Chronic/classic silicosis, the most common,
occurs after 15–20 years of moderate to low
exposures to respirable crystalline silica. Symptoms
associated with chronic silicosis may or may not be
obvious; therefore, workers need to have a chest
x-ray to determine if there is lung damage. As the
disease progresses, the worker may experience
shortness of breath upon exercising and have clinical
signs of poor oxygen/carbon dioxide exchange.
In the later stages, the worker may experience
fatigue, extreme shortness of breath, chest pain,
or respiratory failure.