The Science of "Doing it Right"
by Patricia L. Harman
Editor in Chief, Cleaning & Restoration
Many individuals think nothing of leaving their homes for a few
days or even a few weeks. They forward their mail and ask
a trusted neighbor to keep an eye on the place – to
cut the grass, shovel the snow and watch for anything unusual.
if someone isn't going inside to check for leaks or other
problems, they can go undetected for some time and the results
can be disastrous. Such was the case for Louis Lederhaas.
Mr. Lederhaas owns two homes – one in Washington State and
one in New Jersey. He alternates between the two and has his
office based in one of them. Last summer, he received an $800
water bill for the home in New Jersey, where no one had lived
for several months. According to the bill, they had used 301,000
gallons of water. When Lederhaas flew back to New Jersey to
check it out, he found that the rubber hose to the washing
machine had burst and the water had been running for several
weeks. (The city only read the meters every three months,
so the leak could have occurred at anytime during the previous
period.) Fortunately, the water was able to drain out through
a basement shower and the back door, but the damage to the
area was still extensive – major mold and water damage
from the flooding.
Lederhaas called a client who identified the problem and turned
the water off. Then, he contacted his insurance agent who
made several suggestions regarding the next course of action.
Shortly thereafter, the insurance company hired Environmental
Health Investigations, Inc., an indoor environmental firm,
to conduct the initial testing and write the scope for the
Kerbel, president of Environmental Health Investigations,
is a certified industrial hygienist with more than 20 years
experience in the field. A certified industrial hygienist
(CIH) receives certification from the American Board of Industrial
Hygienists, has a minimum of five years experience, an advanced
degree in an associated science, and has passed a rigorous
two-day test similar to the boards passed by physicians or
the exams for the legal or accounting professions.
In cases such as this, the role of a CIH involves the recognition
and evaluation of hazards to determine their potential health
effects, as well as providing engineering controls to abate
or manage the hazard. Sampling during an initial visit frequently
involves a combination of bulk samples (placing affected materials
in a normal, zip-lock bag), wipe samples (swabbing a surface
with sterile swabs) and air samples (utilizing some type of
a vacuum pump to collect air), as well as spore traps and
dust samples. Results of the tests are normally available
in two to three weeks. The sampling method varies according
to the specific types of problems and the materials affected.
the initial visit, the focus also involves a visual, as well
as an invasive (drilling holes and inserting moisture meters)
inspection. The determination of whether or not there is a
problem also takes into consideration the fact that the levels
of spores inside should be lower than the levels outside.
Both indoor and outdoor samples should be taken on any mold
remediation project. Once the hazards and the existence of
mold have been identified, the CIH writes the scope (roadmap)
for the project.
The scope specifies the type of containment to be utilized, whether
affected materials must be disposed of or cleaned (i.e., HEPA
vacuumed, disinfected), personal protective equipment for
workers, decontamination requirements, use of specialized
equipment or materials (i.e., negative air machine) and how
specific surfaces should be cleaned.
In the Lederhaas case, extreme amounts of mold – in excess
of 5 million colony forming units per gram – (100,000
per gram is considered excessive) were found, including: Aspergillus
versicolor, Aspergillus sydowii, Penicillium, Verticillium
leconii, Stachybotrys chartum, Doratomyces sp., Gliomastix
murorum, and Myrothecium roridum.
There has been a lot of information (and some misinformation) in
the mainstream press concerning the health effects of mold
exposure. Not all molds produce toxic health effects, but
they can pose serious problems for individuals whose immune
systems are compromised (i.e., individuals suffering from
AIDS or undergoing chemotherapy). Side effects in a normally
healthy individual can include head congestion, dizziness,
grogginess, sore throat and headaches. The mycotoxins produced
by molds can be harmful to humans and animals if inhaled,
ingested or touched. Symptoms can include respiratory problems,
coughing, sneezing, watery eyes and even more serious health
need a competent person to make the decisions regarding mold,”
explained Kerbel. “Is the mold to the extent that it’s
problematic? What will we need to do to abate it? What is
the scope of the work to be done?” All of these issues
need to be decided by a competent individual who is not involved
in the project. “The CIH is a third-party, independent
quality-control person,” said Kerbel.
need to be able to define the work and to show that it has
been successfully completed,” he added. “There
needs to be a beginning, during and end to the project. We
can’t have the contractor do all of that himself because
it would be a conflict of interest.”
