum (AlB) levels below 7.5 ng/ml. Statistical analysis was performed on the following spirometric parameters: vital capacity (VC), forced vital capacity (FVC), maximum forced expiratory volume in 1 s (FEV1), and mean forced expiratory flow during mid-half of FVC (FEF(25-75%)). Environmental Al levels were also measured at the various workstations. RESULTS: Fifty male workers with an average age 31.82 +/- 5.05 years, occupational exposure of 11.81 +/- 3.71 years, presented with average AlB levels of 32.64 +/- 8.69 ng/ml. Environmental monitoring displayed Al levels higher than TLV TWA for all the workstations studied. None of the sample displayed significant pathological conditions. Statistical comparison of the spirometric parameters showed a decrease in the examined values in exposed workers. This decrease was found to be directly proportional to the AlB level. CONCLUSION: The authors conclude that Al affects respiratory function and that limit values should be reassessed.     

A longitudinal study of lung function in jute processing workers.

A 5-y follow-up study of pulmonary function was conducted in 1982 and in 1987 for 50 current and retired jute-processing workers who had been employed for more than 10 y in a jute mill in China. Control subjects, who had no history of dust or gas exposure, were selected from a paper-packing plant in the same city. Forced expiratory maneuvers were conducted in the same manner in both 1982 and 1987. The jute workers' pulmonary functions, i.e., forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1.0), and forced expiratory flow (FEF25-75%), were more compromised than were pulmonary functions in the controls for the same 5-y period; however, only the increased incidence of abnormal FEV1.0s in jute workers was statistically significant. Male jute workers had significantly higher annual decrements of FVC, FEV1.0, and FEF25-75% than did control workers. Regression analysis indicated that in 1987, predicted values of FEV1.0 and FEF25-75% for the jute workers were related to years of employment. Our results suggest that long-term exposure to jute dust could produce chronic loss of lung function.     

A longitudinal follow-up of pulmonary function and respiratory symptoms in workers exposed to manganese

The purpose of the investigation was to study the effects on the respiratory system in mine workers with long-term exposure to manganese (Mn) in the workplace. The study included a follow-up of pulmonary function and respiratory symptoms among 145 workers employed in a large Mn mine and 65 matched controls, and the assessment of Mn concentrations in environment and biological samples. Lung function was measured by recording spirometric parameters. The Mn-exposed workers reported more respiratory symptoms and a significantly higher prevalence of all grades of pulmonary function impairment. All predicted symptoms except for asthma increased significantly in the current smoking group compared with the non-smoking group. There was a significant decrease in FEV1, FVC, and FEV1% values in exposed workers compared with controls at stages 2 and 3, with an additive effect of the smoking habit. The Mn concentrations in blood, urine, and hair were significantly higher in the exposed workers than in the controls. The level of cumulative exposure index of workplace Mn was notable and did not change significantly over this study. The respiratory effects found in Mn-exposed workers were probably caused by the Mn in the workplace and the synergistic effect of smoking. These effects indicate a need for respiratory protection and improvements in the work environment.     

Lung function in retired coke oven plant workers.

Lung function was studied in 354 coke oven plant workers in the Lorraine collieries (Houillères du Bassin de Lorraine, France) who retired between 1963 and 1982 and were still alive on 1 January 1988. A spirometric examination was performed on 68.4% of them in the occupational health service. Occupational exposure to respiratory hazards throughout their career was retraced for each subject. No adverse effect of occupational exposure on ventilatory function was found. Ventilatory function was, however negatively linked with smoking and with the presence of a respiratory symptom or discrete abnormalities visible on pulmonary x ray films. The functional values were mostly slightly lower than predicted values and the most reduced index was the mean expiratory flow, FEF25-75%. The decrease in forced expiratory volume in one second (FEV1) was often parallel to that in forced vital capacity (FVC), but it was more pronounced for subjects who had worked underground, for smokers of more than 30 pack-years, and for subjects having a respiratory symptom. Pulmonary function indices were probably overestimated because of the exclusion of deceased subjects and the bias of the participants.     

