On top of the numerous functions our cell phones perform, the Department of Homeland Security says they may one day also protect us from toxic chemicals.

In the coming years, Homeland Security's Science and Technology Directorate (S&T)'s Cell-All aims to equip cell phones with a sensor capable of detecting deadly chemicals. A chip costing less than a dollar is embedded in a cell phone and programmed to either alert the cell phone carrier to the presence of toxic chemicals in the air, and/or a central station that can monitor how many alerts in an area are being received. One might be a false positive. Hundreds might indicate the need for evacuation.

How would this wizardry work? Just as antivirus software bides its time in the background and springs to life when it spies suspicious activity, so Cell-All would regularly sniffs the surrounding air for certain volatile chemical compounds.


The sensor in the chip would identify the toxic chemical and send an alert to a central station and the cell phone carrier.

(photo credit: DHS S&T)

When a threat is sensed, an alert ensues in one of two ways. For personal safety issues such as a chlorine gas leak, a warning is sounded; the user can choose a vibration, noise, text message or phone call. For catastrophes such as a sarin gas attack, details—including time, location and the compound—are phoned home to an emergency operations center. While the first warning is beamed to individuals, the second warning works best with crowds. And that's where the genius of Cell-All lies—in crowd sourcing human safety.

Currently, if a person suspects that something is amiss, he might dial 9-1-1, though behavioral science tells us that it's easier to do nothing. And, as is often the case when someone phones in an emergency, the caller may be difficult to understand, diminishing the quality of information that's relayed to first responders. An even worse scenario: the person may not even be aware of the danger.

In contrast, anywhere a chemical threat breaks out—a mall, a bus, subway or office—Cell-All will alert the authorities automatically. Detection, identification, and notification all take place in less than 60 seconds. Because the data are delivered digitally, Cell-All reduces the chance of human error. And by activating alerts from many people at once, Cell-All cleverly avoids the long-standing problem of false positives. The end result: emergency responders can get to the scene sooner and cover a larger area—essentially anywhere people are, casting a wider net than stationary sensors can.

And the privacy issue? Does this always-on surveillance mean that the government can track your precise whereabouts whenever it wants? To the contrary, Cell-All will operate only on an opt-in basis and will transmit data anonymously.

"Privacy is as important as technology," says Stephen Dennis, Cell-All's program manager. "After all, for Cell-All to succeed, people must be comfortable enough to turn it on in the first place."

For years, the idea of a hand held weapons of mass destruction detector has engaged engineers. In 2007, S&T called upon the private sector to develop concepts of operations. Today, thanks to increasingly successful prototype demonstrations, the Directorate is actively funding the next step in R&D—a proof of principle—to see if the concept is workable.

Dennis hopes to have 40 prototypes in about a year, the first of which will sniff out carbon monoxide and fire.