NYC streets, subways to become urban airflow experiment
This July, the New York Police Department plans to release harmless gases into streets and subway stations. Understanding the pathways of airborne contaminants will help prepare the city against chemical, radiological, and biological attacks. Bloomberg Businessweek reports.
These perfluorocarbon tracer gases (PFTs) are invisible, odorless, and nontoxic.
Seven different PFTs will be released at seven locations, on three nonconsecutive days selected for varying weather conditions. As they travel, the gases will be tracked by 200 air sampling devices set up on street light poles and in dozens of stations along 21 subway lines in all five boroughs.
The data from this -- the largest urban airflow study to date -- will be used to build a computer model that predicts how contaminants behave under various situations. “That would help guide us as to what our responders should do and what instructions we should give the public,” says NYPD deputy commissioner Paul Browne. “For example, do you shelter in place or do you evacuate -- and if so, in which direction.”
This Subway-Surface Air Flow Exchange (S-SAFE) project is funded by a $3.4 million Department of Homeland Security Transit Security grant. It’s performed in partnership with the U.S. Department of Energy’s Brookhaven National Laboratory and the Metropolitan Transportation Authority.
Tracer gases have helped track pollutants like coal fire soot and find air leakages in buildings. And PFTs, which also appear in artificial breathing systems, have been used since the 1980s to learn about airflow in big cities.
New York already has several airborne contaminant detection mechanisms in place, although they don’t track the movement of air: Police officers wear radiation detection devices on their belts, and police stations and some subway stations are outfitted with air analysis devices that get checked every 24 hours to see if they’ve collected biological or chemical contaminants.
The public will receive a day’s notice.
[BNL via Businessweek]
Image by Antonio Bonanno via Flickr
This post was originally published on Smartplanet.com