Asbestos exposure is related to restrictive and obstructive lung function impairment. Pulmonary function tests are a series of tests that identify how well the lungs are functioning. These tests determine how much air can be blown out, the amount of air held inside the lungs at different times and the speed of blowing the air out. The tests will also determine how well the lungs function following a surgery, evaluate the severity of symptoms such as coughing or wheezing or how efficient a treatment is.