Health Effects, Pathology, Epidemiology

Effects after mold exposure – which are the causative agents?

Ragnar Rylander, M.D.

Department of Environmental Medicine, University of Gothenburg, Box 414; 405 30 Gothenburg, Sweden; Tel: +46 31 773 3601, Fax: +46 31 82 5004, e-mail: ragnar.rylander@envmed.gu.se

Abstract

This presentation reviews the most well known specific agents in molds and their relation to the different effects caused by exposure to molds. It is emphasized that field studies in principle only describe relationships and that such relationships not always support conclusions regarding causality for individual agents. At present, the general strategy to prevent the mold-related diseases airways inflammation, increased risk for infections, hypersensitivity pneumonitis and neurological disorders must therefore be to remove the mold contamination, viable as well as dead organisms.

Key words: (1 ®3)- b-D-glucan, mycotoxins, polysaccharide

ecology, detection and identification problems of moulds in indoor environments

Robert A. SAMSON Ph.D.

Centraalbureau voor Schimmelcultures, P.0. Box 273, 3740 AG Baarn, The Netherlands, Tel.:+31-35-540-1234, Fax: +31-35-541-6142, e-mail: samson@cbs.knaw.nl

Introduction

For many people working in the building industry or those who are consulting for indoor problems, identification of moulds does not seem a problem. In their opinion mould applying disinfectants or antifungal paints can easily solve problems. Furthermore, it is often recommended to modify the construction and adding ventilation with the result that the conditions for fungal growth can be reduced. However, if we like to know the cause and the degree of biodeterioration, in particular when health implications are involved, it is important to know which organisms are causing the problem. This is particularly true for species of Stachybotrys, Penicillium, Aspergillus and Fusarium.

Identification of mould isolates or specimens is problematic for the inexperienced researcher. This is partly due to the fact that the methods for identification are still based on the phenotypical characters of the moulds, which requires many skills in microscopical observations. In addition the mould flora of indoor environments consists of some problematic genera such as Penicillium, Aspergillus and Fusarium of which there is no general taxonomic consensus. Even experienced mycologists might reach different conclusions hence different names for an isolate.

Several surveys of moulds in indoor environments have revealed that we are dealing with a known and relatively low number of species. To detect these relevant species it is, however, essential to apply the appropriate methods. This paper is focused on the ecology and taxonomic problems of indoor moulds also related to methods of detection.

 

Occupational Exposure to Molds, Diseases and Diagnosis

Kari Reijula, M.D., Ph.D.

Director, Indoor Air & Environment Program; Finnish Institute of Occupational Health; Helsinki, Finland; Address correspondence to: Kari Reijula, MD, PhD, Finnish institute of Occupational Health, Arinatie 3, FIN-00370 Helsinki, Finland, tel (358)-09-4747932, fax (358)-09-5061087, email: krei@occuphealth.fi

Abstract

Exposure to molds has become a significant health risk to an increasing number of workers in various occupations throughout the nations. Fungal antigens are able to cause occupational asthma, rhinoconjunctivitis, hypersensitivity pneumonitis and organic dust toxic syndrome (ODTS) for instance among farmers, construction workers, housekeeping personnel as well as factory and sawmill workers who have to handle moldy and contaminated materials. In recent years, an increasing incidence of mold-induced diseases has been encountered in moldy contaminated water-damaged buildings. This has occured both in homes and workplaces. Symptomatic persons occupying moisture problem buildings may develop asthma, rhinitis, ODTS and HP. However, the majority of the exposed individuals present with conjunctival, respiratory or systemic reactions the immune mechanisms of which remain unclear. In the present summary some aspects will be presented on health effects which appear among workers exposed especially to fungal antigens.

Key words: allergy, occupational, respiratory, molds, moisture problems

Indoor moulds: a public health problem in Belgium: overview of 15 years’ experience

Nicole Nolard, Ph. D.

Head of the section Mycology, Institute of Public Health (IPH), 14 Juliette Wytsmanstreet, B 1050 Brussels, Belgium. phone: 32 2 642 55 17, fax: 32 2 642 55 19

Introduction

This paper is a summary of highlights recorded from 15 years’ experience of surveys in home environments of patients with respiratory disorders linked with allergy, mainly asthma.

Actually, after the 1st oil crisis, in the 1970’s, people began to renovate their house with the aim of best insulating every part from cellar to attic and we registered a continuing increase in complaints correlated with the presence of fungi, not only in damp houses but also in renovated and even new houses. Each survey responded to a specific case with different situation standards (house/flat; city/country, underprivileged/luxurious; pets/no pets....) Moreover, taking into account the evolution of the sampling methods, a standard methodology was rather difficult to elaborate.

Under these circumstances, in 1982, a scheme was set up in our laboratory at the Institute of Public Health, which belongs to the Belgian Ministry of Health, for « environmental control» in homes. It includes:

          a visit to the home,

          a standardized home environment form,

          the sampling of air, surfaces, furniture, wall paper, mattress and carpet dust for fungal moulds

          the isolation, purification and placing in our collection of fungal strains for immunological testing (more than 2000 strains are stored either freeze dried or under liquid nitrogen in the IHEM collection),

          the creation of a serum bank containing not only the serum of the allergic patient but also the sera of people living in the same surroundings,

          the standardisation of a mini-method for preparing fungal extracts from each selected strain,

          finally, the immunological analysis from allergic patients, from subjects exposed to the same environment but not symptomatic and from a pool of test sera. Prick tests and antibody research (IgE and IgG) are carried out, or are in the process of being carried out, with our own extracts and have confirmed the role, in greater and greater numbers, of moulds as pneumoallergens in the home.

Our objective is to present in this article a synthesis of our work at the Institute and to inform about the interest of environmental surveys.

PILOT ANALYSIS OF THE IMMUNE RESPONSE TO FUNGAL ANTIGENS IN SUBJECTS WORKING IN HUMIDITY DAMAGED HOUSES

Anja S. Tiilikainen1, M.D., Ph.D., Irmeli Heikkinen2, M.Sc., Kirsi Vedenpää3, M.Sc., Riitta Karttunen4, M.D., Ph.D.

1 Professor (e) of Clinical Immunology and Microbiology; 2Research Associate; 3Research Associate; 4Acting Professor of Clinical Microbiology; From Department of Medical Microbiology, University of Oulu; Oulu, Finland; Postal address: Department of Medical Microbiology, University of Oulu, FIN-90220 OULU, Finland, Telephone: +358 - 8 - 537 5868, Fax: +358 - 8 - 335 908; Correspondence: Dr. Anja Tiilikainen, e-mail: Anja.Tiilikainen@oulu.fi, or Department of Medical Microbiology, University of Oulu, FIN-90220 OULU, Finland

Abstract.

Although the proportion of anti-mold IgG antibody producers was largely the same among different groups of subjects tested, the highest OD-readings in EIA technique were seldom seen in symptomless controls, but generally in association with any allergy of the ”mold exposed” subjects or in patients referred to specialist analysis at the Oulu University Hospital outpatient clinic for oto-rhino-laryngology. Some subjects in each group were distinctly multi-immune (”responders” = R) and some just occasionally reactive (”low responders” = LR) against a panel of 12-16 mold antigens; of the 34 allergic subjects 6 were R and 3 LR. In vitro cultures of patient lymphocytes usually responded with a lower cytokine production to Aspergillus fumigatus antigen than to other mold antigens, in contrast to responses of lymphocytes from healthy controls. More often than not, R lymphocytes showed higher cytokine production than did LR lymphocytes; more frequently in healthy controls than in patients.

Key words: Anti-mold IgG antibodies, lymphocyte stimulation by mold antigens, anti-mold immunity, anti-mold immunity and health impairment, mold-induced cytokine excretion in vitro

CAN MICROBIAL VOLATILE METABOLITES CAUSE IRRITATION AT INDOOR AIR CONCENTRATIONS?

Anna-Liisa Pasanen, Ph.D., Anne Korpi, Ph.Lic., Jukka Pekka Kasanen, M.Sc., Pertti Pasanen, Ph.D.

University of Kuopio, Department of Environmental Sciences, Kuopio, Finland; Corresponding author: Prof. Anna-Liisa Pasanen; University of Kuopio, Department of Environmental Sciences; P.O.Box 1627, FIN-70211 Kuopio, Finland; tel. +358-17-163 157, fax +358-17-163 230; email: annal.pasanen@uku.fi

ABSTRACT

Sensory irritation potency of selected volatile organic compounds assumed to be of microbial origin (MVOCs) was estimated theoretically by using the data of the recent chamber experiments and the results of volatile organic compounds (VOCs) measurements in water-damaged buildings. According to the estimations, a possible risk for complaints of irritation caused by exposure to the mixtures of those MVOCs in moisture problem buildings was evaluated. Exposure to mixtures of the selected non-reactive VOCs at the theoretical airborne concentrations calculated from the data of the chamber experiments would not result in sensory irritation in humans, and, thus, microbial growth in constructions should not increase the probability of irritating symptoms considerably. The data on MVOC concentrations measured in some problem buildings also supported this hyphothesis. Irritation would be expected when the airborne concentrations of single assumed MVOC approach a level of hundreds of m g/m3 or mg/m3.

