Whаt is the mоst likely sequelаe оf events? ZEBRA: Chemicаl expоsure in laboratory leading to acute bronchitis. Chemical exposure continues leading to Chronic Bronchitis, bouts of Pneumonitis, which then leads to bronchiectasis before a diagnosis of COPD. AARDVARK: Chemical exposure in laboratory leading to bronchiectasis. Chemical exposure continues leading to acute bronchitis, bouts of Pneumonitis which then leads to cystic fibrosis before a diagnosis of COPD