Over the next six months, the United States Department of Homeland Security’s Science and Technology Directorate is releasing a harmless bacterium into the underground train system as part of its “Detect to Protect” program. It’s purpose isn’t to frighten commuters, but to test sensors designed to detect biological weapon attacks.

Every since the infamous Aum Shinrikyo anthrax attack in Kameido, Japan in 1993 and the anthrax attacks in the United States in the wake of 9/11, the possibility of a biological weapon being released in a densely populated area has concerned security services worldwide. Though no specific threat is currently identified against any U.S. targets, the Department of Homeland Security is developing new technology to detect and identify dangerous biological elements in real time.

The suite of biosensors, developed jointly by FLir Inc., Northrop Grumman and others are designed to set off an alert if a potentially dangerous biological agent is detected. Meanwhile, other sensors would within minutes identify and confirm the specific pathogens. The current series of tests follow on from a 2009 study where inert gases were released in the Boston subway. This time, Bacillus subtilis (AKA hay bacillus or grass bacillus) will be released while the subway is closed and their spread through the system will be tracked by the new sensors.

Bacillus subtilis is a harmless “food grade” bacterium normally found in the human gut and this particular bacilli will be dead before release, though this may not be much help to those not comfortable with the idea of government-sanctioned germs on the public transport.

Source: Department of Homeland Security