Key words: indoor air concentration, microbial volatiles, sensory irritation, theoretical estimation

GROWTH CONDITIONS OF STREPTOMYCES ANULATUS REGULATE INDUCED INFLAMMATORY RESPONSES AND CYTO TOXICITY IN MACROPHAGES.

Maija-Riitta Hirvonen Ph.D., Merja Suutari Ph.D., Ulla Lignell M.Sc, Marjo Ruotsalainen Ph.D. Aino Nevalainen Ph.D.

Division of Environmental Health, National Public Health Institute, Division of Environmental Health P.O.Box 95, FIN-70701 Kuopio, Finland. Correspondence: Maija-Riitta Hirvonen, Ph.D, National Public Health Institute, Division of Environmental Health, Laboratory of Toxicology, P.O.Box 95, FIN-70701 Kuopio, Finland, Telephone +358 17 201 303, Telefax +358 17 201 265, E mail Maija-Riitta.Hirvonen@ktl.fi

ABSTRACT

RAW264.7 macrophages were exposed for 24 hrs to the spores of Streptomyces anulatus (doses of 105 106, 107 spores/million cells), isolated from a moldy building and grown on 23 different kind of media. Production of nitric oxide (NO) in macrophages was induced dose dependently by spores of S. anulatus reaching the level from 4.2 mM to 39.2 mM depending on the composition of the medium. The expression of inducible NO synthase (iNOS) was detected in the macrophages after the exposure to the spores collected from all tested growth media. The production of reactive oxygen species (ROS) was significantly increased when compared to controls by the highest dose of the spores from two media. The growth media affected the production of cytokines as well; the highest dose dependent levels of IL-6 varied from 400 to 7500 pg/ml and the levels of TNF a from 450 to 3100 pg/ml. The amount of death macrophages after the exposure varied from 11 % to 98% depending on the growth media of the microbe. Altogether, our results suggest that the growth conditions of S. anulatus, have a fundamental role in the ability of spores to induce inflammatory responses and cytotoxicity in RAW264.7 cells.

Clinical findings related to indoor fungal exposure - review of clinic data of a specialty clinic.

Eckardt Johanning1 M.D., M.Sc., Paul Landsbergis2 Ph.D.

1 Eastern New York Occupational and Environmental Health Center, Albany, New York, USA, 155 Washington Ave, Albany, N.Y. 12210, USA; 2Cornell University Medical College, New York, N.Y., USA; Correspondence: johanni2@crisny.org

Abstract

Objective: Review of symptoms, clinical abnormalities and laboratory findings of building occupants with abnormal indoor fungal exposure, primarily allergenic and toxigenic fungi (Stachybotrys atra, Penicillium, Aspergillus).

Design: Descriptive review of 151 cases evaluated at a specialty clinic. Analyses of a standardized health symptom questionnaire and immunological laboratory data.

Subjects: Pediatric and adult specialty clinic population with verified abnormal indoor fungal exposure.

Main outcome measures: Self-reported symptom-complexes, Immunoglobulin E and G, T- lymphocyte enumeration and function.

Results: Widespread contamination of water-damaged building materials primarily with toxin producing fungi were identified in the patients exposure history, who are reporting from a variety of nonspecific”sick building”-like complaints to a history of more serious morbidity of the respiratory system, skin, eye, chronic fatigue-like symptoms (CFIDS) and central nervous system dysfunctions (vertigo, memory, irritability, concentration, verbal dysfunctions). In some cases abnormalities of enumeration and functional laboratory tests (flow-cytology), mainly of the white blood cell system were identified. IgE or IgG antibodies used as exposure markers, were positive in about less than 25% of all cases. Removal from exposure typically resulted in improvement in the majority of cases.

Conclusion: Indoor air exposure to mycotoxin and allergen producing fungi results in a high frequency of health complaints, variant multi-organ and laboratory abnormalities requiring a detailed exposure assessment and clinical evaluation. Removal from fungal exposure and symptomatic treatment generally results in noticeable improvement of most patients. I propose to name these presentations and clinical findings-if certain criteria are met: “fungal syndrome”.

Key messages:

Many patients with fungal indoor exposure have a variety of symptoms, primarily the skin, mucous membrane, respiratory organs, central nervous system and constitutional symptoms.

Laboratory results suggest other than type I allergy, IgE mediated health responses.

Diagnosis of fungal disease should be based on exposure history, medical history and clinical findings.

The prognosis appears good provided the exposure can be stopped.

Pulmonary Hemorrhage among Infants with Exposure to Toxigenic Molds: An Update

Ruth A. Etzel1, M.D., Ph.D., Dorr G. Dearborn2, Ph.D., M.D.

1Centers for Disease Control and Prevention, Atlanta, Georgia 30341; 2Rainbow Babies and Childrens Hospital, Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio 44106; Address for correspondence: Ruth A. Etzel, M.D., Ph.D., 1400 Independence Avenue, SW, Washington, D.C. 20250-3700, phone: 202-501-7373, FAX: 202-501-6982

Abstract

In 1994, we investigated a geographic cluster of 10 cases of acute idiopathic pulmonary hemorrhage among infants in Cleveland, Ohio. Our matched case-control study demonstrated that infants with this condition were more likely than control infants to live in homes with toxigenic Stachybotrys chartarum and other fungi in the indoor air. The risk appeared to increase when both S. chartarum and environmental tobacco smoke were present in the home. Since the completion of the 1994 investigation, 27 additional infants in the Cleveland area have been diagnosed with acute idiopathic pulmonary hemorrhage. Of the 37 infants, 30 were African-American infants, all of whom lived in a limited geographic area of eastern metropolitan Cleveland, an area of older housing stock. Twelve deaths with extensive idiopathic pulmonary hemosiderosis have been identified, including seven originally thought to be due to Sudden Infant Death Syndrome (SIDS).

To determine how common this problem might be, we actively solicited reports of idiopathic pulmonary hemorrhage in infants from pediatricians throughout the United States. We have received physician reports of an additional 101 cases of acute idiopathic pulmonary hemorrhage among infants under 1 year of age. This paper reviews the risk factors for this condition and discribes the ongoing surveillance efforts.

Key words: hemorrhage, mold, Stachybotrys, lung, infant

IAQ and Human Toxicosis: Empirical Evidence and Theory

Harriet M. Ammann, Ph.D., D.A.B.T.

Office of Environmental Health Assessment Services, Washington State Department of Health, P.O. Box 47846, 7700 Cleanwater Lane, Olympia, Washington 98504-7846, Phone: 360-236-3171, FAX: 360-236-2257, e-mail: HMA0303@doh.wa.gov

Abstract

Studies of injury, illness and death occurring in mold-exposed animals and people in the field, observe that the illness called mycotoxicosis results from more complex exposures than can be observed in laboratory experiments with pure mold toxins. Response in field exposures occurs at lower exposure concentrations than those from controlled experiments. Occurrence of signs and symptoms at low exposure levels may result from a number of factors, including a greater spectrum of susceptibility in heterogeneous populations, additive or synergistic actions of multiple toxins, actions of other toxic microbial compounds, allergic and irritant response, as well as concomitant exposure to other contaminants. Changes in the immune system, often reflected as increased susceptibility to infectious illness, are a common finding of low level exposure to toxigenic molds that inhibit protein synthesis. Changes in the immune system are extremely complex, but changes in the endocrine and nervous system accompany them, and may reflect changes in the central neuroendocrine-immune control system. Evaluation of illness of individuals exposed to a combination of irritant, allergenic and toxigenic biological contaminants in wet buildings requires more information about basic effects of individual agents as well as interactive effects of the complex mixtures. In the meantime, case definition for such illness needs to include exposure parameters that actually reflect the nature of the agents capable of effecting illness, rather than some isolated component such as a single mycotoxin. A definition of mycotoxicosis borrowed from agricultural animal and worker exposures, “illness resulting from exposure to one or more toxic molds and their products,” could serve. A case definition should also include location of individuals relative to the location of suspect contaminants, time of contact with or exposure to molds and their products, and a list of signs and symptoms gleaned from investigations of known animal or human toxic exposures. Commonality of signs and symptoms in those who show similar time and place exposure parameters could be used to further focus definition of a case. Prudent public health practice recognizes the potency of the toxic agents produced by toxigenic molds, and seeks to protect occupants of buildings once moisture incursion with resultant microbial growth has been discovered.

Cognitive Impairment Associated with Exposure to Toxigenic Fungi

Wayne A. Gordon1, Ph.D., Eckardt Johanning2, M.D.,M.Sc. Lisa Haddad3, B.A.

