HARD TO SEE MOLD, SPOTTING - CONTENTS: How to look for and find hard-to-see mold - Photographs provided here can help you find mold - Are toxic black molds the only molds to look for in buildings? - Are there some light colored harmful molds that are hard to see?
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How to find hidden or hard-to-see mold in buildings: as we detail in this "how to" article, the fact that mold is "hidden" in buildings, such as inside a wall cavity, does not mean one cannot find where the problem mold is located. We look for hidden mold contamination by context: where do we see leak stains,
or where do we see building practices most likely to have produced a hidden leak or moisture problem?
Ice dam leaks in walls,
hidden plumbing leaks, roof spillage by the foundation, are all common clues that often track to a wet building wall or ceiling cavity and
from there to a hidden mold problem which may need to be addressed.
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.
How to Spot Hard-to-See Mold on Paneling or Other Surfaces in Buildings
USING LIGHT - Using proper lighting to see important mold contamination in buildings
How and where you shine light is of crucial importance when looking for mold in buildings. Light-colored
mold such as some members of the Aspergillus sp. and Penicillium sp. groups are often
the dominant problem-mold in buildings but these offenders are often missed by a casual inspection
because they can be hard to see on surfaces.
You need a bright flashlight and you need to know
how to use it.
Shine the light along the surface being examined, not straight at it.
As you'll see in the mold photographs below, using your light carefully can make a big difference
in what mold you find and where you find it.
Just looking for "black mold" risks missing the
important mold in a building.
Light colored mold next to obvious black mold:
Aiming a bright flashlight along this wall surface where dark mold wasobvious shows a light gray/green fungal colony which in fact was far more toxic
and thus important to select as an additional source for surface sampling using adhesive tape.
Light colored toxic mold on paneling can be hard to see in ordinary lighting and requires careful inspection.
But notice how the lighting shows
that this paneling is buckled.
We 'd suspect that it has been exposed to high moisture if not water, and that there is risk of hidden mold on the
cavity side of this material.
Further inspection was needed.
Light colored toxic mold on paneling is not visible
because light is being shone directly onto the wainscot wood paneling surface.
Now try shining a light along the surface - this easily shows the white mold colony.
The point of these illustrations is to demonstrate that "hidden mold", like the purloined letter,
may in fact be hiding in plain view - you just don't know how to see it.
Is Toxic Black Mold the Only Mold To Worry About in Buildings?
In short, no, absolutely not. Here are some details:
Recent news articles have made some people terrified at the mere mention of "toxic black mold" such as
"Stachybotrys chartarum." Actually it is common to find Stachybotrys chartarum in
small amounts in houses where there has been prolonged leakage or water entry. It's a toxic mold
that should be removed.
But don't assume that anything and everything black on a building wall is a highly toxic mold.
Some black stuff is not mold at all. See STUFF THAT IS NOT MOLD for details of black stains or debris on walls that have no mold hazard whatsoever.
common mold species look black but may be of low or no toxicity. For example, Chaetomium globosum has been reported to be allergenic rather than toxic. Cladosporium sphaerospermum is often found growing indoors on bathroom tile or refrigerator
gaskets. It's a member of the most common mold family, Cladosporium, the "universal
fungus." It can look pretty "black" on some surfaces.
Still other black molds found in buildings are completely harmless. See Recognize Cosmetic Mold and Recognize Harmless BlackMold for details about these cosmetic molds and easy ways to spot some of them with no testing whatsoever. Just common sense can tell you that some molds have been on a surface since the time of construction.
Finally, there are plenty of highly toxic or highly allergenic or irritating molds found in buildings that are not black or even dark, especially including most members of the Aspergillus sp. and Penicillium sp. families. See LIGHT COLORED MOLD for details.
Is it Possible to Identify a Mold Just by Looking At It On a Building Surface?
Can you tell what genera or species a mold is that's growing on a surface just by the naked eye?
No. Though I've inspected and tested so many molds on so many surfaces that like a bird watcher,
I know what's likely to be present in a given habitat. (Refrigerator gasket mold is usually
a Cladosporium, often C. sphaerospermum and mold growing on window muntins will
be a genera/species tolerant of UV light. A normal person can't do this, though a mold investigator and a few mold remediators with plenty of experience can make a reasonable guess. (Such guesses are not always right.)
You cannot determine the mold genera and species just by looking at mold on the wall. Skip those do-it-yourself mold test kits that rely on culture or settlement plates. The methods the kits use are fundamentally inaccurate and
in a few cases so are their laboratories. (90% of mold species will not grow on culture media.)
For small mold problems, spend your money on some soap
and water instead.
For larger mold contamination problems hire an expert to survey your home, or send your own mold
sample to a competent testing laboratory. The services of an experienced mycologist or
aerobiologist are necessary to know what you've got. (C)DJF Copyright protection trap.(C)Daniel Friedman
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Questions & answers or comments about how to find hidden mold in buildings, both on exposed surfaces but hard to see and mold hidden in building cavities, insulation, or other areas.
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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.
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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
Allergies, Allergens, Allergy Testing in Buildings - References & Products
Allergen Tests in Buildings advice about how to test, what to look for, in evaluating the level of dog, cat, or other animal allergens in a building
"IgG Food Allergy Testing by ELISA/EIA, What do they really tell us?" Sheryl B. Miller, MT (ASCP), PhD, Clinical Laboratory Director, Bastyr University Natural Health Clinic - ELISA testing accuracy: Here is an example of Miller's critique of ELISA
http://www.betterhealthusa.com/public/282.cfm - Townsend Letter for Doctors and Patients
The critique included in that article raises compelling questions about IgG testing assays, which prompts our interest in actually screening for the presence of high levels of particles that could carry allergens - dog dander or cat dander in the case at hand.
http://www.tldp.com/issue/174/IgG%20Food%20Allergy.html contains similar criticism in another venue but interestingly by the same author, Sheryl Miller. Sheryl Miller, MT (ASCP), PhD, is an Immunologist and Associate Professor of Basic and Medical Sciences at Bastyr University in Bothell, Washington. She is also the Laboratory Director of the Bastyr Natural Health Clinic Laboratory.
Allergens: Testing for the level of exposure to animal allergens is discussed at http://www.animalhealthchannel.com/animalallergy/diagnosis.shtml (lab animal exposure study is interesting because it involves a higher exposure level in some cases
Allergens: WebMD discusses allergy tests for humans at webmd.com/allergies/allergy-tests
Animal Allergens: Dog, Cat, and Other Animal Dander - Cleanup & Prevention Information for Asthmatics and regarding Indoor Air Quality.
Recognizing Allergens: What various indoor allergens look like - identification photos to help identify pollen, dust mites, animal dander, toxic or allergenic mold - Common Mold and other Allergens, Irritants, Remedies & Advice
Rodent control issues, including dander, fecal, and urine contamination of Buildings and Building insulation are discussed at our
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.