Major fungal genera reported from various indoor substrates include Cladosporium sp (19.04%), Stachybotrys chartarum (12.07%), and colorless spores typical of Penicillium/Aspergillus (10.32%). About 76,000 samples from homes, offices, and schools were examined from substrates like paper, insulation, drywall, wood, cloth, carpet, dust, and soil. Over 225 fungal species/groups were identified, with some found for the first time indoors. Stachybotrys chartarum was frequently observed on cellulose-containing materials like drywall paper. Cladosporium sp. were common on insulation. Dust samples often contained Cladosporium

1. Cumulative index of fungi reported
from various indoor substrates
Subramani Thiagarajan, Payam Fallah, Harriet Burge and Janet Gallup
Environmental Microbiology Laboratory, Inc., Sacramento, CA USA
Major fungal genera reported on few indoor
About 76,000 direct microscopic examinations were performed on
substrates
samples from various indoor environments such as homes,
apartments, office and schools. Samples were collected as bulk
Drywall paper Insulation materials
samples, tape samples and swab samples. The fungal recovery data
was sorted according to different substrates categories. The frequency
30% 45%
of occurrence of each fungus on each substrate was calculated and Cladosporium sp
Stachybotrys chartarum
reported in terms of percentage of samples of the particular substrate 40%
Chaetomium sp colorless spores like Pen/As
25%
on which the fungus occurred. 35%
colorless spores like Pen/As Stachybotrys chartarum
30%
Cladosporium sp
20% Penicillium sp
About 8 different categories of substrate were examined. These were:
Ulocladium sp
(i) Paper substrate, (ii) Insulation materials, (iii) Building materials, 25% Chaetomium sp
15%
(iv) Wood substrate, (v) Cloth substrate, (vi) Carpet substrate, (vii) Aspergillus sp Aspergillus sp
20%
Dust, and (viii) Soil material. Alternaria sp Alternaria sp
15%
10%
Penicillium sp
Acremonium sp
10%
About 225 species/groups of fungi were reported, of which many 5% Acremonium sp
brown hyphae, ID unknown
species were reported for the first time from indoor environments. 5%
brown hyphae, ID unknown
Stachybotrys chartarum
0%
0%
Building materials Wood substrate
Cumulative index of fungal genera reported on different
substrates in indoor environments Cladosporium sp
16%
30%
colorless spores like Pen/Asp
Stachybotrys chartarum
14%
Aspergillus sp
25% Chaetomium sp
Fungal genera Percentage of total (%) Penicillium sp
12%
Cladosporium sp 19.043%
colorless spores like Pen/Asp
Chaetomium sp
Stachybotrys chartarum 12.065%
20%
colorless spores typical of Pen/Asp 10.325% 10% brown hyphae, ID unknown
brown hyphae, ID unknown
Aspergillus sp 8.930%
Chaetomium sp 6.350% Monodictys sp
Ulocladium sp
8%
15%
Penicillium sp 6.326%
Stachybotrys chartarum
Ulocladium sp 5.586% Cladosporium sp
Fungal genera Percentage of total (%)
Alternaria sp 4.356% brown spore type, ID
6%
unknown
Ceratocystis/Ophiostoma group 3.662% Zygosporium sp 0.015% 10% Aspergillus sp Acremonium sp
Acremonium sp 3.166% Beauvaria sp 0.014%
