Lung function in workers exposed to soft paper dust

In a cross-sectional study, 13 nonsmoking men with heavy exposure to paper dust were compared with 14 unexposed men, mainly office workers, employed at the same paper mill. They were studied using questionnaires, physical examinations, pulmonary function studies, and chest radiographs. Among those exposed there was an increased lung elastic recoil pressure (Pel) compared with controls which was significant (p less than 0.05) at the maximal level of total lung capacity (100% TLC). Furthermore, among the exposed workers there was also a significantly (p less than 0.05) decreased residual volume (RV). Two of the exposed men underwent lung biopsies, one of which showed fibrotic alveolar walls. Among the exposed there was also a significant (p less than 0.05) predominance of symptoms from the lower respiratory tract. We suggest that the observed pulmonary function impairment taken together with the histological examination of the lung biopsies are signs of a nonspecific reaction to high levels of paper dust.     

某火力发电厂接触煤尘工人肺通气功能测定分析

本文通过对某火力发电厂２４８名接触低浓度煤尘的工人进行肺通气功能测定分析,发现即使接触低浓度煤尘,无论对男性还是女性,都可造成肺通气功能一定程度的损伤,ＶＣ值低于对照组（Ｐ〈０．０５）;接尘工人吸烟可使肺通气功能损伤程度加重,ＶＣ、ＦＶＣ、ＦＥＶ１及ＦＥＶ１／ＦＶＣ％值均低于对照组（Ｐ〈０．０５）。另外,接尘工人的肺通气功能操作有随接尘工人工龄的延长而加重的趋势。     

Incidence of cancer among workers exposed to vinyl chloride in polyvinyl chloride manufacture

Based on results from two previous studies where an excess of melanomas was found in a cohort of workers exposed to vinyl chloride (VCM), a follow up of the incidence of cancer in the same cohort of 428 workers was carried out to scrutinise whether or not the excess could be confirmed by new cases. The total number of deaths in the study group from 1953 to the end of 1993 was 132 v 141 expected, and the total number of incident cancer cases was 56 v 57 expected. There were 11 cases of lung cancer v eight expected, seven cases of melanomas v 2.07 expected, and two cases of thyroid cancer v 0.34 expected. Five of the seven melanoma cases had occurred in the group that had been most heavily exposed to VCM v 0.7 expected. In the present follow up we also found five cases of the spinocellular cancer of the skin v 1.7 expected. Out of these five cases four were diagnosed after 1984. Two of the five cases v 0.7 expected had occurred in the most heavily exposed group. The total number of skin cancers (melanomas and spinocellular cancers) were 12 v 3.7 expected. There was one new case of melanoma between 1985 and 1993 v 0.7 expected. Hence, the strength of the relation between the observed and expected number of cases was reduced compared with the last follow up, and does not strengthen the previously indicated causal relation between exposure to VCM and development of malignant melanoma. There was no excess of testicular cancers in this study. The present results may indicate that occurrence of spinocellular skin cancer could bear some relation to work in the manufacture of polyvinyl chloride (PVC). Confirmation is needed from studies on other cohorts exposed to VCM.


Keywords: cohort study; aetiology; exposure; melanomas; spinocellular cancers     

Ventilatory function in workers exposed to tea and wood dust.

Changes in ventilatory capacity during the work shift were studied in workers exposed to tea dust in tea-packing plants, wood dust in two furniture factories, and virtually no dust in an inoperational power station. The FEV1 and FVC in workers exposed to dust were found to decline during the work shift by a small but significant volume. The MMFR, Vmax 50% and Vmax 75% were to variable to display any trend. No dose-response relationship could be discerned between the fall in workers' ventilatory capacity and the concentrations of airborne dust or microbes to which they were exposed. Bronchodilators could reverse the fall in FEV1.     

