Symptoms Of Asbestosis And Mesothelioma

Here we will deal with asbestosis and all its clinical features and explain if, and in which cases does asbestosis turn into mesothelioma. Asbestos inhalation causes several diseases of lungs with interstitial pulmonary fibrosis (scarring) being one of the most common of them. While a better understanding of the disease, strict regulations, discontinuation of mining and use of asbestos by various industries have resulted in the decline of asbestos-related ailments, including interstitial lung disease. But incidences have not halted altogether, and new cases continue to be diagnosed.

Asbestosis may be diagnosed several years after the primary exposure due to extended latency period. Majority of cases being diagnosed in the US today are due to the exposure that happened much earlier, even several decades back in many cases. Treating asbestosis remains a challenge for medicine as corticosteroids and immunosuppressants seem to help in a limited way, and even worse if asbestosis turn into mesothelioma afterwards.

Asbestos is a complex mineral that occurs naturally. Asbestosis is characterized by the development of collagen in the interstitial space, because of chronic inflammatory responses and secretion of profibrotic mediators.

Although asbestosis has been known since long and has been well studied from the clinical point of view, however the mechanism of development of disease at the cellular level is still poorly understood. Also, it is not well understood if at some point asbestosis turn into mesothelioma during any point of the lifecycle of this disease.

Clinical features of asbestosis

Long-term inhalation of asbestos fibers leads to diffuse interstitial fibrosis of both the lungs. Some of the most common symptoms are:

  • A chronic cough that responds poorly to most conventional treatment
  • Progressive shortness of breath
  • Wheezing
  • Extreme tiredness
  • Pain in the chest and shoulders
  • As the disease progresses, fingers may become swollen

Chest x-ray, CT-Scan, lung function testing like spirometry may help to diagnose the cases that do not show any symptoms, thus contributing to diagnose the disease in the very early stage.

The doctor or medical specialist cannot diagnose asbestos exposure purely on the bases of functional lungs tests or imaging. Many other diseases of lungs may have a similar picture. Thus the history of asbestos exposure over an extended period of time may help to come to a decision.

In tough to diagnose cases, medical specialists may use biopsy, where examination of lung tissue under the microscope would confirm the diagnosis.

Research studies indicate that asbestos only develops after heavy and prolonged exposure in the majority of cases. Hence, it is more common in those involved in certain professions like miners, insulators, textile workers, and similar occupations. Significant for asbestosis is the amount of exposure to the substance; it can sometimes happen in a very short time too.

How long does it take for asbestosis to develop?

The latency period is directly proportional to the amount of exposure, meaning that heavy exposure would have a shorter latency period, while less exposure means longer latency time. At present, because of discontinuation of asbestos by various industries, or only limited usage exposure is small and thus latency time has increased. In an early 20th century, latency time was around 5-6 years, whereas by early 21st century it grew to anywhere between 12-20 years. Such a considerable variance in latency period only proves that asbestosis happens only when a certain threshold level of exposure is reached. This latency period calculation includes the cases where asbestosis turn into mesothelioma.

It does not mean that small doses of asbestos exposure are safe. Lower doses may just cause a sub-clinical fibrosis of lungs. If exposure is very small than the defensive mechanism is able to remove asbestos from the lungs, but as exposure becomes more intense, the risk of asbestosis increases proportionally.

Further, it is essential to know that risk of developing asbestosis in increased in those who smoke regularly. Because smoking damages the clearance mechanism of the respiratory tract, resulting in higher retention of asbestos particles: more chances of developing asbestosis and even more that asbestosis turn into mesothelioma after the aforementioned latency period.

Finally, it should be understood that there are different types of asbestos, with certain kinds posing a higher risk as compared to others.

Mortality related to asbestosis

Epidemiological studies show that the use of asbestos in the US started to fall sharply after the 1970s. Thus the people who worked in high-exposure industries before that period were at higher risk of death due to asbestosis, while those exposed to asbestos after that were at much lower risk.

One of the epidemiological studies demonstrated that in the US, 25 564 people died between 1968-2004. It also demonstrated that 1290 people would continue to die due to asbestosis for next couple of decades. After 2027 we can expect a steep decline in the mortality due to asbestosis.

Who is at risk of asbestosis these days?

Nowadays, very few industries are using asbestos. Mining in the US has been completely halted. Moreover, a better understanding of the risks means that excellent safety measures are in place in industries where it is still in use. Thus the risk of high-level asbestos exposure, that is required to cause asbestosis is close to zero. Nowadays, risk to high exposure may happen only in some places due to lack of awareness, like during the renovation or demolitions of some old building where asbestos has been used in large quantities. Likewise, it is possible that asbestosis turn into mesothelioma also in lower proportions than in the past.

Complications of asbestosis

Those living with asbestosis are at higher risk of developing specific complications, one of them is that asbestosis turn into mesothelioma. Regarding mesothelioma, this is a rare but dangerous complication; it is very aggressive and difficult to treat cancer that mostly arises in the pleura. People who have been exposed to asbestos or are suffering from asbestosis are at higher risk of developing various types of lung cancers: asbestosis turn into mesothelioma and can also turn into another tye of cancer as well. Finally, asbestosis thickens the lung lining called pleura.

What is the treatment of asbestosis?

Many therapies have been tried in asbestosis, but most drug therapies have failed to produce satisfactory results. In the 20th century, aggressive treatment with corticosteroids and immunosuppressants was used to decrease the inflammatory responses. However, both these treatments did not improve the outcomes.

Hence, oxygen therapy along with exercise therapy is helpful, without the toxic effects seen with the drugs.

Can a person get compensation?

Yes, if a person has developed asbestosis, a person can claim compensation through various channels, when asbestosis turn into mesothelioma or for asbestosis itself due to the . Till date, billions have been paid as compensation by various industries.

References

  1. Farioli A, Violante FS, Vecchia CL, et al. 0174 Mortality due to asbestosis in a cohort of former asbestos textile workers. Occup Environ Med. 2017;74(Suppl 1):A53-A53. doi:10.1136/oemed-2017-104636.141.
  2. Markowitz SB, Levin SM, Miller A, Morabia A. Asbestos, Asbestosis, Smoking, and Lung Cancer. New Findings from the North American Insulator Cohort. Am J Respir Crit Care Med. 2013;188(1):90-96. doi:10.1164/rccm.201302-0257OC.
  3. nhs.uk. https://www.nhs.uk, www.nhs.uk, www.nhs.uk/conditions/asbestosis/. Published July 8, 2017. Accessed December 14, 2017.
  4. Mossman BT, Churg A. Mechanisms in the Pathogenesis of Asbestosis and Silicosis. Am J Respir Crit Care Med. 1998;157(5):1666-1680. doi:10.1164/ajrccm.157.5.9707141.