Air quality assessment in a domestic property

Is poor indoor air quality to blame for respiratory difficulties?

We were invited to a two storey detached property, situated in Derbyshire, with brick external walls and a pitched tiled roof. The building dates back to the 1890’s and has been refurbished and extended in the recent years. 

At the time of our assessment the property was under partial refurbishment in the ground floor kitchen and the first floor bathroom. The property owners have been living at the property for approximately 3 years, however one of the residents living in the property have been experiencing respiratory difficulties, asthmas-like symptoms, fatigue and eye irritations. The adverse health symptoms have been reported in all rooms of the property, with no seasonal or diurnal variations. The symptoms were first reported approximately 1 and 1/2 years ago while a small extension was being built to the side of the building. 

Air quality assessment in a domestic property

Conducting an assessment of indoor air quality

Many things can influence the indoor air quality so it is important that we take all factors into consideration when making an assessment. We must take into account; the outdoor environmental conditions, whether there were any unusual activities in close proximity to the property, any airborne moulds and bacteria and finally any moisture in the property. 

At the time of the assessment the outdoor environmental conditions were: temperature 19.4°C ; Relative humidity 62.7% ; Atmospheric pressure 998 hPa ; Wind SW direction 0-0.5 m/s. There were no unusual activities (ground works, building works, harvest) observed near the property. We collected samples of airborne samples onto Vesta spore Trap cassettes using high flow 1600 air sampling pump. We also collected samples of airborne viable moulds and bacteria onto tryptone soy and sabouraud dextrose agar 90mm plates using MAS-100 high volume microbiological sampler. Moisture mapping was then carried out using a Hydromette HB30 moisture meter and a Tramex Moisture encounter plus. We also measured the wind speed with a rotating vane anemometer LCA301. 

air quality assessment in a domestic property

Is poor indoor air quality the root cause?

Moisture mapping and investigation revealed that the property is not affected by penetrating, condensation damp or leaking services. However there was evidence of minor rising damp on the living room walls, although there was no damage to the decorative finishes. With the exception of the living room the damp survey of the rest of the property did not identify any areas with elevated moisture in construction materials. 

Based on the results of moisture mapping, visual observation and microbiological sampling and identification we can conclude that; the overall indoor air quality in the property is not effected by elevated numbers of fungal spores and bacteria as there was no evidence of fungal contamination to the property. Some of the property occupants can be considered at an increased risk to health due to personal circumstances, however the overall risk to health from exposure to fungal spores is low. It is our opinion that the adverse health symptoms experienced by the occupants are unlikely to be caused by the indoor air quality.

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