1Professor, Department of Rehabilitation Medicine, Mount Sinai School of Medicine; 2Eckardt Johanning, M.D., Adjunct Instructor, Department of Community Medicine, Mount Sinai School of Medicine; 3Lisa Haddad, B.A., Research Assistant, Department of Rehabilitation Medicine, Mount Sinai School of Medicine; Research performed at Mount Sinai School of Medicine, Correspondence: Wayne A Gordon Ph.D., Department of Rehabilitation Medicine, Mount Sinai School of Medicine, 1 Gustave L. Levy Place, Box #1240, New York, NY 10029-6574, telephone: (212) 241-7917, fax: (212) 348-5901

Abstract

The objective of the study was to examine whether cognitive impairment was associated with exposure to Stachybotrys atra. 20 individuals were examined using a standard neuropsychological battery and a symptom checklist. Results indicate that all individuals seen meet at least 1 of the criteria for a cognitive impairment, with 13 of the 20 (65%) meeting at least 3 of the criteria for cognitive impairment. Preliminary findings suggest that exposure to toxigenic molds are associated with cognitive impairment, specifically deficits in verbal memory, verbal learning, attention/concentration and set shifting. In addition to these cognitive deficits, the sample reported a high number of cognitive, physical and behavioral symptoms. Validation on a larger sample of individuals is indicated.

Key words: Cognitive impairment, neurotoxic molds, memory, learning, intelligence, Stachybotrys atra

Symptoms associated to work in a water damaged school building

T.Sigsgaard1 MD., PhD., H.L.C.Jensen2 B.Sc., E.Nichum2 B.Sc., S.Gravesen3 M.Sc., L.Larsen4 M.Sc., M.Ø.Hansen5 B.Sc.

1: Institute of Environmental and Occupational Medicine, Aarhus University; 2: Occu-pational health consultancy, Vejle; 3: Danish Building Research Institute, Hørsholm: 4: ALK-Abello; Copenhagen, 5: Environmental Consultancy; Copenhagen, DENMARK. All correspondence to: Torben Sigsgaard, MD. PhD., Associate professor Institute of Environmental and Occupational Medicine, Aarhus University, University Park Bldg 180, DK 8000 Aarhus, Denmark, Phone: +45 8942 2945 Fax: +45 8942 6199, E-mail: TS@mil.au.dk

Abstract

This paper describes a cross sectional study of employees from a school, where an annex had a long history of water damage. The annex had infestations by a range of moulds with Penicillium, Aspergillus, Cladosporium most often encountered. The employees filled in a questionnaire with questions on sick building syndrome extended with symptoms of toxic alveolitis. After allocating the employees into three groups according to the weekly hours spent in the annex of 0-7 h/week, 8-15h/week and more than 15 hours/week. We found a positive trend for headache, tiredness, nausea and sleeping difficulties with increasing time spent in the annex. This was also true for episodes of fever, shivering or a flue-like feeling. This study emphasises the need for a standardised way to perform investigations of water damaged buildings and indicates a dose response relationship between exposure to water damaged buildings and symptoms of inflammation and CNS-irritation even in low exposure situations.

Key words: Moulds, water-damage, school, teachers, fever, CNS-symptoms, dose-response, sick building.

Sensory irritation of microbially produced volatile organic compounds in mice during repeated exposures

Anne Korpi, PH. LIC., Jukka-Pekka Kasanen, M.Sc., Anna-Liisa Pasanen, Ph.D.

University of Kuopio, Department of Environmental Sciences, Kuopio, Finland; Corresponding author: Anne Korpi, University of Kuopio, Department of Environmental Sciences, P.O.Box 1627, 70211 Kuopio, FINLAND, tel. +358-17-163 220, fax. +358-17-163 230, email: anne.korpi@uku.fi

ABSTRACT

Microbially produced volatile organic compounds (MVOCs) are suspected to cause eye, nose and throat irritation in occupants of moldy buildings. The effect of repeated exposures (30 minutes per day during 4 consecutive days) of mice to 3-octanone (3531 mg/m3), 1-octen-3-ol (36 mg/m3), or to a mixture of five MVOCs (58 mg/m3) via inhalation was studied with a standardized method (ASTM E 981-84). With single MVOCs, no changes in the responses between repetitions of exposure were seen, and only a very slight adaptation in the respiratory response was noted along with the repetition of exposure to a mixture of MVOCs. Thus, during a short-term experiment, repeated exposure to MVOCs did not provoke changes in the sensation of irritation nor cause permanent effects on upper respiratory tract.

Key words: microbial volatile metabolites, MVOC, repeated exposure, sensory irritation, indoor air

IMMUNOLOGICAL BIOMONITORING IN THE ASSESSMENT OF EXPOSURE TO AIRBORNE FUNGI FROM WASTE HANDLING

J. Bünger1, M.D., M. Müller, Ph.D., K. Stalder, M.D., Prof., E. Hallier, M.D., Prof.

Center of Environmental and Occupational Medicine, Department of Occupational and Social Medicine, Georg-August-University, Waldweg 37, D-37073 Göttingen, Germany, Address of authors: E. Hallier, M.D., Prof., K. Stalder, M.D., Prof., M. Müller, Ph.D., J. Bünger1, M.D., Department of Occupational and Social Medicine, Georg-August-University, Waldweg 37, D-37073 Göttingen, Germany, Phone: 49-551-394950, Fax: 49-551-396184, e-mail: ehallie@gwdg.de, mmuelle3@gwdg.de, jbuenge@gwdg.de, 1 Address correspondence to this author at the Department of Occupational and Social Medicine, Georg-August-University, Waldweg 37, D-37073 Göttingen, Germany

ABSTRACT

The immunologic reaction of workers in different waste treatment facilities to inhalation of mold antigens was studied by determination of specific IgG antibody levels and compared to exposures. Antigens were prepared from cultures of fungi which were dominant in dust samples at these workplaces. In 520 waste workers, 32 patients with symptoms of hypersensitivity pneumonitis (HP), and 98 control subjects, serum concentrations of specific IgG antibodies to antigens of molds (Aspergillus and Penicillium species) were determined by an indirect immunofluorescence test (IIFT). The highest antibody levels were found in workers in compost plants, followed by employees of garbage sorting facilities. Lower levels were determined in workers at landfills and lowest in collectors of household biowaste. This order reflects the ranking according to the exposure measurements. About 5% of workers had elevated antibody levels, but none complained about typical symptoms of HP. The IIFT proved to be a very sensitive method of antibody detection since even IgG levels of persons subjected to environmental exposure alone (control) could be measured. High exposure to organic dust at workplaces with waste handling is correlated with elevated mold-specific IgG antibody levels.

Key words: Organic dust, mold exposure, biomonitoring, specific immunoglobulins, aspergillus, penicillium, hypersensitivity pneumonitis, indirect immunofluorescence technique

Waste handling is strongly associated with dyspnoea

Niels Ebbehøj1, M.D. D.M.Sc., Niels O Breum2, M.Sc. D.M.Sc., Gerard J Coenen2, M.Sc., Ulla I Ivens2, M.Sc. Ph.D., Birgitte Kjær2, M.Sc., Thomas Lund2, M.Sc., Poul Suadicani1, D.D.S., Uffe Midtgaard2 D.Sc., Helle Würtz2 M.Sc., Torben Sigsgaard3, M.D. Ph.D.

Department of Occupational and Environmental Medicine, Bispebjerg Hospital, University of Copenhagen, Denmark¹, National Institute of Occupational Health, Copenhagen Denmark ², Institute of Environmental and Occupational Medicine, University of Aarhus ³, Corresponding author: Niels Ebbehøj, Department of Occupational and Environmental Medicine, Bispebjerg Hospital, DK 2400 Copenhagen NV, Denmark, Telephone +45 35 31 60 60, Fax + 45 35 31 60 70, E-mail ne01@bbh.hosp.dk

Abstract

In a cross-sectional study, we examined the health of the employees in the Danish paper and glass recycling industries. Health was assessed by questionnaire, general health examination, and lung function tests. The exposure to airborne organic dust, moulds, bacteria, and endotoxin was measured by a personal carried sampler during a full working shift.

The predominant result was dyspnoea, reported by 40.7 % in the glass recycling industry against 5.7% in the control group. The measured lung function parameters showed minor but significant decrease in VC and FVC, whereas dynamic values were equal. The dyspnoea was strongly associated with glass handling (OR 14.2, 95%CI: 4.0-50.6), and female sex (OR 4.5, 95%CI: 2.2-9.3). The results were partially explained by variation in the levels of mould, but hardly any other air microbiological air pollution. The presence of 0.5 mm diameter glass particles qualitatively identified at microscopy at the glass recycling plants is an other possible cause.

AN ASSESSMENT OF EXPOSURE AND RESPIRATORY HEALTH AMONG SEWAGE TREATMENT PRESSROOM WORKERS

MICHAEL B. LAX, M.D., M.P.H., GREG SIWINSKI, C.I.H., Ms., FEDERICA A. MANETTI, M.D., Ms.

