March 4, 2004

Asbestos: Think Again: Tiny amounts are deadly

pull quote from asbestos companies

[Excerpt | Full document]

No one is in favor of compensating individuals for a disease or injury they do not have. But asbestos diseases, particularly the early stages of asbestosis, do not lend themselves to a simple diagnosis. For asbestosis, which is progressive and in many cases fatal, the absence of observable physical impairment by X-ray or other measures is no guarantee that the disease is not present and that significant damage has not already occurred. A person may have lost more than 25 percent of their lung capacity due to scarring from asbestos and have no observable damage at all.

Diagnosing early stage asbestosis is a multifaceted procedure. Specialized reading of X-ray results is just one of five components of a complete diagnosis that typically involves an evaluation of pulmonary function, documentation of a history of asbestos exposure, shortness of breath, and clubbing of fingers.

The original X-ray reading system for workers exposed to asbestos was devised by the National Institute for Occupational Safety and Health and involved four different specialists, called B readers, reading and classifying X-rays independently. The outlier result, most often the most severe classification, was then discarded, and the classification for the individual was derived as the average of the remaining three ratings. A diagnosis was not considered complete, however, until a full evaluation, including all the components listed above, was performed.

Today's "unimpaired" asbestos worker could easily be tomorrow's mortality statistic. Any asbestos compensation fund set up by the Congress must account for this medical fact and not deny, delay, or complicate future assistance based on current lack of impairment.

Policies to protect potential asbestos victims must be flexible and inclusive because:

  • Bodily injury begins with the first inhalation of asbestos fibers, yet lung damage from asbestos cannot be detected by X-ray until an estimated 30 percent of lung capacity has been lost. Inability to detect damage via X-ray does not mean that a person does not have the disease.
  • Asbestosis is a progressive disease. Twenty-eight (28) to 38 percent of persons with the disease progress to a more severe classification within 2 to 10 years (Markowitz 1997).
  • People with early stage asbestosis, many of whom would be classified as unimpaired in the proposed Senate legislation, are at substantial risk for lung cancer or mesothelioma. In the definitive study of asbestos insulation workers, 30 percent of workers with no X-ray evidence of lung damage (a zero classification on the ILO system) died of mesothelioma or lung cancer within 27 years of the initial diagnosis. Those with "minimal X-ray change" fared even worse. Nearly 40 percent (39.9 percent) of individuals initially diagnosed as ILO classification 1, died of these two cancers within the 27 years analyzed. [View document]

If unimpaired people are in fact being compensated, the compassionate response is to upgrade the quality of diagnoses, not to deny compensation to entire categories of individuals based solely on X-ray classifications.

But in fact it is not at all clear that so-called "unimpaired" people are having any significant impact on compensation. David Austern, General Counsel for the Manville Trust, estimates that between two thirds and three quarters of the 200,000 non-cancer claims brought before the Trust were legitimate Level II cases, a clearly impaired asbestosis diagnosis [View document]. An analysis of insurance industry data on compensation awarded under the Babcock and Wilcox asbestos trust found that 70 percent of claims qualified as substantial impairment or greater (Peterson 2003b). The rest were simply not paid.

Perhaps a more serious concern is that very few asbestos workers ever step forward and seek any compensation at all. Most die with or from their disabilities and diseases, leaving their families bearing the brunt of medical costs as well as the emotional strain of a prolonged and preventable illness. A great number of experts, particularly those not employed by defendant companies, feel that misdiagnoses of asbestosis cases are a significant source of underreporting bias (Markowitz 1997). Many, and perhaps even the majority, of workers with asbestosis are misdiagnosed with emphysema or other respiratory ailments.