Lung disorders of workers exposed to rush smear dust in China

The aim of this study was to evaluate the lung disorders of the workers exposed to rush smear dust. A cross sectional study was carried out on 1,709 current workers (788 male, 921 female) in 80 factories. All subjects were asked by questionnaire, and health examination including chest X-ray was conducted for 661 workers in 35 factories. Lung function test was also examined for 119 non-smoking males among 661 subjects. Dust samplings were collected and total and respirable dust concentrations at 127 spots in 35 factories were measured. The geometric mean dust concentration in the workshops was up to 20.00 mg/m(3), and the geometric mean respirable dust concentration reached 8.22 mg/m(3). The mean quartz concentration of accumulated dust was 29.2%. The prevalence of radiographic small opacities profusion category > or = 1/0, according to the ILO 1980 Classification System, was 2.6% among 661 employees. One worker was found to have pneumoconiotic findings of 2/2 profusion accompanied with large opacity. The prevalence of pneumoconiosis (1/0 or more) correlated with cumulative dust exposure (r=0.192, p<0.0001). The similar relationship was found between the prevalence rate of cough or sputa and worksite dust concentration. In non-smokers, a positive association was found between the prevalence of cough and occupational exposure duration (r=0.080, p=0.004). Approximately 19.3% and 34.5% of employees suffered from respiratory impairment for FVC and FEV1.0, respectively. This is the first report of "rush" pneumoconiosis in China. Rush mat workers were found to be at high risk for pneumoconiosis, a preventable disease. Our results showed a dose-response relationship between rush-mat dust level and the prevalence of pneumoconiosis. Similar relationship between the prevalence of cough and sputum and the work duration was found for non-smoking workers but not for smoking workers.     

Pulmonary effects of polyvinyl chloride dust exposure on compounding workers

Spirometry, chest radiography, environmental measurements, and a questionnaire on respiratory symptoms were used to evaluate the effects of exposure to polyvinyl chloride (PVC) dust on 171 Chinese and Malay PVC compounding workers in comparison with an unexposed reference group. Workers with high cumulative PVC dust exposure had a lower forced expiratory volume in 1 s and forced vital capacity, and a higher prevalence of radiological profusion of small opacities. Wheezing or chest tightness was also significantly more frequent in this group. Unlike previous studies, the PVC compounding workers in this study were exposed to only negligible amounts, if any, of vinyl chloride monomer or thermal degradation products of PVC such as hydrogen chloride, phosgene, or chlorine. The conclusion was drawn that a low grade of pneumoconiosis and a small degree of lung function impairment is associated with PVC dust exposure. Reversible airways obstruction is also likely and warrants further investigation.     

Liver function assessment in workers exposed to vinyl chloride

Objective: To investigate liver function in vinyl chloride workers and assess its relation with current/past occupational exposure to vinyl chloride monomer (VCM). Methods: A medical examination including the execution of liver function tests (LFTs) and liver ultrasonography was executed in a group of 757 workers with a long-standing service in the production of VCM/polyvinylchloride (PVC). Cumulative and maximum VCM exposures were calculated. History of viral hepatitis and alcohol intake were carefully investigated. Regression analysis explored the association between abnormal LFTs and a group of possible determinants (VCM cumulative and maximum exposure, BMI, age, history of viral hepatitis, alcohol and triglyceride levels). Also, synergistic effect between VCM and a history of hepatitis was analysed, as well as the possible association between VCM exposure and aspartate aminotransferase/alanine amino transferase (AST/ALT) ratio >1. Distribution of abnormal LFTs was also assessed in relation to the results provided by liver ultrasonography. Results: The most frequently abnormal serum parameters were, in decreasing order: total cholesterol (27.3%), triglycerides (12.2%), total bilirubin (9.1%), gamma glutamil transpeptidase (GGT; 9.0%) and ALT (8.2%). The AST/ALT ratio >1 was present in 28.1% of workers. Abnormal LFTs were not found to be associated with current or past VCM exposure. High ALT resulted positively associated with BMI, AST with alcohol intake, GGT with alcohol intake and triglycerides. No synergistic effect on LFTs of exposure to VCM and a history of hepatitis was observed. The AST/ALT ratio >1 was not found to be associated with VCM exposure. The prevalence of abnormal LFTs was higher in case of liver steatosis (ALT) or periportal fibrosis (GGT), but not in case of pure hepatomegaly, as documented by ultrasonography. Conclusions: Liver function assessment only including LFTs is not able to detect VCM-induced liver damage, but reveals alterations due to non-occupational factors, such as dietary and/or metabolic disfunctions. The LFTs are however of importance to detect conditions that could recommend avoidance of exposure to VCM and are useful for medical counselling and health promotion purposes.     