CENTRAL NEW YORK OCCUPATIONAL HEALTH CLINICAL CENTER, DEPARTMENT OF FAMILY MEDICINE, SUNY HEALTH SCIENCE CENTER AT SYRACUSE, Correspondence: Michael B. Lax MD, MPH, CNYOHCC, 6712 Brooklawn Parkway, Suite 204, Syracuse, New York 13211 Tel: 315-432-8899, Fax: 315-431-9528

ABSTRACT

An exposure and health assessment was carried out to investigate reports of illness among pressroom workers at a large sewage treatment plant. The investigation included environmental monitoring and a self-administered health survey. Environmental monitoring revealed several relevant exposures including predominantly gram-negative bacteria, endotoxin, ammonia, and a volatile organic compound. The health surveys showed a very high prevalence and frequency of a number of respiratory symptoms among workers spending 20% or more of their time in the pressroom. The vast majority reported symptom improvement away from work. The findings suggest that pressroom workers at this plant were experiencing respiratory symptoms as a consequence of workplace exposures. Likely exposures contributing to the symptoms include gram negative bacteria and endotoxin. Ammonia and volatile organics may also have been contributing factors.

KEY WORDS: espiratory health, sewage industry, waste treatment, sewage treatment workers, endotoxin, gram-negative bacteria, microorganisms, aerosols, organic dusts.

Chronic toxic encephalopathies apparently related to exposure to toxigenic fungi.

Pierre L. Auger1 M.D., Pierrot Pépin2 H.I., J. David Miller3 Ph.D., Manfred Gareis4 D.V.M., Ph.D., Julien Doyon5 Ph.D., Rémi Bouchard5 M.D., Marie-France Pinard6 Ph.D., Claude Mainville6 Ing.

1 CLSC Haute-Ville, Santé au travail, 530 Boul. de l'Atrium, #101, Charlesbourg, (Québec), Canada, G1H 7H1. 2 CLSC Rivières et Marées, 22, rue St-Laurent, Rivière-du-Loup, (Québec), Canada, G5R 4W5. 3 Research Branch, Agriculture Canada, Ottawa, (Ontario), Canada, K1A 0C6. 4 Institute for Microbiology and Toxicology, Federal Center of Meat Research. E.-C.-Baumann-Str 20, D-95326, KUMLBACH, Germany; 5 Département de Psychologie et Centre de Recherche en Neurobiologie, Université Laval, Québec, Canada,G1K 7P4; 6 Laboratoire VITAL/AIR, Microbiologie et biochimie, Salubrité des bâtiments(M.F.P.) and NATUR’AIR-KIWATIN (C.M.) 1264 Sherbrooke

ABSTRACT

This report concerns four cases of neurotoxic encephalopathies possibly caused by a prolonged exposure to toxin producing filamentous fungi (molds) in the workplace. We will also demonstrate that complete fungal evaluation with species identification and complementary cytotoxicity testing can be useful to identify possible causes of health effects of mold exposures.

Key words: toxic encephalopathy, toxigenic fungi, molds, mycotoxins, Aspergillus fumigatus,Penicillium crustosum, Penicillium brevicompactum, Fusarium incarnatum, Penicillium aurantiogriseum, biological contamination.

INHALATION OF (1 ®3)- b-D-glucan IN HUMANS

L Beijer, Ph.D., J Thorn, M.D., R Rylander, M.D.

Department of Environmental Medicine, Göteborg University, Gothenburg, Sweden; Correspondence to: Lena Beijer, Department of Environmental Medicine, Box 414, 405 30 Gothenburg, Sweden, Tel +46 31773 3614, Fax +46 80 5004, E-mail lena.beijer@envmed.gu.se

Abstract

Fourteen persons living in houses with levels of airborne glucan of at least 4 ng/m3 (G-high) and 14 subject living in houses with levels of airborne glucan of less than 3 ng/m3 (G-low), were exposed to grifolan suspended in saline as well as to saline alone. Comparing the groups before exposure showed that the G-high group had an increased TNFa secretion from the blood mononuclear cells and a lower number of cytotoxic T cells in blood compared to the G-low group. These results suggest that persons living in homes with higher levels of glucan (indicator for molds) show changes in the inflammatory and immunological system. The inhalation exposure to saline induced an increase in the secretion of TNFa, IFNg and IL-10 in PHA-stimulated blood mononuclear cells, while the exposure to the combination of glucan and saline abrogated the saline effect. This downregulation of the saline induced inflammation by glucan is in accordance with previous results in animals exposed to endotoxin and glucan.

Key words: (1 ®3)- b-D-glucan, inhalation, tumor necrosis factor a, cytotoxic T cell

BUILDING-RELATED ILLNESS IN OCCUPANTS OF MOLD-CONTAMINATED HOUSES: A CASE SERIES

JAMES CRANER, M.D., M.P.H.

Consultant in Occupational & Environmental Medicine, Verdi, Nevada, Assistant Clinical Professor, Department of Medicine, Division of Occupational Medicine, University of California, San Francisco School of Medicine, Address for correspondence: P.O. Box 1161, Verdi, NV 89439, Phone: (775) 345-1407, Fax: (775) 345-1404

Abstract

The clinical presentation and course of individuals and families who developed illnesses related to non-infectious fungal exposures inside their homes is described. Occupants developed their illnesses shortly after their homes had been water damaged. A few occupants had a specific building-related illness, such as hypersensitivity pneumonitis or asthma exacerbation, but most had a “sick building syndrome” symptom complex involving irritation/inflammation of the mucous membranes, respiratory tract, and skin; fatigue; and/or neurocognitive dysfunction. All cases required months or years to correctly diagnose. Air, surface, and/or bulk microbiological sampling in most of the homes yielded high concentrations of toxigenic fungi, including Stachybotrys chartarum and Penicillium and Aspergillus species, emanating from water-damaged building materials. Most of the ill individuals had complete clinical improvement shortly after their removal from the contaminated indoor environment, but a few individuals continued to experience symptoms in response to a variety of environmental irritants. The author proposes a new clinical syndrome entity to describe the non-infectious, mold-related, building-related illness.

Key words: Building-related illness, sick building syndrome, toxigenic fungi, environmental disease, Stachybotrys chartarum, hypersensitivity pneumonitis.

DIAGNOSING THE CAUSE OF A “SICK BUILDING:” A CASE STUDY OF AN EPIDEMIOLOGICAL AND MICROBIOLOGICAL INVESTIGATION

JAMES CRANER1, M.D., M.P.H., LINDA D. STETZENBACH2, Ph.D.

1 Consultant in Occupational & Environmental Medicine, Verdi, Nevada, Assistant Clinical Professor, Department of Medicine, Division of Occupational Medicine, University of California, San Francisco School of Medicine, P.O. Box 1161, Verdi, NV 89439, Phone: (775) 345-1407, Fax: (775) 345-1404

2 Director, Department of Microbiology, Harry Reid Center for Environmental Studies, University of Nevada-Las Vegas, Las Vegas, Nevada, 4505 Maryland Parkway, Box 454009, Las Vegas, NV 89154-4009, Phone: (702) 895-1419, Fax: (702) 895-3094; Work performed privately (JC) and at University of Nevada-Las Vegas (LS); Address for correspondence: James Craner, MD, MPH, P.O. Box 1161, Verdi, NV 89439

ABSTRACT

This report describes the methods and outcome of a physician-led investigation of occupants’ prolonged, unexplained illnesses associated with working inside a large, modern office building. Occupants (cases) complained of building-related symptoms including eye, nose, and throat mucous membrane irritation; rashes; respiratory symptoms; profound, unexplained fatigue; and neurocognitive symptoms, including difficulty concentrating and short-term memory impairment. No functional ventilation problems or chemical contamination were detected in a walk-through evaluation and basic air quality testing. An epidemiological survey of the building’s 700 occupants was then conducted. With 86% of the occupants responding to the survey, there was an average case prevalence of health-related complaints of nearly 25%, evenly distributed among floors. Cases were geographically distributed in a pattern which coincided with the location of the ceiling-mounted variable air volume (VAV) boxes which distributed ventilated air to the occupied spaces. Re-inspection revealed previously undetected, focal water-staining of 40% of ceiling tiles located underneath the VAV boxes throughout the building. Active growth of Stachybotrys chartarum (atra) and other fungi was detected on many of the damaged tiles. All water-damaged tiles were replaced and VAV hot water valves were tightened. Occupants reported significant improvement of symptoms within weeks after these changes.

Key words: Sick building syndrome, toxigenic fungi, indoor air quality, environmental disease, Stachybotrys chartarum (atra).

FUNGAL EXPOSURE AND IgG-LEVELS OF OCCUPANTS IN HOUSES WITH AND WITHOUT MOLD PROBLEMS

Hyvärinen1* A., M.Sc., Reiman2 M., Ph.D., Meklin1 T, M.Sc., Husman1 T., M.D, Vahteristo1 M, M.Sc., MD., Nevalainen1 A, Ph.D.

