References on Asbestos Lung Disease

How does smoking affect asbestos diseases?

Neuberger M, Kundi M. Individual asbestos exposure: smoking and mortality -- a cohort study in the asbestos cement industry. Brit J Indust Med 1990;47:615-20.

Why is there so much argument over asbestos?

Kook Sim Q. As asbestos claims continued to grow, broker of settlements closes its doors. Wall Street Journal, February 7, 2001.

Schmitt RB. Asbestos litigation continues to grow as suits widen net for deeper pockets. Wall Street Journal, March 5, 2001; Page 1.

Berenson A. A surge in asbestos suits, many by healthy plaintiffs. New York Times, April 10, 2002.

Glater JD. Defending a United Detroit on Asbestos. New York Times, November 3, 2002.

Hudak S, Hagan JF. Asbestos litigation overwhelms courts. Cleveland Plain Dealer, November 5, 2002.

Why is There Controversy Over Diagnosis of Pleural Plaques?

Muller. Imaging of the Pleura. Radiology 1993;186:297-309.

Do Pleural Plaques Lead to Cancer?

Hillerdal G. Pleural Plaques and Risk for Bronchial Carcinoma and Mesothelioma. A Prospective Study. Chest 1994:105:144-50.

Smith D. Plaques, Cancer, and Confusion (Editorial). Chest 1994:105:8-9.

Van Cleemput J, et. al. Surface of localized pleural plaques quantitated by computed tomography scanning: no relation with cumulative asbestos exposure and no effect on lung function. Am J Resp Crit Care Med 2001;163:705-710.

What is the Browne Hypothesis?

Browne K. Is asbestos or asbestosis the cause of the increased risk of lung cancer in asbestos workers? Brit J Indust Med 1986;43:145-149.

Jones RN, Hughes JM, Weill H. Asbestos exposure, asbestosis, and asbestos-attributable lung cancer. Thorax 1996;51:S9-S14.

The mortality statistics for asbestos workers found by Hammond and Selikoff are often quoted to support the notion that asbestos exposure alone, without asbestosis, is a cause of lung cancer. However, as pointed out by Jones in this 1996 article, the workers with lung cancer who died and were autopsied in fact had asbestosis. (Quote from page S10).

"Selikoff's cohort study of US insulation workers provided the most widely quoted estimates of lung cancer mortality from asbestos "exposures" and cigarette smoking (Hammond EC, Selikoff IJ, Seidman H. Asbestos exposure, cigarette smoking, and death rates. Ann NY Acad Sci 1979;330:473-91.)

"For many years, whether in estimates of the proportion of occupational lung cancers, in projections of their future numbers, or in disputed causation in individual cases, experience of the insulation workers was routinely offered as quantifying the carcinogenic effect's of "exposure". The interaction between "exposure" and smoking was multiplicative or synergistic, which was regarded as evidence that asbestos was implicated in the majority of lung cancer deaths among the "exposed population". When this was controverted it was usually on the grounds that the insulation workers were the most heavily exposed group, and their cancer experience would not apply in individuals or groups with lesser exposures. Then, in a 1987 publication, Kipen and others (including Selikoff) reported surgical or necropsy results in a series of consecutive cases of insulation workers with lung cancer (Kipen, et al. Brit J Ind Med 1987;44:96-100) Of 138 cases with acceptable tissue and radiographs, all had histological evidence of lung fibrosis and 113 (82%) also had radiographic evidence of fibrosis. The mortality experience from lung cancer in the insulation workers therefore derived not merely from exposure to asbestos but from asbestosis."

Weiss W. Asbestosis: A Marker for the Increased Risk of Lung Cancer Among Workers Exposed to Asbestos. Chest, February 1999;115(2):536-549

Banks DE, et al.; Asbestos Exposure, Asbestosis, and Lung Cancer (Editorial). Chest, February 1999; 115(2):320

What are the standard criteria for diagnosing asbestosis?

Murphy RLH Jr., Becklake MR, Brooks SM, et al. The diagnosis of nonmalignant diseases related to asbestos. Official statement of the American Thoracic Society. Am Rev Resp Dis 1986; 134:363-368.

(See also follow up letters to the editor: Franzblau A, Lilis R. Am Rev Resp Dis 1987;136:790-1, arguing for a more liberalized definition of asbestosis; and Murphy RLH Jr., et al, Am Rev Resp Dis 1987, 136:1516-17 who argue for the definition given in the original ATS statement.)

Gaensler EA, Jederlinic PJ, Churg A. Idiopathic pulmonary fibrosis in asbestos-exposed workers. Am Rev Respir Dis 1991;144:689-696. (See also Jones RN. Editorial: The diagnosis of asbestosis. Am Rev Resp Dis 1991;144:477-478.)

Gaensler, et al found an approximately 5% false-positive rate for the clinical criteria formulated in the 1986 ATS standards (see first reference), i.e., that 95% of the clinically diagnosed cases did have asbestosis, and 5% had other disease.

Harber P, Smitherman J. Asbestosis: diagnostic dilution. J Occup Med 1991;33:786-93.

Rosenberg D. Asbestosis: A Realistic Perspective. Chest 1997;111:1424-26.

Beckett WS. Diagnosis of Asbestosis: Primum Non Nocere. Chest 1997;111:1427-28.

