Impact of light rail transit on traffic-related pollution and stroke mortality

This paper evaluates the changes in vehicle exhaust and stroke mortality for the general public residing in the surrounding area of the light rail transit (LRT) in Houston, Texas, after its opening. The number of daily deaths due to stroke for 2002-2005 from the surrounding area of the original LRT line (exposure group) and the control groups was analyzed using an interrupted time-series analysis. Ambient concentrations of acetylene before and after the opening of LRT were also compared. A statistically significant reduction in the average concentration of acetylene was observed for the exposure sites whereas the reduction was negligible at the control site. Poisson regression models applied to the stroke mortality data indicated a significant reduction in daily stroke mortality after the opening of LRT for the exposure group, while there was either an increase or a considerably smaller reduction for the control groups. The findings support the idea that LRT systems provide health benefits for the general public and that the reduction in motor-vehicle-related air pollution may have contributed to these health benefits.