Toxic black mould has made one Tauranga City Council worker sick and forced 35 others to be shifted to safer parts of their building.
The mould issues were discovered after a staff member, who had been at the council for about six weeks, had become ill, said Garry Poole, council chief executive.
"He raised the issue that the work area he was in contained some mould. We relocated the staff member and undertook some testing of his work environment.
"The results came back on December 4 that we had a positive test for Stachybotrys, black mould."
Mr Poole said there had been no visible patches of mould, but there were signs such as flaking paint and stained carpet that could have been mistaken for wear and tear.
The report showed carpet and underlay from the ground floor administration building had Stachybotrys present and abundant with active growth. Other fungal spores were also noted.
The same result was found in carpet and underlay of a corner office on the first floor.
Upon receiving the report, Mr Poole said advice was sought from the Bay of Plenty District Health Board, the Medical Officer of Health and Worksafe New Zealand, and the remaining employees in the affected ground floor and first floor rooms were relocated to other rooms on the second floor of the council building.
The affected staff worked in the environmental management and asset management departments.
"We've extended the testing to wider areas that there is some mould evident in.
"We're also extending tests to the whole building because we want to be sure we are providing a safe work environment for all of our people."
Air samples would also be analysed as black mould could become airborne when it dried out, he said.
Mr Poole was unsure what had caused the mould or how long it had been present in the affected rooms.
"There have been cases of people working in an environment that contains this stuff with nil symptoms. Our people in this workplace that tested positive, some have been in there for years and have displayed nil symptoms.
"This is very much an individual reaction."
To find out what caused the mould, the council was trying to "track back the history of the building".
"There were major alterations done to the building around 2000 to 2001.
"We're trying to put together a timeline of the history of the building. As part of that, we're talking to our property people about when leakages have occurred. At this point, there are no indications of what caused the mould."
Mr Poole was unsure how long these investigations would take, particularly with the Christmas break coming up.
Tauranga Mayor Stuart Crosby said the issue was being taken seriously.
"Every endeavour will be made to ensure it's a safe workplace and that the work the staff do can continue seamlessly."
Mr Crosby said the scale of the problem would be revealed once more thorough testing was completed.
Stachybotrys and other toxic moulds often grow only inside wall cavities. When the mould is contained in a sealed environment, it is not a threat to occupants. However, if the mould spreads to walls and floors and is visible, or if wall cavities are opened, the spores can be released.
Some moulds can produce adverse health affects such as allergies, aggravation of respiratory problems, eye and skin irritation, headaches, nausea and flu-like symptoms.
- Ministry of Business, Innovation and Employment