Dr. Jack Thrasher has a PhD in cell biology from the UCLA School of Medicine, and is an expert on the impact of mold on human health. Here, he discusses the health effects of toxic molds and bacteria, as well as his recommendations for remediation.
Dr. Mercola's Comments:
Jack Thrasher, PhD, is extremely knowledgeable on the topic of mold and how it impacts your health. Interestingly, from a toxicity point of view, some mycotoxins that molds produce are actually far more toxic than heavy metals, in terms of concentration. Mold mycotoxins also tend to affect more biological systems in your body than pesticides or heavy metals do.
"For example, stachybotrys produces mycotoxins referred to as trichothecene. They inhibit protein synthesis. It infects every organ of your body from your toes to the top of your head," Dr. Thrasher says. "I really think that the molds are much more dangerous from that point of view."
This flies in the face of what is commonly appreciated about toxic contaminants. Most would assume that pesticides or heavy metals would be far more dangerous. However, mold is a very significant health issue. And despite the fact that molds have been around forever, mankind has not developed greater tolerance against them than more modern chemical toxins. Part of that is because they tend to rapidly mutate.
"Let's take a look at Cryptococcus for example," Dr. Thrasher says. "Cryptococcus used to be endemic to the desserts of southwest United States. Now there is a new species… that was accidentally released up in Vancouver, Canada. It's spreading from the northwest throughout the country. It's a mutated form, [and] highly pathogenic to humans. About 25 to 30 percent of the humans who have become infected with it die… When they mutate they avoid our immune system.
The other thing they can do is produce chemicals that suppress your immune system at the same time. So therefore, I don't think we'll ever become resistant to these organisms."
Mold—A Hidden Pandemic in America?
According to Dr. Thrasher, the prevalence of mold in America is so great, he refers to it as pandemic. As many as 40 percent of all American schools and at least 25 percent or more of all homes are believed to be affected by mold and microbial growth due to water intrusion. A large portion of the problem stems from shoddy construction.
He explains:
"One thing that I have seen and observed by working with individuals in the field who understand construction, is that construction is extremely poor in the homes we have today. Plus, they're using building materials that are tremendous good food material for the microbes.
When I was a child… all the homes were built with genuine lath and plaster on the inside. [Now] you walk in and knock on any wall and you have what we call wallboard. That wallboard loves and is a good growth medium for all forms of mold. Everyone that I can think of, almost everyone now has carpets. The backside of carpets is also a great growth medium for mold and bacteria.
… The other type of home that I'm seeing that is of tremendous potential problems to the homeowner is homes that are built with a basement… [T]hey put the concrete down, and there is no water barrier between the earth and the concrete wall of the basement.
The same thing with the foundation, there is no water barrier. So when you water your yard, when there are heavy rains and things like this, the moisture… goes right to the foundation and into the basement or underneath the house, and then the moisture wicks up through the home, increasing humidity.
All of that increasing humidity, anything above 60 percent is going to lead to growth of mold and bacteria… People have to be very careful about this situation. That's the reason why I call it a pandemic."
Gutters can also cause problems. You need to be mindful of the drainage from your roof. I didn't realize this myself, and suffered the consequences when one of the gutters on my home drained onto the ground directly beside the wall, and the water seeped straight through to my basement. So you want to make sure the downspout is far enough away from the building. Ideally, it should empty at least 5 to 10 feet from the wall.
You also want to take care that the soil next to the walls of your home slopes away from the walls, to prevent water from collecting around the foundation. And make sure your lawn sprinklers do not spray the walls. Other common construction issues that can contribute to water intrusion and subsequent mold proliferation include:
Using polyethylene PVC piping instead of copper or galvanized piping, which can be easily punctured by nails or staples
Bath tubs installed with improper sealing around the drain
Improperly sealed sinks and garbage disposal
Installing particleboard (waferboard) after it has been rained on during construction
Bacteria—Another Health Risk Related to Mold Damage
Growing right along with mold are what's called 'gram negative' and 'gram positive' bacteria. Just like mold, they require moisture and organic material to thrive, and the synergistic action between mold and bacteria further increase and worsen inflammatory health conditions.
"The gram positive are group of bacteria that are being totally overlooked," Dr. Thrasher says.
"These positive bacteria consist of several bacilli, cocci, and one group called the actinomycetes. The actinomycetes contain several different groups of bacteria like mycobacterium. We're all familiar with… mycobacterium tuberculosis.
There are 139 other species of mycobacterium that can grow in our environment and 11 to 12 of those in the indoor environment are very serious human pathogens and can cause a condition called mycobacterium avium complex... and this is a very dangerous situation. It causes serious infection of the lungs and can spread throughout the body. Many of the symptoms are those of hypersensitivity pneumonitis. The condition can go on and develop into an asthma-like condition and then also into sarcoidosis particularly of the mediastinum.
Then the other group are the streptomyces… Streptomyces gave rise to a lot of antibiotics. Also, streptomyces are a source of many of the chemotherapeutic agents that are used today. These organisms are growing in the indoor environment."
