CONDUCTING BUILDING MOLD INVESTIGATIONS
2.2. BASELINE INVESTIGATION
Building investigations do not start with sampling for mold. They start with getting as much relevant background information as possible. Possible sources of relevant information could include the following:
. Building owner
. Building manager
. Building maintenance personnel
. Building architect or architectural plans
. Building occupants
. Other consultants, including various engineers or environmental consultants The kind of information needed may vary somewhat depending on the nature of water intrusion but commonly includes the following:
. The Leak History (i.e., a Chronology of Water Intrusion Events) Including Known or Suspected Sources, Location in the Building, and Duration of the Leak and Wetness. It is rare that an entire structure is water-damaged, although there have been such instances (e.g., complete submersion in a flood, during construction before the roof assembly is complete). The length of time that a material remains wet can predict the kinds of fungi that colonize it.
. Building Plans and Drawings Such as Floorplans (with Scales), Mechanical Plans, and Plumbing Plans. Floorplans are needed to estimate the number of air sampling locations needed to appropriately characterize the indoor air quality.
. Reports from Consultants (e.g., Architects, Engineers) Who Have Conducted Forensic Water Intrusion Investigations. These reports can be very helpful because fungal growth can occur in the presence of sufficient moisture on a sub- strate capable of supporting its growth. The opposite is also true; fungal growth does not occur in the absence of sufficient moisture. Documented fungal growth in locations not explained by water intrusion experts begs explanation. The absence of fungal growth in locations known to have been wetted is most likely due to a lack of adequate nutrients and/or lack of the continued moisture due to drying. However, the mold investigator must verify the absence of growth in known or suspected wetted areas.
. Reports from Other Environmental Consultants Who Have Conducted Indepen- dent Investigations in the Past. Laboratory data from samples collected by others can serve as the reference to expand an independent baseline survey. For example, given the following (1) Penicillium/Aspergillus spores excessively
dominate indoor spore trap samples, (2) airborne culture samples are not domi- nated by undifferentiated Penicillium species on malt extract agar (MEA) media, and (3) tape lift samples indicate growth of undifferentiatedPenicillium species, it is prudent to conduct a second survey including culturable air samples using various fungal isolation media, including a selective medium for xerophilic fungi, and surface samples submitted for culture with species identification on MEA and DG-18 media. This sampling design will likely be sufficient to support or refute the hypothesis that the likely source of growth was due to the flooding incident. If the species of surfacePenicilliumgrowth differs from thePenicillium degrading the indoor air quality, then additional investigation that may involve destructive testing is required to find the source of thatPenicilliumspecies. (Caution is urged if the original spore trap data were collected with an Air-O-Cell cassette; see Section 2.2.2.2). That growth site may still be related to crawlspace flooding or not, depending on location of the growth site and remainder of the leak history. But the obvious fact remains, without identifying growth sites, mold remediation will fail.
. Age and Use of the Building. The older a building is, the more likely that it has a water damage history. An investigator needs to know whether the building is in use and whether occupancy might restrict the investigation. Is the building furnished, or have contents been removed? If yes, why? Does the building have electrical power, and is adequate lighting available? What information has been shared with occupants? Are there any access issues with respect to occupants? The use of many commercial and institutional buildings can predict the amount of building occupant generated sources of moisture, such as, laundry facilities. It is also very important that qualified consultants conduct asbestos and lead surveys if the age of the building indicates that these contaminants are likely in various building construction or finish materials. This information must be collected prior to destructive testing and preparing written technical specifications for mold remediation to ensure that the appropriate steps are taken to minimize remediation worker exposure and prevent atmospheric contamination of all contaminants that will become airborne, not just fungal. Investigators should be thoroughly familiar with all applicable federal and state regulations involving asbestos and lead or must depend on investigations of those who are qualified. An example of an appro- priate step would be the inclusion of using wet methods (required in OSHA asbestos regulations1) to remove asbestos containing-materials that are rarely included in mold remediation protocols.
. Occupant Health Status. In general, the mold investigator needs to know whether building occupants include infants, persons recovering from recent surgery, people with immune suppression, hypersensitivity pneumonitis, severe allergies, sinusitis, or other chronic inflammatory lung diseases.2,3 Health status should be taken into account when interpreting laboratory data relative to occupancy. A knowledgeable physician may be consulted for making a final decision on occupancy.