1 National Public Health Institute, Division of Environmental Health, P.O.Box 95, FIN-70 701 Kuopio, Finland; 2 Kuopio Regional Occupational Health, P.O.Box 93, FIN-70701 Kuopio, Finland; 1* Corresponding author, tel. 358-17-201 364, fax 358-17-201 155, Email: Anne.Hyvarinen@ktl.fi

Abstract

The aim of the study was to evaluate the relevance of serum antifungal-IgG antibodies to reflect the individual´s exposure to building related fungi. The concentrations of viable fungi were higher and composition of fungal flora was different in the index houses with moisture problem compared to those in the reference houses. Positive IgG-findings were common in both groups, although higher antibody levels against most of the fungi were found in the study group than in the control group. However, compatibility between fungal flora found in each house and elevated IgG-levels of its occupants were seldom found in either of the groups. This study suggests that microbial sampling gives information of the building at the time of the measurements, whereas IgG-antibodies reflect long-term integrated exposure of an individual from total environment including the work place.

Key words: Fungal exposure, IgG antibodies, mold problem buildings  

The immunopathology of hypersensitivity reactions

Vincent A. Marinkovich, M.D.

Clinical Associate Professor, Stanford Medical School, 801 Brewster Avenue, Suite 220, Redwood City, CA 94063, Telephone: (650) 482-2800, Fax: (650) 482-2802

Abstract

Overactivity of the immune system, either allergy (IgE) or hypersensitivity (non-IgE) is responsible for more illness than is generally appreciated, even by the medical profession. The least understood are the non-IgE mechanisms which involve either immune complex formation (type III of Gell and Combs) or direct killer T-cell involvement (type IV). Type III reactions may be localized with a large deposition of antigen at a focal point where immune complexes are formed and tissue damage ensues including necrosis. This is termed the Arthus reaction. A systemic dissamination of antigens will provoke a systemic inflammentory reaction which is most closely modeled by the well studied acute and chronic serum sickness reaction. Serum sickness was identified as the constellation of symptoms which followed the aadministration of antitoxins (antisera given for infectious disease before the advent of antibiotics) which were derived from non-human sources, most often horses. Chronic serum sickness was observed when otherwise heaalthy subjects were given repeat doses of antisera experimentally over relatively short periods of time. The symptoms observed in spontaneous and experimental serum sickness included fatigue, rash, cognitive changes, myositis, arthritis, headache, weight-loss, cardiovascular symptoms etc., which are often seen during heavy chronic exposure to fungal spores. The dynamic nature of circulating immune complexes, their complexity, their rapidly changing exquilibrum patterns aaand their pathogenicity must be appreciated before the clinican can properly interpret the patterns of illnes his patients’ describe. The best simple test identifying and thereby allowing the avoidance of serum sickness is a specific IgE test to a panel of high exposure antigens including fungi, food and occupational antigens.

Key words: Mechanism’s of Hypersensitivity, Immune complexes, Immunopathology of fungal reactions

EXPOSURE TO STACHYBOTRYS CHARTARUM INDUCES IMMUNOGLOBULIN A ANTIBODY RESPONSE IN MAN

Päivi Raunio1 M.Sc, Anna-Liisa Pasanen1 Prof., Tuula Husman2 M.D., Tuomas Virtanen3 M.D.

1 University of Kuopio, Dept. of Environmental Sciences, P.O.Box 1627, FIN-70211 Kuopio, Finland; 2 National Public Health Institute, P.O.Box 95, FIN-70701, Kuopio, Finland; 3 University of Kuopio, Department of Clinical Microbiology, P.O.Box 1627, FIN-70211 Kuopio, Finland; Corresponding author: Päivi Raunio, fax 358-17-163 230, tel. 358-17-163, e-mail: Paivi.Raunio@uku.fi, University of Kuopio, Dept. of Environmental Sciences, P.O.Box 1627, FIN-70211 Kuopio, Finland

ABSTRACT

The levels of serum immunoglobulin (Ig) E, G and A antibodies against Stachybotrys chartarum were measured in patients with asthmatic or mycotoxicosis symptoms (n=6), their family members (n=10) and control subjects (n=18) with indirect enzyme-linked immunosorbent assays. The Stachybotrys-specific IgG and IgA levels correlated with each other significantly (r=0.71, p<0.01) in the group of exposed subjects (patients and family members), but not in the control group. The IgA levels were significantly higher (p<0.01) and the IgG levels slightly higher (p<0.05) in the patient group than in the control group. IgE levels did not differ between the subject groups. The results of this study suggest that the exposure to Stachybotrys does not cause IgE-mediated allergy in humans. It is possible that the IgA response reflects better exposure to the fungus than the IgG response does.

Key words: Serum antibody level, Stachybotrys chartarum, exposure, enzyme-linked immunosorbent assay, IgA, IgG, IgE

Impacts of Airborne Viruses on Indoor Environments

Douglas T. Reindl

Assistant Professor, College of Engineering, Director, HVAC&R Center, University of Wisconsin-Madison, 432 North Lake St., Madison, WI 53706, (608) 626-6381 - voice, (608) 263-3160 - fax

ABSTRACT

The presence of airborne viruses in the indoor environment can lead to a significant incidence of occupant morbidity. Although many of the illnesses caused by airborne viruses are relatively benign or self-limiting, there are strains of viruses, e.g. influenza, which can result in mortality. Certain populations, such as immunocompromised, are especially at risk. Respiratory disease accounts for approximately 75-80% of all acute morbidity in the U.S. with nearly 80% of the illnesses viral (Ray 1994).

In the U.S., we spend over five billion dollars annually on remedies for relief of the common cold caused, primarily, by rhinoviruses (Radetsky 1991). The common cold is also responsible for an aggregate of thirty million sick days from work and school due to its debilitating effects (Radetsky 1991). The principle modality for transmission of the common cold is via an airborne pathway (Dick and Inhorn 1992).

Properly designed, implemented, and operated engineering control strategies may be an effective intermediate term approach to breaking the chain-of-transmission of illness attributed to respiratory viruses. This paper reviews some background on the prevalence of airborne viruses in the indoor environment, currently available engineering control strategies, and research needs in the area of indoor environmental virology.

Key words: Viruses, indoor environment, ventilation, common cold, airborne transmission

SENSITIZATION TO MOLDS AND RESPIRATORY SYMPTOMS IN SCHOOL CHILDREN

Taskinen1 T., M.D., Hyvärinen2 A., M.Sc., Meklin2 T., M.Sc., Husman2 T., M.D., Nevalainen2 A., Ph.D., Korppi1 M. M.D.

1 Kuopio University Hospital, 1Department of Paediatrics, P.O.Box 1777, FINLAND 70211 Kuopio, Finland., Telephone: + 358-17-172396, Telefax: + 358-17-172410; 2 National Public Health Institute, Division of Environmental Health, Kuopio, Finland. Address of correspondence: Taina Taskinen, Lypsäjänpolku 3, FIN- 74700 Kiuruvesi, FINLAND, Telephone: + 358-17-752549, Telefax: + 358-17-753601, E-mail: Taina.Taskinen@ktl.fi, taina.taskinen@kiuruvesi.fi

Abstract

We performed a questionnaire study in 622 school children; asthma or asthmatic symptoms were present in 208 (33%) children. Moisture and mold problems were documented in the index school (N=414; 168 (41%) were symptomatic); the control school (N=208; 40 (19%) were symptomatic, p<0.001) had no such problems. Skin prick tests to 13 molds (9 occurring in environment and 4 indicating moisture problems in buildings) were performed in the 208 symptomatic children. A positive reaction (>3mm) was observed in only 5 (2%) children. Children who were exposed to molds in the school had more often emergency visits (OR=2.0, p<0.01) and also they had used more antibiotic courses (OR=2.1, p<0.01) than nonexposed pupils, but only during spring. Our results show that skin test positivity to molds is rare in school children. This is true in pupils with asthmatic symptoms, and also in the pupils from the school with moisture or mold problems. In addition, respiratory infections seem to be associated with mold exposure.

Key words: Allergy, asthma, dampness problem, epidemiology, moisture problem, mold growth, mold exposure, sensitization to molds, respiratory manifestation in children, moisture problems in school buildings.

Glucan exposure and airways inflammation among household waste collectors in two municipalities in Sweden

Jörgen Thorn, M.D., Lena Beijer, Ph.D., Ragnar Rylander, M.D., Ph.D.

Department of Environmental Medicine, University of Gothenburg, Box 414, 405 30 Gothenburg, Sweden. Tel +46 31 773 3600, Fax +46 31 82 5004; Correspondence to: Prof Ragnar Rylander, Department of Environmental Medicine, Box 414, 405 30 Gothenburg, Sweden. Tel +46 31 773 3601, Fax +46 31 82 5004

ABSTRACT

Objective: To study effects of household waste handling two studies were performed. A first study included 17 workers collecting unsorted household waste, eight workers collecting organic/non organic separated waste and 24 controls. The second study included 15 workers collecting organic/non organic separated waste and 27 controls.

