New Sewer Sensors Sniff Out Signs of Bombs and Drugs
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Bomb-makers and chemists with Breaking Bad crystal-meth type labs better watch out. A sewer system full of chemical sensors could sniff out their homemade labs as part of a €4.5 million European Union-funded research program called Emphasis.
The idea is that once a sewer sensor finds telltale traces of home-brewed explosives, it sounds an alarm and a police team carrying a portable, high-resolution sensing unit can be dispatched to narrow the search and pinpoint the exact location. The technique could also be modified to look for signs of illegal drug factories.
According to New Scientist, Emphasis is led by Hans Önnerud, an analytical chemist with the Swedish Defense Research Agency in Kista, north of Stockholm. His approach relies on the fact that some liquids and gases from bomb or drug production will leak into the sewers through sinks, baths or toilets, and into the air via windows and skylights. He says a hint that such gases might be detectable became clear in the wake of the London bombings on 7 July 2005 that killed 54 people. Fumes from the explosives made at a house in Leeds, U.K., killed plants in the garden.
IHLS – Israel Homeland Security
Önnerud‘s team claims that they have successfully tested their sensors in the lab. The sensors are designed to pick up signs of explosives precursors, such as chemical reagents and reaction breakdown products. Each sensor comprises a number of 10-centimetre-long devices called ion-selective electrodes that are submerged in the wastewater flow of a sewer.
Only ions that come from the breakdown products of bomb-making chemicals can diffuse through the membranes in the electrodes, changing a resistor’s voltage in a telltale way. Software looks for patterns in the concentration of target ions. Above ground, an infrared laser carries out a sweep of an area looking for the spectra of target gas molecules. The Emphasis sensors have been developed and tested on faeces-rich wastewater in the lab and will be tested in real sewers next year.
Instead of ad-hoc sampling, sensors could track drug use in real time – for example, monitoring usage patterns to inform public-health programs. “We are thinking about illicit drugs detection and this could be the next aim we focus on,” says the project’s sensor specialist Frank Schnürer of the Fraunhofer Institute in Germany. The country’s Ministry of Education and Research will be looking for research proposals for sewer-based drug detection soon, he says.
