The Subway-Surface Air Flow Exchange (S-SAFE) project

The New York Police Department and the Brookhaven National Laboratory will jointly conduct an airflow study of risks posed by contaminants in the New York City subways.

The NYPD said it would use data collected during three days of research in July to optimize emergency response to an intentional or accidental release of hazardous materials.

“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 Kelly, adding that “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 NYPD, in partnership with the MTA, is responsible for keeping more than 5 million daily subway customers safe and secure,” said Metropolitan Transportation Authority acting Chairman Fernando Ferrer. “This study will bolster the NYPD’s understanding of contaminant dispersion within the subway system as well as between the subway system and the street, thereby improving its ability to better protect both our customers and the city population at large.”

What is known as the Subway-Surface Airflow Exchange was commissioned by the NYPD and funded through a $3.4 million U.S. Department of Homeland Security grant. It is the first of its scale to study airflow in a dense, complex urban environment both below and above ground.

The research will be carried out in daylight hours in parts of Queens, Bronx, Brooklyn, Staten Island and Manhattan from 59th Street to the Battery.

Perfluorocarbon tracer gases, to be used in the research, present no health or environmental hazard. They are non-toxic, inert, odorless and invisible and have been used in previous airflow studies since the 1980s.

In addition to a study in Manhattan in 2005, previous airflow studies were conducted in subway systems in Boston and Washington, D.C., but none was as extensive as the one planned for New York City this summer.

Weather conditions will determine on which days the research will be carried out.

The study is designed to have zero impact on commuting and other public activity.

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