The two editorials by Rosenberg and Beckett in the 1997 issue of Chest are presented as opposing viewpoints on the question: "Are claims of asbestosis being made in excess of the true number of claims?" In fact, a careful reading of both editorials shows the authors are more in agreement than apart. Rosenberg: "...due to inaccurate diagnoses, far fewer individuals probably have asbestos-related disease than are implied by the number of personal injury claims that have been made." Beckett: "...our practice should be, as in all other situations, guided by informed clinical judgment. The [1986 ATS criteria for diagnosing asbestosis; see first reference in this section] wisely settled on a thorough but noninvasive evaluation which would be expected to have a high degree of sensitivity and specificity, recognizing that all tests have some fasle-positives and false-negatives."

What are the Helsinki Criteria?

Asbestos, asbestosis, and cancer: The Helsinki criteria for diagnosis and attribution. Scand J Work and Envir Health 1997;23:311-16.

How are claims based only on the chest x-ray?

Egilman D. Asbestos screenings. Amer J Indust Med 2002;42:163

Weiss W. Cigarette smoking, asbestos and small irregular opacities. Am Rev Resp Dis 1984;130:293-301.

"The long term inhalation of cigarette smoke is associated with the appearance of diffuse small irregular opacities of mild profusion on chest roentgenograms of some subjects in a limited number of reports.. Human histologic and experimental animal studies have shown the presence of pulmonary interstitial fibrosis. The radiographic abnormalities may be explained by interstitial fibrosis, although bronchiolar wall thickening may also be involved." (Page 293)
"Given that both cigarette smoke and asbestos can each cause pulmonary fibrosis histologically, the assessment of each agent's contribution during combined exposure cannot be made in the current state of knowledge. This is especially true because the human response to each agent is quite variable, and some exposed persons show no discernible fibrotic reaction to either material." (Page 300)

Ducatman AM, Yang WN, Forman SA. 'B-Readers' and asbestos medical surveillance. Journal of Occupational Medicine 1988; 30:644-647.

"Analysis of 23 participating observers, interpreting more than 105,000 radiographs, demonstrated a 300-fold prevalence range of perceived "definite" pulmonary parenchymal abnormalities...Individual diagnoses, legal decisions, and population assessments ought to rely on multiple readings...The data presented here show the probable scope of the problem and underline a need for new quality assurance in the B-reading program."

Reger RB, Cole WS, Sargent EN, Wheeler PS. Cases of alleged asbestos-related disease: a radiologic re-evaluation. J Occup Med 1990;32:1088-90.

Chest radiographs were re-evaluated from 439 active and retired tire workers previously designated as having a condition consistent with an asbestiform mineral exposure...The percentage of cases with abnormalities consistent with an asbestiform mineral exposure found separately by the three radiologists was 3.7, 3.0, and 2.7%...A more detailed review, however, revealed that only 11 workers, or 2.5% of the total, would have a reasonable likelihood of having such a condition. Most cases were normal and the majority of abnormalities present on the radiographs evaluated were nonoccupational in origin.

Weiss W. Cigarette smoking and small irregular opacities. Br J Indust Med 1991; 48:841-844.

"The prevalence [of small opacities] increased with increasing age to 31.6% among smokers aged 50-64. Prevalence was 10% among ex-smokers of cigarettes. Among current cigarette smokers, prevalence was 5.3% in those who smoked less than one pack per day, 31.3% in heavier cigarette smokers, and 52.9% in 17 heavy cigarette smokers aged 50-64. Profusions of 0/1 and 1/0 are classified as "suspect" pneumoconiosis according to the ILO guidelines. The data in this study indicate that such abnormalities are directly related to age and smoking habits among workers not exposed to hazardous dust."

Dick JA, Morgan WKC, Muir DFC, et al. The significance of irregular opacities on the chest roentgenogram. Chest 1992;102:251-260.

"Scanty irregular opacities are not uncommonly observed on the chest roentgenogram in the absence of interstitial fibrosis of the lungs. In such circumstances the irregular opacities, when present, tend to be relatively scanty and seldom, if ever, exceed ILO category of 1/1. They are found in association with cigarette smoking, especially when emphysema is also present. (Page 251)
...Among the factors known to influence the prevalence of small irregular opacities on the chest roentgenogram are radiographic technique, age, obesity, cigarette smoking, and exposure to dusts encountered in the workplace. Small irregular opacities may be seen in asbestos workers in the absence of asbestosis, besides being present in various interstitial fibroses, the etiology of which are non-occupationally related. (Page 251)
...It therefore seems that the weight of the evidence indicates that cigarette-smoking asbestos workers can develop small irregular opacities in their lungs which closely mimic the changes of asbestosis. Such opacities may be present in the lungs of those exposed to asbestos but who have no evidence of asbestosis. These observations argue compellingly against the hypothesis that cigarette smoking delays clearance of asbestos fibers from the lung and that the hypothetic delay is solely responsible for the increased prevalence of irregular opacities in smokers. (Page 258)
...Clearly, several factors are involved in the pathogenesis of irregular opacities, but there is no justification for assuming that their presence in an asbestos-exposed population is always related to asbestos in the absence of the other criterial listed by the American Thoracic Society [ATS: The diagnosis of non-malignant respiratory diseases related to asbestos. Am Rev Respir Dis 1986;134:363-68.] as necessary for diagnosing this condition." (Page 259)

Meyer JD, Islam S, Ducatman AM, et al. Prevalence of small lung opacities in populations unexposed to dusts. A literature analysis. Chest 1997;111: 404-10.

"...a background level of opacities consistent with the radiographic appearance of pneumoconiosis exists in populations considered to be free of occupational dust exposure. Environmental and unaccounted exposures, as well as reader variability, all may play a role in the determination of small opacity prevalence in these subjects..."

Copyright © 2000-2994, Lawrence Martin, M.D.