Moulds are notoriously difficult to find. They love damp, dark places, shunning the cleansing effects of sunlight in particular. All they need to grow is moisture and an adequate food source, and these can be found in the most unlikely of places under flooring, in wall cavities and behind cupboards for example.
Detection of moulds when they are growing in inaccessible areas is often impossible without resorting to expensive damage to a property - if none is found then there are hefty repair bills to be paid not to mention the time it takes to carry out the work in the first place.
There has long been a need for a quick, cheap and reliable method for the detection of mould growth in buildings and the solution might have been found at last. It has long been known that moulds emit vapours as they grow, known as volatile organic compounds (VOC).
A recent paper by Moularat et.al. attempts to establish the characteristic pattern of VOC's emitted by moulds growing on building materials. They measured the VOC's being emitted by uncontaminated building materials and compared them with those emitted by materials infested with moulds.
Despite the finding that VOC's emitted by moulds accounted for only 1% of all the VOC's emitted by contaminated building materials, they were able to find a characteristic fingerprint of VOC for moulds growing in buildings and successfully validated it by provings the usefullness of their findings in 11 test buildings. All that was needed to carry out the analysis was a sample of air from within the building.
This study was restricted to the use of 3 species: Aspergillus niger, A. versicolor, Penicillium brevicompactum and relatively few building materials so needs to be expanded but clearly suggests a way forward in this most difficult area of envoronmental health.