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<br />Environmental Solutions Group ● 7 Maple Leaf Drive., Greensboro, NC 27401 ● 336-373-1538 ● www.Go-ESG.com 32 <br />Report with Protocols for Remediation <br />Environmental Solutions Group <br />Leading people, companies and communities to live, <br />work and prosper in a sustainable environment. <br /> <br /> <br /> <br /> <br /> <br />Mold in Moisture-Free Buildings <br /> <br />Published studies of airborne fungal contamination in complaint buildings with known moisture <br />issues are plentiful, while well-designed studies that propose baseline levels for airborne fungal <br />spores in buildings without obvious moisture problems are scarce. Three recent studies <br />conducted in Georgia1, Florida2 and southern Finland3 have focused on the levels of viable and <br />non-viable airborne fungi in modern buildings in order to better define what are considered a <br />typical number of airborne molds. The studies found that the number of non-viable and viable <br />airborne fungi in an indoor environment without a known moisture issue are consistent regardless <br />of geographical location or season. <br /> <br />The studies primarily examined the airborne concentrations of leaf fungi (Cladosporium, <br />Curvularia, Epicoccum & Alternaria species), soil and moisture-indicator fungi (Aspergillus, <br />Paecilomyces & Penicillium species) and water-indicator fungi (Chaetomium, Stachybotrys & <br />Ulocladium species). <br /> <br />The researchers found that the water-indicator fungi are almost never identified in homes without <br />a moisture issue and are equally uncommon outdoors. Therefore, the presence of airborne <br />spores from Chaetomium, Stachybotrys & Ulocladium typically suggest the presence (or prior <br />presence) of wet materials in the vicinity of the air sampling location. Furthermore, as these fungi <br />do not normally release high levels of spores and these spore types do not remain airborne for <br />extended periods of time, even low levels of these spore types (compared to other spore types <br />released in large amounts such as Aspergillus/Penicillium species) are an indication of an <br />elevated level of fungal spores. Therefore, the presence of Chaetomium, Stachybotrys or <br />Ulocladium in an indoor air sample is extremely relevant in the interpretation of laboratory reports. <br /> <br />The studies determined that the following spore types are most common and present in the <br />following counts for non-viable fungi in homes without a known moisture issue: <br /> <br />Spore Type Average Count/m3 (Indoors) Range <br />Aspergillus/Penicillium 194 0 - 656 <br />Ascospores4 53 0 - 317 <br />Basidiospores 9 0 - 279 <br />Cladosporium 18 0 - 176 <br />Myxomycete/Smut-like spores 9 0 - 106 <br />Curvularia 4 0 - 88 <br />TOTAL 335 8 - 999 <br />Table 1: average and range counts of the most common indoor non-viable airborne fungi in homes without a <br />known moisture issue <br /> <br />The Georgia and Finnish studies utilized cultured air sampling to generate results for viable airborne <br />fungi. These researchers found that the leaf fungi dominate the composition of air cultures in buildings <br />without a moisture issue. As with the Florida study, which used the non-viable air sampling method, <br />water-indicator fungi were rarely identified in the non-problem buildings studied. While soil & moisture- <br />indicator fungi were found to be present in air cultures but at a much lower ratio than for leaf fungi. The <br />Georgia study concluded that the interpretive guidelines that emphasize using the ratio of indoor to <br />outdoor molds as well as the ratio of leaf fungi to soil or water indicator fungi will result in an accurate <br />assessment. All three studies conclude that investigators can compare their results from a home with a <br />suspected problem to their data from homes known not to have problems and be relatively assured <br />they are coming to the right conclusion. <br /> <br /> 1 “Air- and dustborne microflora in houses free of water damage and fungal growth”, Applied and Environmental <br />Microbiology, Nov. 2004:6394-6400. <br /> 2 “Typical levels of airborne fungal spores in houses without obvious moisture problems during a rainy season in Florida, <br />USA”, Investigative Allergology and Clinical Immunology, 2008 Vo. 18(3):156-162. <br /> 3 “Fungal species in mold-damaged and nondamaged office buildings in southern Finland”, Swedish Journal of Work and <br />Environmental Health, 2008 No. 4:18-20. <br /> 4Ascospores and basidiospores were found to be the most abundant spore types in the outdoor air samples collected as <br />reference data. As these spores do not commonly grow in buildings, their detection indoors typically suggests infiltration of <br />outdoor air. <br /> <br />DocuSign Envelope ID: A9A4637A-BE59-4285-99BE-D253C29FA836