Prevalence and relation to underground exposure of radiological irregular opacities in South Wales coal workers with pneumoconiosis.

Abstract

A total of 124 coal workers and ex-coal workers receiving disability benefit for coal worker's pneumoconiosis and routinely reattending the Cardiff Pneumoconiosis Medical Panel during a 10-week period were studied. Those with complicated pneumoconiosis were excluded. Their current chest radiographs and their chest radiographs at the time of certification were read in random order by three readers using the 1980 ILO Classification of Radiographs. An irregularity score was derived from the readings. The x-ray findings were examined for changes since certification and for relationships with age, smoking, and underground coal work exposure. One-fifth of the current radiographs showed mainly irregular opacities, whereas nearly all of those from the time of certification showed mainly rounded opacities. Irregular opacities were related to age, smoking, and underground exposure. The exposure effect remained after excluding the older men. The findings suggest that radiological irregular opacities, and their associated pathology and lung function changes, commonly develop in coal workers with pneumoconiosis and should be considered part of the condition.There has recently been increasing interest in the importance of radiological small irregular opacities in coal workers. Coal workers with irregular opacities have reductions in ventilatory capacity' 2 and gas transfer factor3 4 compared with those with rounded opacities only. Postmortem surveys have shown more emphysema and interstitial fibrosis in coal workers with irregular, rather than only rounded, opacities.' 3 The frequency of irregular opacities among men with simple coal workers' pneumoconiosis is not known, however. There is also the question of whether they are an integral part of simple coal workers' pneumoconiosis. It may be argued that coal workers with irregular opacities are rare overall but tend to undergo special investigations and be included in studies, also that irregular opacities are not uncommon in other lung conditions and may be present only co-incidentally in coal workers. Studies on the

Lung Disease Caused by Exposure to Coal Mine and Silica Dust

“…The clinical features of the disease have been described in coal miners. 29,[33][34][35] It is associated with irregular opacities on the chest radiograph, 36,37 diffusion impairment (low DLCO), hypoxemia, and a restrictive pattern on pulmonary function testing. 34,35 It may have clinical, radiological, and functional characteristics mimicking IPF.…”

“…[33][34][35] The category of irregular opacities correlates with dust exposure. 36,37 Pathologically the interstitial fibrosis takes two major forms. The most common is a bridging fibrosis between the nodular and macular lesions of CWP or silicosis 29 (Fig.…”

“…46 Silica exposure is also considered to play a role in the accelerated form of PMF in coal miners with rheumatoid disease, known as rheumatoid pneumoconiosis or Caplan syndrome. 37 OBSTRUCTIVE LUNG DISEASE CAUSED BY COAL MINE AND SILICA DUST There is a strong and dose-dependent relationship between exposure to coal mine dust and the development of emphysema, chronic bronchitis, and lung function impairment. [48][49][50][51][52][53][54][55][56][57][58][59] This relationship can be independent of the presence of radiological pneumoconiosis on chest radiograph and may cause significant morbidity.…”

The national sheet metal worker asbestos disease screening program: Radiologic findings

“…It is important to note that the presence of either pleural or parenchymal abnormalities cannot be attributed to cigarette smoking alone. While several authors have suggested that smoking is independently associated with small opacities on chest radiograph, [ThCriault et al, 1974;Amandus et al, 1976;Cockcroft et a]., 19831, these studies did not include subjects without dust exposure, precluding the possibility of accurately identifying an independent effect of smoking. In one important investigation of this issue, NIOSH-certified B readers found a prevalence of parenchymal abnormalities (ILO score of 110 or greater) of less than 1% in a large population of blue collar workers with minimal exposure to occupational respiratory hazards [Castellan et al.…”

Diagnostische Herausforderungen bei Mischstaub-Pneumokoniosen – 5 Fallbeispiele

“…irregulär) und Lokalisation der Lungenschatten eine verlässliche Zuordnung zu einem Krankheitsbild, insbesondere der Silikose und Asbestose, möglich ist, lässt sich nach eingehenderen Studien nicht halten. Vielmehr zeigen Untersuchungen insbesondere der Arbeitsgruppe Petsonk [51] und auch anderer Untersucher [52,53], dass praktisch stets rundliche und irreguläre Schatten nebeneinander bestehen und auch deren bevorzugte Lokalisation variieren kann. Diese Heterogenität der radiologisch fassbaren Lungenveränderungen trifft in noch weit größerem Maße für Mischstaub-Pneumokoniosen zu.…”