. Building Design and Construction Including Accurate Information on the Building Envelope and Foundation. It is impossible to specify materials to be remediated unless those materials are known. It is also impossible to specify the method of remediation unless construction and finish materials are known.
. A Chronology of Water Loss Restoration (if Any) or Prior Mold Remediation (if Any). Some important questions to be answered include the following:
Where was the initial water intrusion observed?
What steps were taken and when to repair the leak and dry out the building?
What mold remediation steps were taken at what locations, and when?
An example follows that illustrates why this information is critical:
Baseline air sampling was conducted in a building that was extensively water- damaged by a high-pressure pipe leak onto crawlspace framing for as much as 2 weeks. The crawlspace framing was never dried out or completely remediated of fungal growth. However, water-damaged and moldy gypsum wallboard and hardwood flooring were removed during mold remediation without containment of affected areas followed by 30 h of detailed cleaning of interior surfaces from which contents had been removed. Baseline air sampling after these activities indi- cated the presence of low concentrations ofPenicilliumspecies in the indoor air not found in the outdoor air that was documented growing on crawlspace framing.
More likely than not, detailed cleaning reduced levels of airbornePenicilliumbased on these and additional data and information. Additional investigation revealed extensive growth not remediated in the crawlspace and elsewhere. In other circum- stances, low concentrations of airbornePenicillium, particularly in the absence of documented growth sites ofPenicillium, might not have been significant.
This example demonstrates the importance of detailed, thorough informed investigations and the importance of good air sample data.
2.2.1. Physical Inspection
Physical inspection requires access to all areas of the subject building unless there is a clearly defined, justifiable reason not to inspect one or more areas. The underlying reason for this is that a moisture problem in one area of a building can impact another. This includes occupied areas and unoccupied areas such as attics, hot-water-heater closets, storage rooms, garages, and crawlspaces. In part, all of the relevant areas investigated depend on the type and use of the building, such as, single-family residence, hospital, hotel, school, office building, and retail commer- cial space. Gloves should be used when actually handling suspect moldy materials.
The investigator should have all of the appropriate equipment for personal protec- tion and investigation immediately available as needed. Construction areas may require a hardhat, reflective vest, and steel toe footwear. If significant visible mold growth is evident or independently collected air sample data indicate that the indoor air quality is degraded, then respiratory protective equipment is needed.
Boots or walking shoes should be worn to climb ladders and access rooftop areas.
It is important to take the right tools, equipment, and supplies to the site for inspection. Please refer to Table 2.2 for a list of these and comments on their use.
2.2.1.1. Visual Inspection. The primary objectives in a visual inspection portion of a building mold investigation are to note the presence or absence of suspect water staining, suspect water damage, and suspect fungal growth relative to architectural details first, and finishes and contents, second. Therefore, these will be discussed in depth. However, it is impossible to mention all conditions here that are critical to note because they are as diverse as are the buildings
TABLE 2.2. Inspection Tools, Equipment, and Supplies
Item Comment
Generator Needed if electrical power is not
provided
Ladder Needed to access some areas, including
ceilings
Extension cords —
Plug conversion adapter Older buildings do not accept two-prong male ends Flashlight or other auxiliary lighting Often necessary for attics and
crawlspaces Pocket knife, utility knife, or other
sharp edge for cutting
Often needed for collecting bulk samples
Screwdriver Needed to access components of a
heating, ventilating, or air conditioning system
Extra batteries —
Tape measure Needed to measure distances to relevant
architectural details
Needed to measure the square footage of suspect fungal growth
Reflecting mirror Often needed to view inaccessible areas
Clip chart Needed to hold inspection forms in an
orderly fashion
Forms and plans Floorplans are very useful for
orientation and making notes relevant to architectural details
Graph paper —
Smoke tube or tissue Qualitative assessment of working order of exhaust fans
Camera and film —
Moisture content meter —
Compass —
Air sampling equipments
with media, supplies, and tripod
Supplies include alcohol wipes, parafilm, labeling pens
Coolers with blue ice —
Surface sampling equipment Including, but not limited to, sterile swabs, transparent tape, Rodac surface contact plates
investigated. For example, the conditions inside single-family homes are unique to each home. A few of these will be discussed. In addition, the reader is provided with forms appended to this chapter (see Figs. 2.1, 2.2, and 2.6) that may be useful and can be adapted or revised as needed. They illustrate the level of detail that is necess- ary to conduct professional, competent investigations.
