Key Takeaways
- U.S. asbestos use increased dramatically during the 20th century and peaked in 1973 at approximately 803,000 metric tons.
- Asbestos was widely used in construction, shipbuilding, manufacturing, automotive work, insulation, industrial maintenance, and other industries.
- Mesothelioma can take decades to develop after asbestos exposure, helping explain why diagnoses increased long after the heaviest periods of asbestos use.
- Workers exposed during the asbestos boom of the mid-20th century may not have developed mesothelioma until 30 to 40 years later or more.
- Pennsylvania workers in steel mills, railroads, factories, power plants, construction sites, and other industrial settings may have encountered asbestos-containing materials.
- Although the overall U.S. mesothelioma rate is now declining, people exposed to asbestos decades ago may still be diagnosed today.
- Employment history, job duties, workplaces, equipment, and materials can all help reconstruct a possible asbestos exposure history.
For much of the 20th century, asbestos was widely used throughout American industry. Its resistance to heat and corrosion made it useful in insulation, construction materials, automotive parts, manufacturing equipment, and many other products. Asbestos use in the United States eventually reached its peak in 1973, when approximately 803,000 metric tons were used. But the health effects of this widespread exposure did not appear immediately. Because mesothelioma can take decades to develop after asbestos exposure, the effects of the asbestos boom and mesothelioma became closely connected. Many workers exposed during the height of asbestos use would not develop mesothelioma until decades later.
What Was the Asbestos Boom?
Asbestos use grew dramatically throughout the 20th century. The material was valued because it was durable and resistant to heat and corrosion.
Asbestos-containing materials could be found in products such as insulation, fireproofing materials, wallboard, automotive brakes, and other construction and industrial products. According to the CDC, U.S. asbestos use increased from approximately 1,000 metric tons in 1900 to 803,000 metric tons in 1973.
This widespread use created opportunities for workers in many different occupations to encounter asbestos-containing materials on the job.
Why Did Industries Use So Much Asbestos?
Asbestos had several characteristics that made it attractive to industrial companies. It could withstand high temperatures, resist corrosion, and provide insulation.
As a result, asbestos-containing products were used in industries such as:
- Construction
- Shipbuilding and ship repair
- Manufacturing
- Automotive repair
- Insulation work
- Industrial maintenance
Workers could encounter asbestos while installing materials, operating equipment, performing repairs, removing insulation, or working near others who disturbed asbestos-containing products.
When these materials are disturbed, microscopic asbestos fibers can become airborne. If inhaled, some fibers can remain in the body for a long time and contribute to inflammation, scarring, and serious asbestos-related diseases.
Which Workers Faced Asbestos Exposure?
Millions of American workers experienced occupational asbestos exposure beginning in the early 20th century. The National Cancer Institute identifies historical exposure among workers in shipbuilding, construction, insulation, asbestos-product manufacturing, demolition, automotive work, and other trades.
Workers potentially exposed to asbestos included:
- Steelworkers
- Shipyard workers
- Construction workers
- Pipefitters and plumbers
- Boilermakers
- Insulators
- Electricians
- Railroad workers
- Factory workers
- Automotive workers
- Maintenance workers
- Demolition workers
The exact level of exposure depended on the person’s occupation, workplace, materials present, and tasks performed.
Pennsylvania and the Asbestos Boom
Pennsylvania’s industrial history makes the asbestos boom especially relevant to workers and families across the state.
Throughout the 20th century, Pennsylvanians worked in industries such as steel production, rail transportation, manufacturing, construction, power generation, shipbuilding, and other heavy industrial trades. Many of these were among the types of workplaces where asbestos-containing insulation, construction products, machinery components, and other materials were historically used.
Workers who repaired boilers, maintained steam pipes, replaced gaskets, removed insulation, repaired machinery, or worked around construction materials could potentially have encountered asbestos if asbestos-containing products were present and disturbed.
For some Pennsylvania workers, understanding where they worked and what equipment or materials they handled decades ago can be an important part of reconstructing a possible asbestos exposure history.
Why Did Mesothelioma Cases Rise Decades Later?
One of the most important parts of understanding the asbestos boom and mesothelioma is the disease’s long latency period.
Mesothelioma usually does not develop immediately after asbestos exposure. The National Cancer Institute reports that asbestos-related conditions may take 10 to 40 years or more to produce symptoms. Other federal health guidance describes a typical mesothelioma latency of approximately 30 to 40 years.
That means someone exposed to asbestos at work in 1955, for example, might not develop an asbestos-related disease until decades later.
This delay helps explain an important historical pattern. According to federal health data, mesothelioma incidence in the United States increased from the early 1970s through the mid-1990s as disease developed among people who had been exposed during the peak asbestos exposure years of approximately 1940 through 1970.