Methods: Measurements of airborne endotoxin and (1 ®3)- b-D-glucan were made in their working environments. Examinations consisted of a questionnaire for symptoms, spirometry, measurements of airway responsiveness, and blood and sputum sampling for determination of differential cell counts, eosinophilic cationic protein (ECP), myeoloperoxidase (MPO) and cytokines (study 2).

Results: The waste collectors reported more respiratory and general symptoms as compared with controls. In the first study, the number of blood lymphocytes and monocytes were higher among waste collectors. The effects were associated with higher amounts of airborne (1 ®3)- b-D-glucan. In the second study, the number of blood lymphocytes was lower and the number of monocytes higher among waste collectors. The exposure levels were lower in this study as compared with the first.

Conclusion: The results suggest that exposure to household waste dust may cause an activation of inflammatory cells.

Key words: Household waste, waste collectors, airways inflammation, (1 ®3)- b-D-glucan, endotoxin, organic dust

MOISTURE OBSERVATIONS AND HEALTH

Vahteristo1 Mikko, M.Sc., Räsänen2 Jouni, Husman3 Tuula, M.D., Nevalainen4 Aino, Ph.D.,

1 National Public Health Institute of Finland, Di-vision of Environmental Health, Laboratory of Environmental Microbiology, 2, Civil Engineer, National Public Health Institute of Finland, Di-vision of Environmental Health, Laboratory of Environmental Microbiology; 3 National Public Health Institute of Finland, Di-vision of Environmental Health, Unit of Environmental Epidemiology; 4 National Public Health Institute of Finland, Di-vision of Environmental Health, Laboratory of Environmental Microbiology; Correspondence: Mikko Vahteristo, National Public Health Institute, P.O.Box 95, 70701 Kuopio, Finland, Phone: +358 17 201 153, Fax:+358 17 201 155

ABSTRACT

Two tenements, one with 252 and the other with 144 separate apartments were studied for their moisture problems and the symptoms of occupants. There were signs of moisture in 97% of the apartments of the index building and in 59% of the reference building. Among adults, the prevalence of nearly all respiratory symptoms was higher in the index building. The prevalence of nocturnal shortness of breath was more than twice as high in the index building than in the reference building. There was a statistically significant difference in adult’s visits to a physician because of the respiratory symptoms between the two buildings. When the groups that were defined by the severity of moisture problems in the apartments was considered as an exposure variable, in hoarseness of voice, in nocturnal cough and in nocturnal shortness of breath ORs were high and showed a tendency of dose-response relationship. These results support the conclusion that good maintenance of buildings is necessary in order to prevent moisture problems and corresponding health consequences.

Mycotoxin Cytotoxicity Screening of Field Samples

Manfred Gareis, D.V.M., Ph.D., Prof., Eckardt Johanning1, MD., M.Sc. Ritchie Dietrich2, Ph.D.

Institute for Microbiology and Toxicology, Federal Centre for Meat Research, E.-C.-Baumann-Str. 20, D-95326 Kulmbach, Germany; 1Eastern New York Occupational & Environmental Health Center, 155 Washington Avenue, Albany, New York 12210; 2Institute for Hygiene and Technology of Food of Animal Origin, Veterinary Faculty, Ludwig-Maximilians-University of Munich, Veterinaerstr. 13, D-80539 Munich, Germany; Address for Correspondence: M. Gareis, PhD, Director and Professor, Institute for Microbiology and Toxicology, Federal Centre for Meat Research, E.-C.-Baumann-Str. 20, D-95326 Kulmbach, Germany; Tel.: +49-9221-803-220, Fax: +49-9221-803-331, e-mail: gareis.baff@t-online.de

Abstract

Several hydrophil fungi produce very potent chemical metabolites (mycotoxins) that may pose a particular health risk in indoor settings. However, these properties have not been routinely assessed in similar field investigations, due to a lack of readily available screening test methods. A total of 166 moulded samples of building materials (gypsum boards, wallpaper, ceiling tiles, fiberglass and other insulating materials, carpets, dust and air filters) from 44 case investigations conducted during the time period from 1993 to 1998 in various areas of the United States were tested with the MTT-cytotoxicity screening assey for the presence of cytotoxic mycotoxins and compared with controls. A subset of samples was analysed by an enzyme-immune assay (EIA) for occurrence of macrocyclic trichothecenes produced by strains of Stachybotrys chartarum. In addition, presence of fungi were examined by culture methods and scanning electron microscopy. Different levels of cytotoxicity were detected in particular of field samples of gypsum board or wall paper visibly contaminated with fungal growth. Samples with highly cytotoxic effects reacted positive in the MTT-bioassay at concentrations of less than 5 mg of sample aliquot per ml of cell culture medium and indicated the presence of cytotoxic contaminants. Twentythree field samples (52%) of all case investigations were positive for cytotoxicity compared with controls. Most frequently detected fungi in toxic samples were Stachybotrys chartarum (85%), Trichoderma sp. (31%) and Chaetomium sp. (38%) compared to non-cytotoxic samples with a proportion of 38%, 10% and 5%, respectively. These results indicated the presence of non-toxigenic strains or alternatively the non-production of cytotoxic mycotoxins by toxigenic strains on these particular samples. The level of toxicity obtained by the MTT-bioassay highly correlated with the amount of macrocyclic trichothecenes detected by use of the EIA in the samples contaminated with or without Stachybotrys chartarum. Toxicity detected in samples not contaminated with Stachybotrys chartarum indicates the presence of cytotoxic mycotoxins produced by other fungi. In conclusion, the results support the usefulness of the MTT cytotoxicity assay as an important diagnostic tool for the assessment of potential mycotoxin exposure inside buildings with fungal contamination.

THE EFFECT OF INHALED SPORES OF MYCOTOXIN PRODUCIN FUNGI ON ANIMALS

Eeva-Liisa Hintikka, D.V.M., Ph.D.

Head of the Department of Bacteriology, National Veterinary and Food Research Institute, PO Box 368, FIN-00231 Helsinki, FINLAND, Telephone: + 358 9 393 1826, Fax: + 358 9 393 1811

Abstract:

Animals in contact with a mouldy environment are exposed to respiratory fungal infection, lung mycosis. Toxic fungal spores in the air create a risk of respiratory effect. Animal experiments have shown that pure mycotoxins administered to the respiratory organs have only a transient or no effect in the lungs. Toxin-containing spores of Stachybotrys atra administered to the respiratory organs of mice cause severe haemorrhages and lung inflammation.

Key words: mycotoxins, Stachybotrys, aerosol exposure, lung mycotoxicosis

Trichothecenes as a potent inducer of apoptosis

Hiroki OKUMURA1, Naoto YOSHINO1, Yoshitsugu SUGIURA1, Masao SUGAMATA2, Eeva-Liisa HINTIKKA3, Bruce JARVIS4, Yoshio UENO1

1)Department of Toxicology and Microbial Chemistry, Faculty of Pharmaceutical Sciences, Science University of Tokyo, Ichigaya, Tokyo 162-0826, 2) Department of Pathology, Tochigi Institute of Clinical Pathology, Nogi, Tochigi 329-0112, Japan, 3) National Veterinary and Food Research Institute, Helsinki, Finland, and 4)Department of Chemistry and Biology, University of Maryland, Maryland, USA. Correspondence, Yoshio UENO Prof., Faculty of Pharmaceutical Sciences, Science University of Tokyo, Ichigaya, Tokyo 162-0826, Japan, TEL +81-3-3260-4272 (ext. 5069), FAX +81-3-3267-1320, E-mail <youeno@kagu.sut.ac.jp

Abstract

Induction of apoptosis by the trichothecenes was examined in promyelotic leukemia cell line HL-60 and mice. An early elevation of intracellular Ca++ ion followed by disruption of observed mitochondrial transmembrane potential, induction of caspase-3, and DNA fragmentaion was oberved in T-2 toxin-treated cells. An induction of apoptotic cell death in the tissues of mice given T-2 toxin was confirmed by electron microscopic analysis. The induction of apoptosis was proposed as a novel cell death mechanism of T-2 toxin as well as macrocyclic trichothecenes.

Key words: Trichothecenes, T-2 toxin, verrucarins, satratoxins, HL-60 cells, mice Apoptosis, DNA fragmentation, caspases, Ca++ ion, electron microscope

Analysis for Stachybotrys Toxins

Bruce B. Jarvis1, Ph.D., Prof., Simon F. Hinkley

Department of Chemistry and Biochemistry, and Joint Institute for Food Safety and Nutrition, University of Maryland, College Park, MD 20742, 1Corresponding author: Phone No. (301)-405-1843; Fax no. (301)-314-9121, e-mail address: bj6@umail.umd.edu

Abstract:

Analytical conditions have been developed for the detection and quantitation of several classes of mycotoxins produced by the toxigenic mold, Stachybotrys atra (S. chartarum). Fungal cultures or environmental samples are extracted with methanol-chloroform and the crude extracts passed through a PEI silica cleanup column. The fractions from this cleanup column are analyzed by reversed phase chromatography (C-18, acetonitrile-water-formic acid) coupled to a diode array detector. Three major classes of mycotoxins are produced by S. atra: trichothecenes, phenylspirodrimanes, and, a new class of diterpenoids, the atranones. Thirty-eight isolates of S. atra were assayed for their mycotoxin production, and the S. atra isolates fell into two distinct classes: those that produce trichothecenes (12/38) and those that produce atranones (22/38).