Lederhaas, the next step was to locate an environmental remediation
firm to handle the project. Another client referred Lederhaas
to Ira Finger, president of Consolidated Environmental, Inc.,
for the restoration and clean up of the basement.
Environmental has three specialties – mold remediation;
cleaning and disinfecting HVAC systems; and fire and water
damage restoration. Finger first saw the house on September
11, 2001, and began work on the project in early November.
Testing, remediation and restoration of the 800-square-foot
project spanned a period of several weeks. (It takes approximately
two to three weeks to receive results for each round of testing.
Samples are taken before, during and after a project.) The
mold contamination in the basement was extremely visible,
but there were no obvious signs of moisture before the remediation
the initial phase of the project, several steps were taken
to protect the company’s employees and the rest of the
house. First, the basement was placed under negative air pressure.
This was accomplished by placing several HEPA-filtered negative
air machines inside the house and by sealing critical openings
with 6-mil poly. A pressure differential data logger was also
used to ensure that the proper negative air pressure was maintained.
A contained entrance booth was then set up outside the back
door. Workers entered only through this contained entrance
to the basement. The workers were also required to wear disposable
Tyvek suits and respirators with HEPA filters. The purpose
of the containment was to prevent the mold contamination from
spreading any further.
and his crew removed all of the sheetrock walls and ceilings
as specified in the scope prepared by Kerbel. This is typically
done, even if there isn’t any visible mold on the outside
of a section, because hidden mold growth can frequently be
found in the wall cavities or backsides of drywall. The wood
that was badly damaged was also removed and the rest was cleaned.
After disposing of the contents, the crew was instructed to
pull up the linoleum floor. They cleaned the area until it
looked visibly clean and wiped down all of the surfaces with
two different types of disinfectants.
“We found a ‘hidden wall’ with mold growth in one
area,” said Finger. “The front of the wall showed
visible signs of mold growth, so the wall was removed, revealing
yet a second sheetrock wall that was heavily contaminated
and subsequently removed. Behind that was the exterior wall
constructed of cinderblock. Apparently, a previous owner had
painted the wall with black waterproofing paint, which held
the water in.”
Finger then took moisture readings on the exterior walls and the
concrete floor – both of which had been concealed until
the walls and flooring had been removed. An unacceptably high
level of moisture was found, so refrigerant dehumidifiers
were used over a two to three-week period to further dry out
the space. After the moisture levels were lowered, the remaining
wood framing was removed and the entire basement was re-cleaned
prevent cross-contamination in other parts of the house, Consolidated
Environmental set up a containment barrier. “We used
a laser particle counter to measure the dust levels upstairs,”
explained Finger. “We cleaned upstairs twice even though
it passed [clearance testing] the first time. We cleaned it
again to prevent recontamination.”
Once the remediation was complete, Bill Kerbel took additional
samples. The clearance testing showed a lower reading for
mold spores inside the house than outside during the winter
months (when the levels would normally be low).
Each indoor air quality remediation project demands thoroughness
and flexibility, whether it is a mold remediation, a sewer
backup or a flood. A literal “work in progress,”
the multi-step process requires patience, ingenuity and accuracy
from the professionals involved.
company philosophy is that we do it right or we don’t
do it at all,” concluded Finger. “With the health
of building and home occupants on the line, we can’t
afford to do anything less.”
*Reprinted with permission from the July 2002
issue of Cleaning & Restoration, © 2002,
Association of Specialists in Cleaning & Restoration.