Ventilatory function of factory workers exposed to tea dust

The Acknowledgement section should have read: ‘The guidanceprovided by the late Professor S. Balasuriya, the support byDr D. Bandara of the Janatha Estates Development Board, theassistance provided by the two Radiologists, Dr C. G. Uragodaand Mrs P. Amarasinghe and the secretarial assistance of MsPadmini Angunawala, Priyani Jayawickrema and M. Sugathapalaare gratefully acknowledged’.     

Ventilatory function of factory workers exposed to tea dust

A cross-sectional study was conducted in order to determinethe prevalence of respiratory symptoms and the effect on ventilatorycapacity in workers exposed to tea dust for at least five yearsduring the sifting process of tea manufacture compared to acontrol group of field workers who were not exposed to tea dustpreviously. Fifty-three subjects each in the study and controlgroups were matched for age, sex, ethnic group and height. Prevalenceof chronic respiratory symptoms was obtained by questionnaire.Spirometric measurements included forced vital capacity (FVC),forced expiratory volume in the first second (FEV_1.0) and forcedmid-expiratory flow rate (FEF_25–75%). The study grouphad a chest radiograph. The odds ratio for any chronic respiratorysymptom was 11.6 (95% confidence interval [Cl] = 3.7–39.4)in the study group. Mean values for the spirometric tests werelower in the study group; the differences in FEV_1.0 and FEF_25–75%were significant. Tuberculosis was not found in the study group,while one subject (2.4%) had radiological evidence of bronchiectasis.It may therefore be concluded that chronic tea dust exposurecauses increased prevalence of respiratory symptoms and a significantdegree of small airways obstruction.     

Mortality experience of workers exposed to vinyl chloride monomer in the manufacture of polyvinyl chloride in Great Britain.

Identification particulars were obtained for over 7000 men who were at some time between 1940 and 1974 exposed to vinyl chloride monomer in the manufacture of polyvinyl chloride. Approximately 99% of these men have been traced and their mortality experience studied. The overall standardised mortality ratio, 75-4, shows a significant reduction compared with the national rates. Four cases of liver cancer were found. Two of these have been confirmed by a panel of liver pathologists as angiosarcoma and two as not angiosarcoma. There is no evidence to support the hypothesis that cancers other than those of the liver are associated with exposure to vinyl chloride monomer. The two cases of angiosarcoma were found in men who had been exposed to high concentrations of the monomer although the second man died only eight years after first exposure. The industry in Great Britain has expanded considerably since the second world war with over 50% of men having entered with the last decade. Conclusions drawn about the effect of vinyl chloride monomer on the mortality experience of men in this industry must consequently be tempered by the reservation that the full impact may not yet be in evidence.     

Lung cancer risk in workers exposed to poly(vinyl chloride) dust: a nested case-referent study

Background: There have been few investigations of an association between poly(vinyl chloride) (PVC) dust exposure and an increase in lung cancer incidence, and their conclusions have been inconsistent.

Aims: To determine whether PVC and/or vinyl chloride monomer (VCM) is the associated risk factor(s), by means of a nested case-referent study, in order to estimate lung cancer risk, avoiding selection, information, or confounding biases.

Methods: Thirty eight cases of histologically verified lung cancer and 224 control subjects without a history of cancer were selected from an Italian cohort of 1658 vinyl chloride workers. Information sources included clinical records (diagnosis, smoking habits) and plant records (occupational history). The risk of lung cancer was estimated by odds ratios (OR) with 95% confidence intervals (CI), calculated using logistic regression models.

Results: In PVC baggers exposed to high levels of respirable PVC particles in the workplace, the lung cancer OR increases by 20% for each extra year of work (OR = 1.2003; 95% CI 1.0772 to 1.3469; p = 0.0010), when the influence of age and smoking habits is controlled. No relation was found between lung cancer and cumulative VCM exposure.

