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DocuSign Envelope ID:B94F2D40-3B3C-47A7-86C2-6F1B4F92C62C ESG tnvlronmental 3olunon5 urvup Leading people,companies and communities to live, Report with Protocols for R e m e d i a t i o n work and prosper in a sustainable environment. Mold in Moisture-Free Buildings Published studies of airborne fungal contamination in complaint buildings with known moisture issues are plentiful,while well-designed studies that propose baseline levels for airborne fungal spores in buildings without obvious moisture problems are scarce.Three recent studies conducted in Georgia',Floridan and southern Finland have focused on the levels of viable and non-viable airborne fungi in modern buildings in order to better define what are considered a typical number of airborne molds.The studies found that the number of non-viable and viable airborne fungi in an indoor environment without a known moisture issue are consistent regardless of geographical location or season. The studies primarily examined the airborne concentrations of leaf fungi(Cladosporium, Curvularia,Epicoccum&Alternaria species),soil and moisture-indicator fungi(Aspergillus, Paecilomyces&Penicillium species)and water-indicator fungi(Chaetomium,Stachybotrys& Ulocladium species). The researchers found that the water-indicator fungi are almost never identified in homes without a moisture issue and are equally uncommon outdoors.Therefore,the presence of airborne spores from Chaetomium,Stachybotrys&Ulocladium typically suggest the presence(or prior presence)of wet materials in the vicinity of the air sampling location.Furthermore,as these fungi do not normally release high levels of spores and these spore types do not remain airborne for extended periods of time,even low levels of these spore types(compared to other spore types released in large amounts such as Aspergillus/Penicillium species)are an indication of an elevated level of fungal spores.Therefore,the presence of Chaetomium,Stachybotrys or Ulocladium in an indoor air sample is extremely relevant in the interpretation of laboratory reports. The studies determined that the following spore types are most common and present in the following counts for non-viable fungi in homes without a known moisture issue: Spore Type Average Count/my-Indoors) Range Ajr illus/Penicillium 194 0-656 As ores 53 0-317 Basidios ores 9 0-279 Clados orium 18 0-176 M xom cetelSmut-likes ores 9 0-106 Curvularia 4 0-88 TOTAL 335 8-999 Table 1:average and range counts of the most common indoor non-viable airborne fungi in homes without a known moisture issue The Georgia and Finnish studies utilized cultured air sampling to generate results for viable airborne fungi.These researchers found that the leaf fungi dominate the composition of air cultures in buildings without a moisture issue.As with the Florida study,which used the non-viable air sampling method, water-indicator fungi were rarely identified in the non-problem buildings studied.While soil&moisture- indicator fungi were found to be present in air cultures but at a much lower ratio than for leaf fungi.The Georgia study concluded that the interpretive guidelines that emphasize using the ratio of indoor to outdoor molds as well as the ratio of leaf fungi to soil or water indicator fungi will result in an accurate assessment.All three studies conclude that investigators can compare their results from a home with a suspected problem to their data from homes known not to have problems and be relatively assured they are coming to the right conclusion. '.,Air-and dustborne microflora in houses free of water damage and fungal growth",Applied and Environmental Microbiology,Nov.2004:6394-6400. 2„ Typical levels of airborne fungal spores in houses without obvious moisture problems during a rainy season in Florida, USA",Investigative Allergology and Clinical Immunology,2008 Vo.18(3):156-162. 3"Fungal species in mold-damaged and nondamaged office buildings in southern Finland",Swedish Journal of Work and Environmental Health,2008 No.4:18-20. 4Ascospores and basidiospores were found to be the most abundant spore types in the outdoor air samples collected as reference data.As these spores do not commonly grow in buildings,their detection indoors typically suggests infiltration of outdoor air. Environmental Solutions Group 9 1000 N. Elm St., Greensboro, NC 27401 • 336-373-1538 • www.Go-ESG.com