Changing approaches to assessment of environmental inhalation risk: a case study.

Approaches to assessing environmental inhalation risk from asbestos have undergone profound change. In addition to social and political changes, a number of factors have come into play: 1. new technologies 2. new measuring instruments 3. new biological data 4. increased utilization of asbestos 5. regulatory imperatives 6. a redefinition of health risks associated with asbestos. This has occurred over a period of little more than 60 years. Early air-sampling instruments were developed to measure particles and fibers in air. Because asbestosis was a fibrotic disease, all measurements quantitated fibrotic disease risk in the environment by focusing on fibers and particles. Subsequently, the understanding that asbestos forms only fibers in air refocused measurement on fibers, not fibers and particles. As research clarified which fibers reached the lungs, new ways to sample and evaluate air were required. At the same time, changes in understanding of the disease process created the need for a better way to measure risk. In the 1960s, acceptance of the knowledge that asbestos causes both cancer (based on the no threshold assumption for carcinogens) and fibrosis raised the question of which fiber sizes should be measured and what the standard should be. The scientific assumption, prevailing both in 1985-86 and today, of a linear nonthreshold dose-response curve for carcinogens was applied to estimates of risk for asbestos exposure in the workplace, which led OSHA to lower the U.S. standard. In summary, we have attempted to illustrate the close link between state-of-the-art scientific and technical knowledge and policy decisions to control a toxic substance in industrial society. In the best of all possible worlds the science should permit valid estimates of risk and construct measurement techniques that lead to the desired control. If awareness comes early, then the process of policy making should be an iterative one, with incrementally more restrictive control as knowledge of the toxicant improves. The imperative for control of asbestos, as with many other toxic materials, was regulation, not science. That, however, is another story. Regulation of the workplace environment activated use of the science that permits valid estimates of risk and the techniques for measurement and control. The evolving science became part of the debates on control and constantly refocused them. Setting acceptable workplace exposure levels to control inhalation risk from asbestos did not occur on a wide scale until after 1970.(ABSTRACT TRUNCATED AT 400 WORDS)

Historical perspective on asbestos: policies and protective measures in World War II shipbuilding.

Current public health consequences of poorly controlled utilization of asbestos in the past can be traced back, in part, to decisions made 45 or more years ago. This paper focuses on the extensive use of asbestos as a fireproofing and insulating material in shipbuilding in the 1940s, when World War II industrial expansion brought about a hitherto unprecedented rise in the amount of asbestos utilized. Twenty years after World War II, asbestos diseases began to manifest themselves, affecting thousands of shipyard workers as well as other workers who had been exposed in the 1940s and during the postwar period. By scrutinizing past actions, the paper argues that social forces, as well as science and technology, affect the setting of priorities and the determination of policy regarding needed but hazardous materials.

Byssinosis--an historical perspective.

Based on the history of the growing awareness and recognition of ailments associated with the manufacture of cotton, it is concluded that recognition of byssinosis in the United States came late. In the American south byssinosis existed in an industry and within a social framework that helped to retard the acceptance of byssinosis as an undesirable but controllable disease. As late as the 1960s, United states medical opinion declared the disease nonexistent in American textile mills. In 1970, the scientific community showed that byssinosis existed in the United States. Mobilization of public opinion, changes in social attitudes, new scientific evidence, and the Occupational Safety and Health Act led to the setting of a standard to control and eradicate byssinosis. Controversy and debate over policy have brought the impact of scientific, sociopolitical, and economic inputs into health policy decisions, the altering perceptions of hazard, and the continually changing definition of risk into focus.

Historical aspects of industrial hygiene--II. Silicosis.

The extension of knowledge about silicosis, one of civilization's oldest known occupational diseases, is traced from antiquity to the twentieth century. In the past, silicosis was widely misunderstood and inadequately defined. As silicosis became widespread and concomitant with industrial and technological growth and as the numbers of workers at risk increased, new interest generated new information, and new concepts of control and prevention. Today, although we possess the significant medical and technical knowledge to prevent silicosis, there has been a failure to eradicate the disease.

Historical perspective to a current controversy on the clinical spectrum of plumbism.

Concepts of health risk associated with lead usage have undergone profound change. In the past observations of the relationship between lead usage and lead poisoning were severely limited by lack of knowledge and the relatively small quantity of the metal used. The benefits of lead usage, when contrasted with the risk incurred, outweighed the known hazards. Industrial growth contributed to the increased interest in lead poisoning. A significant increase of workers at risk generated new interest in an old disease. A concept of control developed based upon the principle of a dose-response relationship. The old idea of benefit versus risk remained because technological society needed lead but agreed that by controlling the factory environment lead could be used safely. The criteria for injury remained climical plumbism. Growth and change in lead utilization, once again, brought lead hazard to the forefront. New applications distributed lead throughout the environment exposiing both workers and the general population. A segment of the scientific community now suggests that the old criteria to judge risk, clinical symptoms of plumbism, are inadequate.