One of the most important steps to take initially is to stand outside the building and determine the orientation of the building on the lot, its relationship to surround- ing buildings, and the direction it faces. Building use and design of adjacent buildings may be important, such as the location of a dumpster beside a lower- story window of the subject building that contributed to atypical concentrations of Aspergillus fumigatus. Activities on or adjacent to the property may also affect sample data and therefore are important to note during the visual inspection portion of a baseline investigation. Examples are grass-cutting and weed-eating or earthmoving equipment preparing ground for a new housing development.
An investigator should inspect all walls, the ceiling, and the floor for suspect water stains, water damage, and fungal growth in every room inspected. Either the presence or absence should be recorded. One such description could read
“Suspect water stain noted on the ceiling of the dining area, round in shape, located approximately one foot from the exterior west wall. No suspect fungal growth seen.” This location should also be photographed and the photograph number clearly recorded with the description.
Sometimes what appears to be a water stain, water damage, or fungal growth is not; thus the description as “suspect.” Suspect water stains should be docu- mented by forensic water intrusion experts. Suspect water damage may or need to be documented by others, especially if damage is severe and moisture content readings are elevated. Suspect fungal growth should be described by color, coverage area, location relative to architectural details, and general appearance. One such description might be “16 ft2 of suspect visible growth on painted gypsum wallboard at a height of approximately two feet above the finished floor running the entire length of the bed placed approximately 3 in.
from the east exterior wall. Visible after bed was pulled out from the wall.
Growth is dark and spotty. There is no suspect growth above the level of the bed. Moisture content readings are all normal, n¼32. . ..” All of these obser- vations are critical in terms of causation, remediation, and implications of the growth.
It is important to note that visiblefungal growth sometimes is hidden and not apparent in the inspection. In the preceding example, although the top edge of suspect growth was visible without moving the bed out from the wall, it would not have been possible to describe the amount and appearance of growth or take moisture content readings without moving the bed. This suspect growth can cor- rectly be called suspectvisiblegrowth even though occupants placed the bed too close to the wall to allow for ventilation and rendering the area somewhat inaccess- ible. Suspect growth behind a refrigerator due to a water supply line leak is nor- mally hidden from view and therefore should not be described as visible.
Suspect fungal growth within a wall cavity on any surface that can be seen only
after destructive testing or demolition is seldom visible or accessible. Thus, it is correctly described as “hidden” growth. Said another way, just because you can see growth, this does not mean that it is visible growth. Visibility to relates with location and accessibility. As long as investigatorsdefinetheir terms and arecon- sistent, their documentation is clear. This also serves to emphasize the importance of detailed descriptions; there cannot be too much detail. When it comes time to interpret all the findings, taking into account all the background information gath- ered, a complete physical inspection, and air and surface sampling, you will find this level of detail and documentation valuable.
Suspect fungal growth is verified by surface sampling using an appropriate method after air sampling is completed to avoid potential bias of the air sample data. It is strongly recommended that surface sampling be done for two major reasons: (1) to confirm and determine the species of fungal growth and (2) to deter- mine whether vegetative growth only or if vegetative and reproductive growth exists on the surface sampled (please refer to Table 2.3).
Investigators should inspect interiors to the level of detail described in Table 2.4.
Observations should then be recorded on field notes sheets or photograph logs (see Figs. 2.1 and 2.2).
Everything that is noteworthy, literally, should be photographed with the photograph number and a description of why the photo was taken. Photographic documentation will be discussed in greater detail in Section 2.2.1.2, below.
Investigators should inspect exteriors and nonoccupied areas to the level of detail described in Section 2.2.1.2 and record on a combination of field notes sheets, photograph logs, and photograph depictions (see Figs. 2.1 – 2.3).
2.2.1.2 Documentation. All suspect water stains, suspect water damage, and suspect visible fungal growth must be documented in writing, drawings, or photo- graphs, and via surface sample data. The previous section discussed written descrip- tions and subsequent sections, and Chapters 4 and 5 discuss documentation verification of the presence or absence of fungal growth through surface sampling and laboratory testing. This section presents some principles of photographic documentation and recommends good practices.
