Interpreting Numerical Data of Viable Airborne Mould Samples

Viable Air sample taken on RCS agar strip

Another article on airborne mould samples provides guidelines for interpreting numerical data of viable air samples. To see the guidelines for non-viable air samples click Guidelines for Interpreting Non-viable Air Samples. The guidelines may be used to decide whether further investigations are required after initial investigations. As was indicated in the last Issue, numerical laboratory results cannot be used as the primary determinant of whether there is a mould problem but should always be … [Read more...]

When Should One Use Viable, Non-viable or Both Air Sampling Methods?

An air quality investigation may require determining airborne mould (spores and hyphal fragments) concentration. Air can either be sampled onto some growth media for culture analysis or on a sticky surface or a filter membrane for direct microscopic examination. It is sometimes debated as to whether one should take non-viable samples, viable samples or a combination of the two. Either method can be used without the other or both can be used together (at the same time) depending on the objectives … [Read more...]

How To Interpret Laboratory Results for Airborne Fungal (Mould) Samples

Mould spores sampled from air

Laboratory results for airborne mould and bacteria concentrations can be difficult to interpret for two major reasons. Maximum exposure limits have not been set Currently, there are no set maximum exposure limits (MELs) or threshold level values for airborne indoor mould and bacteria concentrations. Setting MELs would be difficult for reasons which include limitations in air sampling techniques (Kung'u, 2004), variability in sensitivity to microbial exposure among the human population, … [Read more...]

How IAQ professionals could help improve laboratory reports

Quality Microscope for Quality Service

Currently there are no standardized methods for the analysis of indoor samples for microbial contamination. Neither are there guidelines for the limit of what is to be reported by laboratories and how to present the results. Without guidelines reports from different laboratories are difficult to compare. The quality of laboratory reports is also sometimes compromised. Despite lack of standards and guidelines, the quality of laboratory reports could be improved with better communication between … [Read more...]

Guidelines for Interpreting Numerical Data of Non-viable (Spore Traps) and Viable Airborne Mould Samples

Chaetomium and Aspergillus spores

In this article we discuss additional guidelines for interpreting numerical data for viable and non-viable airborne mould samples. The guidelines may be used to decide whether further investigations are required after initial investigations. However, numerical laboratory results cannot be used as the primary determinant of whether there is a mould problem but should always be used together with visual inspection data and other available information such as the building history. Generally, … [Read more...]

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