U.S. flag

An official website of the United States government

Government Website

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Safely connect using HTTPS

Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


  1. Home
  2. About Us
  3. Site Links
  4. Archived
  5. News Archive
  6. DHS S&T to Conduct Airflow Study in NYC Subway

Archived Content

In an effort to keep DHS.gov current, the archive contains outdated information that may not reflect current policy or programs.

DHS S&T to Conduct Airflow Study in NYC Subway

Release Date: May 6, 2016

For Immediate Release
DHS Science & Technology Press Office
Contact: John Verrico, (202) 254-2385

Experiment to Collect Data on Airborne Contaminant Behavior Scheduled for May 2016, Poses No Public Risk

NEW YORK - The Department of Homeland Security (DHS) Science and Technology Directorate (S&T) will conduct a week-long airflow study in portions of the New York City (NYC) subway system to gather data on the behavior of airborne particles in the event contaminants were released. This study poses no risk to the general public and will run from May 9 to May 13. 

The study will use only inert particle tracers, or harmless, non-toxic, inert gases, and results from the tests will be used to validate airflow and transport models for the subway environment.

“This study is part of the Department’s ongoing commitment to preparedness and the shared responsibility of protecting the nation’s critical infrastructure,” said DHS S&T Program Manager Dr. Donald Bansleben. “The results of this study will provide us with a greater understanding of airflow characteristics, informing the research and development of next generation systems that continue to ensure the safety and security of the general public.”

There will be a single 20-minutes release period of tracers in multiple stations, and daily release locations over the course of the week will include any two of the following stations: Grand Central, Times Square and Penn Station. Air sampling will occur in approximately 55 subway stations around Manhattan over a four-hour window following these tracer releases. During the test period, commuters and travelers may see equipment, or experimenters in regular clothes, safety vests and badges.

“The Metropolitan Transportation Authority continues to be an active partner in safeguarding the New York City subway system and this study will generate valuable information on protecting against airborne contaminants,” MTA Chairman and CEO Thomas F. Prendergast said. “These inert gases are safe for our customers and employees, and the entire test will be performed with no impact on them and no interruption to service. We are fully committed to keeping our nearly six million daily subway customers safe and secure, and this test will bolster the MTA and our partners’ ability to protect them and the city at large."

Prior to the airflow study, S&T conducted and posted for public comment a draft Environmental Assessment (EA) and proposed Finding of No Significant Impact (FONSI) for the use of the various tracer materials. The final EA and FONSI can be can be downloaded from the DHS website: http://www.dhs.gov/national-environmental-policy-act. Questions about the NYC test may be directed to the email box: mtanycttest@hq.dhs.gov.


Last Updated: 01/12/2021
Was this page helpful?
This page was not helpful because the content