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Return to Asbestos BlogShort Answer: Between 20 and 50 years, in rare cases as much as 70 years after asbestos exposure.
Like most asbestos-related diseases, mesothelioma has a long latency period, meaning it takes a long time after exposure for symptoms of related diseases to appear. The exact time can depend on how much asbestos a person was exposed to, and how long a person was exposed, as well as general health and genetics. But miliions of industrial workers and their families were exposed to asbestos before the 1980s, and even a small exposure (or a single asbestos fiber) can eventually cause mesothelioma. Accordingly, those exposed in their youth may be at higher risk.
Mesothelium and Mesothelioma
The layer of tissues that surrounds various organs of the body like the lungs, abdomen, heart and pelvis is the mesothelium. The functions of the mesothelium are to protect these organs and facilitate breathing and movement.
Besides movement and breathing, the mesothelium has protective features similar to the appendix and tonsils. Its regulatory activities of moving and transporting fluids in the abdominal and chest cavities give rise to other vital roles like body balance, healing, blood clotting and immunity response against spread of tumors and infection.
What does the mesothelium do?
The immune functions of the mesothelium are facilitated by the secretion of substances that fight bacteria such as the ones that cause tuberculosis. Similarly, the secretions inhibit the propensity of cancer cells to adhere to the mesothelium, decreasing the metastasis of some tumors.
Being an important part of the body, the mesothelium is prone to disease conditions of effusions, adhesions and cancers. Mesothelioma is a deadly form of cancer that affects the mesothelium.
Despite the mesothelium’s inherent property of offering protective features to prevent metastasis of cancers, the mesothelium is prone to cancers, which are known as mesotheliomas.
What does asbestos do to the mesothelium?
Exposure to asbestos fibers is known to cause mesotheliomas that affect the mesothelium of all the four important organs – the lungs, abdomen, heart and testicles.
The most common mesothelioma is pleural mesothelioma, which is the cancer of the lining or mesothelium covering the lungs. This accounts for 70-90% of all mesotheliomas. This cancer occurs the most in people who are exposed to asbestos for a long time.
While mesothelioma of the lining of the abdomen is known as peritoneal mesothelioma, the cancer affecting the lining of the heart is known as pericardial mesothelioma and the cancer affecting the lining of the pelvis, especially the testicles is known as testicular mesothelioma.
Causes of Mesothelioma
Research into mesothelioma has been progressing quite briskly, but so far things are not that clear that the causes of mesothelioma can be clearly enunciated.
However, research has pointed to factors that contribute to increasing the risk of developing mesothelioma.
Genetics and mesothelioma
Like all cancers, mesothelioma occurs when cells’ DNA is damaged. Chemical in the cell is the DNA that forms the genes. DNA of a child comes from parents and this DNA could also transmit the same genes and if the parents have had cancer, then heredity could be a cause of that cancer, including mesothelioma.
Like asbestos, erionite is also a fibrous mineral, exhibiting similar properties as asbestos. Just like asbestos fibers, erionite fibers also cause mesothelioma, although not much research on its culpability is available.
Asbestos exposure is responsible for most mesothelioma cases
The main cause of pleural mesothelioma is asbestos exposure, as research points to 80% of mesothelioma patients have been subject to asbestos exposure.
The Dangers of Asbestos Friability and Latency
Asbestos displays two important characteristics that are relevant to mesothelioma.
Latency of asbestos-related diseases like mesothelioma
(They can take decades to appear.)
One is the latency, which is the time elapsed between first exposure to asbestos and the time the cancer is diagnosed. According to one research study, mesothelioma latency isbetween 33 and 57 years after first asbestos exposure to show up as mesothelioma.This would mean that if a child is exposed to asbestos at age 10, the child could be diagnosed with mesothelioma any time between age 43 and age 67.
Friability of asbestos fibers (lose, airborne, easy to inhale or ingest)
The second characteristic is the one of asbestos being friable. The property of asbestos being friable is displayed when simple hand pressure can break up the asbestos fibers into thousands of microscopic asbestos fibers and dust that are invisible to the naked eye. These fibers can be seen only under a microscope and in some cases only through an electron microscope.
There is also non-friable asbestos, which cannot be crumbled with simple hand pressure, but over efflux of time and wear and tear, this kind of asbestos can turn into friable asbestos. Further, non-friable asbestos can also be broken up when higher external force is applied like when hammering a nail into an asbestos containing drywall or drilling a hole in a wall with asbestos cement.