Gram negative bacteria are also extremely harmful. When they die, they release their cell walls, which are referred to as lipopolysaccharide, or endotoxins. These endotoxins can severely exacerbate asthma and other conditions because they are highly inflammatory. According to Dr. Thrasher, research indicates the inflammation they cause can also affect your brain and other organs.
How to Detect a Mold Problem
Clearly, the first step would be to conduct a visual inspection. A musty, mildew odor is a tip-off that you need to check the area in question for any visible signs of mold. If you can't see any visible traces of mold, Dr. Thrasher recommends taking an air sample, and using a moisture meter to determine the moisture level in the area.
"I use a moisture meter on every wall of the building or the home looking for hidden moisture. The moisture content of wood flooring, for example, should be no more than 10 to 12 percent. I'm finding floors that have moisture content of 48 percent. Exterior walls shouldn't have anything more than 15 percent, and I'm finding exterior walls with 40, 50, 60 percent.
… The other thing I recommend is to not rely on air samples from mold spore counts. Invariably, that will give you misinformation. The number of mold spores that are in the indoor environment and the outdoor environment vary over the day; it's a diurnal type variation… So it's not a very reliable test for what's in the air.
Secondly, there are certain bacteria that do not release their spores into the air very regularly and you won't find them in the air… So become educated as to what to look for and how to look for it, and don't accept somebody coming in, taking an air sample and saying, "There is nothing wrong with this because the indoor counts are less than outdoor counts." That's wrong logic. Certain species of mold grow indoors much more regularly than they do outdoors. So you have to look at the species of mold, not just the spores."
A better option is to do 24-hour monitoring. However, this type of testing cannot be performed by a typical mold inspector. You need to hire a high-level mold expert for this type of air testing. (I'll list several sources for finding a qualified expert below.) Dr. Thrasher also suggests interviewing the expert in question to find out who they typically work for.
"If they're doing work for insurance companies stay away from them," he says. "You want somebody who is unbiased… [Also] ask them the question, "If you take the airborne mold in the indoor environment can it hurt you or cause toxic reaction?" If the person says, "No, don't worry about it. All it can do is cause allergies," then stay away from that person. That person is not well informed."
After air sampling, Dr. Thrasher also takes swab and bulk samples of the mold growth; actually cutting out a piece of the affected area if necessary, for proper lab testing. Dr. Thrasher explains what he typically tests for:
"We culture for the bacteria. We culture for the mold. We do what we call ERMI (Environmental Relative Moldiness Index), which is an EPA test that was developed by a group in the EPA. This is a PCR-DNA analysis for 31 different species of mold… that is very inexpensive, relatively speaking. It costs $350 to do that test… [W]e take swab samples looking for endotoxins. We also look for… polysaccharides called 1,3-beta-D-glucans… We want to get a good idea what's going on in the indoor environment."
Next Step: Remediation
As soon as you've identified the problem, you have to stop the water intrusion and remediate the problem at its source.
"Let's say you have an infested wall that's in the middle of the home between the living room and say, the adjoining den; what is recommended is that the whole area must be walled off from the rest of the house… In other words, you drape them with a plastic and you have to tie the plastic down with masking tape so that that area will not, theoretically, contaminate the rest of the house," Dr. Thrasher explains.
While you can clean affected metal objects, all organic materials (such as wood, particle board, and carpets) must be completely removed and replaced. You want to make sure that the contractor you hire for the job uses a HEPA (High Efficiency Particulate Arresting) filtration machine to trap minute particles, and that they're meticulous when using it.
WARNING!! Be Careful How You Chose Your Remediator
There is no question that a high quality active air purifier can help control mold issues but it will NOT remediate against them. You can use the best air filters and purifiers and they will never solve the problem if you continue to have water intrusion into you home that increases the humidity and feeds the growth of the mold.
You will need to stop the water at its source and carefully remove and clean the mold infested materials. While this may superficially seem an easy task, let me assure you that it isn't.
I recently had a leak in my basement that was improperly remediated for $10K. The cause was not addressed so the problem worsened, which more than tripled the price to properly clean it up. That is part of the reason that prompted me to contact some of the leading experts in this area and learn how to do this properly.
So let me tell you from personal experience, you need to find a qualified expert and professional that is certified by one of the agencies below. I would also suggest getting several bids for the work. You can find contractor or professional listings on the following sites. Both the IICRC and NORMI are certifying organizations for mold remediation, but the IICRC certification is perhaps the most widely used:
IICRC (Institute of Inspection, Cleaning and Restoration Certification)
ACAC (American Council for Accredited Certification)—a certifying body that is third-party accredited.
The IAQA (Indoor Air Quality Association)—a membership organization with no certification program (the ACAC handles this by agreement)
RIA (Restoration Industry Association)
NORMI (National Organization of Remediators and Mold Inspectors)
Keep in mind that a mere certification or listing may not be enough. Also evaluate the remediator's qualifications and insurance (liability as well as workman's comp). With the ACAC, there are a few different levels.
