CBS WBZ-TV | April 30, 2012
By Karen Anderson

BOSTON (CBS) – The Department of Homeland Security (DHS) will be releasing bacteria into the MBTA tunnels to test the safety of the subway.

The DHS has installed sensors in the MBTA system to detect biological agents and they’ve been testing to see how the air moves.

Now they want to release particles in the tunnels to see how well the sensors work.

The tests will be held at stations in Cambridge and Somerville.

Federal officials say they test the subway sensors by releasing dead bacteria called B-subtilis. They say it is used in food supplements, has been rigorously tested and has no adverse health effects for low exposure in healthy people.

The tests will be held during the off hours this summer, likely overnight. As part of the legal process, a hearing will be held May 16, from 5:30-7:30pm at the Cambridge YMCA in Central Square. The public will be able to voice concerns and comments.

While the systems are being evaluated, Massachusetts public health officials will be working closely with DHS and the MBTA to monitor the results. The MBTA and DHS are coordinating these efforts with the Massachusetts Department of Public Health, the Cambridge Public Health Department, and the Somerville Health Department, with support from the Massachusetts Emergency Management Agency.