Fungal Data Interpretation – Part II – Effects of Tossing a Moldy Apple Pie into the Trash Before Mold Air Sampling
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.
Unfortunately, there are a lot of “Scare Tactics” used within the microbial investigation and mold remediation industry. As with any industry, there are always going to be people out there who try and scare people into using their services. They may do so by embellishing facts, giving misinformation or by simply telling you things that are completely untrue. I want to give you, the consumer, a couple tips for what to watch out for if you are ever in a situation of having to enlist services within the microbial and mold remediation industry.
1) Pay close attention to each company’s website. Most companies have a website nowadays, and that can give you a good insight as to what type of company you will end up dealing with. Some companies websites are littered with misinformation and pictures geared towards scaring you into using their services. I have seen websites with embellished pictures of microscopic mold spores, but in reality just about anything looks scary when you magnify it 500 times. Also, if anywhere on their website you see the terms “Black Mold” or “Toxic Mold”, consider that a big red flag. Those terms were created by the media, and it wasn’t for their feel-good story of the evening if you know what I mean. It was to create interest as a result of fear. After all, who isn’t afraid of the term “toxic”? You don’t hear many stories that start with toxic and end with a smile. You may also want to avoid companies that over emphasize the potential health effects of mold on people. Although it is good to be informed of potential signs of mold exposure and basic information regarding health, if a company’s main content of their website is to make you believe that you are definitely going to get sick after being around mold, it is probably another thing to be cautious of. And lastly, if somehow you have come across a company that does not even have a website, approach them with caution. If a company is not willing to provide basic information about them including their contact info, certification and affiliation information and a basic company profile it may be for good reason. They may be attempting to fly under the radar, or be quite new to the industry and have not yet put any effort into a website. I don’t know about you, but I don’t think I would trust a mold problem to the new guys on the block.
2) Be wary of remediation companies that do their own testing. Within our industry it is a direct conflict of interest for a remediation company to perform their own testing. A large majority of the public has never dealt with a mold problem, or had to interpret a laboratory analysis of microbial samples. Therefore, it could be somewhat easy for a remediation company to embellish sample results. It is not uncommon to hear about a remediation company coming into a home and pulling some microbial samples, and upon receiving the results inform the client that the home is completely contaminated and they must vacate immediately or pay for expensive remediation. I had a client once tell me that a remediation company told her that she was being a bad mother because she was allowing her family to live in a mold infested home. And that was based on a visual inspection alone. Upon further investigation by an independent third party microbial investigator it was revealed that yes, they had a minimal mold problem but it was far less intense then the remediation company would have had her believe. You have to remember that a remediation company makes money off of cleaning up mold. Therefore, the more they have to clean or the larger the project, the more potential money they will make. So avoid being scared into expensive work that may not be needed and have an independent party look at the situation.
3) If you are ever in the middle of a microbial investigation and the inspector or contractor attempts to tell you what type of mold is present just by looking at it, be very cautious. I have heard multiple stories about contractors or inspectors coming in to look at a mold problem and attempting to identify what type of molds are present just by looking at it. Unfortunately, this is just not possible. There are literally tens of thousands of types of molds, many of them grow to be similar colors and textures and may display consistent growth patterns. The reality of it is, the only way to determine what type of mold is present is to analyze the growth under a high powered microscope, and this should only be done by a mycologist or technician within a laboratory setting. We hear about these tactics not only being used to scare people into remediation work that is not necessary, but also to deter people that really have a problem from realizing it. For example, it is not uncommon for people in rental situations to be informed by maintenance personal that whatever microbial growth they have in their apartment or home is not the “bad kind”, or not toxic. I guess we would call this scenario an “Anti-Scare Tactic”. But again, the only way to know is to have microbial samples collected and properly analyzed. So unless the person you are dealing just so happens to have microscopes for eyes, which actually be pretty cool, watch out for this one.
If you really believe that you may have a mold problem, it is important to know that whomever you turn to for advice has your best interest in mind. The safest way to ensure this is to make sure that you always deal with an independent third party that has nothing to gain from finding a problem. You should also do all you can to research any companies that you may be considering using. Make sure they are a legitimate company, they are properly certified and they should have a positive track record through organizations such as the Better Business Bureau. You may be surprised what you find after doing a little investigation, for better or for worse.