How to Clean Up Minor Surface Mold
If you have just a small area of surface mold, you probably don't have to call in an expert. However, only attempt to clean it if it's limited to the surface of a small area. You cannot "clean" deep-rooted mold. Dr. Thrasher has one word for those of you who have bought into the home-remedy advice to "kill off mold" with ammonia or bleach: Don't.
"What happens is you'll kill the mold but you'll leave the carcass behind," Dr. Thrasher explains. "The carcass will disintegrate and release toxins into the air. So you really went from one problem (mold growth) to another problem; dead mold and the release of all of their toxins… and then once water is reintroduced in the environment, the mold will grow right back to the surface."
However, for minor visible surface mold on say a baseboard, or on a piece of furniture, you could use a little bit of sodium bicarbonate (baking soda) and vinegar to wipe it off.
"I just use the concentrated vinegar and baking soda," he says. "All you need is a couple of tablespoons [of baking soda] to a quart of water. The vinegar I just take straight out of the bottle… I generally do the vinegar first and then follow it with the baking soda… The vinegar will kill the mold and the bacteria but you're going to leave residue on the surface and so you scrub the surface to try to get rid of the residue.
… I never validated that procedure, but that's what I recommend; what I do use and it seems to work, but I haven't validated it with research data. I have to be honest with the population out there."
What about Ozone Generators?
While Dr. Thrasher does not recommend using an ozone generator, other indoor air experts do. Ozone generators essentially generate photocatalytic oxidation that can help destroy airborne mold. However, Dr. Thrasher strongly cautions against their use, stating that oxidizing an organic chemical of any kind will create free radicals, and he also points out that ozone can be highly irritating to your mucous membranes and lungs.
Personally, I believe the claim that ozone generators facilitate the removal of volatile organics is correct… But do beware that they should not be used when you're in the room at levels higher than the EPA recommends, and they do pose a danger to both plants and pets. However, the ozone dissipates quickly, so after airing the area out for about 20 minutes, it's safe to return.
Keep in mind that this is different from air filtration, as the ozone generator actually purifies the air and neutralizes any odors at the source, on the molecular level.
Could Your Health Problems be Related to Mold?
Common health problems that can be attributed to poor and potentially toxic indoor air quality include:
Frequent headaches
Depression
Chronic fatigue
Allergies
Neurological problems; poor concentration and forgetfulness
Skin rashes
Stomach and digestive problems, such as dysbiosis, leaky gut, and frequent diarrhea
Chronic sinusitis
Joint aches and pains
Muscle wasting
Frequent fevers
Asthma or trouble breathing
If you have any of these issues, it may be worthwhile to consider your indoor air quality, and the possibility that your health problems may be related to mold. A meta-analysis, published in last year in the journal Environmental Health, concluded that:
"Residential dampness and mold are associated with substantial and statistically significant increases in both respiratory infections and bronchitis. If these associations were confirmed as causal, effective control of dampness and mold in buildings would prevent a substantial proportion of respiratory infections."
It's important to determine whether or not your health problems are indeed due to mold, in order to properly treat it. Most doctors will simply prescribe an antibiotic for chronic sinusitis, for example. But if your sinusitis stems from bacteria- and mold growth in your home, it's not going to clear up. The next step is typically to prescribe either prednisone or a corticosteroid, which could further worsen your condition.
"You want to stay away from the corticosteroids; you want to stay away from the antibiotics," Dr. Thrasher warns. "What you need to do is to do a culture. Go to a good ENT physician and actually get a diagnosis of what is going on inside of your sinuses. You want to stay away from the corticosteroids because two weeks use -- or even less than this -- of corticosteroids will increase your risk of other infections. Corticosteroids inhibit the oxidative burst produced by macrophages… Let's say you have mold that's growing in your sinuses. So the macrophages in your body, called the innate immune system, are in there gobbling up the spores of the mold, correct?
Then what happens is they put you on corticosteroids, and the role of the macrophages, they'll gobble them up, engulf them, and then produce oxidative burst that kill the spores and the bacteria. The corticosteroids do not inhibit the engulfing aspect of it so they take up the spores and the bacteria, but the corticosteroids inhibit the extra oxidative burst produced by the macrophages. Now, the macrophages contain live spores and bacteria. Now where do they go?
They go any place else in the body they want to go to. So therefore you have increased your risk of other infections particularly fungal infections. I've seen individuals who have been put on corticosteroids because they have been exposed to these indoor environments and then, sometime down the road, have been diagnosed with Aspergillosis."
That's definitely a concern. Additionally, long term use of steroids has other side effects that are well documented, including increasing your risk of osteoporosis and cataracts, and disrupting your hormone balance. So, educate yourself on indoor air quality, and particularly on mold. For more information about mold and its health consequences, check out Dr. Thrashers website at www.DrThrasher.org.
