The effects of open leaf burning on spirometric measurements in asthma.

The purpose of our study was to determine the effects of open leaf burning on asthmatic subjects. Seven subjects with known asthma of varying severity, along with three normal control subjects, were walked 0.5 mile with and without exposure on the same day, under very similar environmental conditions. An acute spirometric broncho-constrictive response was observed within 30 min of exercise with exposure to leaf burning in two of the seven asthmatic subjects. Five of the seven showed an overall drop in parameters measured. No significant change in the FEV1 was seen in the normal subjects with either protocol, nor in the asthmatic subjects during low level exercise alone. The results of our study suggest that open leaf burning under normal community-allowed conditions may represent a significant health hazard for some asthmatic subjects.