“…Elevated H 2 O 2 levels have been documented in different populations of patients with asthma, 37,38 pulmonary fibrosis, 39 primary lung cancer, 40 and asbestosis 41 compared with control subjects. In asthma, a negative correlation between H 2 O 2 , forced expiratory volume in 1 second, and peak expiratory flow rate have been reported, 42 as well as a positive correlation between expired H 2 O 2 , sputum eosinophils, and airway hyperresponsiveness.…”