Between 1940 and 1979, an estimated 27.5 million workers were exposed to asbestos at work, and in 18.8 million workers exposure levels would be considered high (Nicholson 1982). Millions more have been exposed since then. For some jobs, asbestos levels would routinely exceed the current OSHA guidelines by 200 to 400 times (Welch 2003). An extremely high percentage of workers in asbestos-exposed occupations will develop some form of asbestos-related disease. A 1980 estimate of potential asbestos claims by the American Insurance Association (AIA) noted that "lung cancer deaths occur in approximately 20-25 percent of all deaths of asbestos workers, and mesothelioma deaths in 7-10 percent of all deaths of asbestos workers..." [Excerpt | Full document ]. This same document estimated that 25 to 33 percent of potential claims from exposed workers in 14 industries would be based on asbestosis. [Excerpt | Full document ]

Worker monitoring confirms these projections. Thirty-eight percent of pipe insulators in ship construction develop asbestosis 20 years after first exposure (Department of Health and Human Services 1978); 27 percent of asbestos exposed construction workers had radiographic evidence of asbestosis (Kilburn 2000). Although today's workers breathe less asbestos than workers prior to 1980, it is exposures 20 and 30 years ago that are producing casualties today.

Just 730,000, or 2.5 percent, of the 27.5 million workers exposed on the job to asbestos through 1978, have filed suit for compensation.

Deterioration from a diagnosis of "unimpaired" to death can be relatively rapid, even for non-cancer outcomes. Almost one in a hundred (0.9%) North American insulators with normal baseline X-rays [International Labor Office (ILO) Category 0] followed for ten years died due to asbestosis (Markowitz 1997). Insulation workers in ILO category 1, the least severe asbestosis classification, have a 2.4 percent risk of dying from the disease within ten years (Markowitz 1997).

People at these early stages typically do not have any evidence of a functional impairment, meaning that they do not experience symptoms such as shortness of breath, coughing, chest pain and tightness. Only later, when the disease has progressed to the point of reducing lung capacity by more than 30 percent do people begin to notice symptoms.

Once a diagnosis has been made, asbestosis typically progresses to increasingly serious stages. In what has become a classic memo, Dr. Kenneth Smith, the medical director at Johns Manville stated, "The fibrosis of this disease is irreversible and permanent..." (Brodeur 1985, pg. 102).

Estimates from a Finnish cohort of asbestosis cases found that the disease progressed to a more severe form in 28 to 38 percent of patients during a two to ten year follow-up (Oksa 1998). Selikoff's classic study of insulation workers shows that the number of asbestos insulation workers with ILO categories 2 and 3 greatly increased in the decades following first exposure, reaching 65 percent after 40 years (Selikoff 1976).

Asbestosis is a Progressive Disease

Years since exposure

Asbestosis Diagnosis by ILO classification (Percent)






2 & 3




































(Modified from Selikoff, 1976, as cited in Walker, 1983).

If asbestosis becomes severe, classified in ILO category 3, 35 percent of insulation workers will die from the disease within ten years (Markowitz 1997). One third of workers with advanced asbestosis (ILO categories 2 and 3) will die of lung cancer (Selikoff 1990).

Additional research links asbestosis progression with lung cancer. In a ten-year Finnish study, risk of lung cancer increased dramatically if asbestosis progressed during the period analyzed; approximately 46 percent of progressors developed lung cancer compared to nine percent of patients whose asbestosis did not progress. All lung cancer cases were current or former smokers (Oksa 1998b). According to an insurance industry association (AIA) review, approximately 50 percent of patients diagnosed with asbestosis will die of or with lung cancer. [Excerpt | Full document]

More than one third of asbestos insulation workers diagnosed as "unimpaired" died from asbestos disease within 27 years. (Selikoff 1990).

Cause of Death After 27 Years

Initial Diagnosis ILO category
(0/0, 0/1)

Initial Diagnosis ILO category
(1/0, 1/1, 1/2)

Initial Diagnosis ILO categories
2 and 3

Lung cancer












Total Asbestos-related deaths




Percent who progress to higher stage

28 to 38% within 2 to 10 years (Oksa 1998)

Asbestos industry and insurance experts readily acknowledge in court proceedings that asbestos fibers begin causing tissue or cellular damage shortly after asbestos fibers are first deposited in the lung and that the disease is progressive and irreversible. These experts also agree that the disease is typically diagnosed only in the advanced stages.

