Assessing Indoor air quality in relation to biological and non-biological contaminants

Is indoor air quality contaminated?

Most recently we travelled to Somerset where we were asked to carry out an assessment of indoor air quality in relation to selected biological and non-biological contaminants. The property was a residential building which dated back to the 1930’s. The current owners had occupied the property for approximately 13 years. One occupant reported that during this period she had not observed any adverse health symptoms however back in 2014 a leak developed to both chimneys which had resulted in relatively minor water damage to the first floor ceiling plaster. This damage did not result in mould growth but was repaired almost immediately. 

After the repairs were completed the occupant reported a plaster-like taste in her mouth however she did not experience any coughing. Since the incident she regularly suffers from minor respiratory irritation and reduced or complete lack of taste. At the time of our assessment she was undergoing steroid-based treatment for allergic rhinitis and the ongoing treatment had significantly improved the symptoms. She was also allergic to penicillin. 

The occupant believed that the adverse health symptoms intensified during periods of elevated temperatures and during the evenings when the house is more sealed. During the day the property is intensively ventilated and she spends a majority of the day outdoors. Adverse health symptoms appeared to be most intense in the kitchen, office and adjacent bedroom on the first floor. 

assessing indoor air quality in relation to selected biological/non-biological contaminants

Are biological/non-biological contaminants to blame?

Our surveyor begun his assessment by means of a visual inspection of the property. This revealed that there were no visible areas of fungal contamination throughout the property. Our surveyor then used the moisture mapping process in order to locate areas of elevated moisture. This identified several areas of elevated moisture most significantly affected was the property entrance porch. The distribution of the moisture content in the wall construction was indicative of rising damp. The deterioration of the wall construction in this area is significant. Several other areas on the ground floor were also identified as having elevated moisture content most likely due to rising damp. In all of these areas the water damage to the wall construction is not significant and is mostly of cosmetic character.

So based on the results of moisture mapping, visual observation and microbiological sampling and identification it is our opinion that the most likely reason for adverse health symptoms is initial sensitisation of the occupant to elevated concentration of fine organic and inorganic dust and fungal spore which occurred during initial the water leak incident to the property chimneys. Continuous sensitisation might be a result of much lower concentration of contaminants than the one initial present in the environment. It has been observed that some openings to the chimneys were inadequately sealed. Open apertures into the chimneys are likely to be a source of fine particulate dust during periods of high wind.

assessing indoor air quality in relation to selected biological/non-biological contaminants

What did we recommend our client?

We strongly recommended to clear the rooms of all the stored materials, remove wooden skirting boards and remove all deteriorated wall plaster. It is strongly recommended to appoint a qualified building engineer to identify the exact origin of the dampness and suggest appropriate remedial solution suitable for this type of construction. The room construction should be dried out using dehumidifiers once the underlying water penetration issue has been resolved.

We also strongly recommended that all the chimney apertures were adequately sealed, all water damaged materials removed from the rooms affected and if the symptoms persisted to remove all animals from the house. After all potential sources of irritants have been  removed it is recommend to carry out a specialised deep clean of the property with the aim to clean the surface areas of dust, fungal spores and filtrate and neutralise the indoor air of all airborne contaminants 




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