Guidelines for the assessment of viable fungal hygiene on indoor surfaces using RODAC petri plates

Abstract

It is recognized that damp indoor living and working environments can promote microbial growth from fungi, bacteria and yeasts causing occupant infection, exposure or sensitivity to spores, cellular debris, allergens and a range of inflammatory toxins. Although indoor dampness is recognized as a public health threat causing a variety of adverse effects, defining specific thresholds for identifying potentially unhealthy levels within existing buildings in required. In turn, developing practical guidelines that trigger remediation or other actions is important to minimize or prevent respiratory and other disease. This paper demonstrates how the replicate organism detection and counting (RODAC) plate can be used to bio monitor surfaces in the built environment; especially those that are damp or suspected of being mould contaminated. Several case studies are provided illustrating their use before reviewing some key metrics from the literature. Support for the Australian Mould Guideline is shown by the strong numerical correlation between the assessment of the hygiene ratings using colony forming unit counts on surfaces or from the air. This demonstrates a type of universality between fungal growth and its interpretation in either dimension.