Prediction of Toxigenic Fungal Growth in Buildings by Using a Novel Modelling System

ABSTRACT There is growing concern about the adverse effects of fungal bioaerosols on the occupants of damp dwellings. Based on an extensive analysis of previously published data and on experiments carried out within this study, critical limits for the growth of the indoor fungiEurotium herbariorum, Aspergillus versicolor, and Stachybotrys chartarum were mathematically described in terms of growth limit curves (isopleths) which define the minimum combination of temperature (T) and relative humidity (RH) at which growth will occur. Each growth limit curve was generated from a series of data points on a T-RH plot and mathematically fitted by using a third-order polynomial equation of the form RH =a3T3 +a2T2 +a1T + a0. This fungal growth prediction model was incorporated within the ESP-r (Environmental Systems Performance [rstands for “research”]) computer-based program for transient simulation of the energy and environmental performance of buildings. For any specified location, the ESP-r system is able to predict the time series evolution of local surface temperature and relative humidity, taking explicit account of constructional moisture flow, moisture generation sources, and air movement. This allows the predicted local conditions to be superimposed directly onto fungal growth curves. The concentration of plotted points relative to the curves allows an assessment of the risk of fungal growth. The system’s predictive capability was tested via laboratory experiments and by comparison with monitored data from a fungus-contaminated house.

[1]  A. Pasanen,et al.  Stachybotrys atra Growth and Toxin Production in Some Building Materials and Fodder under Different Relative Humidities , 1994, Applied and environmental microbiology.

[2]  Exposure to airborne microbes during the repair of moldy buildings. , 1996, American Industrial Hygiene Association journal.

[3]  P. Morey,et al.  Health and immunology study following exposure to toxigenic fungi (Stachybotrys chartarum) in a water-damaged office environment. , 1996, International archives of occupational and environmental health.

[4]  J. Tuite,et al.  Temperature and relative humidity requirements of species of Penicillium isolated from yellow dent corn kernels. , 1970, Mycologia.

[5]  E. Cole,et al.  A review of mycotoxins in indoor air. , 1993, Journal of toxicology and environmental health.

[6]  A. Wexler,et al.  Relative humidity-temperature relationships of some saturated salt solutions in the temperature range 0 degree to 50 degrees C , 1954 .

[7]  S. T. Hill,et al.  Influence of temperature and water activity on germination and growth of Aspergillus restrictus and A. versicolor , 1982 .

[8]  D. Sudakin.  Toxigenic fungi in a water-damaged building: an intervention study. , 1998, American journal of industrial medicine.

[9]  G. Ayerst,et al.  The effects of moisture and temperature on growth and spore germination in some fungi. , 1969 .

[10]  R. Burnett,et al.  Respiratory health effects of home dampness and molds among Canadian children. , 1991, American journal of epidemiology.

[11]  P. Winston,et al.  Saturated Solutions For the Control of Humidity in Biological Research , 1960 .

[12]  D SNOW,et al.  The germination of mould spores at controlled humidities. , 1949, The Annals of applied biology.

[13]  R. Burnett,et al.  Adverse health effects among adults exposed to home dampness and molds. , 1991, The American review of respiratory disease.

[14]  C. T. Dieter,et al.  Effect of temperature and relative humidity on spore germination of mycotoxic species of Aspergillus and Penicillium. , 1975, Mycologia.

[15]  B. Flannigan,et al.  Mould in buildings: the air spora of domestic dwellings , 1988 .

[16]  L. Bullerman,et al.  Prevention of Mold Growth and Toxin Production through Control of Environmental Conditions. , 1982, Journal of food protection.

[17]  Icmsf.  4 – Reduced Water Activity , 1980 .

[18]  A. F. Bravery,et al.  The moisture requirements of moulds isolated from domestic dwellings , 1989 .

[19]  P. Pasanen,et al.  Growth and volatile metabolite production of Aspergillus versicolor in house dust , 1997 .

[20]  B. Jarvis,et al.  Airborne outbreak of trichothecene toxicosis , 1986 .

[21]  S M Hunt,et al.  Damp housing, mould growth, and symptomatic health state. , 1989, BMJ.

[22]  Naresh Magan,et al.  Effect of temperature and pH on water relations of field and storage fungi , 1984 .

[23]  J. Silliker.  Microbial ecology of foods , 1980 .

[24]  D. Eveleigh.  The growth requirements of Phoma violacea, with reference to its disfiguration of painted surfaces , 1961 .

[25]  Robert A. Samson,et al.  Introduction to food-borne fungi. , 1989 .

[26]  W. Sorenson.  Mycotoxins as potential occupational hazards. , 1990 .

[27]  M. Northolt.  The effect of water activity and temperature on the production of some mycotoxins , 1979 .

[28]  J. B. M. Coppock,et al.  The effect of humidity on mould growth on constructional materials , 1951 .

[29]  Significance of fungi in indoor air: report of a working group. Prepared by the Health and Welfare Canada Working Group on Fungi and Indoor Air. , 1987, Canadian journal of public health = Revue canadienne de sante publique.

[30]  R. Simmons,et al.  Effect of relative humidity on fungal colonization of fiberglass insulation , 1994, Applied and environmental microbiology.

[31]  John G. Anderson,et al.  The Presence of Mycotoxin-Associated Fungal Spores Isolated from the Indoor Air of the Damp Domestic Environment and Cytotoxic to Human Cell Lines , 1994 .

[32]  P. Strachan,et al.  Model validation using the PASSYS Test cells , 1993 .

[33]  Abdullatif E. Nakhi.  ADAPTIVE CONSTRUCTION MODELLING WITHIN WHOLE BUILDING DYNAMIC SIMULATION , 1995 .

[34]  P. Morey,et al.  Building-associated pulmonary disease from exposure to Stachybotrys chartarum and Aspergillus versicolor. , 1998, Journal of occupational and environmental medicine.

[35]  Joseph Andrew Clarke,et al.  An approach to the simulation of coupled heat and mass flows in buildings , 1991 .

[36]  J. I. Pitt,et al.  Further Studies on the Water Relations of Xerophilic Fungi, Including Some Halophiles , 1987 .

[37]  A. Wexler.  Relative humidity-temperature relationship of some saturated salt solutions in the temperature range 0° to 50℃ , 1954 .

[38]  Ailsa D. Hocking,et al.  Water relations of some Penicillium species at 25 °C , 1979 .

[39]  M. Burr,et al.  Indoor Moulds and Asthma , 1988, Journal of the Royal Society of Health.

[40]  E. M. McCabe,et al.  Allergenic and toxigenic micro-organisms in houses. , 1991, Society for Applied Bacteriology symposium series.

[41]  J. Pitt,et al.  Water relations of xerophilic fungi isolated from prunes. , 1968, Applied microbiology.

[42]  W. Scott,et al.  Water Relations of Food Spoilage Microorganisms , 1957 .

[43]  John I. Pitt,et al.  Xerophilic Fungi and the Spoilage of Foods of Plant Origin , 1975 .

[44]  J. Dutkiewicz,et al.  Bioaerosols and occupational lung disease , 1994 .