Surface and passive/active air mould sampling: A testing exercise in a North London housing estate

Yasemin Didem Aktas; Ioanna Ioannou; Hector Altamirano; Morten Reeslev; Dina D'Ayala; Neil May; Melisa Canales

doi:10.1016/j.scitotenv.2018.06.311

Surface and passive/active air mould sampling: A testing exercise in a North London housing estate

Sci Total Environ. 2018 Dec 1:643:1631-1643. doi: 10.1016/j.scitotenv.2018.06.311. Epub 2018 Jul 10.

Authors

Yasemin Didem Aktas¹, Ioanna Ioannou², Hector Altamirano³, Morten Reeslev⁴, Dina D'Ayala⁵, Neil May⁶, Melisa Canales⁷

Affiliations

¹ Epicentre Research Group, Department of Civil, Environmental and Geomatic Engineering (CEGE), University College London (UCL), London, UK; UK Centre for Moisture in Buildings (UKCMB), London, UK. Electronic address: y.aktas@ucl.ac.uk.
² Epicentre Research Group, Department of Civil, Environmental and Geomatic Engineering (CEGE), University College London (UCL), London, UK.
³ UK Centre for Moisture in Buildings (UKCMB), London, UK; Institute of Environmental Design and Engineering (IEDE), University College London (UCL), London, UK.
⁴ Mycometer A/S, Horsholm, Denmark.
⁵ Epicentre Research Group, Department of Civil, Environmental and Geomatic Engineering (CEGE), University College London (UCL), London, UK; UK Centre for Moisture in Buildings (UKCMB), London, UK.
⁶ UK Centre for Moisture in Buildings (UKCMB), London, UK.
⁷ Healthy Infrastructure Research Group, Department of Civil, Environmental and Geomatic Engineering (CEGE), University College London (UCL), London, UK.

PMID: 30189579
DOI: 10.1016/j.scitotenv.2018.06.311

Abstract

Despite indoor mould being one of the most common problems in residential properties in the UK, there are not any widely accepted methodologies for its measurement. This paper focusses on this problem of measurement and reports on the findings from a rigorous testing scheme carried out to quantify air and surface mould concentrations and particle counts within 71 rooms from 64 properties in North London, some with and some without visible mould. The aim was to investigate the potential of passive and active air sampling strategies (sampling from still and actively mixed air, respectively) to explain visible mould, and understand how home/room characteristics correlate with the obtained readings. Airborne mould levels were quantified using an Andersen sampler (passively and actively), as well as by a chemical method based on the quantification of the N-acetylhexosaminidase (NAHA) activity (actively), which was also used to quantify surface mould. The mould levels were then correlated against physical characteristics of the tested homes/rooms, collected by means of survey sheets developed as part of this study. The findings did not reveal any independent variable governing all or most of the response variables, but a complex analysis suggested that whether it is a house or a flat could depict mould levels in the air and on the surfaces. It was also shown that a robust testing protocol should combine air and surface based methods, and an active air sampling strategy leads to a more accurate appraisal of airborne mould levels. Finally, the results showed that while there is some correlation between visible mould (and other moisture induced problems such as condensation) and measured air mould concentrations, lack of visible mould within a room does not necessarily mean low air mould concentrations, and thus one should not rely solely on visual inspection.

Keywords: Active/passive sampling; Andersen sampler; Mould; NAHA; Particle count; Residential indoor environment.

MeSH terms

Air Microbiology*
Air Pollution, Indoor / statistics & numerical data*
Environmental Monitoring / methods*
Fungi
Housing / statistics & numerical data*
London