"The undisputed medical facts [are that] ... [a]ctual bodily injury, in the form of tissue or cellular damage caused by lodged asbestos fibers, begins shortly after such fibers are first inhaled."

      (Source: Pittsburgh Corning Corporation, 1984, at 8.)

"injury and the onset of fibrosis occur soon after the initial deposition of asbestos fibers in the lung supported by the overwhelming weight of the medical evidence."

      (Source: Armstrong World Industries, Inc. 1987, at 21.)

"The only conclusion that can be drawn from the medical evidence is the conclusion that is virtually uniform in the medical literature — asbestos-related injuries are the result of a continuous injurious process, beginning with first exposure and continuing through clinical manifestation."

      (Source: Post-Trial Phase III Brief of Policy Holders on the Medical Evidence, 1986, at 8.)

"Moreover, that injury occurs continuously from the first day of occupational exposure through clinical diagnosis whether or not there has been an intervening period of no exposure"

      (Source: Post-Trial Phase III Brief of Policy Holders on the Medical Evidence, 1986, at 20.)

"The first injury leading to the development of bronchogenic carcinoma or mesothelioma ... is the inflammatory reaction and onset of fibrosis which occur at the time of initial exposure."

      (Source: Armstrong World Industries, Inc., 1987, at 41.)

"Once the gas exchange capacity of an individual alveolar/capillary unit is compromised, the loss is permanent."

      (Source: Armstrong World Industries, Inc., 1987, at 10.)

"The accumulation of scar-like tissue decreases the functional volume of the lungs, stiffens the passage ways, and impedes the transfer of gases in and out of the blood. If the process continues, the functional capacity of the lungs becomes inadequate to support normal activities and may eventually be unable to support life."

      (Source: Brief of The Travelers Insurance Co., 1981.) [View document]

"The injury to the body begins at the first inhalation of the asbestos fibers. Although the eventual change in the lungs begins to develop at this time, it is not until the disease is relatively advanced that a firm diagnosis of asbestosis can be made."

      (Source: Internal Memo of The Travelers Ins. Co., Liability Claims Administration, Section 18, Injurious Exposure Claims, at sec. 18.1.)

"It is estimated that in order for the disease asbestosis to be clinically diagnosed, the gas exchange function of at least 100 million alveolar/capillary units [1/3 of the lung] must be affected."

      (Source: Armstrong World Industries, Inc., 1987, at 12.)


Statements of Pittsburgh Corning Corporation in Pittsburgh Corning Corp. v. The Travelers Indemnity Co. v. PPG Industries, Inc., et al, United States District Court for the Eastern District of Pennsylvania, Civil Action No. 84-3985, filed October 24, 1984, at 8.

Internal Memo of The Travelers Ins. Co., Liability Claims Administration, Section 18, Injurious Exposure Claims, at sec. 18.1.

Armstrong World Industries, Inc., Fibreboard Corporation and GAF Corporation Statements, Policyholders' Proposed Medical Findings of Fact, In re Asbestos Ins. Coverage Cases, Superior Court of California, City and County of San Francisco, Dep't No. Nine, Judicial Council Coordination Proceeding No. 1072, January 26, 1987.

Post-Trial Phase III Brief of Policy Holders on the Medical Evidence, Superior Court of the State of Ca., City & County of San Francisco, Dept. No. 9, Judicial Coordination Proceeding No. 1072, Filed Dec. 9, 1986.

Brief of The Travelers Insurance Co. re Exposure v. Manifestation, Commercial Union Inc. Co. v. Pittsburgh Corning, et al., U.S.D.C., E.D.P.A., filed July 14, 1981.

Brodeur, Paul. (1985). Outrageous Misconduct: The Asbestos Industry On Trial, Pantheon Books, New York.

Department of Health and Human Services (HHS) (1978). "Asbestos: An information resource [Cited in: American Insurance Association, Estimates of potential liability from asbestos and DES related injury (draft preliminary report). Presented to the task force on tort liability for cumulative trauma and latent injury, 1980]."

