Aircraft mechanics, whether working in the United States military or in the civilian sector, experienced significant asbestos exposure prior to the replacement of asbestos parts in the industry. A variety of factors contributed to the exposure, and the severity of the results of that exposure depend on the relationship of the aircraft mechanic to the particular asbestos products in aircraft components.
Usage of Asbestos in Aircraft
Asbestos was used in US Naval aircraft prior to the 1981 decision to institute a program of asbestos replacement. Prior to 1981, asbestos was used in several aircraft components, including engine insulation, electrical insulation, brake pads and adhesives.
Because of the natural ability of asbestos to resist heat and fire, engine insulation could mitigate the risk of engine fire. Electrical components with a tendency to spark if damaged would not catch fire, and brakes - particularly aircraft brakes under extreme engineering stress while landing - would resist heat damage and fire.
It is in this latter case - aircraft brakes - that a significant risk factor manifested itself. While braking under high stress, these asbestos brake pads would shear off their outer layer and be ground to powder. Any aircraft mechanic then exposed to the brake dust would be at risk of inhaling or otherwise ingesting the asbestos residue.
Additional risk presented itself if any work on the plane required the removal of parts that had been adhered with asbestos-based epoxies. These glues would release asbestos into the air if broken or ground down in an effort to replace a damaged component.
It should be noted that a still greater risk presented itself in the case of aircraft mechanics aboard US Navy aircraft carriers. All of the danger of asbestos used in planes was compounded by the extensive use of asbestos in insulation and paint used on vessels constructed prior to the 1981 policy shift.
It is a given that almost all occupations come with at least some risk of work-related injuries. Still, in America today, people expect that jobsite hazards will be minimized, risks will be clearly explained, and employers will attempt to create a safe work environment. When it came to asbestos exposure, however, these expectations were not always met, and even in recent history employees were subjected to conditions that placed their lives at risk.
The Varieties of Asbestos and Their Effects on Human Health
There are two major categories of asbestos. Chrysotile, often called "white" asbestos, is the sole mineral of the serpentine group and was the kind most commonly utilized. Usually not associated with asbestos cancer or mesothelioma, this type is a relatively pliable variety of the mineral. Irritation to the interior surfaces of the lungs does result when serpentine particles are breathed in, however. Asbestosis can be the outcome when abrasions build up in the pulmonary system.
The other category is known as amphibole asbestos; of the two types, it is much more dangerous to human health. Lung cancer and pleural mesothelioma, an unusual and all too often lethal cancer of the mesothelium (the tissue that lies between the lungs and the chest cavity), are the most common cancers to result from being exposed to amphibole asbestos. More unusual forms of mesothelioma include peritoneal and pericardial mesothelioma; these diseases are also caused by exposure to amphibole asbestos.
The Strengths of Asbestos
Ironically, asbestos was used in building construction and in many products due to its ability to save lives. Serpentine asbestos is one of the most effective insulators known when it comes to combustion and high temperature and has been used for this purpose since ancient times. Amphibole forms of asbestos also had other traits that caused them to be useful for industrial situations. For instance, "brown" asbestos, or amosite, has a high iron content, making it impervious to caustic chemicals. "Blue" asbestos, or crocidolite, was frequently utilized in areas with electrical equipment because of its resistance to electrical current. Depending on the application, various types of fibers were combined to form asbestos-containing materials (ACMs) that safeguarded people and property against fire, extreme temperatures, electrocution and caustic chemicals.
As long as it was solid, asbestos offered no immediate hazard. As these ACMs got older, however, they were prone to becoming friable, or able to be reduced to powder by hand pressure alone. Friable asbestos is dangerous because in this condition the fibers are easily dispersed into the atmosphere, where they can be easily inhaled or ingested and thereby cause health problems. Unfortunately, it wasn't just aircraft mechanics who were at risk; secondary exposure often happened when workers carried asbestos fibers home on their skin, in their hair, or on their clothing.
A Time Bomb
Asbestos-related diseases, unlike many job-related injuries, which are easily observed and known about soon after the incident, may take ten, twenty, or even thirty years to develop. It can also be difficult to diagnose asbestos-related disorders since the symptoms can be mistaken for those of other, less serious conditions. New drugs are being developed as well as treatments like mesothelioma radiation, and early detection provides the patient and his or her doctor the best chance of beating the previously always-fatal disease. Accordingly, it is vital for all that worked as an aircraft mechanic, as well as anyone who resided with them, to tell their doctors about the possibility of exposure to asbestos as the mesothelioma survival rate traditionally has been grim.
Bowker, Michael. Fatal Deception: The Untold Story of Asbestos (New York: Touchstone, 2003)
Defense Technical Information Center - Replacement of Asbestos Aboard Naval Aircraft
University of Wisconsin - Asbestos Containing Material (ACM) - Laboratories and Shops
University of Wisconsin - Asbestos Disposal