Can Asbestos Exposure Cause Lung Nodules?

Yes, asbestos exposure is associated with the development of lung nodules.  However, asbestos exposure does not necessarily result in lung nodules in all, or even most cases.  The vast majority of people exposed to asbestos do not develop lung nodules, but asbestos exposure is a risk factor for nodules, and this risk increases in correspondence with longer durational or higher exposure to asbestos over a person’s lifespan.

What are Lung Nodules?

‘Lung nodule’ is used to refer to round or oval lesions on the lung that are 3 cm in diameter or less.  They are typically detected through an x-ray or CT scan of the lungs, and are often initially discovered accidentally when a patient receives one of these scans for a separate concern.  The detection of lung nodules can be an early sign of cancer, and as a result can be the cause of considerable concern.

Nodules can be caused by a variety of factors, including asbestos.  However, most nodules are attributable to other causes, including:

  • In response to an infection, the immune system will sometimes respond with inflammation, or create a granuloma, in order to contain and eliminate the infection.
  • Inflammation due to exposure to irritating substances or certain inflammatory conditions
  • Benign tumors
  • Malignant tumors
  • Metastases from cancers afflicting other organs of the body

Lung Nodules and Asbestos

Lung nodules are among the early signs of possible lung cancer, and both the US government and the medical and research communities have recognized asbestos as a known carcinogen.  Although little research has been conducted to definitely link asbestos exposure with lung nodules, one study found lung nodules in 86 out of 633 asbestos-exposed workers, or roughly 14%.

Not all lung nodules will necessarily be malignant.  More than 60% of lung nodules detected in x-rays or CT scans are non-cancerous.  However, if you have a history of occupational exposure to asbestos, it is far more likely that a lung nodule indicates cancer.

Lung nodules are common, showing up in roughly 1 in 500 x-rays and 1 in 100 CT scans.  Most are asymptomatic, and both benign and malignant nodules are treatable.