What Are the Health Hazards of Asbestos?

The fact that asbestos is harmful to human health is well documented and researched. Because of its extensive use, tens of thousands in Hawai‘i have been exposed to this carcinogen. Asbestos-related diseases in Hawai‘i such as malignant mesothelioma, lung cancer, and asbestosis have claimed lives for as long as people have worked, lived, played and grown up with or around asbestos. The reason is simple.

The properties which make asbestos so versatile for industry are the same as those that become deadly in the human body. The extremely small size and thin shape of asbestos fibers allow it to penetrate deep into the lungs when inhaled. Its durability and chemical resistance blocks the body’s immune system’s attempt to dissolve, neutralize or get rid of the asbestos fibers. Since the fibers can persist in the body for a long time, they can cause a lot of damage to the lungs and other tissue. Asbestos is so dangerous because the hazards are hidden, its effects are gradual and progressive, appearance of symptoms and disease are delayed and the injuries are permanent.

Some of the earliest known accounts of disease occurring in people working with or around asbestos were recorded by the Ancient Greeks and Romans. They noted that slaves weaving asbestos cloth developed lung diseases and died much younger than other individuals. Asbestos-related health concerns were recognized as a serious matter at the beginning of the 20th century in the United Kingdom by factory inspectors.

As demand for asbestos in the US rose through World War II, the incidence of asbestos-related lung diseases also increased dramatically. Prolonged and heavy exposure to asbestos dust caused scarring of the lungs that were visible on chest x-rays of insulators, factory and textile workers, miners and other trades. Workers’ compensation claims for asbestosis were filed and awarded for permanent impairment and injuries.

Asbestos Hazard Kept Hidden

Tragically, although the asbestos industry knew that asbestos could be toxic, the companies did everything they could to keep the dangers hidden. The asbestos industry failed to warn workers and consumers about the dangers of asbestos, and even took steps to suppress early scientific research about the links between asbestos and cancer.

By the early 1960s, however, it was clear that asbestos could cause malignant mesothelioma and lung cancer. Further, researchers discovered that lower exposure levels such as household or take-home exposures were sufficient to cause illness and disease. Even as the scientific evidence mounted, however, the industry continued to distort the truth about asbestos. Internal company documents make it clear that the asbestos industry wanted to keep marketing their toxic product as long as they could.

No Safe Level

Over many years, progressively lower limits and increased regulation of exposure to asbestos have reduced the risks of developing asbestos-related diseases. However, many workers, navy seamen, shipyard workers, and their families were exposed before these rules were enacted. The current permissible exposure limit (PEL) for asbestos set by OSHA for workers is no more than 0.1 fiber per cubic centimeter of air as an eight hour time-weighted average (TWA), but there is no known safe level of exposure to asbestos. The vast majority of asbestos fibers cannot be detected without the aid of an optical or electron microscope. In some situations, millions of individual asbestos fibers can be present in the air yet remain invisible to the naked eye. Also, injury and disease are not evident until a certain amount of time, often many years, has passed since the initial exposure to asbestos. This concept is known as latency and is another reason why asbestos is such a hazardous and dangerous substance.

Today asbestos is a highly regulated and controlled substance in the U.S. Various federal and state agencies are responsible for the safe handling of asbestos containing materials (ACM) at the job sites, in public buildings or private residences and around former mines and factories. Asbestos abatement including removal and disposal, or encapsulation to prevent fiber release, is used to minimize the risks associated with asbestos. Attempts to ban asbestos completely in the US have not succeeded to date.

If you think that you may have been exposed to asbestos, you should be sure to tell your doctor. People in high risk groups, such as those with known occupational exposure or take home exposure, should consult their physician and have regular physical exams.


U.S. Geological Survey Open-File Report 02-149 “Asbestos: Geology, Mineralogy, Mining, and Uses” by Robert L. Virta.

Substances Profiles: Asbestos CAS No. 1332-21-4 in Report on Carcinogens, Eleventh Edition.

U.S. Department of Labor OSHA Regulations (Standards – 29 CFR) for Asbestos – 1910.1001.