On With the Lights, Off With the Germs

Ultraviolet germicidal lights may reduce contamination of office ventilation systems

THURSDAY, Nov. 27, 2003 (HealthDayNews) -- A special type of ultraviolet lighting installed in office heating, ventilation, and air conditioning systems can cut the contamination of employees with respiratory infections that may be spread in the workplace. That's the conclusion of a Canadian study in the Nov. 29 issue of the journal The Lancet.

The researchers note that employees in modern office buildings frequently suffer unexplained work-related symptoms or combinations of symptoms.

The study included 771 volunteers in office buildings in Montreal. Drip pans and cooling coils within office ventilations systems were exposed to ultraviolet germicidal irradiation (UVGI). The UVGI was alternately turned off for 12 weeks and on for four weeks. This cycle was done three times.

The study found that UVGI reduced by 99 per cent the concentrations of microbial (imcrospopic organisms) and endotoxins on irradiated surfaces within the ventilation systems. The volunteers reported no adverse effects and the use of UVGI was associated with significantly fewer workplace symptoms overall.

The study authors conclude that installation of UVGI in most North American offices could resolve work-related symptoms in about 4 million employees. They suggest that the cost of UVGI installation could prove cost effective in the long run compared with the cost of employee absence due to building-related illness.

One of the most virulent forms of buiding-related contamination is Legionnaire's disease, which infects an estimated 8,000 to 18,000 people each year in the United States alone. Legionnaire's disease can be fatal.

More information

Here's where you can learn more about sick building syndrome.

SOURCE: The Lancet news release, Nov. 27, 2003
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