4%
brown hyphae, ID unknown 2.068% Ramichloridium sp 0.014% Ceratocystis/Ophiostoma
brown spore type, ID unknown
Gonatobotryum sp 1.516% Geomyces sp 0.012% 5% Ulocladium sp
brown spore type, ID unknown 1.242% Monacrosporium sp 0.012% 2%
Acremonium sp
Scopulariopsis sp 0.891% Myrothecium sp 0.012% Petriella sp
Graphium sp 0.816% Geotrichopsis sp 0.011% Alternaria sp
Trichocladium sp
0% 0%
Trichoderma sp 0.772% Sporormiella sp 0.011%
Monodictys sp 0.692% Syncephalastrum sp 0.011%
colorless spore type, ID unknown 0.689% Fusariella sp 0.010%
Pithomyces sp 0.665% Trichothecium sp 0.010%
Cloth substrate
Dust
Aureobasidium sp 0.654% Acrodontium sp 0.008%
Phoma/coelomycete 0.635% Ampelomyces sp 0.008%
colorless hyphae, ID unknown 0.632% Anthopsis sp 0.008% 18%
35% colorless spores like Pen/Asp
Petriella sp 0.621% Coniochaeta sp 0.008%
Cladosporium sp
yeasts 0.544% Neurospora sp 0.008% 16%
Cladosporium sp
Trichocladium sp 0.441% Phaeoisaria sp 0.008% 30%
Aspergillus sp
basidiomycetes 0.373% Septonema sp 0.008%
14%
Aspergillus sp
ascomycetes 0.368% Brachysporium sp 0.007%
Penicillium sp
25%
Taeniolella sp 0.364% Cephaliophora sp 0.007%
12%
Chaetomium sp
Paecilomyces sp 0.351% Exophiala sp 0.007% Stachybotrys chartarum
coelomycetes 0.286% Hyalodendron sp 0.007%
20% brown hyphae, ID unknown 10%
Memnoniella sp 0.279% Scolecobasidium sp 0.007% Alternaria sp
Rhinocladiella sp 0.275% Sporomiella sp 0.007%
Stachybotrys chartarum 8%
Epicoccum sp 0.274% Stemonitis sp 0.007% brown hyphae, ID unknown
15%
Arthrobotrys sp 0.256% Veronaea sp 0.007%
Scopulariopsis sp
Gliomastix sp 0.256% Acladium sp 0.005% 6% brown spore type, ID unknow
Bipolaris/Drechslera group 0.214% Cacumisporium sp 0.005% 10%
Alternaria sp
Fusarium sp 0.210% Spegazzinia sp 0.005% colorless spore, ID unknown
4%
Torula sp 0.191% Sporotrichum sp 0.005%
5% myxomycete colorless spores like Pen/Asp
Humicola sp 0.188% Stemphylium sp 0.005% 2%
Oidiodendron sp 0.183% Sterigmatobotrys sp 0.005%
Ulocladium sp
Ulocladium sp
Sepedonium sp 0.163% Acrogenospora sp 0.004% 0%
0%
Dicyma sp 0.162% Amphobotrys sp 0.004%
Myxotrichum sp 0.142% Annellophora sp 0.004%
Mucor sp 0.138% asterophyses structure 0.004%
Ascotricha sp 0.133% Botryomyces sp 0.004%
myxomycetes 0.129% Monocillium sp 0.004%
Carpet substrate
Soil material
Diplococcium sp 0.117% Pestalotiopsis sp 0.004%
Papulaspora sp 0.105% Pyrenochaeta sp 0.004%
Phialophora sp 0.102% Rhizomucor sp 0.004%
colorless spores typical of Penicillium
zygomycetes 0.093% Sporoschisma sp 0.004% ascomycetes
16% 18% / Aspergillus
Rhizopus sp 0.090% Thamnidium sp 0.004%
Chaetomium species
Cephalotheca sp 0.082% brown hyphae, ID unknown
Brachysporiella sp 0.003% 16%
14%
Chloridium sp 0.078% Chalara sp 0.003%
Ceratocystis/Ophiostoma Cladosporium species
Botrytis sp 0.071% chlamydospore 0.003% 14%
12%
Curvularia sp 0.067% Cladophialophora sp 0.003% colorless spores like Pen/Asp
Stachybotrys chartarum
Tritirachium sp 0.067% Cunninghamella sp 0.003% 12%
Dactylaria sp 0.061% Dictyosporium sp 0.003% 10% Cladosporium sp
Aspergillus species
Microascus sp 0.059% Echinobotryum sp 0.003% 10%
