Measuring asthma indicators at New York City public schools

Although New York State laws restrict bus and truck idling duration, lack of knowledge about the law and difficulties in enforcement present obstacles in compliance. A three-year study is in progress to characterize the idling and traffic conditions outside New York City public schools leading to elevated concentrations of PM_2.5 and elemental carbon (EC), which have both been linked to asthmatic response. This is a joint endeavor between environmental scientists at Hunter College and Asthma Free School Zone (AFSZ), a program of Real World Foundation, a New York City-based not-for-profit organization. During the 2006-07 school year, real-time monitoring for PM_2.5 and EC took place over a three-week period at three schools during child pick-up time. Simultaneous traffic observations were recorded and categorized by vehicle type, idling status, parking, and traffic light stoppages. Daily maximum PM_2.5 and EC levels were observed to have increased as a function of total daily minutes of diesel vehicle idling, with correlations suggesting that 62% of the peak PM_2.5 and 34% of the peak EC were explained by diesel idling. Weakly increasing trends were observed for daily maximum PM_2.5 and EC with respect to total minutes of automobile idling, which explained 33% of peak PM_2.5 and 20% of peak EC. This finding suggests that idling is the major cause of elevated PM_2.5 (beyond background levels) and a contributor to elevated EC. Repeated sampling at each of the three schools is planned for the second year following an anti-idling educational campaign delivered to each school by AFSZ.