Quick Dips

Bogeys in your Office Air

Bacterial levels inside Auckland offices are significantly higher than those in Wellington, yet the city's indoor fungal levels are significantly below those of the Windy City despite having three times the outdoor fungal levels.

This is one key finding from a study undertaken by Hany Fouad, a Masters in Building Science student in the School of Architecture at Victoria University. The study used data, collected in Wellington and Auckland from 1990 to 1995, on the levels of indoor airborne bacteria and fungi in fully sealed, mechanically ventilated offices.

There were no significant differences observed in airborne bacterial and fungal levels between offices where complaints had been made and those which were complaint-free. Indoor airborne bacterial and fungal levels in New Zealand offices appeared to be within the levels of those of offices in Europe, the US and Canada, though differences in sampling techniques meant the need for caution in making such camparisons.

"Hany realised that a new evaluation tool was needed which could identify the existence of a fungal problem in an office environment, and determine the likely sources of the problem regardless of the measurement technique used in collecting and analysing the fungal samples," says Fouad's thesis supervisor Dr George Baird.

The tool which Fouad developed could indicate if an external fungal source is the issue, if there is a filter problem or if an internal fungal source is the cause of concern.

"The new evaluation tool can determine how successful the ventilation system is in preventing outdoor air pollutants from penetrating the office environment," Baird says.