Volume-based tomography for the diagnosis of incipient silicosis in former gold miners.

OBJECTIVE: To evaluate silicosis diagnosed through CT, with integration of clinical-occupational data, in silica-exposed workers presenting chest X-rays within International Labor Organization (ILO) category 0. METHODS: Cross-sectional study with 339 former gold miners, with comparable exposures and X-rays classified as ILO subcategory 0/0 (n=285) and 0/1 (n=54) were submitted to volume-based CT. The findings were classified according to the International Classification of HRCT CT for Occupational and Environmental Respiratory Diseases. RESULTS: A profusion degree of round opacities (RO)>1 was found in 22.4% (76/339) of the CT exams. After integrating the CT findings with clinical and occupational data, silicosis was diagnosed as follows: 43/285 (15.1%) and 14/54 (25.9%) in workers whose X-rays had been classified as 0/0 and 0/1, respectively. There was an upward trend towards longer exposures, reaching 38.9% when working more than 10 years underground and classified as 0/1 (p=0019). Those with presence of RO whose final diagnosis was not silicosis were mainly cases of tuberculosis or 'indeterminate nodules'. Emphysema was found in 65/339 (19.1%), only 5 being detected in the X-ray. CONCLUSION: Volume-based CT proved to be useful in the investigation of silicosis among individuals with a relevant exposure to silica, capturing diagnoses that had not been identified on X-rays. A response gradient of silicosis was showed by CT even in this population with ILO category 0 radiographs. It can be indicated based on quantitative and/or qualitative criteria of occupational exposure, especially considering the possibilities of low CT dosage.

Investigating the association between occupational exposure to asbestos and ovarian carcinoma: results from a pilot study in Germany.

BACKGROUND: The aim of this pilot study was to assess the feasibility of a large-scale epidemiologic investigation elucidating the quantitative association between occupational exposure to asbestos and ovarian cancer in former German asbestos workers. METHODS: Between December 2017 and May 2018, a random sample of one thousand insured woman registered at the health service of a German trade association as formerly occupationally exposed to asbestos were invited to participate in a pilot study. Participation included a phone interview using a standardised questionnaire. The feasibility of the project was evaluated using a priori defined criteria. They included response, number of cases, eligibility of the questionnaire data for exact estimation of asbestos fibre-years, and availability of relevant medical documentation (imaging procedures, medical reports, and histologic materials). RESULTS: The response (17%) was clearly below the intended number of 60%. With six tumour suspects, of which two could be confirmed by medical documents, the number of cases was within the expected range of two to eleven cases. Exact asbestos fibre-year estimations could be performed for 29% of all interviewees, but only for one suspected case. Medical documentation could be collected for only few participants, while no histology reports could be obtained for all cases. Thus, only the feasibility criterion of the expected number of cases was fulfilled. CONCLUSION: The results of the pilot study indicate that the planned project is feasible only to a very limited extent. For further planning of the study, measures to improve recruitment of participants are necessary.

The validity of static lung compliance in asbestos-induced diseases.

BACKGROUND: Pulmonary compliance can be viewed as an indicator of distensibility of the lungs, not only in asbestos-induced pulmonary disorders but also in visceral pleural fibrosis extending into the lung parenchyma. In this study we evaluated static compliance measurements in asbestos-derived diseases, especially in patients with parietal pleura plaques. Lung function analyses, especially static lung compliance, were correlated with high-resolution computer tomography examinations. METHODS: Sixty-three patients with parietal pleural plaques, 10 with visceral pleural fibrosis, 39 with parenchymal pulmonary asbestosis together with parietal pleural plaques, and 42 with parenchymal pulmonary asbestosis together with visceral pleural fibrosis were enrolled in the study. RESULTS: In comparison with patients having only parietal pleural plaques, those having asbestosis and visceral pleural fibrosis showed significant decreases in static lung compliance, diffusing capacity, and vital capacity. Visceral pleural thickening was also associated with significantly reduced FEV(1), MEF(50), and FEV(1)/FVC ratios. Multiple regression analyses indicated that the existence of visceral pleural fibrosis (p = 0.017) is the most important factor accounting for a decrease in static compliance. Reference values of static lung compliance differ notably. In comparison with mean reference values, the sensitivity of detecting reduced lung compliance was calculated to be between 9.7 and 45.5 %. Other respiratory function variables failed to show any significant differences. CONCLUSION: Our data indicate that the measurement of static compliance is not sufficient for early detection of pulmonary function impairment in patients with parietal pleural plaques.

Development of standard digital images for pneumoconiosis.

We developed the standard digital images (SDIs) to be used in the classification and recognition of pneumoconiosis. From July 3, 2006 through August 31, 2007, 531 retired male workers exposed to inorganic dust were examined by digital (DR) and analog radiography (AR) on the same day, after being approved by our institutional review board and obtaining informed consent from all participants. All images were twice classified according to the International Labour Office (ILO) 2000 guidelines with reference to ILO standard analog radiographs (SARs) by four chest radiologists. After consensus reading on 349 digital images matched with the first selected analog images, 120 digital images were selected as the SDIs that considered the distribution of pneumoconiosis findings. Images with profusion category 0/1, 1, 2, and 3 were 12, 50, 40, and 15, respectively, and a large opacity were in 43 images (A = 20, B = 22, C = 1). Among pleural abnormality, costophrenic angle obliteration, pleural plaque and thickening were in 11 (9.2%), 31 (25.8%), and 9 (7.5%) images, respectively. Twenty-one of 29 symbols were present except cp, ef, ho, id, me, pa, ra, and rp. A set of 120 SDIs had more various pneumoconiosis findings than ILO SARs that were developed from adequate methods. It can be used as digital reference images for the recognition and classification of pneumoconiosis.