Kilburn, K. H. (2000). "Prevalence and features of advanced asbestosis (ILO profusion scores above 2/2). International Labour Office." Arch Environ Health 55(2): 104-8.

Markowitz, S. B., A. Morabia, et al. (1997). "Clinical predictors of mortality from asbestosis in the North American Insulator Cohort, 1981 to 1991." Am J Respir Crit Care Med 156(1): 101-8.

Nicholson, W. J., G. Perkel, et al. (1982). "Occupational exposure to asbestos: population at risk and projected mortality--1980-2030." Am J Ind Med 3(3): 259-311.

Oksa, P., M. S. Huuskonen, et al. (1998). "Follow-up of asbestosis patients and predictors for radiographic progression." Int Arch Occup Environ Health 71(7): 465-71.

Oksa, P., M. Klockars, et al. (1998b). "Progression of asbestosis predicts lung cancer." Chest 113(6): 1517-21.

Peterson, M. A. (2003). "Testimony at the United States Senate Committee on the Judiciary Solving the Asbestos Litigation Crisis: S. 1125, the Fairness in Asbestos Injury Resolution Act of 2003 (June 4, 2003)."

Peterson, M. A. (2003b). "Forecasting the Costs of S.1125 As Amended on July 10, 2003." Prepared for Caplin and Drysdale, September 8, 2003.

Selikoff, I. J. (1976). "Asbestos disease in the United States 1918-1975." Rev Fr Mals Respiratories 4 (suppl 1): 7-24.

Selikoff, M.D., I.J, R. Lilis, M.D., and H. Seidman, M.B.A., Predictive Significance of Parenchymal and/or Pleural Fibrosis for Subsequent Death of Asbestos-Associated Diseases, (unpublished manuscript).

Walker, A. M., J. E. Loughlin, et al. (1983). "Projections of asbestos-related disease 1980-2009." J Occup Med 25(5): 409-25.

Welch, L. S. (2003). "Testimony at the United States Senate Committee on the Judiciary Solving the Asbestos Litigation Crisis: S. 1125, the Fairness in Asbestos Injury Resolution Act of 2003 (June 4, 2003)."


ILO Categories Explained

Testimony of Laura Welch, MD
Medical Director, Center to Protect Workers Rights On Asbestos Related Diseases

Medical Criteria, Populations at Risk and Disease Projections Before the Senate Judiciary Committee June 4, 2003

Excerpt, page 3:

The International Labor Organization developed a way of grading chest x-rays for dust diseases of the lung. The most recent version is the1980 Classification of the Radiographic Appearance of Pneumoconioses (dust diseases of the lung). This system is accepted around the world. It provides a standard notation, so that if one reader calls a film a "1/1" another reader will know what the first reader is referring to. The classification uses a 12-point scale to define the degree, or severity, of increased lung markings. Classification of pleural changes (involvement of the membrane lining the chest wall and the lung) uses a separate scale, with specific notations made for side of the chest, whether or not the plaques contain calcium deposits, and the specific type, length, and width of the thickening of the pleura.

This 12-point scale runs from 0/- to 3/+; a "0" film is normal and a "3" film is the most severe scarring. Each reading on the scale is characterized by a number between 0 and 3, and a second number, separated by "/". The first number, preceding the "/", is the final number assigned to that film by that reader. The second number, following the "/", is a qualifier. The numbers 0, 1, 2, and 3 are the main categories. An x-ray read as a category 1 film might be described as 1/0, 1/1, or 1/ 2. When the reader uses 1/1, he is rating the film as a 1, and only considered it as a 1 film. If he uses 1/0, he is saying is rating the film as a "1", but considered calling it a "0" film before deciding it was category 1. Finally, when the reader uses 1/2, he is saying he is rating the film as a "1", but did consider calling it a "2" film. In clinical practice, any category "1" film is abnormal; therefore a 1/0 film is consistent with asbestosis.

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