The Basics of Mold Remediation – Part III of III – Final Cleaning of the Containment and Affected Areas
See my posts “The Basics of Mold Remediation – Part I of III – Containment of the Affected Area” as well as “The Basics of Mold Remediation – Part II of III – Gross Removal of Mold Growth and Impacted Materials” for background information important for understanding this part of the mold remediation process. At this point in our process, the mold impacted area has been isolated from all non-affected adjacent living spaces. This was accomplished by establishing containment of the area, which included the installation of HEPA Filtered Negative Air machines and installation of physical barriers which, in turn, would have created a negative pressure environment. Gross removal of all impacted non-structural materials would have occurred as well as the removal and cleaning of mold growth from all of the structural materials. The next step is to perform the final clean of the work area.
Part III of III – Final cleaning of the containment and affected areas.
Now that the nitty gritty portion of the removal has been accomplished, the work area has typically seen a fair share of debris. Not only does the removal of building materials create lots of dust and debris, but the disturbance and removal of the mold source itself typically creates very large quantities of microscopic mold spores. So, how do we make sure we account for all of those spores that we can’t even see with our naked eye? Well, the simple answer is by cleaning everything, and doing it very well. That means every crack, crevice, cavity, ceiling, wall, floor and the air itself must be cleaned.
The first step in the final cleaning is typically a complete HEPA vacuuming of the entire space. Every surface within the containment area will be HEPA vacuumed to gather any dust, debris, and yes, lots and lots of mold spores. The vacuums used are not the typical vacuum you can find at the hardware store, but specialized HEPA vacuums that prevent those microscopic spores that are being sucked up from being re-distributed throughout the space.
Once the area has been HEPA vacuumed, the remediation contractor will typically perform a wet wipe of the area at this time. They will use a cloth that is wetted with some sort of antimicrobial agent or cleaner, and every hard surface will be wiped down. The rags are kept wet not only to aid in the cleaning process, but to help in picking up mold spores and preventing them from becoming airborne.
At this point, some remediation contractors may choose to repeat the previous two steps, and HEPA vacuum the entire space as well as do another wet wipe to ensure that every surface has been accounted for. And after all, it’s better to be safe than to be sorry, or at least that’s what they say.
During all of the previous cleaning efforts, the HEPA filtered negative air machines have been running the entire time. As a result, airborne mold spores have been pulled out of the air and into the filtration device. As the cleaning has become more and more detailed, the airborne mold spore quantities should have been continually getting smaller. Unfortunately though, the quantities of airborne mold spores at this time will typically still be in excess of actual clearance standards. So, at this time the negative air machines are swapped out for HEPA filtered air scrubbers. Instead of air continually being drawn out of the space and as result unconditioned air being drawn into it, the air within the space will now be recycled through the HEPA filtered air scrubbers. As the air is continually pulled through the HEPA filters over and over again, it will become “cleaner” as more and more of those microscopic mold spores are trapped within the HEPA filter. This process is usually continued for a minimum of 24 hrs, and depending on the amount of contamination in the space may go on for multiple days.
At this point, the remediation project has come a long way. We have gone from a mold contaminated area, to what we hope is considered to be a “normal” living space. But, to truly verify whether the space has been returned to normal a Post Remediation Verification Inspection should be performed. This should be performed by an independent mold inspector who has no financial ties with the remediation contractor. They will perform a visual inspection of the space to ensure that all of the impacted materials have been removed and/or cleaned, test the moisture content of the building materials to ensure that everything has been adequately dried, and ensure that the area has been properly cleaned. If the visual inspection is adequate, then they will perform ambient air sampling of the work space. This will test for the presence, types and quantities of mold spores within the space and will be compared to an outdoor sample taken at the same place and time. If the sample is within clearance standards, the project will be considered successful, and the mold remediation project complete. All that is left at this point is reconstruction of the space to return it to a normal living space. After all that we have gone through, that should be a walk in the park…
The Basics of Mold Remediation – Part II of III – Gross Removal of Mold Growth and Impacted Materials
See my post “The Basics of Mold Remediation – Part I of III – Containment of the Affected Area” for background information important for understanding this part of the mold remediation process. At this point in our process, the mold impacted area has been isolated from all non-affected adjacent living spaces. This was accomplished by establishing containment of the area, which included the installation of HEPA Filtered Negative Air machines and installation of physical barriers which, in turn, would have created a negative pressure environment. The next step is to perform the removal of impacted materials and mold growth.