Conclusion: This nested case-control study showed, in the VCM/PVC industry, an increased risk of lung cancer associated with exposure to PVC dust; previous cohort studies failed to recognise such excess, probably because they used VCM exposure as the risk indicator.

     

Lung function of office workers exposed to humidifier fever antigen.

Office workers who became sensitised to antigens derived from humidifier sludge developed episodes of fever, malaise, and other symptoms, including polyuria and mild chest tightness. The episodes usually occurred on a Monday evening and were to some extent dose-related. Lung function was assessed over a day shift on two occasions, including one after which almost all the susceptible subjects developed symptoms. The symptoms were preceded by a 6% reduction in forced expiratory volume and vital capacity, a corresponding increase in residual volume, and a reduction in flow rate after 75% vital capacity had been expired. There were no changes in peak expiratory flow, forced expiratory flow at 50% of vital capacity, or transfer factor. In some subjects the transfer factor was apparently reduced 36 hours later, but for this there may have been another explanation. The physiological features were considered to reflect narrowing of small airways in the lung. The changes, however, were minimal and not the main cause of the symptoms. A feature of the episode was the severity of the constitutional symptoms despite the low airborne dust levels.     

Pulmonary function and intradermal tests in workers exposed to soft-paper dust

A survey was carried out in the processing department of a paper mill, consisting of environmental and personal monitoring, a short questionnaire concerning chronic non-specific lung disease (CNSLD), spirometry, and intradermal tests. Spirometry was performed on Monday, Wednesday, and Friday. Exposures to paper dust regularly exceeded the Dutch Maximal Allowable Concentrations (MACs) for total and respirable dust. There were indications of a qualitatively different exposure to molds inside the mill in comparison with the outdoor air. A comparison between a group of workers exposed to paper dust and a control group showed significantly more persons with positive late and delayed intradermal test reactions in the exposed population. The analysis of the spirometric measurements after correction for differences between the groups in age, height, and smoking habits gave evidence of the existence of lower FEV1, MMEF, MEF50, and MEF25 among exposed workers with a positive immediate intradermal reaction on Friday. The same workers showed a decline in pulmonary function over the week compared with the controls. These changes suggest an obstructive airway reaction with an immunologic mechanism to dust exposure in a paper mill.     

Biliary function in workers occupationally exposed to aluminium dust and fumes

This study investigated biliary secretory function in workers occupationally exposed to aluminium dust and fumes. It included a group of 34 male workers aged (44.1+/-7.8) years and exposed up to 4.6 mg m-3 of aluminium dust and fumes in workplace air for (21.6+/-2.5) years, and a group of 30 unexposed control male workers. Serum and urine aluminium levels were measured in both groups before and after chelating treatment with 1 g deferoxamine by intramuscular injection. Biliary function was assessed by measuring gamma-glutamyl transpeptidase, alkaline phosphatase, 5-nucleotidase, cholesterol and its fractions, total and indirect bilirubin, and bile acids. We then analysed the relationship between Al exposure and biliary function.In the exposed group mean serum aluminium was significantly higher [(4.91+/-3.86) microg L-1] than in controls. The same was true for urine Al before [(1.57+/-1.93) microg L-1] and after deferoxamine [(11.51+/-14.97) microg L-1]. Total and indirect bilirubin and alkaline phosphatase were significantly higher in the exposed than in control workers, and they correlated with urine Al after the chelating treatment.Our findings suggest that chronic occupational exposure to aluminium dust and fumes leads to a significant body retention of aluminium. The impaired biliary secretion in the exposed workers manifested itself in subclinical signs of cholestasis.     

