How to find light-colored, hard-to-see mold in buildings
LIGHT COLORED MOLD - CONTENTS: How to find light-colored, hard-to-see mold growth on building surfaces. Guide to toxic or harmful light-colored mold and fungal contamination proves that "black molds" are not the only and perhaps not even the most serious indoor mold contaminationsource.
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Light colored toxic or allergenic mold contamination: this article explains how to find and test for light or hard-to-see mold growth on building surfaces.
The photo at page top shows a hard-to-see light-colored (possibly toxic) mold on the surface of an interior door. It is
easy to miss large areas of light colored mold like this unless a careful inspection is made and careful use of light is
Too many "mold inspectors" are quick to test the obvious "black molds" found on building surfaces while they may fail to
find and identify possibly more harmful mold species simply because they ignored the light-colored mold growth.
This document describes how to find mold and test for mold in buildings, including how and where to collect mold samples using adhesive tape - an easy,
inexpensive, low-tech but very effective mold testing method.
This procedure helps identify the presence of or locate the probable sources of mold reservoirs in buildings, and helps decide which of these need more
invasive, exhaustive inspection and testing.
Spotting light colored, hard to see, toxic molds indoors
Other mold species are light in color or nearly invisible when growing on an interior surface
unless you look carefully. This desk sat in a wet basement for only two months yet it was rapidly
covered with a toxic mold, Aspergillus niger. Aspergillus molds indoors can be difficult to see.
A. niger spores
are tiny and are easily made airborne by the smallest disturbance. The basement housing this moldy
chest had Aspergillus levels in air enormously higher than the outdoor sample.
Aspergillus mold growth on furniture
We find as much or more Penicillium/Aspergillus in houses than Stachybotrys, but
these light green, gray or tan mold colonies are more difficult to see if you don't know how to
To check more carefully and thus more successfully for mold, shine your flashlight along the
wall surface in an area that has been damp or wet.
Don't shine it right at the wall or you won't
see much. Look where things have been wet or damp, regardless of whether it was a single event
(washer flood) or one that happens at every rainstorm.
Keep in mind that different molds like different moisture, temperature, and food.
Watch out: One reason
that S. chartarum has been "over-reported" as a problem in some studies is that the
field "experts" didn't look for lighter molds, and maybe they didn't even carry a flash
light. The photo here shows three tape samples being taken from different heights on a
laundry room wall.
Three different mold species were found, one in each
area. Only the lowest black mold was obvious.
In this wall test of three molds which were growing quite close together, I've marked each tape sample
so that you can see where it was on the wall. #1 =Stachybotrys chartarum,
#2 = Ulocladium chartarum, #3 = Aspergillus sp.. - it is this third mold which, in a larger quantity,
would be airborne and more likely to bother building occupants. Yet nearly 100% of home owners and 80% of industrial hygienists and
90% of home inspectors who send mold samples to our lab are going to tape-sample only the "dark mold" on this wall.
Why are there three different genera/species on this drywall? Most likely because each of them prefers a different moisture level
in the paper which they're digesting. I can generally track the mold genera up the wall as a function of the moisture gradients in
the wall. When a wall has been wet because of wet floor conditions, the drywall and in-cavity wall insulation will be wettest at
the wall bottom.
At MOLD LEVEL REPORTING we explain the errors you can expect if you do not choose a properly-representative area of a surface when collecting mold or dust samples and at MOISTURE GRADIENTS & MOLD we explain why we find different mold genera/species at different locations on moldy drywall.
Be sure to review our notes above on use of lighting at Use of a flashlight to find mold
since if you don't know exactly how to use a flashlight, as simple as it seems, you're not going to find important light-colored
molds in buildings.
Photo of light-colored mold inside of a Florida air conditioning air handler unit above, courtesy of Mark Cramer, Tampa.
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Mold Safety Warnings for Do-It-Yourself'ers Planning to Inspect for or Clean Up Mold Contamination
Guidelines defining what's a "large amount" of mold and what's reasonable for a homeowner to handle have been published by several states including New York and California.
