Exercise while Breathing High Ambient Auto/Truck Emission causes Decreased Lung Function in Non-Asthmatic Subjects

Abstract

Chronic inhalation of internal combustion derived ultrafine particulate matter (PM1) is associated with airway inflammation and decreased resting lung function and may be causal to the reported high prevalence of exercise-induced asthma (EIA) in ice rink athletes. PURPOSE: To evaluate effects of 30 min of high [PM1] exposure exercise on lung function in non-asthmatic subjects. METHODS: Twelve non-asthmatic male college athletes performed random order exercise for 30 min while breathing either low (7,380±1650 particles/cm3) or high (252,300±74,200 particles/cm3) auto/truck emission PM1. Lung function was measured before and after exercise. RESULTS: Resting lung function was above age/gender/height predicted values (110, 117, 120 percent predicted for FVC, FEV1, FEF 25–75; respectively). For low PM1 exercise, no change in FVC, FEV1, or FEF25–75 was noted. However, for high PM1 exercise statistically significant falls in FEV1 and FEF25–75 were found (3%1 (60 ml) and 6% (400 ml) for FEV1 and FEF25–75, respectively p<0.005). Change in FEV1 and FEF25–75 were significantly correlated to [PM1] (R=−0.57, p =0.004 and R=−0.63, p=0.001, respectively). For every 10,000/cm3 increase in PM1 a decrease of 5.3 ml in FEV1 and 26 ml in FEF25–75 occurred. CONCLUSION: Although the decrease in lung function after high PM1 exercise in non-asthmatic subjects is statistically significant, it was not clinically significant. Chronic inhalation of PM1 during exercise may cause increased airway reactivity; exercise in high ambient pollutant areas should be minimized. This study provides support for the notion that exposure to exhaust fumes from hourly ice resurfacing by fossil-fueled machines is responsible for the high observed prevalence of EIA in ice rink athletes.