The Department of Homeland Security will be pumping an innocuous
bacterium into parts of the MBTA to test a system of biological
detection sensors at certain stations.

According to MBTA officials, the partnership with the DHS Science
and Technology Directorate, the first of its kind in the country, will
evaluate the ability of new sensors to detect hazardous biological
materials in the subway in the event of a real-life emergency.

Using a “food-safe test bacterium,” the faux-scenario will happen in
Cambridge and Somerville at night over the summer when no riders are
using the transit system, according to T officials.

“We are testing new biological testing systems to help us understand
how a biological threat would impact public transit,” said MBTA Transit
Police Deputy Chief Lewis Best.

According to Best, the testing agent is “commonly used in food
supplements so there is no risk, and it does not affect [peoples’]
health. Ultimately, it’s about making the system safer and protecting
the riding public,” he said.

The sensors are designed to enable rapid responses and protective
measures within 20 minutes to reduce the impact of a biological
terrorist attack, according to the MBTA.