Verticillium sp 0.056% Endophragmia sp 0.003% colorless spore, ID unknown
8%
Bispora sp 0.053% Penicillium species
Malbranchea sp 0.003% 8%
basidiomycetes
Eurotium sp 0.050% Oidium sp 0.003%
6%
Arthrographis sp 0.049% Ostracoderma sp 0.003% Ulocladium species
6%
colorless hyphae, ID unknown
Leptographium sp 0.048% Pachnodium sp 0.003%
arthrospore-former 0.046% Phaeostalagmus sp 0.003% 4% brown spore type, ID unknown
Graphium sp 4%
Engyodontium sp 0.041% Sordaria sp 0.003%
Botryotrichum sp 0.040% Triadelphia sp 0.003% Peziza sp Alternaria species
2% 2%
Sporothrix sp 0.040% Tridelphia sp 0.003%
Stachybotrys chartarum
Geotrichum sp 0.038% Trochophora sp 0.003% Monodictys species
0%
0%
Gymnoascus sp 0.037% Troposporella sp 0.003%
Doratomyces sp 0.035% Absidia sp 0.001%
Periconia sp 0.035% Achaetomium sp 0.001%
Gliocladium sp 0.033% Basidiobolus sp 0.001%
Acrodictys sp 0.031% Blastobotrys sp 0.001%
Dactylella sp 0.031% Botrytrichum sp 0.001%
Oedocephalum sp 0.031% Calcarisporium sp 0.001%
Ochroconis sp 0.027% Camposporium sp 0.001%
Cheiromycella sp 0.026% Chaetosphaeria sp 0.001%
Sporidesmium sp 0.026% Ciliciopodium sp 0.001%
Bactrodesmium sp 0.022% Conoplea sp 0.001%
Chrysosporium sp 0.022% Custingophora sp 0.001%
Wallemia sp 0.022% Dendryphiopsis sp 0.001%
Nigrospora sp 0.020% Diploospora sp 0.001%
•Stachybotrys chartarum was found to be a dominant fungus present on cellulose containing indoor
Peziza sp 0.020% Endophragmiopsis sp 0.001%
Gilmaniella sp 0.019% Fuligo sp 0.001%
substrate materials such as drywall paper (26.6 %), wallboard (21.8 %), paper material (22.7 %),
Aphanocladium sp 0.018% Lecythophora sp 0.001%
building material with drywall paper (26.6 %) and gypsum material (33.3%).
Acremoniella sp 0.016% Leptosphaeria sp 0.001%
Emericella sp 0.016% Menispora sp 0.001%
Arthrinium sp 0.015% Pachnocybe sp 0.001%
• Cladosporium species were recovered from 40.7 % of insulation material samples overall, and 29.1
Melanospora sp 0.015% Peronospora sp 0.001%
Phialocephala sp 0.001%
% of fiberglass samples.
Preussia sp 0.001%
Scedosporium sp 0.001%
Scleroderma sp 0.001%
• Dust samples were dominated by Cladosporium, Aspergillus and Penicillium species, which
Septocylindrium sp 0.001%
Spadicoides sp 0.001%
accounted for 46.6 % of total frequency.
Taeniolella rudis 0.001%
Xylaria sp 0.001%
• Other substrate such as asphalt paper which is widely used in building for waterproofing roof
coverings, exterior wall coverings, and flooring tile showed high frequency of Acremonium species
(24.2 %).
Macro fungus species/families reported
on indoor substrates • The number of fungal species reported on different substrate varied on different indoor substrates.
Wood samples collected from indoor environment had high diversity of fungi. More than 100 fungal
Macrofungus species/family
types, including some macro fungi were recovered.
Aphyllophorales
Coltricia sp
Peziza domiciliana
Phellinus species
Polyporaceae
Trametes sp
Scleroderma sp
Coprinus sp
Gloeophyllum sp
Grandinia sp
Meruliporia incrassata
Peziza sp
Poria incrassata
Suillus sp