Wednesday, May 18th, 2016 by Anthony Picarello
Two Types of Evidence
One of the reasons that the debate about health effects related to mold continues so vigorously is that the two
sides typically use different types of evidence to support their conclusions. Individuals skeptical of mold related
health effects tend to gravitate toward carefully controlled scientific studies. Although such studies
produce accurate information, typically they are narrow in their application. After all, in order to control
variables you often have to reduce the number of variables. This tends produce results that are not reflective
of the real world where individuals are subject to a number of environmental exposures and little is known
about the synergy that may develop between unrelated exposures, magnifying the negative impacts.
Conversely, many advocates who aggressively trumpet the connection between mold in buildings and
detrimental health effects often rely on case studies. To a great extent case studies involve anecdotal data–
individuals report symptoms and conditions which then must be extrapolated in an attempt to determine the
exposure levels and the connection between the conditions and the symptoms. It is difficult to have tight
controls on case studies as exposure levels are often not measured, or measured only after symptoms have
been reported. Also, it is extremely difficult to record or regulate ancillary exposures other than mold in
everyday situations. Since stress, diet, chemicals, and a host of bacterial and viral organisms may produce
symptoms similar to those associated with mold exposure, proving that mold is the primary culprit is
This sort of debate about health consequences from exposure to a particular contaminant is not new. The
ancient Romans debated whether smelting lead was truly the cause of significant illnesses. Eventually the
government decided that the dangers were real enough that Roman citizens should not work such a trade, so
they made lead work part of the prison punishment for foreigners. A more recent example of a suspected
problem eventually being confirmed is the work related to asbestos health effects conducted by Dr. Irving
Selikoff in the 1970’s. He was able to make the transition from anecdotal data to scientific data by
aggregating enough individual cases that the similarities in outcomes could be verified statistically. It is
interesting to note that today’s general acceptance of the correlation between asbestos exposure and lung
cancer was as vigorously debated 35 years ago as the mold connection to health effects is today.
With this in mind we have always taken the approach in our organization that it is important to look for
trends in data, even if it is soft data, such as reports from homeowners, rather than hard data like
measurements or sample results.
Case Studies Can Serve as Examples
Over the past ten years we have talked to hundreds of home and business owners about health symptoms and
indoor mold growth. Our experience parallels that of Dr. Selikoff’s with asbestos. We have been in contact
with too many individuals that exhibit a cluster of similar symptoms, with the only consistent connecting
factor being mold exposure to disregard this data. In that respect, one case study can serve as an example of
many situations that have convinced us that there is a provable link between exposure to mold indoors and
serious health symptoms. A recent project involving a family, which we will refer to as the V's, clearly
illustrates our experience over the past decade.
We were called in to do an IAQ investigation of a 2,400 square foot ten-year-old two-story home in a nice
neighborhood. The V’s were the original purchasers of the home. The family consists of a father, a stay-at-home
mother, and three children, ages eight, four, and one. They sleep upstairs. The mother reported that
when the house is closed from October to May the family is sick. They didn’t see or smell any mold.
Over the course of numerous conversations with the V’s we were able to compile a list of symptoms (see
sidebar). When we got a sense of the magnitude of the health problems they had experienced, we asked Mrs.
V to compile a list of doctor visits during the past year. We were stunned when the listing yielded 51 visits–
nearly one a week! No wonder some of the doctors had accused Mrs. V of suffering from Munchausen
syndrome, a psychological disorder where a mother calls attention to herself by magnifying, or in more
severe cases causing, illnesses in her children.
This information led us to question Mr. and Mrs. V carefully regarding past incidents of water intrusion.
They indicated that they had numerous leaks over the years in the northeast corner of the kitchen, and just a
few weeks prior to our inquiry had identified a gap in the siding that was the probable cause. The builder
had agreed to fix the siding and reported that a whole sheet of orient strand board under the siding above the
kitchen had to be replaced because it was “…black and so soft that you could put your finger through it”.
Following replacement of the board the four-year-old was sick; but the blood test was inconclusive for
mononucleosis. Previously, Mr. V had exhibited the fewest symptoms, but after investigating the attic area
where the siding was replaced, he was stricken with disabling headaches and upper respiratory distress. Mrs.
V contracted pneumonia following the removal of the orient strand board.
This new information was cause for some real concern as we understand that one of the key truisms of mold
situations is that “bad mold remediation is worse than no remediation at all”. The homeowner allowed us to
conduct a mold investigation. We found substantial residue in the attic that was confirmed as Stachybotrys.
We also recovered elevated levels of Aspergillus/Penicillium throughout the house and Stachybotrys contamination in the HVAC system, with the worst levels in the eight-year-old’s bedroom. This correlation
between the highest mold counts and most significant symptoms of the occupants is an association that we
Based on the results of our investigation we recommended that a local restoration firm (ASCR member and
certified mold specialist) conduct the remediation. The family moved out of their home while the
remediation was conducted. Within a week of moving out they noticed that they were not having upper
respiratory problems. Within a month all the symptoms had subsided.
The remediation effort involved the removal of the siding for a second time where the leak occurred. This
aggressive approach uncovered additional material with visible fungal contamination. After all the source
material was removed, cleaning and air scrubbing were conducted in a small, isolated area of the attic. This
was followed with a complete HEPA sandwich cleaning (HEPA vacuuming, damp wiping with an antimicrobial,
and HEPA vacuuming a second time) of all exposed surfaces in the living area of the house. After
cleaning the interior of the house, the entire HVAC system was cleaned following NADCA guidelines. Postremediation
air samples confirmed that the remediation process had eliminated all of the residual
Stachybotrys and other mold types.
The true testament to successful remediation is that since the family has returned to their home they have not had any doctor visits. Although this is only one case, it is not uncommon in our experience, and it serves to
bolster our belief that many people really do get sick from a little mold in their home.
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