Changes in respiratory function after one and three hours of exposure to formaldehyde in non-smoking subjects.

OBJECTIVE To determine the changes in respiratory function within one hour and three hours of exposure to formaldehyde and investigate the relation between exposure to formaldehyde and acute changes in respiratory function. METHOD Respiratory function of 50 non-smoking medical students exposed to formaldehyde in a gross anatomy laboratory were compared with respiratory function of 36 non-exposed, non-smoking physiotherapy students. Formaldehyde concentrations were measured in the breathing zone of each exposed subject and in the general work environment. RESULTS Formaldehyde concentrations in the breathing zone of exposed subjects generally exceeded recommended standards. On average, the variables of respiratory function of both the exposed and the control subjects increased significantly within one hour and from one to three hours after exposure. The increase in respiratory function of the exposed subjects was significantly less than that of the control subjects. There was no meaningful correlation between concentration of formaldehyde in the breathing zone and changes in the respiratory function of exposed subjects. CONCLUSION As the increase in the respiratory function of the subjects can be attributable to normal diurnal variation, the significantly lower increase in respiratory function of the exposed group than in the control group is probably due to exposure to formaldehyde. The results of this study do not, however, support a dose-response relation.