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MOLD REMEDIATION
GENERAL INFORMATION
In dealing with molds and mildews, we must first understand that they
are fungi,
primitive plant-like organisms. Unlike plants, fungi do not produce chlorophyll,
they spread through fungal roots, called mycorrhizae, and produce spores
rather than
seeds. Occasionally, they emit mycotoxins.
There are many kinds of molds
and mildews, just as there are green plants. Some are
beneficial to mankind, while others can be deadly. Mushrooms are an example.
Fungi
prefer warm, moist, dark environments.
When mold and mildew spores
find a suitable location, they "plant" themselves and
go into the vegetative state. This means that the spore sends out mycorrhizae,
the
fungal roots, and begins to grow. The purpose of which is, of course,
to reproduce.
Since molds, mildews and other
fungi do not photosynthesize, they draw their
nutrients from the surface on which they are growing, decomposing it.
Many methods of controlling
fungi have been used with various levels of success. For
instance, corn smut is best managed using a chemical spray.
However, using a chemical spray
in an inhabited area where people might be exposed
to fumes just as toxic or allergy-inducing as those produced by molds
and mildews is not
a wise choice.
The best decision for the remediation
of fungi is ozone. Ozone not only oxidizes the
body of the organisms, but the fungal roots and spores as well. The oxidized
fungi can
usually be wiped away from the surface with a dry rag, however, vacuuming
is
recommended to prevent the oxidized particles from becoming air-borne.
Even these can
become irritants to highly sensitive people.
Ozone has a half-life of 36
minutes in air and then begins to revert to natural oxygen.
There is no film or fumes left behind to cause respiratory problems in
people who may
be sensitive to chemicals.
The Marhoc system is the only
ozone generator available that can be used effectively
against fungi. Because of the uniquely designed and patented reactor we
are the only
manufacturer that has discovered the secret of capturing the ozone at
the point of
generation giving you total control. This means you can cover the affected
area with
plastic sheeting, run the ozone hose underneath and direct the ozone stream
to the
isolated target area.
Molds and mildew often grow
deep within walls or under foundations. A small
opening is sufficient to direct the ozone into these areas using the narrow
poly tube,
rather than gouging large holes in walls or tearing up flooring or undermining
the
strength of the foundation.
The Marhoc unit produces ozone
at 0.7 grams per cubic meter per minute. Strong
enough to oxidize molds, which no other "small" or portable
ozone generator can
accomplish.
Killer Mold
* Stachybotrys
When doing mold and mildew remediation, it's usually not important to
"question the ancestry" of the fungi. Any moldy environment
is not a healthy one.
However, there has been a lot of media attention lately to a specific
species of mold that can cause serious illness in humans - Stachybotrys.
The three strains of Stachybotrys - Chartarum, Alternans, and Atra may
produce Tricothecene mycotoxin - Satratoxin H - which is poisonous by
inhalation.
The toxin is actually found on the fungal spore. These spores are contained
in a gelatinous mass. Once released they will readily die, but are still
allergenic and toxigenic.
Stachybotrys requires material with a high cellulose, low nitrogen content
to grow. This material must be water soaked for fungal growth. Relative
humidities above 55% with fluctuating temperatures are ideal for toxin
production.
Water soaked wood, ceiling tiles, wall paneling, unpainted plaster board,
cotton items, cardboard boxes and stacks of newspapers are ideal for the
growth of Stachybotrys. Gypsum board, fiber board, straw and hay are also
places where Stachybotrys might be found.
Stachybotrys is a black mold which appears slimy when wet and may be white
around the edges. When dry it is not as shiny or slimy appearing. There
are lots of other black molds, such as the type that grows on shower tiles.
Stachybotrys is fairly uncommon in residences. It is a slow growing fungi,
and does not compete well with other faster growing molds.
REMEDIATION
First of all, the hvac system must be shut down. If mold is growing in
the ductwork, air movement will spread spores throughout the building.
Next, the source of the water problem must be corrected. All roof or plumbing
leaks must be fixed. Areas where sewage backup has occurred or other flooding
must be thoroughly dried. Throw away water soaked ceiling tiles, wet newspapers,
cardboard boxes, whatever is disposable.
After the area dries, the fungus will not be able to continue to grow.
However, a black dust, which is actually spores, may be left behind. This
can be sucked up by the furnace blower and distributed throughout the
inhabited areas, if it was not shut down.
It is quite likely that Stachybotrys "dust" can be found throughout
the duct-work, spreading the toxic spores into every corner each time
there is air movement.
Traditionally, the accepted method for cleaning up any mold is to thoroughly
wash the area with a hot solution of water, chlorine bleach and dishwashing
liquid. This is not a good idea, because rewetting the area will only
prolong the favorable environment, and chlorine is not the best oxidizer
available. Chlorine can cause respiratory distress, when fumes are inhaled.
Some "experts" on indoor air quality will suggest the use of
filters, after a cleanup has been completed. These simply trap some spores.
Of course, when the filter is changed, these spores are released into
the ambient air, and nothing has been accomplished, except to temporarily
confine the spores for a short period of time. Filter advocates will tell
you to change the filters frequently. The more often the filters are changed,
the more often the toxic dust is stirred up.
