This article describes how make effective use of light such as from a good flashlight to find hard to see mold in buildings. How we aim the light and how we actually look makes the difference between finding or completely missing light and hard-to spot indoor mold contamination on building surfaces and materials.
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USING LIGHT to FIND MOLD - Using proper lighting to see important mold contamination in buildings
Proper use of and aiming of light or a flashlight when looking for mold in buildings can make the difference between
seeing and missing what might be the most important mold reservoirs in a given structure.
Like the Purloined letter problem mold may be in plain sight but may be hard to see, until you know how to look.
One result is that people who
are testing mold often collect the "easy to see" mold but perhaps not the most important mold in a building. Here's how
to do it right - in this brief article.
For a more extnsive article with more photos and advice on how to use lighting and how to aim a flashlight to spot hard to see mold,
read USE A FLASHLIGHT. In most
cases, proper use of a flashlight can help spot mold on paneling and other building surfaces.
How and where you shine light is of crucial importance when looking for mold in buildings.
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 shown here, 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 was obvious 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.
I'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.
Aiming a light or flashlight at roughly right angles to a surface means most of the light rays bouncing back to your eye are coming off
that surface at the same angle - the light will have trouble showing the profile or edges of light-colored or other small particles.
Now try shining a light along the surface - this easily shows the white mold colony that was practically invisible before.
a light or flashlight along the surface means that some of the light rays are bounced off of the profiles or sides of small particles
on that surface, making them easier to see. I'm simplifying the physics of light a bit but you can see the point of these illustrations of finding
hard-to-spot light colored mold on a building surface.
Even dust, or any other surface irregularities show up better with this method of
inspection. we have used this method of oblique light direction to spot drywall nails as a quick way to find a wall stud when hanging a picture.)
For our longer article with more photos and advice on how to use lighting and how to aim a flashlight to spot hard to see mold,
read Mold Detection - using a flashlight to find mold - proper use of a flashlight can help spot mold on paneling and other building surfaces.
Another example of use of oblique lighting to find building defects is illustrated at PLASTER BULGES & PILLOWS.
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Technical Reviewers & References
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Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
- 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.
- Environmental Health & Investigation Bibliography - our technical library on indoor air quality inspection, testing, laboratory procedures, forensic microscopy, etc.
- Adkins and Adkins Dictionary of Roman Religion discusses Robigus, the Roman god of crop protection and the legendary progenitor of wheat rust fungus.
- 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
- Air Conditioning System Blower Fans & Filters Cascading for Optimum Indoor Air Quality
- 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.
- Atlas of Mold Related Illness Symptoms & Complaints - long list of both documented, studied mold related illness, and complaints ascribed to mold contamination or allergens in buildings
- Cat Dander: how to inspect and test a building for past or current presence of cats, cat hair, cat dander, and cat allergens
- Clinical Atlas of Mold Toxicity - An Online Description of Toxic, Pathogenic, Allergenic Fungi, Fungal Diseases
- Fiberglass Insulation Contains Mold© 2005 comments about a field study in process, & more about health hazards from fiberglass insulation
- Humidity: What indoor humidity should we maintain in order to avoid a mold problem?
- Mold Action Guide detailed guide on finding, removing, and preventing indoor mold contamination
- Odors, Odor Detection, Smells, & Gases how to find and identify sources of noxious or toxic odors and gases
- Other environmental risks, Our much longer list: Asbestos, carbon monoxide, electromagnetic fields, etc.
- Ozone: The Use of Ozone Indoors for Control of Odors and Mold
Removal in Buildings: A Summary of Hazards and False Claims.
- Pollen Allergens: identification, plant pollen and indoor air quality
- Products to Reduce Mold & Allergy Problems to reduce indoor mold or allergen levels: air cleaners, air purifiers, dust mite covers, vacuum cleaners, crawl space vents
- 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
- Sewage and Septic backup contamination in Buildings: inspection, testing, remediation, & references to expert sources
- Action Guide: What to do about mold, mildew, and other indoor allergens
Mold Contamination Testing, Cleanup, Prevention: references & products
- The Mold Information Center: What to Do About Mold in Buildings, When and How
to Inspect for Mold, Clean Up Mold, or Avoid Mold Problems
- Aerobiology, Building Science, Microscopy, & Laboratory References, an extensive technical bibliography
- Allergens: what they look like in buildings
- 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
- Atlas of Mold Related Illness: Index of Symptoms and health, physical, neurological, psychological, and other complaint which people suspect may be mold or building-related.
