An Israeli researcher has developed a new infrared system inspired by the vision of snakes and bats that can monitor water supplies, and keep us safe from chemical attack.
Chemical terrorism, or chemo-terrorism for short, doesn’t get as much press as bio-terrorism, but the objectives are the same and the means even more readily available.
In both cases, the purpose is to intimidate or coerce governments or civilian populations, to further political or social objectives. The difference is the method: chemo-terrorism means poisoning the air, water and food supply using chemicals such as caustic acids, arsine, benzene, cyanide, hydrofluoric acid, mustard/T, ricin, sarin, and others.
Bioterrorism involves releasing biologic agents or toxins, such as anthrax, brucella, cholera, e.coli 0157:H7, glanders, ricin toxin, typhoid fever, viral hemorrhagic fever, or any communicable disease. And while it may be difficult to get hold of anthrax, many poisons are as easy to get as going down to the local hardware or gardening store.
Urban water supplies are particularly vulnerable to chemoterror, says Israeli physicist Prof. Abraham Katzir. Colorless and odorless liquids can’t be seen by the human eye and water supplies aren’t necessarily subject to daily testing.
With many skyscrapers holding water reserves on the top of the building, a terrorist only needs to introduce poison into a tank to wreak havoc. “A terrorist wouldn’t have to kill tens of thousands of people. Only 50 deaths – as horrible as that would be – would cause nationwide panic.”
Now, to combat the threat of contamination due to sabotage, industrial spillage or natural disaster, Katzir has developed a new system that uses a part of the infrared (IR) spectrum seen only by snakes or vampire bats, to monitor the safety of a building or community’s water supply – and in real time.
A personal challenge
Under Katzir’s direction, Tel Aviv University’s applied physics group has been involved for more than 10 years in research and development of devices that operate in the mid-IR spectrum (3-30 microns).
The group has developed semiconductor lasers, electro-optical systems and optical fibers for this spectral range, in particular, crystalline fibers made of silver halides (AgClBr). One development, a laser bonding system that would allow surgeons to weld instead of suture tissue, has already received a great deal of media interest.
Now Katzir is making news again, this time with a special IR fiber that could help protect water supplies from bio and chemo-terrorism as well as ecological disaster.
Katzir has personal reasons for warning ordinary citizens against the threat of attack. His father, world-renowned scientist Prof. Aharon Katzir, was killed in 1972 at the Lod Airport Massacre, in which three members of the Japanese Red Army, on behalf of the Popular Front for the Liberation of Palestine, (PFLP), killed 24 people and injured 80 others at Israel’s national airport.
“I am trying to walk in his footsteps by doing applied research that can be a practical tool in an important battle,” says Katzir.
Seeing water like snakes do
The modified optical fiber can detect “colors” in the IR spectrum that distinguish between pure and contaminated water. The spectrum is invisible to the naked human eye and perceived only by certain animals that use it to track down prey.
“With our naked eyes we can’t distinguish between pure water and water that contains a small amount of alcohol or acetone. They’re all clear. We can’t do it even with a spectrophotometer, which measures visible colors,” explains Katzir. “But we can clearly distinguish between liquids using an infrared spectrometer which can distinguish between ‘colors’ in the invisible infrared spectrum.”
Connected to a commercial IR spectrometer, the fibers serve as sensors that can detect and notify authorities immediately if a contaminant has entered a water reservoir, system, building or pipeline. Such an instrument could be used to detect hazardous chemicals, pollutants and threats in the water.
The special fiber sensors enable real-time monitoring of water quality in remote locations, such as a lake, a river, or a pipeline. Currently, there is no system in place to detect chemical threats, whether intentional or accidental, instantaneously. Katzir says that the system he proposes can be ready for use in less than a year.
According to the US Centers for Disease Control and Prevention, “drinking water can be tested around the clock, including hourly, monthly, quarterly, and annually, depending on the location and size of the public water system”. Note the word ‘can’, not ‘is’. In practice, water authorities in the US test water reservoirs usually once every day or two. Katzir notes that his automatic notification system “can cut millions of dollars from the cost of testing water manually.”
Skyscrapers at risk
In lab tests, the fiber-optic system detected poisons such as pesticides in amounts well below the World Health Organization safety threshold.
Preliminary field experiments have already been done at several European sites, and the results were reported recently in the Journal of Applied Spectroscopy. Katzir says that water management executives in Florida’s Everglades and officials in Germany are among those who have expressed an interest in the technology.
The sensors are biocompatible, non-soluble and non-toxic, he adds. “You can eat them and nothing will happen to you.”
And how real is the threat of chemo-terrorism? “Toxic materials are readily available as pesticides or herbicides in the agriculture industry, and can be harmful if consumed even in concentrations as low as few parts per million,” says Katzir, who feels that skyscrapers in cities such as New York are a likely point of attack.
“It’s unlikely that someone will poison the water supply in Afghanistan, but America is in grave danger and needs to arm itself against chemical threats to its drinking water,” he concludes.