DHS Office of Health Affairs Chemical Defense Program Analyzes Subway Safety Against Chemical Terrorist Threats

In an article for the journal Domestic Preparedness, Joselito Ignacio examines how to protect subway riders from chemical attacks. Ignacio graduated from the Center for Homeland Defense and Security in 2011 and is currently acting director of the Chemical Defense Branch with the Department of Homeland Security’s Office of Health Affairs.

The article, “Protecting Subway Riders from a Chemical Attack,” notes that subway usage in New York City alone, at 1.6 billion riders yearly, outpaces commercial air travel, at 713 million passengers annually, in the entirety of the United States. Ignacio noted the March 1995 sarin attack on the Tokyo subway system by the cult Aum Shinkrikyo.

“Despite this significant difference, the nation’s subway systems have not imposed strict passenger or baggage screening requirements similar to those in civil aviation,” he wrote.


Ignacio describes some uniform measures to establish a chemical prevention and detection plan for subways systems.



1)     The impetus for the research was the Chemical Defense Branch’s desire to make subway travel safer by providing guidelines that could be applicable to any metropolitan subway system.


“Right now, if transit authorities want to develop a chemical detection program, they call a vendor,” Ignacio said.  “Of course, vendors will attempt to sell you products that may not necessarily be suited to your needs, and those products may not be evaluated by a third party.”


The article aims to take a logical approach to designing, developing and implementing a detection protocol with the capability to save lives.

“My hope was that the research could be shared with state and local land transportation officials to show the way to do this without purchasing off the shelf,” he noted.

The article ends with suggestions on building a detection network: develop the risk assessment methodology to gauge threats and assess vulnerabilities; establish detection performance specifications; evaluate the information available about the various types of detection technologies; use a detector placement method; develop a concept of operations; create and implement a training and exercise program to help first responders familiarize themselves with the actions that they must take after a detector has signaled a release.

2)     This research reinforced Ignacio’s view that more research and work is needed in this area.

“I’ve always felt there was a mission space for this kind of research to analyze the needed information,” he said. “It frankly reinforced my view of a complex approach to solving problems. Mass transit is huge in the United States. Major cities have thousands of people per day riding mass transit. You multiply that with all the systems and that is a lot of patrons.”


3)     A demonstration is currently under way in Baltimore which implements some of Ignacio’s research. DHS is funding two additional pilot projects, though the locations have yet to be decided. He further wants to explore whether chemical detection technology could be applied in other areas such as arenas, sports stadiums and ports.