Part II of III – Gross removal of mold growth and impacted materials
Unfortunately, when a mold problem is present within a home it typically means that some materials are going to have to be removed. If mold growth is within a wall cavity or under flooring materials, to be accessed, the materials around the source must be removed. If mold and/or water damaged non-structural materials are present, they are typically removed and discarded. These types of materials would include: baseboards, drywall, carpeting, carpet pad, tack strip, underlayment, insulation, building paper, etc. The bottom line is that most remediation projects involve the demolition of building materials. The removal of materials is typically well planned and, on most projects, only the necessary materials will be removed while salvaging the non-affected materials.
Once the removal of the non-structural materials is accomplished, mold growth must be cleaned and removed from the structural materials. Mold is often found growing on organic structural materials such as framing, subflooring, roof sheeting and just about any organic material that is used in construction. As long as the structural integrity of these materials has not been compromised, the mold growth will be cleaned and removed from the materials. The first step in this process is to HEPA vacuum the surface of these impacted materials. This is done to remove as much of the mold source as possible in a controlled manner in an effort to prevent the mold spores from becoming airborne. Next, the impacted materials are scrubbed and cleaned to remove all physical mold growth. This is a very important step because mold sources imbed themselves into the materials they are feeding on with hyphae. Hyphae are thread like components of the mold used to bind itself to the material and can penetrate it as far as a 1/32nd of an inch. Some contractors will remove the hyphae with wire brushes or sanding, while others may use more intense methods such as dry ice blasting or media blasting. Either way, the mold must be removed in its entirety. This process typically creates lots of dust and debris, so HEPA vacuuming is often done in combination with the cleaning.
During the cleaning of the structural materials, many contractors use liquid based cleaning products in combination with the cleaning. This is done for multiple reasons: to physically kill the mold, to penetrate the affected materials and aid in loosening the hyphae, to wet the mold source and make the spores less likely to become airborne, to bleach the materials and remove evidence of staining, etc. There are many different types of products used: some are “Green” products considered to be environmentally safe, some are biocides designed to kill all biological organisms, some are fungicides designed to kill fungal based organism, and some are based on everyday homeowner liquids such as Hydrogen Peroxide (quite a bit stronger then the stuff in your medicine cabinet though).
Once all of the impacted non-structural materials have been removed, and all of the physical mold growth has been cleaned and removed from the structural materials, the next step of the remediation project may begin. Stay tuned Part III of a basic mold remediation project…
Yesterday, I had the privilege of attending a webinar presented 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 first of several normal household scenarios that can drastically impact fungal sample data and could lead to incorrect interpretation of that data.
Scenario – “Effects of Vacuuming”
A group of EMLab P&K scientists studied the impact on fungal distribution in a normal home after the occupants vacuumed their carpets. Here is the data set:
- The first air sample was collected in the home before vacuuming the carpet.
- The air sample contained numerous types of mold spores. I will focus on three types: Basidiospores, Cladosporium, and Penicillium/Aspergillus types.
- All of the spores counts found in this first air sample were within “normal tolerances” — they were all lower than the corresponding spore counts found in the outdoor baseline sample.
- The second air sample was collected during the act of vacuuming the carpet
- All of the spore counts were significantly elevated compared to both the outdoor control sample and the first sample collected before vacuuming.
- This is how the data looked:
- Basidiospores: before vacuuming ~70 spores/cubic meter | during vacuuming ~ 800 spores/cubic meter.
- Cladosporium: before vacuuming ~80 spores/cubic meter | during vacuuming ~ 1,000 spores/cubic meter.
- Penicillium/Aspergillus types: before vacuuming ~110 spores/cubic meter | during vacuuming ~ 1,100 spores/cubic meter.
- The third air sample was collected in the home 30 minutes after vacuuming.
