The New York City Urban Dispersion Program field studies were conducted in the city’s urban canyons in March and August of 2005. Data gathered from the study have helped improve models of how a gas or chemical release might move around Manhattan’s tall buildings and canyons. Emergency management, law enforcement, and intelligence personnel use these models to plan for, train for, and respond to potential terrorist attacks and accidents involving harmful airborne contaminants. They also indicated the importance of conducting a comprehensive evaluation of the role of the subway system on the transport of air in NYC.
In addition to the study in Manhattan in 2005, air flow studies have been conducted in subway systems in Boston, and Washington, D.C. — but none as extensive as the one planned for New York City in July.