Fungal Data Interpretation – Part II – Effects of Tossing a Moldy Apple Pie into the Trash Before Mold Air Sampling

October 23, 2012 at 8:59 am 1 comment

Moldy Apple Pie

This post is the second blog posting in a series based on information presented in a webinar by Dave Gallup, co-founder of EMLab P&K.  The topic of the webinar was Fungal Data Interpretation.  The two-hour presentation covered many interesting topics that are relevant to mold inspection and testing companies as well as the general public that are facing mold problems in their home or business.

One of the first points that Mr. Gallup made is the interpretation of the sample data that EMLab P&K provides must be combined with the on site mold inspection information.  Trying to interpret fungal sample data from a mold inspection and testing project without also having field inspection information from a qualified mold inspector is highly problematic.  In this blog entry I will focus on the second of several normal household scenarios that can drastically impact fungal sample data and could lead to incorrect interpretation of that data.

Scenario – “Effects of Tossing a Moldy Apple Pie into the Trash”

A group of EMLab P&K scientists studied the impact on fungal distribution in a normal home after the occupants tossed a mold apple pie into the kitchen trash.  Here is the data set:

  • The first air sample was collected in the home before tossing the moldy pie.
    • The air sample contained numerous types of mold spores.  I will focus on just one type, Penicillium/Aspergillus types (Pen/Asp).
    • The spore counts of Pen/Asp found in this first air sample were within “normal tolerances” — they were lower than the corresponding spore counts found in the outdoor baseline sample.
  • The second air sample was collected during the act of tossing the moldy pie
    • The spore counts of Pen/Asp were significantly elevated compared to both the outdoor control sample and the first sample collected before the toss.
    • This is how the data looked:
      • Pen/Asp types: before tossing ~13 spores/cubic meter | during tossing ~ 1,000,000 spores/cubic meter!

If the on site inspector did not notice that there was moldy food in the trashcan (apple pie in this case) or had not asked the homeowner if they had recently performed any housekeeping activities such as cleaning out the refrigerator of moldy food, incorrect conclusions could have been made with respect to this project.  For example the airborne Pen/Asp types prior to tossing were ~13 spores/cubic meter.  After tossing the moldy pie into the trash, the spore counts of Pen/Asp were drastically elevated (over one million spores/cubic meter!).  If the inspector did not know about the moldy food, these air sample results would be cause for real concern and unnecessary steps would likely follow (more testing, invasive exploration for mold, and the like).  Armed with the knowledge that the client recently threw away moldy food, the inspector could either take that into consideration when analyzing the sample data or, better, not collect the sample for several hours after.

Many people place too much emphasis on the mold sampling aspect of our business.  It is a useful tool, but it is only truly valuable in conjunction with the on site, visual inspection data.

Michael Bains

by Michael Bains, President, Mold Inspection Sciences


Entry filed under: General Mold Information, Indoor Air Quality, Mold and Health, Mold Inspections, Mold Testing. Tags: , , , .

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1 Comment

  • 1. Mold Testing San Diego  |  November 1, 2012 at 2:13 pm

    Excellent insight. When mold testing San Diego homes, businesses are always advised to ask clients about throwing out moldy food or other items recently, just to be sure they don’t get false positives. Thanks for posting this!

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