Mortality experience of workers exposed to vinyl chloride monomer in the manufacture of polyvinyl chloride in Great Britain

Identification particulars were obtained for over 7000 men who were at some time between 1940 and 1974 exposed to vinyl chloride monomer in the manufacture of polyvinyl chloride. Approximately 99% of these men have been traced and their mortality experience studied. The overall standardised mortality ratio, 75-4, shows a significant reduction compared with the national rates. Four cases of liver cancer were found. Two of these have been confirmed by a panel of liver pathologists as angiosarcoma and two as not angiosarcoma. There is no evidence to support the hypothesis that cancers other than those of the liver are associated with exposure to vinyl chloride monomer. The two cases of angiosarcoma were found in men who had been exposed to high concentrations of the monomer although the second man died only eight years after first exposure. The industry in Great Britain has expanded considerably since the second world war with over 50% of men having entered with the last decade. Conclusions drawn about the effect of vinyl chloride monomer on the mortality experience of men in this industry must consequently be tempered by the reservation that the full impact may not yet be in evidence.     

Biochemical abnormalities in workers exposed to molybdenum dust.

Exposure to molybdenum in dust was measured in a molybdenite roasting plant. This exposure was accompanied by large elevations of serum ceruloplasmin and smaller increases in mean serum uric acid levels in the workers. Absorption of molybdenum from the dust was demonstrated by increases in plasma and urinary molybdenum levels. It remains necessary to demonstrate whether such exposure results in long-term health effects.     

烟草粉尘对接触工人肺功能损害的调查分析

将接触烟草粉尘的175名男工、126名女工的肺功能指标从多个方面与同一地区非接尘的对照组进行比较.结果 显示不论男女,FVC%、FEV1%,MMEF%、V50%、V25%观察组均低于对照组,差异有统计学意义.观察组MMEF%、V50%、V25%异常个体比率高于对照组,差异有统计学意义.吸烟、专业工龄延长可加重这些变化.     

Respiratory symptoms and pulmonary function in mill workers exposed to wood dust

This study surveyed wood dust exposure levels and pulmonary hazards among wood mill workers. Dust concentrations as measured by six-stage cascade impactors were high in work areas of grinding and screening. Total dust concentrations for these dusty activities ranged from 4.4 to 22.4 mg/m³, and the respirable proportions were between 2.4% and 50.2%. The dust level in the sawing work was 2.9 mg/m³. Although symptoms of cough and phlegm were higher in smoking workers than in nonsmoking workers, the prevalence of respiratory symptoms in the exposed workers was not significantly higher than in the controls. However, the incidence of symptoms such as chronic phlegm and chronic bronchitis in the nonsmoking high-exposure workers was significantly higher than in nonsmoking controls. The mean values of MMF, PEFR, and FEF25% were significantly lower in the exposed workers than in controls for both smokers and nonsmokers. The pulmonary function deficits, with the exception of FEV1.0/FVC, also showed a significant trend with increasing levels of wood dusts exposure classified by job titles for both smokers and nonsmokers. After adjustment for age, sex, height, and smoking status, all parameters of pulmonary function were significantly lower in exposed workers than in controls and showed a declining trend with increasing exposure levels classified by job titles. These results indicate that high level of wood dust exposure in the wood mill industries may lead to pulmonary hazards. Engineering control and industrial hygiene are mandatory for dusty activities. © 1996 Wiley-Liss, Inc.     

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。     

Pulmonary function and symptoms of Nigerian workers exposed to cement dust

The pulmonary and nonpulmonary effects of cement dust exposure in 52 randomly selected, directly exposed cement workers and 24 maintenance workers were investigated. Compared with the nonindustrially exposed population, both subgroups had significantly (P less than 0.001) lower lung function. The lung function of the exposed subjects was probably influenced by the level of physical activity and the level of dust exposure. The more directly exposed cement packers had significantly (P less than 0.05) lower lung function than the less exposed cement loaders. There was no significant difference in the lung function of the directly exposed groups and the maintenance group, but the physically more active cement loaders showed higher lung function values than the maintenance workers. The lung function of the cement workers also decreased with the duration of employment. Cement dust produced significant (P less than 0.001) workshift depression in the lung function of the subjects. The symptoms presented by the subjects were cough and phlegm production, skin irritation, chest tightness, conjunctivitis, catarrh, stomachache, and boils. The prevalence of stomachache among the subjects becomes significant in the light of a finding by other workers of hepatic granuloma in cement workers. The measured dust level in the cement depot was 30.81 mg/m3.