New York City to conduct urban airflow test

New York Times : To prepare for a possible catastrophic gas leak, such as from a terrorist attack or accidental chemical spill, the New York City police department has commissioned Brookhaven National Laboratory to conduct several city-wide tests this summer. On three separate, nonconsecutive days in July, invisible and odorless gases will be released in seven different locationsâmdash;three above ground and four in the subway system. Monitoring equipment positioned throughout the city will track how the gases get dispersed. Because of the city’s extensive subway system, airflow through the city can be affected both below and above the groundâmdash;sometimes in surprising ways. The tests are designed to monitor airflow so that officials can better determine what to do should a catastrophic gas event occur, such as whether to shut down certain subway lines to limit the spread of the hazardous material.