Acute pulmonary response of asthmatics to 3.0 ppm formaldehyde

Previous studies have failed to demonstrate bronchoconstriction in unselected asthmatics after brief (less than or equal to 1/2-h), controlled exposures to formaldehyde (HCHO). This study was designed to evaluate the acute pulmonary response to 3 ppm HCHO in nine nonsmoking asthmatic volunteers over a more relevant exposure duration (3 hrs). Pulmonary function, nonspecific airway reactivity and symptoms were assessed before and at intervals during the exposure. No significant changes in pulmonary function (FVC, FEV1, FEF25-27%, SGaw, or FRC) or airway reactivity were observed. There was a significant increase in nose/throat irritation at 30 min. (P less than 0.05) and in eye irritation at 60 min (P less than 0.05) and 180 min (P less than 0.01). These results suggest that individuals with asthma will not experience significant bronchoconstriction when exposed at rest to 3 ppm HCHO; however, most will experience eye and upper respiratory tract irritation.