People who are allergic, asthmatic, infant, elderly, immune-impaired, etc., should not disturb mold and should
not be in the area where mold remediation is being performed. Consult with your doctor, health
department or other professional before tackling this job yourself.
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
Or choose the The Home Reference eBook for PCs, Macs, Kindle, iPad, iPhone, or Android Smart Phones. Special Offer: For a 5% discount on any number of copies of the Home Reference eBook purchased as a single order. Enter INSPECTAEHRB in the order payment page "Promo/Redemption" space.
Carson Dunlop, Associates, Toronto, have provided us with (and we recommend) Carson Dunlop Weldon & Associates' Technical Reference Guide to manufacturer's model and serial number information for heating and cooling equipment Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.
Kansas State University, department of plant pathology, extension plant pathology web page on wheat rust fungus: see http://www.oznet.ksu.edu/path-ext/factSheets/Wheat/Wheat%20Leaf%20Rust.asp
"A Brief Guide to Mold, Moisture, and Your Home",
U.S. Environmental Protection Agency US EPA - includes basic advice for building owners, occupants, and mold cleanup operations. See http://www.epa.gov/mold/moldguide.htm
US EPA - Mold Remediation in Schools and Commercial Building [Copy on file at /sickhouse/EPA_Mold_Remediation_in_Schools.pdf ] - US EPA
US EPA - Una Breva Guia a Moho - Hongo [Copy on file as /sickhouse/EPA_Moho_Guia_sp.pdf - en Espanol
Associations: Sick House, Sick Building, SBS - Air Quality, Government, Private Associations and Information Resources
Atlas of Clinical Fungi, 2nd Ed., GS deHoog, J Guarro, J Gene, & MJ Figueras, Centraalbureau voor Schimmelcultures, Universitat Rovira I Virgili, 2000, ISBN 90-70351-43-9 (you can buy this book at Amazon) - The Atlas of Clinical Fungi is also available on CD ROM
"A Brief Guide to Mold, Moisture, and Your Home", U.S. Environmental Protection Agency US EPA - includes basic advice for building owners, occupants, and mold cleanup operations. See http://www.epa.gov/mold/moldguide.htm
"Disease Prevention in Home Vegetable Gardens,"
Department of Plant Microbiology and Pathology,
Department of Horticulture, University of Missouri Extension - extension.missouri.edu/publications/DisplayPub.aspx?P=G6202
Fifth Kingdom, Bryce Kendrick, ISBN13: 9781585100224, is available from the InspectAPedia online bookstore - we recommend the CD-ROM version of this book. This 3rd/edition is a compact but comprehensive encyclopedia of all things mycological. Every aspect of the fungi, from aflatoxin to zppspores, with an accessible blend of verve and wit. The 24 chapters are filled with up-to-date information of classification, yeast, lichens, spore dispersal, allergies, ecology, genetics, plant pathology, predatory fungi, biological control, mutualistic symbioses with animals and plants, fungi as food, food spoilage and mycotoxins.
Ozone Warnings - Use of Ozone as a "mold" remedy is ineffective and may be dangerous.
Rot concerns in buildings-some building mold such as Meruliporia incrassata "Poria" risks serious rot and hidden structural damage
US EPA: Una Breva Guia a Moho - Hongo [Copy on file as /sickhouse/EPA_Moho_Guia_sp.pdf - en Espanol
OTHER IAQ ISSUES: How To Find and Address Other Indoor Air or Indoor Environment Contaminants Besides Mold
Mold or allergens may not be the only or even the main indoor environmental contaminant. Don't let media attention to mold
cause so much enviro-scare fear that other, possibly more urgent hazards go un-addressed.
Rodents, Mice, Squirrel Control - I find high levels of mouse and rodent dander, fecal dust, and urine-contaminated dust in some buildings,
and high levels of these materials in building insulation in those locations. If you have a mouse problem, particularly if mice and their waste (fecals or urine) are contaminating
the building HVAC or building insulation, may need both steps to clean up or remove infected materials and steps to stop an ongoing
rodent problem. If squirrels are a problem, the cleanup needs to include closing off entry openings into the building. Get some
help from a licensed pest control expert.