Prevalence of spirometric abnormalities in a representative sample of the population of Michigan

A random sample of a large industrial state in the United States (Michigan) was studied via respiratory questionnaire, medical history, physical examination, and spirometry: 976 white adults performed a battery of spirometric tests (FVC, FEV1, FEV1/FVC and FEF25-75%). Using predictive equations derived from normal subjects in the survey and defining spirometric abnormality by the lower 95% confidence interval, prevalences of abnormality were greater in those who had a smoking history. When equations derived from normal non-smokers were used, as has been the general practice, 21.3% of men and 18.5% of women with a positive smoking history had an abnormal FEV1 and 26.7% and 17.8% an abnormal FEF25-75%, respectively. Although FVC is thought to be affected little by smoking, mean values were lower and prevalences of abnormal values higher in smokers. Prevalences are also shown using an adjustment for the effect of smoking and using conventional (percent of predicted value) definitions of spirometric abnormality. The prevalences of spirometric impairments in this cross section of a large state should be useful for comparison with other populations under study in North America.     

Lung function in retired coke oven plant workers.

Lung function was studied in 354 coke oven plant workers in the Lorraine collieries (Houillères du Bassin de Lorraine, France) who retired between 1963 and 1982 and were still alive on 1 January 1988. A spirometric examination was performed on 68.4% of them in the occupational health service. Occupational exposure to respiratory hazards throughout their career was retraced for each subject. No adverse effect of occupational exposure on ventilatory function was found. Ventilatory function was, however negatively linked with smoking and with the presence of a respiratory symptom or discrete abnormalities visible on pulmonary x ray films. The functional values were mostly slightly lower than predicted values and the most reduced index was the mean expiratory flow, FEF25-75%. The decrease in forced expiratory volume in one second (FEV1) was often parallel to that in forced vital capacity (FVC), but it was more pronounced for subjects who had worked underground, for smokers of more than 30 pack-years, and for subjects having a respiratory symptom. Pulmonary function indices were probably overestimated because of the exclusion of deceased subjects and the bias of the participants.     

Respiratory health of plywood workers occupationally exposed to formaldehyde

This study was undertaken to enlarge our understanding of the adverse health effects of formaldehyde exposure in the workplace and community environment. The respiratory health status of 186 male plywood workers was evaluated by spirometric tests, respiratory questionnaires, and chest x-rays. Area concentrations of formaldehyde were measured in the work environment and found to range from 0.28 to 3.48 ppm. The average personal exposure was to 1.13 ppm of formaldehyde. Exposure to formaldehyde was associated with decrements in the baseline spirometric values, i.e., forced expiratory volume in 1 sec (FEV1.0), forced expiratory volume/forced vital capacity (FEV/FVC), and FEF25%-75%, and with several respiratory symptoms and diseases, including cough, phlegm, asthma, chronic bronchitis, and chest colds. The results of the study support the hypothesis that chronic exposure to formaldehyde induces symptoms and signs of chronic obstructive lung disease.     

Pulmonary dysfunction in silica-exposed workers: a relationship to radiographic signs of silicosis and emphysema.

BACKGROUND: It has been established that occupational exposure to silica dust may cause significant impairment of pulmonary function. To compare the contribution of silicosis and emphysema to pulmonary dysfunction, radiographic signs of silicosis and emphysema in silica exposed workers were analyzed. METHODS: Two hundred and twenty workers exposed to silica working in a Chinese refractory plant were selected as study subjects. Their findings of silicosis and emphysematous changes on radiograph were classified and evaluated. A questionnaire on respiratory symptoms, smoking, and occupational history was administered. All the workers performed measurements of spirometry and CO single-breath diffusing capacity. RESULTS: Radiographic hyperinflation was detected in 9% of the workers without silicosis and in 33% of the workers with silicosis. Silicosis was significantly associated with hyperinflation after adjusting for exposure duration, age, and smoking. Respiratory symptoms were more frequent in the more severe cases of silicosis. Regression analysis showed that silicosis was significantly associated with decreases in the parameters of pulmonary function, but the significance disappeared when the hyperinflation term was added to the models. Radiographic hyperinflation was strongly associated with decreases in FEV1 and FEV1/FVC while relevant factors were controlled. Comparison between workers with and without hyperinflation showed that the former had significantly lower pulmonary function values. CONCLUSIONS: The results suggest that emphysema associated with silicosis is likely to be responsible for pulmonary obstruction and decreased diffusing capacity occurring in silica-exposed workers.     

