Exposure and acute exposure-effects before and after modification of a contaminated humidification system in a synthetic-fibre plant

Objective: Follow-up study of exposure and acute exposure-effects after modification to steam humidification of a contaminated cold water system which had caused an outbreak of humidifier fever in a synthetic-fibre plant. Methods: Before and after modification of the system aerobiological measurements were performed. Concentrations of fungi and bacteria, in colony forming units (cfu) per m³, were measured by stationary air sampling with an Andersen sampler. Endotoxin levels (pg/m³) were determined by Limulus Amoebocyte Lysate (LAL) assay in pooled dust from personal air sampling. An indication of exposure levels of oil-mist was obtained by monitoring with a direct reading optical photometer. Changes as acute exposure-effects in spirometry and white blood cell count, during an afternoon shift were compared in exposed and non-exposed workers before and after modification. Results: Measured levels of fungi, total bacteria, Gram-negative bacteria and endotoxins both before and after modification were below levels which would be expected to be associated with the exposure-effects. However, after modification, we found that the statistically significant differences in levels of bacteria and endotoxins with a department without humidification no longer existed. Mean oil-mist concentrations were below 1 mg/m³, with short-time peak exposure during certain tasks of up to 5 mg/m³. Before modification, in exposed workers there was significantly more decline of spirometry, and more increase of white blood cell count during the first afternoon shift, compared with non-exposed workers. In exposed workers, the white blood cell count increase was positively associated with decline of spirometry. After modification, differences between exposed and non-exposed workers no longer existed. Conclusion: Follow-up investigation of acute exposure-effects demonstrated the effectiveness of remedial actions taken against a contaminated humidification system. Follow-up of exposure-effects in particular is recommended when there is doubt about the interpretation of exposure measurements. Received: 27 January 1999 / Accepted: 22 January 2000     

Follow-up study of workers in a nylon carpet yarn plant after remedial actions taken against a contaminated humidification system

Objective: To investigate the effectiveness of remedial actions taken against a contaminated humidification system, after an outbreak of humidifier disease in a nylon carpet yarn plant. Methods: Two and 6 years after modification, a follow-up investigation of a stratified (age, smoking habits) sample of exposed (n=75) and non-exposed (n=56) workers was carried out. Outcome-parameters were: respiratory symptoms, spirometry, skin tests and serology with various humidifier fungi. In addition, the yearly incidence of work-disability because of chronic respiratory disease during the 2 years before, and 11 years after the modification was compared. Results: At follow-up, exposed workers, who remained at the same workplace no longer had significantly more frequent chronic respiratory symptoms. The prevalence of positive serology was still higher (P < 0.05) in exposed workers after 2 years, but at the 6 year follow-up investigation, the difference was no longer significant. Prevalence of positive skin tests after 2 years no longer differed from that of the non-exposed workers. Slopes (ml/years) of the graphs of forced vital capacity (FVC) and one-second forced expiratory volume (FEV₁) during the 6 year follow-up after the first investigation did not differ between exposed and non-exposed workers, both before and after adjustment for age, smoking habits and results of skin tests and serology before modification. Before modification, exposed workers with a positive late skin test had a lower FVC than non-exposed workers. After 6 years of follow-up their FVC was still lower, but the difference was no longer significant. There were no indications of selective loss to follow-up. After remedial actions no new cases of humidifier disease occurred. Moreover, the yearly incidence of work-disability in this plant because of chronic respiratory disease, decreased from 1.30% to 0.27% compared with a decrease from 0.30% to 0.12% in other synthetic fibre plants. Conclusion: Follow-up investigation of exposure-effects demonstrated the effectiveness of remedial actions taken against a contaminated humidification system. Received: 27 January 1999 / Accepted: 22 January 2000     

Impact of spirometry feedback and brief motivational counseling on long-term smoking outcomes: A comparison of smokers with and without lung impairment

Objective

We compared long-term outcomes among smokers with and without impaired lung functioning who received brief counseling highlighting their spirometric test results.

Methods

Participants in this analysis all received a brief motivational intervention for smoking cessation including spirometric testing and feedback (∼20 min), were advised to quit smoking, offered free access to a phone-based smoking cessation program, and followed for one year. Outcomes were analyzed for smokers with (n = 99) and without (n = 168) impaired lung function.

Results

Participants with lung impairment reported greater use of self-help cessation materials at 6 months, greater use of non-study-provided counseling services at 6 and 12 months, higher 7-day PPA rates at 6 months, and were more likely to talk with their doctor about their spirometry results.

Conclusion

Further research is warranted to determine if spirometry feedback has a differential treatment effect among smokers with and without lung impairment.

Practice implications

It is premature to make practice recommendations based on these data.     

The FEV1/FEV6 ratio is a good substitute for the FEV1/FVC ratio in the elderly.

