Monday morning, scientists working for the Department of Homeland Security will begin releasing (nontoxic) gases and particles on crowded subway platforms, beginning a week-long airflow study aimed at measuring the impact of a nightmarish chemical or biological terrorist attack.

It’s not the first such study — most recently the NYPD gassed the subway system in 2013 (also nontoxic) — but this is the first large-scale use of particles, in addition to gases. While gas tests help scientists, counter-terrorism specialists, and emergency responders understand the impact of chemical weapons like sarin gas or mustard gas, the particle test will measure the fallout from aerosol-dispensed biological agents like anthrax or ricin.

Every day this week, particles will be released from machines at busy stations like Grand Central, Times Square, 34th St.–Penn Station. Special machines and filters on platforms and subway cars will gather the particles. Researchers working throughout the system will also wear small patches designed to collect them.

The Department of Homeland Security, along with a MTA and a slew of other agencies, assured New Yorkers that neither the gases nor the particles are a health risk. The study won’t significantly increase the level of particle matter wafting through the air, in part, because New York City subway stations are already brimming with particulate. In fact, as the project’s assessment report noted, the levels of steel, manganese, and chromium in the subway system are 100 times higher than outdoors.

Read full article here: http://nymag.com/daily/intelligencer/2016/05/dhs-will-test-bioterror-air...