Travelling north towards the Pennines, we were off to the town of Oldham to a client who had asked us to perform an assessment of the indoor air quality of their dental surgery. The building itself was a two-storey end of terrace, situated in a residential area, and has four surgery rooms over two floors, a combined waiting and reception room, staff toilet and changing room, a customer toilet and various other rooms/cabinets for storage etc. We were informed that the building has a history of high humidity in the cellar but to date, there had been no staff reports of ill health that could have been attributed to from the building environment.
We decided to start from the bottom and make our way up through the property, as there were historical reports of humidity in the cellar, it was the most logical and sensible place to begin. The basement itself was approximately 3x4x2.3 meters and was built of concrete walls with plaster on top and a timber ceiling. There was evidence of penetrative damp in the front wall, which was characteristically patchy and was most prominent in the center of the wall and there was also elevated moisture in the walls and to the plastering which surrounded the window. Even with evidence of damp, the room appeared to be in seemingly good condition and there were certainly no signs of mould.
We made our way upstairs to the toilets corridor and examined the cabinets which are used for storing cleaning materials, mops, buckets etc. The plaster board and the skirting boards were evidently suffering from higher than normal moisture content and there was obvious mould contamination to the wall surfaces. The internal plywood was particularly stained and colonised by mould and the root cause of this mould we could see, was apparent water damage to the bottom parts of the walls. The situation was further worsened by the fact that wet mops were leaking onto the internal plywood causing rot, and unemptied buckets of water were also stored in the cupboard.
All other parts of the property were inspected and we found no further signs of water damage or mould contamination.
We took samples of airborne moulds, accordance with the Sysco Environmental Ltd procedures manual, which were then analysed in strict accordance with D7391-09 Standard Test Method for Categorization and Quantification of Airborne Fungal Structures in an Inertial Impaction Sample by Optical Microscopy.
Based on the results, our opinion was that the overall indoor air quality was being significantly affected by the mould, but the extent of the contamination was small (~2m²) and we were satisfied that the employees were not at an increased risk of health due to the mould. Recommendations to the client included removal of the existing mould using suitable methods and installing a drainage channel, along with other general housekeeping improvements