A follow-up study of respiratory function in workers exposed to acid aerosols in a food-processing industry

A follow-up investigation was performed on 49 female workers studied 2 years earlier in a vegetable-pickling plant. Acute and chronic respiratory symptoms and ventilatory capacity measurements were recorded during the original and the follow-up studies. Maximal expiratory flow-volume (MEFV) curves were recorded during the Monday morning work shift. The forced vital capacity (FVC), 1-s forced expiratory volume (FEV1), and flow rates at 50% and the last 25% of the FVC (FEF50, FEF25) were measured. There were small increases in the prevalence of chronic symptoms between the two studies for both smokers and nonsmokers, but these did not reach statistical significance. Five workers at the time of the initial study had a diagnosis of occupational asthma; only one of these was still working at the time of follow-up. Workers lost to the follow-up had lower lung function than those seen at follow-up. In workers who were followed, larger than expected mean annual declines were noted for all ventilatory capacity parameters in both smokers (FVC 0.070 l, FEV1 0.070 l; FEF50 0.355 l/s, FEF25 0.270 l/s) and nonsmokers (FVC 0.045 l, FEV1 0.045 l, FEF50 0.285 l/s; FEF25 0.130 l/s). The decrease was particularly pronounced for FEF50 and FEF25. The accelerated decline in ventilatory capacity tests noted in the female nonsmokers suggests an independent effect on lung function of work exposure in this environment. Our data confirm that work in the pickling industry, particularly in small, poorly regulated plants, has deleterious effects on respiratory function. Received: 24 September 1996 / Accepted: 19 June 1997     

A cross-sectional study of pulmonary function in autobody repair workers.

This study evaluated pulmonary function in workers from 39 autobody repair shops. Based on 152 White male workers with known smoking status, the mean percent predicted FEV1, FVC, and FEV1/FVC were 93.6, 96.8, and 96.6, respectively. Twenty-three percent of workers had a FEV1/FVC ratio less than the fifth percentile. Isocyanate levels ranged from nondetectable to 0.06 parts per million (STEL = 0.02 ppm). No shop had an adequate respiratory protection program. We concluded that there was an increase in abnormal pulmonary function in autobody workers. Three recommendations were made to shop owners: functional paint booths should be maintained, respiratory protection programs should be developed, and isocyanate-free paints should be used.     

Ventilatory function among metal workers in Singapore

The ventilatory function of 634 workers in small scale metal working industries was evaluated. Almost five percent (4.7%) of the workers were found to have FEV1.0/FVC ratio of less than 75%. Compared with the lung function of industrial workers reported by Zee, 10.9% were found to have low ventilatory function. Comparison of the ventilatory function obtained from the metal workers with those of occupational groups previously reported shows that the metal workers have lower FVC and FEV1.0 values. Mid and end expiratory flow rates were also measured. These measures have been shown to be very sensitive in detecting obstructions in small airways. It is recommended that future studies should be carried out to obtain ventilatory functions for the normal population. The values reported here of FEV25%-75% and FEF75%-85% would be useful for future investigations in forced expiratory flow rates.     

