Is poor Indoor Air Quality hazardous to Health?
Our next project was a residential property situated in Kingston upon Thames. We were called to the property and instructed to carry out an assessment of Indoor Air Quality as the occupants were experiencing respiratory difficulties in some areas of the property. The respiratory difficulties noted included fatigue and eye irritations and these symptoms appeared to alleviate on exiting the property.
The property itself was a two-storey semi-detached residential property with brick external walls and a pitched tiled roof. The building is surrounded by mature vegetation and decorative gardens on all sides, and is in close proximity to the river Thames. The ground floor of the property consists of a kitchen, a school room, a toilet, a living room, a utility room and a garage. The second floor consists of four bedrooms, three bathrooms and a boiler cupboard. A majority of the rooms have wooden or ceramic floors, plasterboard walls and ceilings and modern double glazed UVPC windows.
Assessing the Indoor Air Quality
It was our job to attend the property and carry out an Assessment of the Indoor Air Quality and evaluate whether or not this was the cause of the respiratory difficulties the occupants had experienced. Our surveyor carried out this assessment by means of a visual inspection and by collecting samples of airborne moulds onto Vesta Spore Trap cassettes. Samples of airborne viable moulds and bacteria were collected onto Tryptone Soy and Sabouraud Dextrose Agar plates. Our surveyor used a process called Moisture Mapping using a Hydromette HB30 moisture meter and a Tramex Moisture Encounter plus in order to locate any moisture within the property which could occur as a result of poor Indoor Air Quality. The wind speed was also measured using a Rotating Vane Anemometer.
Conclusions and recommendations based on moisture mapping
After carrying out moisture mapping, our surveyor was able to come to the conclusion that the property was not affected by penetrating, rising, condensation damp or leaking services. Our surveyor did not identify any areas within the property with elevated levels of moisture within the construction materials. All areas affected by historic leaks showed normal moisture levels. The assessment of hydrothermal conditions did not show significant difference in temperature and humidity between different room of the property therefore this indicated normal conditions. When carrying out a visual inspection of the property our surveyor identified a small scale of fungal contamination to the back of the cabinet units in the utility room. He believed that the root cause of this contamination is a combination of high humidity and poor ventilation in the affected area. The high humidity in the utility room is caused by close proximity to an external single layer garden wall and the use of the room for drying clothing using a condensing tumble dryer. The likelihood of regular disturbance is low however some of the property occupants can be considered at an increased risk to health due to personal circumstances. It is our surveyor’s opinion that the adverse health symptoms experienced by the occupants are unlikely to be caused by exposure to fungal spores.
Based on the results from the moisture mapping and visual inspection our surveyor was able to make recommendations for our client in order to improve the Indoor Air Quality and prevent a build up of moisture. Our surveyor recommended the installation of active ventilation within the room in conjunction with the installation of passive ventilation ports to the cabinets kick boards. Alternatively, the back panels of the units can be completely removed thus significantly increasing air flow in this area and preventing condensation.