Sniffing sensors discern stench from menace
By ASSOCIATED PRESS
Published January 11, 2007
NEW YORK - When a mysterious odor wafted through the city this week, Mayor Michael Bloomberg quickly appeared on television to reassure unnerved New Yorkers that the smell - whatever it was - was harmless.
The pronouncement was more than guesswork.
Over the past three years, the U.S. government has deployed hundreds of air-sniffing sensors in at least 30 metropolitan areas to create an early-warning system for a chemical or biological attack. In some cities, the devices test the air 24 hours a day for traces of anthrax, smallpox and other deadly germs.
When the smell came through New York on Monday, it did not set off any of the system's alarms. And that helped offer the public some reassurance.
Most of these urban monitoring networks are still in a fledgling stage, and authorities warn that they have their limitations. But the surveillance network has been steadily improving.
In some cities, including New York, Boston and Washington, monitors have been installed in major train and subway stations to sample the air for poisonous chemicals or explosive gases. Also, environmental agencies have been given portable air sensors that can be driven around in vans or carried by hand.
The system has its limits. Among them, the devices are at the whim of wind patterns and can detect only substances that have already been released into the air - meaning that their primary usefulness is in getting victims treated quickly and preventing a contagion from spreading.
None of the many air-sampling systems available to investigators was able to actually identity the rotten-egg smell that wafted across parts of New York and New Jersey on Monday, and city investigators relied mostly on traditional methods of analyzing the odor. Investigators have yet to identify the smell.
Some experts have warned that there are far too few monitors in place. A report by the Environmental Protection Agency's inspector general raised questions in 2005 about the reliability and efficiency of what was then a $129-million BioWatch program.
Criticism of the system has lessened somewhat, however, as its technology has improved. For instance, cameras were added to allow operators to see if anything close by might be triggering the alarm.
[Last modified January 11, 2007, 01:15:44]
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