AIMS: To determine the agreement between the FEV1/FEV6 ratio and the FEV1/FVC ratio in an elderly population. METHOD: The study sample consisted of 3874 participants in a cross-sectional population survey in Troms?, Norway, aged 60 years or more, in whom acceptable spirometry had been obtained. Mean differences between the FEV1/FEV6 ratio (%) and the FEV1/FVC ratio (%) were calculated according to age, sex, smoking habit, and the degree of airflow limitation. ROC-curve analysis and Kappa-statistics were used to estimate the utility of the FEV1/FEV6 ratio in predicting an FEV1/FVC ratio < 70%. RESULTS: The mean difference between FEV1/FEV6% and FEV1/FVC% was 2.7% in both men and women. The difference between the two measures increased somewhat with increasing age, and was more pronounced with smoking and decreasing FEV1/FVC ratio. The value for the FEV1/FEV6 ratio which best predicted an FEV1/FVC ratio of 70%, was 73%, and a very good agreement was found between these two cut-off values (kappa = 0.86). CONCLUSION: The FEV1/FEV6 ratio appears to be a good substitute for the FEV1/FVC ratio in an elderly population.     

第6秒用力呼气量在肺功能评价中的临床意义

用力肺活量(FVC)和第1秒用力呼气量是用来诊断与鉴别诊断阻塞性和限制性通气功能障碍的两个重要指标.近几年来的研究显示第6秒用力呼气量能很好地替代FVC,不仅能减少患者呼气时间,降低因呼气延长诱发呼吸困难的风险,使患者更易配合完成合格的测定,同时还能提高气道阻塞高危因素受试者的检出率,为早期诊断和治疗提供可能.     

肺活量的动态测定和比较

本文介绍了肺活量测试的常规参数和测量方法，分析了传统测量方法的局限，提出了动态测量和比较的基本思路和实现方法。     

10 Years After EPISCAN: A New Study on the Prevalence of COPD in Spain—A Summary of the EPISCAN II Protocol

Introduction

The EPISCAN study, published in 2007, was an update of the results of the 1997 IBERPOC study. Changes in demographics and exposure to risk factors demand the periodic update of prevalence and determining factors in COPD. This article is a summary of the protocol and tools used in EPISCAN II.

Respiratory impairment due to asbestos exposure in brake-lining workers

There is extensive evidence that exposure to asbestos causes pulmonary parenchymal fibrosis, pleural disease, and malignant neoplasm in asbestos-exposed workers. However, few data concerning brake-lining workers are available in the literature. In this study, we aimed to assess the long-term effects of chrysotile asbestos exposure on lung function and the risk of asbestos-related diseases in brake-lining workers. Seventy-four asbestos-exposed workers who processed brake-lining products and 12 unexposed office workers were offered pulmonary function tests (spirometry and transfer factor) in 1992 and 1999. In 1999, the mean duration of asbestos exposure was 10.00+/-4.07 and 11.02+/-4.81 years (7-31 years) in nonsmoking and smoking asbestos workers, respectively. Transfer factor (T(L), CO) and transfer coefficient (K(CO)) decline were significant in the 7-year follow-up in both smoking and nonsmoking asbestos workers. However, lung function indices of the control group, whom were all current smokers; were also found to be decreased, including FEF(75), T(L), CO and K(CO). We found minimal reticular changes in 10 asbestos workers who were all current smokers, they underwent high-resolution computed tomography scans of the chest and we found that they had peribronchial thickening resulting from smoking. As a conclusion, even in the absence of radiographic asbestosis, T(L), CO and K(CO) may decrease after a mean 10-year duration of exposure to asbestos in brake-lining workers and this is more noticeable with cigarette burden.     

Central airways stenosis in school-aged children: differential diagnosis from asthma

This study assessed the value of spirometry and chest X-rays in the diagnosis of airways stenosis in the tracheal or laryngeal regions at school age. A series of 14 patients was studied. Six of them had vascular ring anomalies, four subglottic stenosis, two aberrant innominate artery, one tracheal stenosis and one a laryngeal web. Four patients were suffering from chronic cough and ten from dyspnoea, noisy breathing and cough upon physical exercise. Two had had their symptoms since infancy and five since 3-6 y of age, whereas seven had had their first symptoms at school age. Nine patients had previously been suspected of having asthma, and five of them had been using inhaled corticosteroids, one inhaled sodium cromoglycate and one peroral terbutaline without any effect. The ratio of forced expiratory volume in 1 s (FEV 1 ) to peak expiratory flow (PEF) was abnormally high in most of the patients. All six children with vascular ring anomalies also had an abnormal aortic configuration on a chest X-ray, and narrowing of the trachea was seen in two of the four with subglottic stenosis. Two children had both chest X-rays and spirometry values within the normal limits.

Conclusion: The results show that children with stenosis in the laryngeal or tracheal region may not have their first symptoms until school age. Many patients are falsely suspected of having asthma. Simple spirometry and chest X-rays will help the physician to make the correct diagnosis in these patients.