Key words: trichothecenes, immunosuppressants, HPLC-diode array detection, mycotoxins, Stachybotrys, Memnoniella, diterpenes

Assessing Bioaerosols in Elementary School Classrooms

K.H. Bartlett, Ph.D., S.M. Kennedy, Ph.D., M. Brauer, Sc.D., B. Dill, Ph.D., C. vanNetten, Ph.D.

K.H. Bartlett, Ph.D. candidate, Interdisciplinary Studies; S.M. Kennedy, Ph.D., Associate Professor, Occupational Hygiene Programme; M. Brauer, Sc.D., Associate Professor, Occupational Hygiene Programme; B. Dill, Ph.D., Department of Microbiology and Immunology; C. vanNetten, Ph.D., Associate Professor, Department of Health Care and Epidemiology, Occupational Hygiene Programme, Third Floor, 2206 East Mall, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada, Please address correspondence to: Karen H. Bartlett, Occupational Hygiene Programme, 2206 East Mall, Vancouver, B.C., V6T 1Z3, Phone: (604) 822-9573 FAX: (604) 822-9588 email: kbartlet@interchange.ubc.ca

Abstract:

A two year study of elementary school classrooms was begun in 1996. Data collected included: number of occupants and patterns of occupancy, CO2 levels, temperature and percent relative humidity (%RH), total particulate, and air exchange rates using tracer gas (SF6). Indoor and outdoor bioaerosols were collected using an Andersen N-6 impactor.

The effect of measured indoor air quality parameters and building characteristics on the airborne concentrations of indoor bacteria and mesophilic fungi were evaluated using multiple linear regression. The variable with the highest predictive value for bacterial concentrations was indoor CO2 concentration, with the final equation having a R2 of 0.59. In contrast, outdoor temperature had the highest predictive value for indoor mesophilic fungi with the final equation having a R2 of 0.61.

Variables commonly measured during an indoor air quality investigation can be used to understand bioaerosol concentrations. High commensal bacterial counts are clearly related to inadequate ventilation of the occupied space. In a similar manner, the use of mechanical or natural ventilation in buildings and the concentration of fungi in the outdoor environment is related to indoor fungal counts. These data would suggest that indoor air quality investigations benefit from an integrated investigative approach.

Anatomy of a Fungal Problem

Neil Carlson1, M.S., C.I.H., Arif Quraishi2, B.S.M.E., M.B.A.

1University of Minnesota, 410 Church Street S.E., Minneapolis, MN 55455, Phone: 651-626-5714, Fax: 651-624-1949, E-mail: carls001@maroon.tc.umn.edu, N.G. Carlson Analytical, Inc., 216 16th Avenue S.W., MN

2 Institute for Environmental Assessment, Indoor Environments Division, 7101 Northland Circle, Suite 219, Minneapolis, MN 55428, Phone: 612-535-7721, Fax: 612-535-9177, E-mail: schooliaq@aol.com

Institute for Environmental Assessment, 7101 Northland Circle, Brooklyn Park, MN 55428, 612-535-7721 * 800-233-9513 * Fax 612-535-9177, Arif Quraishi, B.S.M.E., M.B.A.

Abstract

Sampling was performed in a school with extensive visible fungal growth to evaluate exposure potential to building occupants. Musty odors and allergy-type symptoms were reported by building occupants. Initial testing using fungal sampling was not successful in identifying risks to building occupants. Additional sampling was conducted using total spore trap sampling, tape sampling and microbial volatile organic compound (MVOC) sampling. Analysis of the samples using total spore trap and tape sampling methods identified exposure potential to Acremonium spp., Alternaria spp., Paecilomyces spp., Aspergillus niger and others. Measurement of MVOCs showed that the indoor MVOCs were almost double the outside level. While sampling performed by traditional viable methods suggested no exposure potential, tape, spore trap and MVOC sampling data revealed greater exposure potential. Based on the results of this study, viable fungal sampling should not be the only method for conducting risk assessments relating to exposure to fungal spores and their bioeffluents.

Key words: Mold, Non-viable fungal growth, Microbial volatile organic compounds (MVOCs), Total spore trap sampling, Indoor air quality

Characterization of Bioaerosol Emissions from a suburbanYard waste composting facility.

Luke Curtis1, M.S., C.I.H., Mary Ross2 Ph.D., Joe Chung3 Ph.D., Peter Scheff1 Ph.D., C.I.H., Victoria Persky1 M.D., Richard Wadden1 Ph.D., C.I.H., Viswanathan Ramakrishnan1 Ph.D., Daniel Hryhorczuk1, M.D., M.P.H.

1- University of Illinois at Chicago, Departments of Environmental and Occupational Health Science and Epidemiology, School of Public Health, Mail Code 922, 2121 West Taylor Street, Chicago, Illinois 60012.; 2 - United States Environmental Protection Agency, Health Effects and Standards Group, Mail Code 15, Research Triangle Park, NC 27711. 3 - United States Environmental Protection Agency, Region 5, 77 West Jackson Street, Chicago, Illinois 60602.; Corresponding Author: Luke Curtis, MS, CIH, School of Public Health West, M/C 922- University of Illinois at Chicago, 2121 West Taylor Street, Chicago, Illinois 60091, Work (312) 996-7887 Home (847) 256-3562 Fax (312) 413-7369, E Mail Luke_Curtis@Juno.com

Abstract:

During the months of September through November, 1995, extensive bioaerosol measurements were made at and around at composting facility over a 10 day sampling period. Airborne bacterial concentrations were much higher on-site than off site and off site bacterial concentrations were significantly higher downwind of the composting facility. Airborne fungal concentrations were not significantly higher closer to the compost facility than further off-site. Particulate, endotoxin and beta 1,3 glucan concentrations were significantly higher on-site than off-site.

Key words: Composting, yard waste, fungi, bacteria, endotoxins, glucans, agricultural dust.

Airborne contamination of Eastern Canada sawmills.

Caroline Duchaine Ph.D.1, Anne Mériaux B.Sc. Yvon Cormier M.D.

Affiliation: Centre de Pneumologie, Hôpital and Université Laval, Sainte-Foy, Québec, Canada. 1Corresponding author: Caroline Duchaine, Centre de Recherche, Hôpital Laval, 2725 Chemin Ste-Foy, Ste Foy, Québec,Canada, G1V-4G5, Tél: (418) 656-4760, fax: (418) 656-4509, duchaine@mediom.qc.

Abstract:

The purpose of this study was to quantify and identify the airborne contamination in sawmills in order to monitor the exposure levels for workers. Seventeen sawmills were chosen to cover a wide range of size, geographic distribution, wood species and, within each sawmill, different work areas (debarking, sawing, sorting, or planing) were studied separately. Microbial contaminants were assessed using all glass-impingers-30 and six-stages Andersen samplers. Tryptic soy agar was used for bacteria, Rose Bengal Agar (RB) was used for culturable molds (30°C) determination. PVC filters were used at a flow rate of 2l/min for at least 6 hours for dust level measurements. Endotoxins were measured in AGI-30 liquid. Temperature and humidity were also measured. Penicillium species were the most predominant molds. We identified up to 40 different Penicillium species in these environments. Debarking was the working site most highly contaminated by molds, bacteria and endotoxins (p=0,0001). At this working site mold levels reached up to 1.5x106 CFU/m3, the culturable bacteria levels were in average 3.3 X105 ± 3.1 X105 CFU/m3 and the median value for endotoxin level was 1081 endotoxin units/m3. Planing site was the most highly contaminated with dust (median: 3.0 mg/m3) (p<0.05). Eastern North America sawmills contain airborne biological contaminants which vary between working sites and their microflora is different from those previously described in European sawmills.

Key words: Aerobiology, Sawmills, Environmental Biological Exposure, Molds, Endotoxins, Wood Dust.

Prevalence of Fungi in CARPET Dust Samples

Mark Hodgson1 LRSC, Richard Scott2 AIA

1 Senior Consultant, 2 Senior Architect, Occupational Health and Safety; 1&2Clayton Environmental Consultants, a division of Clayton Group Services, Inc., 160 Fieldcrest Avenue, Edison, New Jersey 08837 USA, Tel: (732) 225-6040 Fax: (732) 225-4577, Email: Mhodgson@claytongrp.com or Rscott@Claytongrp.com

ABSTRACT

Samples of dust collected from carpeting can provide an indication of the microbial condition of a building with the carpet material having potential to be both an amplifier (growth site) and reservoir for fungi. Interpretation of the data obtained from analysis of the dust is helpful when making a determination as to the overall condition of both the building and the carpet material. The authors have collated data from 243 samples collected in both problem and control buildings across the USA. A comparison is made between the results obtained from both problem and control buildings, with particular emphasis on the biodiversity found and the regional differences observed. The study concludes that despite the ubiquitous nature of fungi there are a number of key indicators which can be used to determine if the dust from a carpet suggests a contaminated building.

