Scoring System for Plain Chest Radiographs in Patients with Asbestos Related Disease

One interesting study is called, "Methods for the quantitative determination of asbestos and quartz in bulk samples using X-ray diffraction" by M. Taylor - Analyst, 1978, 103, 1009 – 1020.  Here is an excerpt: "Procedures are described for the quantitative determination of the asbestos and -quartz contents of bulk samples by use of X-ray powder diffractometry. The method gives satisfactory results for several different types of asbestos and for mixtures of two or more different types. Problems with sample grinding and preferred-orientation effects have been largely overcome. An effective procedure has been developed for grinding samples to a suitable particle size for accurate quantitative work. This procedure works equally well for all the types of asbestos studied and the sample is intimately mixed with the internal standard, nickel (II) oxide, at the same time. A sample press has been designed that enables the same pressure to be applied to each sample when sample holders are filled for the diffractometer, giving the same degree of preferred orientation each time. Calibration lines have been calculated for chrysotile, amosite, crocidolite and anthophyllite, and results are given for mixtures containing two or more types of asbestos as well as other commonly occurring minerals.Similar techniques are used to grind samples containing quartz and to mix them with internal standard. Work on both synthetic and real samples is described and results are compared with those obtained by use of an infrared spectroscopic method."

Another interesting study is called, "A new high resolution computed tomography scoring system for pulmonary fibrosis, pleural disease, and emphysema in patients with asbestos related disease." By N A Jarad, P Wilkinson, M C Pearson, R M Rudd - Br J Ind Med 1992;49:73-84.  Here is an excerpt: "Abstract - The aim of this study was to describe a scoring system for high resolution computed tomographic (HRCT) scans analogous to the International Labour Office (ILO) scoring system for plain chest radiographs in patients with asbestos related disease. Interstitial fibrosis, pleural disease, and emphysema were scored, the reproducibility and the interobserver agreement using this scoring system were examined, and the extent of the various types of disease was correlated with measurements of lung function. Sixty asbestos workers (five women and 55 men) mean age 59 (range 34-78) were studied. The lungs were divided into upper, middle, and lower thirds. An HRCT score for the extent of pleural disease and pulmonary disease in each third was recorded in a way analogous to the International Labour Office (ILO) method of scoring pleural and parenchymal disease on chest radiographs. A CT score for the extent of emphysema was also recorded. Pleural disease and interstitial fibrosis on the plain chest radiographs were assessed according to the ILO scoring system. A chest radiographic score for emphysema analogous to that used for HRCT was also recorded. Two independent readers assigned HRCT scores that differed by two categories or less in 96%, 92%, and 85% compared with 90%, 78%, and 79% of cases for chest radiographs for fibrosis, emphysema, and pleural disease respectively. There was better intraobserver repeatability for the HRCT scores than for the chest radiograph scores for all disorders. Multiple regression analysis showed that scores for interstitial fibrosis, emphysema, and pleural disease on chest radiographs and HRCT correlated to a similar degree with impairment of lung function."

Another interesting study is called, "Declining Relative Risks for Lung Cancer After Cessation of Asbestos Exposure" by Walker, Alexander M. M.D., Dr. P.H. - June 1984 - Volume 26 - Issue 6.  Here is an excerpt: "Abstract All studies that provide follow-up information for workers more than 35 years after initial exposure to asbestos show a declining ratio of observed to expected lung cancer deaths at the end of follow-up. The most parsimonious explanation of this finding is that relative risk for lung cancer begins to decline sometime after cessation of asbestos exposure."

Another interesting study is called, "Scavengers of active oxygen species prevent cigarette smoke-induced asbestos fiber penetration in rat tracheal explants." By A. Churg, J. Hobson, K. Berean, and J. Wright - Am J Pathol. 1989 October; 135(4): 599–603.  Here is an excerpt: "Abstract - It was previously shown that rat tracheal explants first exposed to cigarette smoke and then to amosite asbestos take up more asbestos fibers than explants exposed to air and asbestos. To examine the mechanism of this process, the same experimental design was followed but test groups were added in which the asbestos was mixed with catalase or superoxide dismutase, scavengers of active oxygen species, or deferoxamine, an iron chelator that prevents formation of hydroxyl radical. All three agents protected against the cigarette smoke effect. Heat inactivated catalase or superoxide dismutase was not protective. These observations indicate that active oxygen species, probably derived from the cigarette smoke, play a role in smoke-mediated fiber transport into tracheobronchial epithelia."

If you found any of these excerpts interesting, please read the studies in their entirety.  We all owe a debt of gratitude to these researchers for their hard work.