Mold is a family of the Fungal Phylum. Moisture and organic material are required for growth, and the spores can go dormant for thousands of years until the proper conditions are met for the spores to grow mold structures and reproduce. Fungicide only kill the structures, not the spores, and it is the spores (actively growing or dormant) that impact our health.
MOLD AND MOISTURE ASSESSMENTS WITHIN OCCUPIED STRUCTURES
Omega Southwest Consulting has been directly involved in developing consensus based methods for assessing moisture and mold in occupied structures. The topic is highly controversial and could result in considerable expense due to extremes in perceived hazards. Whereas the health of a most healthy adults may not be impacted by the most common molds, immune-suppressed patients, the elderly, infants (yet to develop their own immune system), and normally healthy adults with a weakened resistance to infections (e.g., flu patients) may become invasively infected (e.g., develop life-threatening illness). Stachybotrys chartarum, sometimes referred to as the “black mold” or “death mold,” has been reported to cause pulmonary hemorrhage in infants and flu like symptoms in adults, and Aspergillus flavus produces aflatoxins which are know human carcinogens. Clearly, time is of the essence in responding to moisture intrusion and potential mold growth and exposures.
Identify Areas of Mold Growth and Determine the Root Cause
Visual inspection
- Indoor surfaces (e.g., floors, walls, and ceilings)
- HVAC systems
- Areas often overlooked include potted plants, garbage, outdoor compost piles, and pet areas
Identify surfaces with excessive moisture
- Contour mapping
- Diagramatic sketching
Determine sources of excessive moisture
- Moisture metering
- Thermal imaging
Surface mold sampling
- Confirmation of growth
- Identification of type
Invasive mold sampling Should be performed under controlled conditions.
- Wall check
- Plug samples
- Wallpaper substrate inspection
Air sampling
- Indoor fungal levels and types
- Compare with the outdoor air
- Compare with non-problem area (if the information allows one to identify a non-problem area)
- Compare mold types from air samples with those of surface samplesn
Report, recommendations, and specifications for remediation.
Special Interest
Often missed by many inspectors and contractors is mold growth in the air supply ducts. In one case, the HVAC contractor of a newly constructed building (e.g., less than 1-year old) denied the possibility that there was mold growth in the duct. There was black staining around the air supply vents, but the contractor was still in denial. He was asked to access the HVAC unit and downwind duct. He was again in denial. When we found extensive mold growth on the duct, he feigned surprise.
Aspergillus flavus and Aspergillus fumigatus are pathogenic and are particularly problematic in hospitals. These species of Aspergillus are particularly invasive and problematic in OR rooms and areas where there are immune suppressed patients. Species is not identified in spore trap air sampling which only groups by spores, not by growth patterns. Pathogenic Aspergillus requires impaction plates and a 7 to 10 day culture time.
Stachybotrys chartarum, sometimes referred to as the “death mold,” produces satratoxin and other mycotoxins under conditions involving competition for food and water with other microbes. When the mycotoxic mold spores and mycelia becomes airborne, they can cause health problems to those exposed. Although the most commonly reported symptoms of excessive exposure to airborne Stacybotrys is an illusive flu-like illness. Airborne exposures have affected, in the past, unwary construction workers when renovating buildings with visible and/or hidden Stachybotrys mold growth. Only when the workforce has been reduced in half or more, due to illness, does the superintendent become suspicious. One case involved construction workers removing mold contaminated sheet rock and trolley it down the hallway of an office building, exposing building occupants to the airborne spores. In this case, one of the occupants developed nose bleeding. Air monitoring was performed around her office and other areas within the path of the waste trolley, and high airborne levels of Stachybotrys were found. Cleanup was extensive.
Oftentimes, air sampling is performed by some consultants as a means to determine if there are elevated mold spores within a building–especially where in a client suspects excessive levels of mold indoors. There is a small problem with this. The findings can be difficult and illusive if an awareness of activities and conditions are not noted. As we decided to put a little research into the topic, Omega took an air impaction sample in a kitchen prior to uncovering mold meat and after uncovering it. The results were astounding. Airborne levels increased 10-fold within only couple minutes and without artificial air movement (e.g., air conditioning).
In one of our projects, there had been a long standing plumbing leak in a residence and mold growth behind the walls and under the wood flooring. The insurance company paid a contractor to remove and replace the wood floors and cut out the gypsum board. This was accomplished with the air conditioning running and no sealed plastic sheeting on the furniture and kitchen counters/food stuff. The result was contamination of the entire residence and elevated airborne levels of Penecillum and Stachybotrys.