An Airway Blockage. An airway blockage also can cause atelectasis. A blockage may be due to a foreign object (such as an inhaled peanut), a mucus plug, lung cancer, or a poorly placed breathing tube from a ventilator. When a blockage occurs, the air that's already in the air sacs is absorbed into the bloodstream.ther lung conditions and medical disorders that can cause atelectasis include pneumonia, lung cancer, and neuromuscular diseases. Rarely, asthma, COPD (chronic obstructive pulmonary disease), and cystic fibrosis are associated with atelectasis.