Kidlington is a large village, 5 miles north of Oxford, and was the home of our next client. The client had requested an indoor air quality report of a dental surgery which was a semi-detached two-storey building and was situated on a major road. The building dates back to the early 1900’s and had recently been developed into a dental practice with the ground floor home to two surgeries, a waiting area including customer toilet, and a reception, and the first floor home to two further surgeries, staff toilet, kitchen and an office. The client informed us that there was a history of high damp in the first-floor staff room, but no reports of ill health because of this.
As we got to the staff room, we observed evidence of condensation mould to the external wall in the stock cupboard but the wall plaster showed normal moisture levels. There was also a crack in plaster at the ceiling-wall junction in the cupboard, but no evidence of water penetration or deterioration. There were however, two water distillers present, and were affecting the room with relatively high humidity levels. Although the ventilation from the window was being used as a way of emitting the water vapour, the actual result was that this method was only partly effective and it was evident that the water vapour was the root cause of the mould spores due to vapour on the walls and a lack of adequate ventilation.
We collected samples of airborne moulds via Vesta Spore Trap cassettes and using a High Flow 1600 air sampling pump, in accordance with the Sysco Environmental Ltd procedures manual. The results 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.
All other parts of the property were inspected and we did find further signs of water damage including a leak from the toilet drain pipe in the staff toilet, and also rising damp was noted in the reception area with a water charge pipe wetting the external wall and damp penetration to the back wall which is situated under the boiler. However, there were no signs of mould spores in these areas.
Based on the results, our opinion was that the overall indoor air quality was only marginally affected by the mould spores, and the extent of the contamination was small (~1m²). We were satisfied that the employees were not at an increased risk of health due to the mould. Recommendations to the client included insulating the external wall in the staff room and more importantly, installing a suitable and effective ventilation port to the door of the cupboard. The mould spores should be removed carefully, using approved methods such as air filtration and localising containment.