New York to test readiness for biological attack by deploying ‘safe gas’ in subways and parks

Test aims to learn about relationship between airflow in street level and underground environments

New York City’s emergency plans for an attack by biological or chemical weapons will be tested later this month as part of a federal government study.

The Department of Homeland Security will work in conjunction with a team of researchers and city agencies, including the Metropolitan Transit Authority, on a project that will see “safe gas” released at key points around the five boroughs.

Some 120 locations will be tested, including parks and below-ground subway stations, over five separate days between 18 and 29 October.

The project includes the release of “low concentrations of safe particle and gas tracer materials” as part of two programs, the Urban Threat Dispersion (UTD) program and the Chemical and Bio-defense Testbed (CBT) program, according to the DHS.

The aim is to simulate "the aerosol release of a biological agent in a densely populated urban environment”.

Researchers will collect air samples and materials that settle on the ground and other surfaces after the dispersal of the gas.

“The results from these tests will be used to learn more about the relationship between airflow in street level and underground environments,” the MTA said.

Results will be used to inform how emergency management officials can plan responses to possible terrorist activity.

Commuters and other New Yorkers are advised that they may see personnel outside and in subways being escorted by New York City Police officers while they perform the airflow tests.

A full list of locations is not available, but a Homeland Security document lists Times Square, Grand Central, Penn Station, Union Square, and the World Trade Center transit hub as sites for tests, with testing both indoors and outdoors.

This is not the first time the city has undertaken a drill of this nature. The last time was in 2016, and similar exercises have been held in other major cities, including Washington, DC, and Boston.