Carrying out a Microbiological Investigation

History of water damage in property

Our next client contacted us and asked us to carry out a partial property inspection and microbiological sampling in the basement of a well known bank in Porthmadog. Our aim of this investigation would be to evaluate the extent of the water damage to the property basement, assess the extent of fungal contamination, evaluate the levels of fungal elements in the indoor air and finally to assess the risk to health of the property occupants.  

The basement level of the property consisted of 6 rooms and associated corridors. One of the rooms was a purpose build vault for the storage of documents, two further rooms were used for the storage of documents and a further three room were currently vacant. The document storage rooms had timber shelving and documents were stored in cardboard filing boxes.

carrying out a microbiological investigation

Results of microbiological sampling

Microbiological sampling revealed that the basement of the property is currently suffering from significantly degraded air quality. Our surveyor noted that there was a strong presence of damp and mould odours in the customer areas of the bank prior to entering the basement. The indoor air of the property is significantly contaminated by Penicillium/Aspergillus types of spores with the presence of toxic Stachybotrys spores. The concentrations of these fungal spores in the air significantly exceeds the normal environmental levels typical for this area. 

Moisture mapping was then carried out with the use of a Hydromette HB30 moisture meter and a Tramex Moisture encounter plus. Moisture mapping revealed that the basement was suffering from penetrating damp to large areas of wall surfaces, very high relative humidity levels and fungal contamination to the wooden shelving and stored documents (see images). Due to this it is our opinion that working in the basement would represent a risk to health. We believe the root cause of the fungal contamination is the high humidity in the atmosphere due to water penetration through the walls. 

carrying out a microbiological investigation

What remediation measures did we recommend?

Our investigation revealed that the rooms in the basement are not suitable for long term document storage without extensive remediation measures. Therefore we strongly recommend that all stored documents are removed from the affected areas in order to prevent further damage from fungi. Any contaminated materials such as the wooden shelving units, should be carefully disposed of, using air management to prevent exposure of employees and public on the ground floor. 

Any employees working in the basement should be equipped with disposable overalls, gloves and respiratory protection of at least FFP3 standard. In order to prevent fungal odours entering the public areas, it is recommended to put the basement under negative air pressure by air extraction from the basement to the outside environment. Opening all basement doors will also encourage air movement throughout the basement, especially in rooms 2,3 and 4 as these are the major sources of moisture and odours in the basement.

Link through to Sysco - Nationwide specialists in hazard exposure monitoring
Hi, I have been working in my job as an Indoor Air Quality Investigator for a number of years and decided to share my experience with you. You can find lot of related information on my website toxic black mould
Leave a comment