Which of the following is a symptom of asbestosis?

Shortness of breath is a hallmark symptom of asbestosis, which is a chronic lung disease caused by inhaling asbestos fibers. As asbestos fibers accumulate in the lungs, they cause scarring (fibrosis) of lung tissue, leading to difficulty in breathing over time. This condition manifests as progressive shortness of breath, particularly during physical activity, and may worsen even at rest as the disease advances.

In contrast, other options like frequent headaches, abdominal pain, and joint swelling are not typically associated with asbestosis. Such symptoms could be indicative of unrelated health issues or conditions, but they do not relate to the specific lung damage and respiratory problems caused by asbestos exposure.