The NYPD is releasing harmless gases into the subway system this morning in the first of three days of its study into the potential risks posed by airborne contaminants.
During the study, which is being conducted by the NYPD and Brookhaven National Laboratory, officials will disperse low concentrations of harmless gases called perfluorocarbons at select subway and street-level locations. Researchers will then study the movement of those gases.
Air sampling equipment was installed around 6 a.m. this morning. The testing is expected to conclude at about 3 p.m.
The remaining two days of the study will be scheduled pending weather conditions and will be announced 24 hours in advance, police said.
The study, first announced in April, is the largest urban airflow study ever conducted and is designed to help the Police Department better understand the risks posed contaminants such as chemical, biological and radiological weapons as they are dispersed into the air and the city's subway system.
"The NYPD works for the best but plans for the worst when it comes to potentially catastrophic attacks such as ones employing radiological contaminants or weaponized anthrax," said Police Commissioner Raymond W. Kelly in April. "This field study with Brookhaven's outstanding expertise will help prepare and safeguard the city's population in the event of an actual attack."
The study includes 21 subway lines and dozens of stations in all five boroughs, according to a statement released in April. Members of the public may notice the air sampling devices in subway stations or on the street, but the study is designed to have zero impact on commuters and public activity, police said.