Zapping airborne germs

A device that is claimed can kill some of the modern world's most deadly and quickly transmitted airborne bacteria and viruses has been developed in the United Kingdom.

Medixair, an ultraviolet air steriliser devised by design engineers Pathogen Solutions, was used to help combat the SARS (severe acute respiratory syndrome) epidemic that swept Asia in 2003. Now the equipment - which exposes the micro-organisms to lethal levels of ultraviolet radiation - is undergoing trials with the UK's National Health Service to help solve the problem of hospital-acquired infections.

John Burrows, managing director of Pathogen Solutions, said: "Medixair generates an energy level of over 22,500 µWs/cm2, enough to kill practically all known airborne bacteria (achieving a log6 reduction).

"There is ample energy to kill Escherichia coli, Staphylococcus aureus - the bacteria behind MRSA (the hospital 'superbug' that has proved to be resistant to conventional antibiotics) - and Pseudomonas aeruginosa, and Acinetobacter."

The system works by drawing air through a central chamber containing four high-power ultraviolet lamps. Air, which contains harmful organisms, is exposed to powerful ultraviolet light that then kills the viruses, bacteria, moulds and fungi.

Ultraviolet light works by breaking up the bases of the DNA helix within the bacteria, therefore stopping the reproduction of the cell. Medixair has been mathe-matically engineered to ensure that there is a high density of energy throughout the radiation chamber, attributable to the position of the UVc lamps and their reflectors.