Ask Dr. Ed: Home kits not always reliable

Dear Dr. Ed: I recently took a home test for mold and it came up positive for Cladosporium. I was also evaluated by my physician and was found to be +4 allergic to molds. What do I need to do to remove this problem from my home? How do I clean for mold? — Tara Heaslip, Naples

Dear Tara: To date, I have not found an effective home test kit for mold. The most common test is the Petri dish kit, which is easily contaminated during setup, and does not provide any information about the quantity or numbers of mold spores in the air. Moreover, the directions provided with these kits, often direct the consumer to incubate the Petri dish somewhere in the home, which is a bad idea, for two reasons.

The first is that in order to accurately assess mold in a Petri dish, the dish must be incubated in a temperature controlled, vibration-free incubator. The second is the danger of false positive mold counts and mold spores escaping into your home if the plate is bumped or dropped.

Let me explain, Cladosporium like most molds, can rapidly produce thousands if not millions of spores. Each of those spores is capable of germinating and producing more spores. Suppose that during the course of sampling, a single Cladosporium spore falls onto your Petri dish. That single spore germinates and forms a colony (circular area of mold growth) that contains several thousand spores. To a qualified lab technician, that one colony represents one spore from the air, which equates to safe mold levels. Unfortunately, that is not the happy ending that comes from most home test kits. Remember that one colony equals a raw count of one spore.

Okay, back to that Petri dish, which by now, is happily incubating on top of your refrigerator, and that single Cladosporium spore has grown into a healthy and happy mold colony in only two days, but the Petri dish still needs to be incubated for three to five more days, and that’s when things often go awry.

On day three you cut the grass. It’s a hot day, so you stop mowing to come inside for a cold drink. You open and close the refrigerator door to get some ice tea. As you’re drinking the tea you stare at the Petri dish. If you were fortunate enough to have microscopic vision, you would be shocked to see that thousands of spores from that single colony are now floating around in the Petri dish, and when they land, they’ll grow into 50 or more colonies.

From here you can probably guess what happens — when its time to send the Petri dish to the lab its covered with mold, which has you biting your nails until the results arrive, which send you into a panic attack, because they tell you your home has high concentrations of Cladosporium (false positive). So buyers beware.

Until there is a mold kit that provides an accurate spore count and guards against mold contamination, please call a certified indoor environmentalist or company to test your home.

Dear Dr. Ed: I am living in a new apartment and have since been feeling ill. I know that I have a mold allergy and suspect that could be causing my recent problems. The apartment that I live in is completely carpeted. Could that be a bed for mold growth? If so, should I consider living in an apartment with hardwood floors? — Lyn Sharp, Knoxville, Tenn.

Dear Lyn: Carpet is like a filter; it traps everything including mold spores. My recommendation to clients who suffer with mold allergies is to get rid of the carpet and replace it with hardwood or some other non-porous laminate.

Dr. Ed: If I know that I’m allergic to dust mites and mold, should I have an annual inspection? — Jo Ann Goodrich, Knoxville, Tenn.

Dear Joann: I suggest that you start an allergy journal. In your journal keep a daily log of your allergies, (none, mild, moderate, severe), also include any symptoms that you may be experiencing, i.e., runny nose, itchy eyes, etc. Be sure to include the time of day that your symptoms first appear and the location in your home where they are most active.

Your journal will become an invaluable document that you can use to determine if you should have your home inspected. For example, if you have been living in your home for a while, and all of the sudden your allergies start to act up, and your symptoms significantly improve when you leave your home or avoid a particular room in your home, I suggest that you have your home inspected by a certified indoor environmentalist or CIE.

Be sure to let your CIE review your allergy journal. The information contained in your journal will expedite the inspection process to identify the source of the allergen contamination. I have posted a copy of a typical journal entry on my Web site under Ask Dr. Ed at www.cleanairinspections.com.

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Edward Sobek, Ph.D., is the director of research and development for Clean Air Inspections and is responsible for developing new technologies that will be beneficial to mold inspectors and mold remediators as well as the entire indoor air quality (IAQ) industry. He is also a nationally recognized expert in mycology (fungi).

If you have questions regarding mold, mold inspections, water intrusion or other indoor air quality issues as they relate to residential and commercial properties, visit www.cleanairinspections.com and click on the Ask Dr. Ed icon.

For those without Internet connections, questions may be asked by calling 239-877-1793 or by writing to: Ask Dr. Ed, C/O 9180 Estero Park Commons Blvd., Suite 6, Estero, Fla. 33928.