New device kills anthrax spores

KES Science & Technology, Inc has modified a technology originally developed to help plants grow onboard spacecraft to create a device that kills anthrax spores.

KES Science & Technology, Inc has modified a technology originally developed to help plants grow onboard spacecraft to create a potentially life-saving device that kills anthrax spores.

AiroCide TiO2 is a new device that reportedly kills 93.3% of airborne pathogens that pass through it. It was developed from already-existing technology that is used to remove ethylene gas, which causes premature ageing in plants, and airborne pathogens from the air.

This patented technology was first developed for use in ASTROCULTURE, a plant growth chamber for commercial experiments on the Space Shuttle.

The technology was jointly developed by the University of Wisconsin-Madison and the Wisconsin Centre for Space Automation and Robotics (WCSAR), a NASA Commercial Space Centre. As a result of a partnership between KES Science & Technology, Inc. and the University of Wisconsin several years ago, the Bio-KES unit — the precursor to AiroCide TiO2 — was developed.

The Bio-KES unit was borne out of the discovery that ultra-thin layers of titanium dioxide (TiO2) exposed to ultraviolet light would efficiently convert ethylene into carbon dioxide (CO2) and water (H2O) – substances that are good for plants. Tests also showed that Bio-KES killed airborne dust mites.

Marc Anderson, a professor and chemist at the University of Wisconsin-Madison explained that when ultraviolet (UV) photons strike something coated by TiO2 – like the tubes inside Bio-KES – positive and negative charges appear on its surface. Those charges tear apart nearby water molecules. The OH- ion, a by-product of the reaction, disrupts organic molecules. It’s deadly to dust mites, anthrax and many other pathogens.

A Bio-KES unit was modified to include 52 germicidal UV bulbs, instead of its usual 6 germicidals and 48 UV black lights.

After testing the new unit, dubbed AiroCide TiO2, in a laboratory, Dr. Dean Tompkins, one of the original developers of the TiO2 technology, determined that AiroCide TiO2 would kill 93.3% of Bacillus thurengiensis (a close relative of anthrax) that went through the unit on the first pass.

Spores that enter AiroCide TiO2 spend at least 5 to 10 seconds in transit through the device. ‘That’s important,’ said John Hayman of KES Science and Technology, ‘because pathogens that remain inside longer are more likely to die.’

To slow the spores, TiO2-coated tubes within the unit are randomly arranged so there’s no direct path through the machine. When air moves across the jumbled tubes, the flow becomes turbulent – forcing spores to linger where they can be attacked by OH- and illuminated by germ-killing ultraviolet light.