What is The Science That Studies Mold?

You may take air samples when trying to identify a hidden mold problem. The total number of spores in the complaint area should be compared to indoor and outdoor controls, or more accurately, “references.” For example, if you find 10,000 spores per cubic meter in the complaint area and only 1,000 in the reference samples, there is a high likelihood of indoor amplification.

Although it’s important to look at the total numbers, it’s critical to also make comparisons of the types of mold. Each type of mold is unique.

There are some types that will predominantly grow on leaves outdoors. These don’t have an appetite for building materials and will rarely be found growing indoors. Other types, however, do have the enzymes needed to digest common building materials in their quest for more food.

A few references of science that study mold can help you make a distinction between types of mold typically found outdoors and those that can grow on building materials.

I’ll summarize a few of this science that studies mold below: 


In the 90′s, the Environmental Protection Agency carried out the Building Assessment Survey and Evaluation (BASE) study, which performed a thorough indoor air quality assessment in 100 office buildings. A document published from the study describes how the EPA categorized their air sampling results, placing each type into one of four fungal groupings. Click Fungal Groupings to download the PDF from the EPA website.

IESO Standard

The Indoor Environmental Standards Organization (IESO) published a non-ANSI standard in 2002 titled “Standards of Practice for the Assessment of Indoor Environmental Quality.” The standard identifies genera of mold that may indicate the potential for moisture and mold. The list includes:

  • Aureobasidium
  • Aspergillus
  • Chaetomium
  • Fusarium
  • Penicillium
  • Trichoderma
  • Stachybotrys
  • Ulocladium

Sampling and Analysis of Indoor Microorganisms

This is an excellent book edited by Chin Yang. In the chapter describing microscopic methods, the book identifies the following genera as water damage indicators:

  • Chaetomium
  • Stachybotrys
  • Memnoniella
  • Ulocladium
  • Aspergillus-Penicillium Group is also mentioned


Researchers from EPA and HUD developed the Environmental Relative Moldiness Index (ERMI) to help identify problem homes. I’ll describe the whole ERMI process in a future post, but for now, we’ll only look at its fungal categories.

  • Water damage indicators: Stachybotrys chartarum, Chaetomium globosum, Cladosporium sphaerospermum, Aspergillus versicolor, Eurotium (A.) amstalodami, Penicillium variabile, Aspergillus flavus, Aspergillus restrictus, Penicillium crustosum, Penicillium chrysogenum, Aspergillus niger, Aspergillus sclerotiorum, Penicillium purpurogenum, Aspergillus fumigatus, Penicillium corylophilum, Aureobasidium pullulans, Aspergillus ochraceus, Penicillium brevicompactum, Paecilomyces variotii, Aspergillus sydowii, Penicillium spinulosum, Wallemia sebi, Aspergillus unguis, Scopulariopsis brevicaulis, Scopulariopsis chartarum, Aspergillus penicillioides, Trichoderma viride.
  • Normal species: Acremonium strictum, Alternaria alternata, Aspergillus ustus, Cladosporium cladosporioides v1, Cladosporium cladosporioides v2, Cladosporium herbarum, Epicoccum nigrum, Mucor & Rhizopus group, Penicillium chrysogenum, Rhizopus stolonifer

Hopefully, the references above will help you better distinguish common outdoor fungi and those that may indicate indoor air contamination. Do you know of any additional references of science that study mold topics? Please leave a comment below!

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About the author
Martina began her writing career in 2011 and worked strictly online. She attempts to be as green as she can, which not only helps the environment, it aids in reducing her monthly expenses.

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