- All of the spore counts were still elevated as compared to both the sample collected prior to vacuuming and the outdoor control sample, though not quite as high (about 50% as high as the during vacuuming sample) as the sample collected during vacuuming.
If the on site inspector did not notice that the carpet had been recently vacuumed (i.e. seeing the vacuum “tracks” in the carpet or notice the dusty smell or see the vacuum sitting out) or had not asked the homeowner if they had recently performed any housekeeping activities such as dusting or vacuuming, incorrect conclusions could have been made with respect to this project. For example the airborne Penicillium/Aspergillus types prior to vacuuming were ~80 spores/cubic meter. A half hour after vacuuming, they were ~500 spores/cubic meter which is approximately 6 times higher. In absence of the vacuuming, this could indicate a mold problem which would entail further investigation such as invasive investigation and could concern the homeowner. Armed with the knowledge that the client recently vacuumed, the inspector could either take that into consideration when analyzing the sample data or, better, not collect the sample for several hours after housekeeping activities.
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.
In my next posting related to Fungal Data Interpretation, we’ll see the impact on the airborne fungal distribution when a moldy apple pie is tossed into the trashcan!
Mold in attic areas can be challenging at times in regards to determining the exact cause and source of mold growth. However, there are some common conditions that we routinely find during our Mold Investigations that contribute to mold growth in attics.
Penetrations in roof systems are common sources of water intrusion into attic spaces. Improper flashing, deteriorated rubber boot flashing, missing or improperly installed flashing around chimneys or other penetration points, and inadequate roof repairs are common causes of roof leaks. Also, water seepage occurs when the roof is beyond the end of its life span and failing. Water damage and mold growth is a common result of roof leaking conditions. Annual inspection of your roof by a roofing specialist and routine maintenance can prevent leaks in the roof system, reducing the likelihood of mold growth in your attic.
Inadequate Roof Ventilation
The lack of proper roof ventilation is a conducive condition to mold growth in attics. Without adequate ventilation, moisture laden air remains in the attic area, often times causing elevated moisture conditions at the roof framing and roof sheathing. During cold winter months, condensation can occur on the cold roof sheathing, creating elevated moisture conditions.
Another common cause of inadequate ventilation is when insulation is blown into the attic and care is not taken to prevent the insulation from blocking the soffit vents. Soffit vents are critical in a passive ventilation system in order to move the air from the lower portion of the attic (intake soffit vents) to the upper roof vents (exhaust vents). Adding additional ventilation ports or a powered roof vent can oftentimes improve and correct inadequate roof ventilation conditions.
Bath & Kitchen Exhaust fans vented into the attic
Exhaust fans should be vented directly to the exterior of the home. However, this often is not the case. When the exhaust fan is missing its exhaust duct or the duct has become separated, that exhaust air is vented directly into the attic space, oftentimes contributing to microbial growth.
Missing or inadequate attic insulation
Attic insulation not only is important in energy conservation, but proper insulation levels can also reduce the chance of mold growth in attics. As air travels up through the structure, insulation provides a barrier to slow the rate of conditioned air loss into the attic area. When an attic has missing insulation, the air movement increases significantly and that warm air can cause condensation conditions on cold roof sheathing. The moisture conditions resulting from such condensation is a catalyst for mold growth. Check your insulation and make sure that you have good and even coverage throughout the entire attic, especially at the lower North side areas.
Gaps or openings in ceilings
Unsealed openings in ceilings, around exhaust fans, can lights, speakers, etc. allow warm conditioned air to escape into the attic area. Sealing all penetrations in the ceiling can be an important preventative step in reducing mold growth in attics.
Finally, we frequently get asked, why is mold in an attic a big deal? While it is true that attic areas are not generally considered living spaces and air communication from upper attic areas to the living space below is relatively uncommon (in most normal situations), attic mold should still be a concern. Why? Because it is possible that if negative pressure conditions exist or occur in the home, air containing mold spores could potentially be drawn from that attic area into the living space. In addition, attic mold is usually an indication of other defects or conditions that could lead to costly repairs down the road. Such as water damage, Mold contamination in the finished living areas, wood destroying organisms and other moisture related conditions. Now go check your attic and if you see unusual staining or mold-like conditions, call a mold professional for a full assessment and appropriate testing.