There is only one logical and safe way to deal with Stachybotrys. Ozone.
Extra precautions must be taken if the mold is suspected to be Stachybotrys.
If conditions are right, chances are Stachybotrys is present. Remember,
that it does not compete well with faster growing molds. To be certain,
cultures must be taken. This is a time-consuming and expensive process,
but well worth it.
The main object in cleaning up Stachybotrys is not to disturb the mold.
The spores are encased in a gelatinous mass. After drying, these are readily
released.
Tent the area surrounding the mold, leaving adequate space all around
to be certain that the entire mold growth is contained and also to not
take chances of physically disturbing the mold. Disturbing the mold at
this point will result in the release of spores.
These could be inhaled (workers should be wearing masks) or lodge themselves
in cracks on surfaces to start a new colony at a later date.
The ozone tubing of the Marhoc Ozone Generator should be run under the
plastic, and the machine turned to continuous run or set for at least
12 hours.
In the Marhoc "Blue Book" kill times are listed for a few mold
spores. This is written in terms of microwatts per second per centimeter
squared. The actual kill time for Stachybotrys spores is not available
at this time. Combining an educated "guesstimation", based on
kill-times for other spores, plus a healthy respect for the possible toxicity,
we suggest that the timer be set for twelve hours.
While specific sites are being tented and targeted, the duct work should
also be ozoned. This can only be accomplished adequately with a Marhoc
Ozone Generator.
Only a Marhoc can provide the high concentration of ozone required while
being small enough to move into position. Only Marhoc harnesses the ozone
at the point of generation™ , so that all of the ozone produced is
guaranteed to go directly into the air duct. We recommend that one Marhoc
be used for each air handler, so that all of the duct work can be cleaned
simultaneously, rather than moving the machine from one place to another.
To accomplish this part of the cleanup, simply insert the Marhoc ozone
tube into the return air grille. If there is air conditioning, turn it
on to the lowest setting. Cold air is denser, and the unit will produce
ozone in an even greater concentration. Make sure the blower motor is
turned on and moving air throughout the system. Turn the unit to continuous
run or set the timer to at least 12 hours.
This is the only safe way to
clean air ducts of deadly mold spores. Conventional methods of duct cleaning
will only result in dislodging the spores, sending them flying through
the supply air to be inhaled by inhabitants.
After all ozoning has been done, and tenting removed, we suggest vacuuming
up any residue with a good quality professional vacuum cleaner. We recommend
one with a HEPA filter and disposable bag that is designed to seal itself
as it is being removed from the machine. This will prevent any particles
from flying back into the ambiant air. The chances of there being any
viable spores left are slim.
COMPILATION
OF CERTIFIED TEST RESULTS FOR CASE # 2415
Background information: An
initial site visit was performed and visual inspections revealed high
concentrations of mold covering the living room walls, hallway, bedroom
and bathroom on the first floor. A toilet tank on the second floor broke,
causing water to flood the first floor for an unknown
period of time. The odor of mold was so strong that it could be detected
outside the side door of the home.
Testing: Testing was performed
by U.S. Micro-Solutions, Inc. on August 2, 2001. Total mould counts were
extremely high in all areas, particularly the first floor living room,
which had counts of 1,142,320 CTS/m3 of Aspergillus/Penicillium. The outdoor
environment count for the same species totaled 3, 930 CTS/m3. Stachybotrys
was also found in the indoor environment while it was not found outdoors.
Initial Remediation: Under
negative pressure and containment, all contaminated building materials
were removed. Duct cleaning was also performed. The home was virtually
void of contents. Neither contents nor the structure were cleaned prior
to testing performed on October 30, 2001.
Testing: Testing was performed
on October 30, 2001 to determine the levels of airborne mould. While results
were significantly lower for the same areas tested, further remediation
was still warranted. Indoor concentrations of Aspergillus/Penicillium
were still unacceptable. In the bathroom the above totaled 15,327 CTS/m3,
opposed to 1048 CTS/m3 in the outdoor air of the same species. Stachybotrys
was still found in sampling.
Ozone: Ozone was utilized to
eliminate high concentrations of moulds in the indoor environment. We
ozoned for three days using the MARHOC SYSTEM, which produces .7 grams/m3
of output. The square footage of the home is approximately 2165 with 8'
ceilings, including the basement. We followed the process for mold remediation
as taught in the Marhoc Certified Ozone Technician Seminar exactly. We
also ran one HEPA filtration unit for the same period of time.
Testing: Additional testing
was performed on November 16, 2001 to determine the effectiveness of using
ozone in mold remediation, especially when airborne particulates are found.
We sampled the same areas as we did in our test on October 30, 2001 for
consistency. Sampling was also performed by the same person, Microbiologist
Herb Layman. Test results were overwhelmingly positive. Stachybotrys was
eliminated from sampling and Aspergillus/Penicillium were reduced to 131
CTS/m3 or less, while the outdoor environment levels of the same were
393 CTS/m3. Total mould counts were reduced significantly as well. In
comparison to the outdoor environment, which recorded to Total Mould count
of 7,205 CTS/m3, all indoor environments were significantly less, with
the highest indoor counts being 524 CTS/m3.
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