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Effects of combinations of diesel exhaust and ozone exposure on lung function in human volunteers.
Citation:
STEVENS, T., M. W. CASE, J. Berntsen, C. Olenick, M. BASSETT, T. MONTILLA, H. Hiers, J. Pleil, D. DIAZ SANCHEZ, AND M. C. MADDEN. Effects of combinations of diesel exhaust and ozone exposure on lung function in human volunteers. Presented at Society of Toxicology (SOT) Annual Meeting, San Francisco, CA, March 11 - 15, 2012.
Impact/Purpose:
We examined whether DE exposure can alter 03-induced FEV1 and FVC
Description:
Ozone (03) exposure induces changes in human lung function, typically seen as a decrease in forced expiratory volume in one sec (FEV1) and forced vital capacity (FVC). Because people are usually exposed to other ambient air pollutants simultaneously with 03, there may be interactive effects between 03 and other pollutants in inducing lung function changes. One common air pollutant is diesel exhaust (DE). We examined whether DE exposure can alter 03-induced FEV1 and FVC. Subjects (n=8) were exposed on Day 1 to 300 ppb 03, 300 ug/m3 DE, both 03 and DE, or filtered air (FA). On Day 2, subjects were exposed to 300 ppb 03. Subjects performed intermittent moderate exercise for 2 hours during exposure on both days. On Day 1, simultaneous 03 and DE exposure induced greater FEV1 (21±5%) and FVC (15±3%) decrements than the sum of only DE (no change in FEV1 and FVC) plus only 03 (FEV1 decrement of 13±3; FVC decrement of 9±3%) exposures decrements. On Day 2, 03 exposure induced greater lung function decrements in subjects exposed to DE on Day 1 (FEV1 decrement of 16±4%; FVC decrement of 13±3%) compared to their Day1 FA exposure (FEV1 decrement of 9±4%;FVCdecrement of 7±2%). Consecutive 03 exposures on Days 1 and 2 induced the greatest lung function decrements. The rate of lung function recovery on both Days 1 and 2 were similar for all exposure sequences and reached pre-exposure values for most subjects by 4 hr. These data suggest that 03-induced FEV1 and FVC decreases can be modified by DE exposure. [This abstract may not represent official US EPA policy.]