Acute pulmonary response to formaldehyde exposure in healthy nonsmokers

The acute pulmonary response to three hours' exposure to 3 ppm formaldehyde (HCHO) during intermittent exercise was evaluated in nine healthy nonsmokers. The protocol consisted of clean air on the first day and HCHO on the second day with a 24-hour follow-up on the third day. Pulmonary function, nonspecific airway reactivity, and symptoms were assessed daily. Thirty minutes of HCHO exposure resulted in a 2% decrease in forced expiratory volume at one second (P less than .05) and a 7% decrease in forced midexpiratory flow rate 25%-75% (P less than .01); however, these effects were no longer present between 60 and 180 minutes. There was also a significant increase in odor (P less than .02), nose or throat irritation (P less than .01), and eye irritation (P less than .01) with exposure. No changes in pulmonary function or airway reactivity were observed 24 hours after exposure. Acute exposure to 3 ppm HCHO produced small, transient decreases in pulmonary function and mild to moderate eye and upper respiratory tract irritation.