Chemical irritants in the air 2.
Many chemicals found in industrial settings can also irritate the bronchi and cause inflammation.
People with respiratory allergies often have asthma as a common symptom. But bronchitis is also present in many of these individuals. The most common cause of acute bronchitis are respiratory infections. Many of the viruses that cause colds and throat infections are also able to grow on the lining of the bronchi, causing inflammation. The main symptom of acute bronchitis is a deep, sometimes rattling cough that brings up sputum that is often grey or yellow in color.