Thus, when friable asbestos is disturbed, it releases thousands of asbestos fibers into the air and people nearby can inhale or swallow these asbestos fibers without their knowledge.
When these fibers are inhaled, they can get into the air passages of the lungs, reaching the mesothelium of the chest. Since asbestos fibers are highly durable, they can stay in the body until death. This is because there is no way to get the asbestos fibers out and these may not show up in any diagnostic tests. Even if they did show up, there are too many asbestos fibers to be removed, which is an impossible task.
Research studies on mesothelioma and asbestos fibers
Professor Seaton at the University of Aberdeen conducted hundreds of post-mortem studies to estimate that overall, in the UK, more than 60% of people in the UK had asbestos fibers in their lungs, with the astounding fact that none of the deaths were caused by asbestos fibers found in the lungs.
In fact, Prof. Seaton conducted more post-mortem studies in UK’s large cities to find that his estimate of asbestos fibers in the lungs were almost 100%, that is all the people in these large cities had asbestos fibers in their lungs and the death was not caused by the asbestos fibers.
Asbestos fibers embed in human tissues and lie in wait, damaging the body and causing disease over many years.
When these asbestos fibers are inside, staying there permanently, they can interact with the tissues of the mesothelium and cause tissue scarring. Over time, this scarring can turn cancerous causing the mesothelioma. This process is perhaps what causes the long latency in mesothelioma cases. Since this happens more in the lungs, pleural mesothelioma is more prevalent.
Swallowing asbestos fibers can also cause diseases, including colon cancer.
A similar process takes place when asbestos fibers are swallowed, again without the knowledge of people. But this time, the process is in the mesothelium of the abdomen cavity and peritoneal mesothelioma is the result.
Occasionally, the mesothelium in the lining of the heart is affected with pericardial mesothelioma and the mesothelium in the testicles is affected with testicular mesothelioma.
How Long Does Mesothelioma Take to Develop?
Asbestos has had a meteoric rise from 1880 to 1980 when it became a highly popular substance most sought after by almost all industries in the United States because of its remarkable properties and the ability to be combined with other materials to be made into what are known as asbestos containing materials (ACM).
Unfortunately, during the time it served its purpose reports of unexplained health issues cropped up and research studies determined that asbestos was the cause of these diseases that were termed asbestos-related disease (ARD).
Discovery of mesothelioma
These studies found that asbestos caused non-cancerous ARDs like asbestosis, pleuritis and pleural plaques and cancerous diseases like mesothelioma.
Further research revealed that mesothelioma was almost always caused by asbestos exposure and the prognosis for mesothelioma was poor. The survival rates were determined to be four to 18 months after diagnosis. Further, the five-year survival rate was just 10% of the mesothelioma cases. However, this rate has increased in the last ten years but when compared to two to three decades ago, the increase has been very significant.
Mesothelioma takes a long time to develop and most cases fall between the time frame of 33 to 57 years.
The reason is simply that mesothelioma does not show symptoms and often patients don’t know that they have developed a deadly disease, until it is too late. This could be one of the reasons for the poor survival rates, as the disease could have progressed to the end stage by the time it is diagnosed.
Although 69 countries have banned asbestos, it continues to be used in the US even now, but under strictly monitored asbestos laws and regulations implemented by state and federal authorities.
However, the danger is still there because of the numerous buildings constructed during most of the 20th century, which contain asbestos and ACMs in them posing risk of asbestos exposure.
People in general are at risk of primary and secondary asbestos exposure, which can lead to cancerous and non-cancerous disease. However, the people who have handled asbestos at their workplaces are at greater risk of primary asbestos exposure. These people also become sources of secondary asbestos exposure for their families, who also face risk of secondary asbestos exposure.
Since asbestos exposure is still a present and real danger to such people, they should take care to get themselves checked periodically for any adverse health conditions.Children need to be paid special attention because latency hits them the hardest. Perhaps it would be beneficial if such people use the services of a B reader while examining x-rays.
https://www.in.gov/idem/asbestos/about-asbestos-containing-materials/
https://www.verywellhealth.com/mesothelium-definition-structure-and-function-2249127
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6630312/
https://www.cancer.org/cancer/types/malignant-mesothelioma/causes-risks-prevention/what-causes.html
https://www.policlinico.mi.it/AMM/medicina_lavoro1/rml/pubblicazioni/art15.pdf
https://www.redalyc.org/journal/496/49647009029/html/
https://www.pennmedicine.org/cancer/types-of-cancer/mesothelioma/prognosis
https://www.atsdr.cdc.gov/asbestos/atsdr_asbestos_work.html