In other words, the consequences of widespread asbestos use continued long after many of the original exposures occurred.
How Is The Asbestos Boom and Mesothelioma Connected?
Mesothelioma is a rare cancer that develops in the mesothelium, the thin tissue that lines areas including the lungs, chest wall, and abdomen.
Asbestos exposure is the major risk factor for mesothelioma. The National Cancer Institute states that most people with mesothelioma have worked or lived in places where they inhaled or swallowed asbestos. However, not everyone exposed to asbestos will develop the disease.
When asbestos-containing materials are disturbed, tiny fibers can enter the air and be inhaled. Some fibers may remain in the body for years.
Because the disease can develop so long after the initial exposure, someone diagnosed with mesothelioma today may need to look back many decades to identify where asbestos exposure may have occurred.
Are Mesothelioma Cases Still Rising Today?
Although mesothelioma cases rose following the peak decades of asbestos exposure, the overall rate of new mesothelioma cases in the United States is now declining.
The CDC reports that the rate is decreasing as fewer people are exposed to asbestos. However, mesothelioma has not disappeared. There were 2,669 new cases reported in the United States in 2022.
Past exposure also remains important because of mesothelioma’s long latency period. People exposed decades ago may still be diagnosed today.
In addition, asbestos has not disappeared from every building or workplace. Older asbestos-containing materials can still create potential exposure concerns when they are disturbed during renovation, repair, demolition, or removal.
Why This History Still Matters
The history of the asbestos boom and mesothelioma helps explain why a disease diagnosed today may be connected to work performed decades earlier.
For Pennsylvania workers and families, an exposure history may involve an old steel mill, factory, railroad facility, shipyard, power plant, construction site, or another workplace that no longer operates in the same way—or may no longer exist at all.
That makes occupational history important.
Remembering employers, job titles, work locations, coworkers, equipment, and materials encountered on the job may help someone better understand where possible asbestos exposure occurred.
Final Thoughts on the Asbestos Boom and Mesothelioma
The asbestos boom left behind health consequences that took decades to fully appear. As asbestos use expanded across American industry, millions of workers encountered the material. Because mesothelioma can have a latency period lasting decades, diagnoses continued to emerge long after many of those exposures occurred.
For Pennsylvania families affected by mesothelioma, understanding this history can help explain why employment from decades ago may still matter today.
At Pennsylvania Mesothelioma Information, our goal is to provide information and resources to individuals and families affected by asbestos exposure and mesothelioma.
If you or a loved one has been diagnosed with mesothelioma and have questions about a possible history of asbestos exposure, call Pennsylvania Mesothelioma Information at 800-505-6000 or fill out our online contact form for a free consultation.
Frequently Asked Questions
What was the asbestos boom?
The asbestos boom refers to the period during the 20th century when asbestos use expanded dramatically throughout American industry. U.S. asbestos use increased from approximately 1,000 metric tons in 1900 to about 803,000 metric tons in 1973.
Why was asbestos used so widely?
Asbestos was widely used because it could withstand high temperatures, resist corrosion, and provide insulation. These properties made it useful in construction materials, insulation, automotive products, industrial equipment, fireproofing materials, and other products.
Why did mesothelioma cases rise decades after asbestos exposure?
Mesothelioma has a long latency period, meaning the disease can take decades to develop after asbestos exposure. Workers exposed during the middle of the 20th century therefore may not have developed mesothelioma until many years later.
How long can mesothelioma take to develop?
Asbestos-related diseases may take 10 to 40 years or more to produce symptoms, while mesothelioma commonly has a latency period of approximately 30 to 40 years. The exact length of time can vary from person to person.
Which workers were commonly exposed to asbestos?
Workers who may have encountered asbestos included steelworkers, shipyard workers, construction workers, pipefitters, plumbers, boilermakers, insulators, electricians, railroad workers, factory workers, automotive workers, maintenance workers, and demolition workers.
Why is the asbestos boom especially relevant in Pennsylvania?
Pennsylvania has a long industrial history involving steel production, rail transportation, manufacturing, construction, power generation, shipbuilding, and other heavy industries where asbestos-containing materials were historically used.
Are mesothelioma cases still increasing today?
The overall rate of new mesothelioma cases in the United States is now declining. However, mesothelioma has not disappeared, and people who were exposed to asbestos decades ago may still be diagnosed because of the disease’s long latency period.
Why is a person’s work history important after a mesothelioma diagnosis?
Because asbestos exposure may have happened decades before a diagnosis, information about previous employers, job titles, work locations, coworkers, equipment, and materials may help identify where possible asbestos exposure occurred.
Sources:
Incidence of Malignant Mesothelioma | U.S. Cancer Statistics | CDC