- Atlas of Indoor Mold, Online Clinical Mold Atlas, Toxins, Pathogens, Allergens and Other Indoor Particles - Medical Health Effects of Mold (separate online document)
- Black Mold that is Harmless Photos of recognizable, usually harmless black mold on wood, bluestain, ceratocystis, ophistoma
- Building Floods: quick steps after a building flood or plumbing leak can prevent costly mold contamination
- Classes of Mold: what types of cosmetic, allergenic, or toxic mold are a problem? Can mold be cleaned-up successfully?
- Clinical Mold References - Detailed bibliography of mold reference texts
- "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 Program for Certain Vegetable Crops," David B. Langston, Jr., Extension Plant Pathologist - Vegetables, University of Georgia (PDF document) original source: www.reeis.usda.gov/web/crisprojectpages/209797.html
- "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
- "Management of Powdery Mildew, Leveillula taurica, in Greenhouse Peppers," Ministry of Agriculture and Lands, British Columbia - Original source: www.agf.gov.bc.ca/cropprot/peppermildew.htm
- Environmental Health & Investigation Bibliography - our own technical library on indoor air quality inspection, testing, laboratory procedures, forensic microscopy, etc.
- Fiberglass: Mold in Fiberglass Insulation© 2005 comments about a field study in process, & more about health hazards from fiberglass insulation - DJF
- 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.
- Fungi, Identifying Filamentous, A Clinical Laboratory Handbook, Guy St-Germain, Richard Summerbell, Star Publishing, 1996, ISBN 0-89863-177-7 (English) (buy at Amazon)
- MOLD in BUILDINGS Procedure: what mold is often found where in buildings - simple technical presentation
- Meruliporia: the house eating fungus or "poria"
- MOLD ACTION GUIDE Step-by-Step Instructions, What to do about mold, mildew, and other indoor allergens
- MOLD APPEARANCE - WHAT MOLD LOOKS LIKE Photos of what mold looks like in buildings
- MOLD APPEARANCE - STUFF THAT IS NOT MOLD Photos of NOT-mold material that is sometimes mistaken for mold
- MOLD ATLAS & PARTICLES INDEX, Pathogens, Allergens and Other Indoor Particles - Medical Health Effects of Mold (separate online document)
- MOLD BY MICROSCOPE Mold under the microscope - photo identification of the most common indoor molds found in buildings
- Mold FAQs Answers to Most Questions about Indoor Mold, Mold Related Illness, Mold Cleanup, Mold Prevention
- US EPA: Mold Remediation in Schools and Commercial Building [Copy on file at /sickhouse/EPA_Mold_Remediation_in_Schools.pdf ] - US EPA
- Mold spores in the Home - a Photo ID Library for detection and identification of mold allergens
- Mold Test Kits - How to Collect and Send Your Own Mold Sample to our mold testing lab or to any mold lab you wish
- Most Common Indoor Molds Found in Buildings, A Table of
- Mycology, Fundamentals of Diagnostic, Fran Fisher, Norma B. Cook, W.B. Saunders Co. 1998, ISBN 0-7216-5006-6 (buy this book at Amazon)
- 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.
- Fiberglass building insulation and HVAC duct work insulation hazards
- Sewage and Septic backup contamination in buildings: inspection, testing, remediation, & references to expert sources
- Other environmental risks: Asbestos, carbon monoxide,
electromagnetic fields, environmental illness, fiberglass, MCS - multiple chemical sensitivity, toxic gases, etc
- Indoor Gas Sampling Plan
for Residential Buildings lists a number of toxic indoor gases which we test for, depending on the building
complaint and building conditions
- Ozone Warnings - Use of Ozone as a "mold"
remedy is ineffective and may be dangerous.
- Pet control - if you can't say goodbye to your bird, cat, dog, guinea pig, hamster, tropical fish, then limit the
areas they occupy and limit the airflow from that area to sleeping or other areas of the building, use allergenic
bedding, eliminate wall-to-wall carpeting, improve housecleaning including use of a HEPA-rated vacuum cleaner. For more details
see our article Dog, Cat, and Other Animal Dander - Information for Asthmatics and Indoor Air Quality
- 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.