惠州市某区宝石加工作业工人肺功能测定分析

目的了解惠州市某区宝石加工作业工人的肺功能损害情况。方法 2009年7月惠阳区疾病预防控制中心对该区宝石加工厂接尘工龄1a以上的214名男工进行肺功能测定,其中切石工人127例,打磨工人87例;另选择该厂的61名非接尘男工作为对照组;并对宝石加工厂空气中粉尘浓度进行测定。结果该宝石加工厂空气中矽尘浓度超标率超过77%,最高超标为9倍。矽尘中游离SiO2含量平均为47.29%。接尘组肺通气功能的异常率显著高于对照组(P0.01),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(P0.01)。结论该宝石加工作业粉尘可致工人肺功能一定程度的损伤,应做好预防工作。     

蔺草染土粉尘对工人肺功能的影响

[目的 ]了解蔺草染土粉尘对接触工人肺功能的影响。 [方法 ]随机选择接尘工龄 1年以上的工人作为调查对象 ,并选择无明显粉尘和毒物接触的工人作为对照 ,进行肺功能测定。 [结果 ]粉尘接触者肺功能各项指标明显低于对照组 ,FVC、FEV1.0 的异常检出率显著高于对照组。不吸烟者肺功能损伤程度与接触粉尘密切相关。 [结论 ]结果提示蔺草染土粉尘对工人肺功能有明显损伤 ,FVC、FEV1.0 、FEV1.0 %等可作为肺功能评价的首选指标     

Ventilatory function in rubber processing workers: acute changes over the workshift.

When considering rubber tyre manufacturing from an occupational health viewpoint, three areas may be identified in which exposure to respirable materials are potentially harmful: the processing, curing, and talc areas. A study of the ventilatory function of the entire work force employed in the processing area in a rubber tyre manufacturing plant was undertaken to determine whether an acute reduction in lung function occurs over the course of their working shift (the plant worked a three shift system) and whether a chronic exposure to the occupational airborne contaminants causes permanent changes in lung function. The ventilatory function was measured at the worksite at the beginning and immediately after the end of the workshift. No evidence of chronic obstructive pulmonary disease was found and in most cases no significant decline in FEV1 was observed. Only one of the 79 individuals showed a moderate obstruction, measured by the ratio FEV1/FVC which gave the value of 0.55, with no variation over the shift. For non-smokers, the FVC, FEV1, and FEF25-75% were lower in those exposed for more than five years than in those exposed for five years or less. A similar pattern was also observed in the FVC and FEV1 of the smokers. None of these differences was statistically significant. Within each exposure group the pulmonary function of the smokers was lower than that of the non-smokers, but the only significant difference was found in the values of FEF25-75%. Only one man showed a decline in the FEV1/FVC ratio over the shift, but during each shift, a decrease in all the lung function tests was observed. The decrease was smallest during the first of the three shifts. These results are thought to support the hypothesis that there are acute adverse effects over an eight hour shift. Further investigations are needed to discover whether these acute changes in lung function result from a chemical stimulation or irritant receptors in the airways.     

某陶瓷企业接尘工人肺功能分析

目的 了解某陶瓷企业粉尘对工人肺功能的影响，为尘肺防治提供科学依据。方法对147例陶瓷生产工人和50名对照组分别进行肺功能测定。结果 肺通气功能测定显示暴露工龄5a～组和10a～组VC、FVC、PEF、FEF 75％明显低于对照组，10a～组FEV，低于其他3组，暴露组FEF25-75、FEF25%。明显低于对照组。暴露组肺通气功能和小气道通气功能异常率高于对照组，其中10a～组与对照组的差异有统计学意义。结论 粉尘对该企业接尘工人的肺功能有危害，且随着工龄增加损伤程度加重。     

Obstructive and restrictive ventilatory impairment in polyvinylchloride fabrication workers

Responses to a standardized respiratory symptom questionnaire, spirometry, and cross-shift decreases in lung function between 70 current employees of a polyvinylchloride (PVC) fabrication plant and a control group consisting of 48 men employed in a vegetable packing plant were compared. FEV1/FVC was significantly lower in the PVC workers. Cross-shift drops in Vmax75 of 15% or more were also more prevalent in the exposed group (p = .01). When examining the association between months of work within the exposed workforce and spirometric indices of airway obstruction, no relationship could be demonstrated. However, an inverse dose-response relationship was seen between level of FVC and duration of employment, suggesting a restrictive impairment. While the specific exposures have not been identified, it appears that employment in PVC fabrication may be associated with both obstructive and restrictive ventilatory effects.