Examples of written descriptions in Section 2.2.1.1 use compass directions:
north, south, east, and west. Another acceptable wall designation utilizes numbering walls 1, 2, 3, and 4 coinciding with the building elevation entered, the left side, the opposite side, and the right side of entry, respectively. Figure 2.4 exemplifies the use of this designation scheme. As long as the method used is consistent, either can be used.
All photographs must be physically labeled with the photograph number used on all field documentation. Professional photographers label the reverse side of photographs.
Basic photo documentation involves, to the extent possible, taking three perspec- tives: overview (the entire view), midrange (the specific object or condition), and
closeup (the specific information about the object or condition). One such example relative to a building mold investigation follows:
. Overview Photo—the entire exterior wall cavity revealed through destructive testing
. Midrange Photo—portion of wall cavity indicating the area of wet exterior sheathing and suspect fungal growth
. Closeup—the location in the cavity where a fastener penetrates the exterior cladding and sheathing
TABLE 2.3. Importance and Use of Species Data
Use Comments Other Data Needed
Determine whether indoor air quality is degraded in a baseline survey
Species identification is required to determine the biodiversity between indoor and outdoor air
Both indoor and representative outdoor air sample species data are necessary for comparison Determine likely cause
of degraded indoor air quality in a baseline survey
Not all fungal growth results in degrading the indoor air quality
Very small areas of growth can have little or no impact on indoor air quality
Hidden fungal growth may not degrade indoor air quality
Species identification in both air and surface samples is required to
“connect the dots”
Verify that surface remediation was effective
Goal of mold remediation is to remove fungal growth; visual inspection is the first step but must be followed by surface sampling to verify the absence of growth—
this is particularly important for wood and wood products remediated in place because they are porous
Surface sampling methodology must be used and same area should be resampled
Initial baseline or destructive test survey data from the same surface are necessary for comparison
Verify that air within containment is not degraded by fungal growth discovered during remediation
Containment barriers should not be removed until air quality is known
Surface sample species and clearance air sample species data are required for comparison
TABLE 2.4. Visual Inspection Checklist
Interior Inspection Crevices between refrigerators and counters or walls
Headers of windows, window frames, window sills, window caulking Condensation on inside surface of windows
Condensation (known as “fogging”) between window dual panes Sink cabinet floors, sides, and back and at sink plumbing lines Underside of toilet tanks and at plumbing lines
Whether windows are fixed, i.e., nonopening and their location Whether doors or windows were open or closed on arrival at the site
Housekeeping practices, e.g., visibly dusty surfaces, food left on plates in sinks, mildew in bathroom tile grout and caulking, dirty and stained carpet, dust bunnies
In general, the amount of contents Placement of furniture adjacent to walls
Presence of an exhaust fan in bathroom and whether it actually exhausts Presence and location of houseplants
Condition of the floor surface underneath plant containers Presence of location of silk and dried plants
Presence and location of aquariums Presence and location of wood stored inside
Presence of cats, dogs, birds, or other pets, or evidence of pets (food bowls, cages, etc.) Presence of smokers or evidence of smoking
Whether clothes driers are exhausted outdoors Clotheslines indoors for hanging wet clothes to dry Presence, location, and type of insects
Whether the range is gas
Presence, use, and location of dehumidifiers and humidifiers; record the manufacturer and model
Presence, use, and location of air purifiers; record the manufacturer and model Presence, location, type, and condition of wallpaper
Presence and location of warping of hardwood flooring Condition of “drip edge” of shower curtain liners
Exterior Inspection Amount of vegetation and proximity to building Presence and location of citrus trees with fruit Efflorescence on concrete masonry
Cracks in concrete slabs
Noticeable negative soil grade toward building and location Presence and location of standing water
Presence and location of algal growth on concrete surfaces Presence or absence of gutters
Termination characteristics of downspouts Presence or absence of scuppers
Condition of exterior cladding, e.g., peeling, cracking paint on wood siding, termination of stucco (presence/absence of weep screed)
Presence and location of suspect dry rot
Presence and location of suspect wood stain fungi