Key words: Fungi, Carpet Dust, Aspergillus, Fungal Contaminated Buildings

Detection and Decontamination of a Facility Contaminated with Fungi Including Stachybotrys chartarum: A Case Study

Ling-Ling Hung, Ph.D.

US Public Health Service, Division of Federal Occupational Health, 150 S. Independence Mall West, Suite 368, Philadelphia, PA 19106, Phone: 215-861-4113, Fax: 215-861-4121, Email:LHUNG@FOH.DHHS.GOV

ABSTRACT

A facility indoor environmental quality investigation was initiated in 1996 due to onset of employees' health symptoms after fifteen minutes exposure in the facility. The investigation was to determine the extent of contamination, identify the causative agents, design decontamination specifications, and develop and implement a monitoring strategy for clearance sampling.

Massive fungal growth was observed on various surfaces. Many types of microbiological samples were collected throughout this two-story facility. Very high fungal levels were detected on bulk and wipe samples (107 CFU/g and 106 CFU/in2). Three rounds of air samplings were conducted. Outdoor fungal levels were at 102 CFU/m3 with Cladosporium as the predominant fungi. However, indoor fungal levels were consistently at least 104 CFU/m3. Indoor fungal flora was dominated by Aspergillus, Penicillium, and Stachybotrys chartarum. Analytical results showed that basement, ground floor, and ductwork were contaminated.

Specifications were developed to decontaminate the facility and the ductwork. Ten percent (10%) bleach solution and Oxine® brand of chlorine dioxide (500 ppm) was used as the disinfectant for the facility and the ductwork, respectively. Final clearance samples were taken to evaluate the effectiveness of the cleaning. Air sampling results showed that airborne fungal levels in the facility were compatible to those of outdoors (230 and 224 CFU/m3, respectively), with a similar fungal flora. Results from final clearance surface samples, taken after completion of second ductwork cleaning, showed that surface fungal burden of this facility was not different from that of a reference building.

Key words: Stachybotrys, Penicillium, Aspergillus, indoor air quality, bioaerosol, fungi, decontamination, duct cleaning.

Case Study: Airborne Concentrations of Trichoderma and Stachybotrys linked to Mycotoxicosis

Larry D. Robertson, M.S., B.S.

Mycotech Biological, Inc., Rt. 1 Box 182 Jewett, TX 75846 U.S.A., Phone/Fax 800-272-3716

Abstract

The affected individual developed symptoms approximately 55 days after exposure to a working environment containing significant fungal contamination. Initial symptoms included bronchitis, swelling, spastic colon, severe headaches, and fatigue. Later, abdominal pain, nausea, diarrhea, and loose teeth were reported. Three physicians having specialties in internal medicine, toxicology, and neurology independently diagnosed exposure to an "unknown" environmental toxin; however, the physicians were not provided with environmental results from the work place. The work environment indicated airborne concentrations of Trichoderma viride and Stachybotrys chartarum at 494 CFU/m3 and 212 CFU/m3, respectively. Active Trichoderma viride and Stachybotrys chartarum growth sites were documented at levels of 3.3 x 104 CFU/g and 2.0 x 107 CFU/g; respectively. Although these contaminants were exclusive to the individuals work area, the CIH/CSP represented the data as “typical” for indoor environments. As a result, no exposure data was provided to the attending physicians. After 5 months of exposure the individual became too ill to return to work. Within 1 month of removal the symptoms begin to subside. Complete symptom cessation resulted after 12 months. The absence of specific human dose-exposure data relative to the various mycotoxins produced by Trichoderma viride and Stachybotrys chartarum does not support a valid medical claim relative to an aerosol-induced mycotoxicosis. However, anecdotal, circumstantial, and environmental information strongly supports the potential for this event to have occurred. This study demonstrates the current void that exists relative to both the knowledge and availability of mycotoxin diagnostic methods in the medical field and suggests the immediate need for education, training, and research relative to aerosol generated mycotoxicoses.

Key words: Stachybotrys chartarum, Trichoderma viride, mycotoxins, mycotoxicosis, airborne concentrations.

FUNGAL GENERA IDENTIFIED FROM FLOODED WALL CAVITIES

CONSTANCE L. JENKINS1, B.S., PETER H. SIERCK

1 Environmental Testing & Technology, 1106 Second Street, Suite 102, Encinitas, CA 92024, Tel: (760) 436-5990, Fax: (760) 436-9448

ABSTRACT

Field investigators are often confronted with the situation of evaluating whether or not fungal amplification is present on the back side of drywall in walls which have sustained a moisture intrusion. When there is no visible source of fungal growth in a room with higher than expected levels of culturable fungi and a pathway exists for migration of fungal spores into the room, growth on the interior of the wall cavity must be considered. This study was conducted to assess if culturable air sampling of wall cavities is a valuable tool to assist in making this determination.

The fungal genera present in the wall cavities were determined by collecting air samples through a hole in the wall with an Anderson N6 stage impaction sampler on selective media with laboratory analysis. The goal of the study was to determine the fungal genera present in the inside of the wall cavities which have sustained a moisture intrusion (flood) and compare them to the fungal genera in wall cavities which have not sustained a water intrusion (non flooded).

The analysis results showed an increase in the total colony counts and a significant shift from Cladosporium species to Aspergillus/Penicillium species in the wall cavities which had sustained the water intrusion. Statistically, in the flooded wall cavities, the sum of Aspergillus and Penicillium is higher by more than three times the standard deviation.

Key words: water damaged walls, water intrusion, drywall, stud bay, fungal genera, Aspergillus, Penicillium, Cladosporium.

Exposure measures for studies of mold and dampness and respiratory health

J. David Miller1 M.Sc., Ph.D., Robert Dales2 M.D., M.Sc. Jim White3, P. Eng.

1Department of Chemistry, Carleton University, 228 Steacie Building, Ottawa, Ontario. K1S 5B6,

2Environmental and Occupational Toxicology, Health Canada, Ottawa, Ontario. K1A 0L2, Canada

3Research Division, Canada Mortgage & Housing Corporation, Ottawa, Ontario. K1A 0P7

Abstract

This paper reviews some basic principles underlying the measurement of fungi in air samples and dust to describe their quantitative and qualitative value. We compare the results of such measurements with our experience in the Wallaceburg study wherein ca. 400 homes in southern Ontario were studied for various exposure and health outcomes. Until more powerful methods to determine quantitative and qualitative exposures to fungi are developed, the attributable risk of fungal contamination in residential housing for public health cannot be estimated with accuracy. The most reliable information on mold exposures in residential housing can be obtained by measuring moisture source strength, detailed study of areas of visible mold plus some mycological testing of building materials to determine where the growth is occurring beyond that visible to the naked eye and qualitative and quantitative analysis of molds in settled dust.

Key words: molds, health, exposure assessment, air samples

Fungal Growth in Buildings: The Aerobiological Perspective

Harriet A. Burge Ph.D.

Harvard School of Public Health, 665 Huntington Avenue, Bldg. 1 Rm G-13, Boston, MA 02115, Tel: (617) 432-4638 Fax; (617) 432-3349

Abstract:

In the search for inexpensive shelter, we have developed indoor environments that are conducive to fungal contamination. While active fungal growth indoors is usually inappropriate and should be controlled, assessing specific health risks associated with such growth remains a challenge. Epidemiological tools are often used to determine relative risks associated with occupancy by groups of people in environments with or without certain factors, including fungal growth, but do not always make clear the role of the growth in the disease process in indiviudals. Aerobiologists assess relationships along a pathway that includes sources, dispersion and decay of aerosols, exposuree to individuals, doses of agents, and responses. Both approaches yield valuable information, but require the development of testable hypotheses.

As a model, we can apply the epidemiological and aerobiological processes to the Cleveland hemosiderosis outbreak, and consider the following hypotheses:

1. The Cleveland babies that develop hemosiderosis are more likely to live in moldy homes than those that did not develop the diseease, all other things being equal.

2. The Cleveland babies that developed hemosiderosis are more likely to live in homes with Stachybotrys than those that did not develop the disease, all other things being equal.

3. (Aerobiology) Babies that developed disease were likely to have received a dose of Stachybotrys chartarum toxins sufficient to cause the reported symptoms.

Some evidence exists to support Hypothesis 1. Hypothesis 2 is suppored by very little evidence and Hypothesis 3 has not been tested. Until Hypotheses 2 and 3 are adequately tested and verified, assuming a cause/effect relationshipfor Stachybotrys toxins in these cases is premature. Premature establishement of cause/effect relationships may lead to unneccessaary conceern, and prevent discovery of actual caauses of disease. This hypothesis development and testing process is essential if we are to accurately determine the role of indoor fungi in human disease.

Why are there Still Problems with Fungal Allergen Extracts? 

W. Elliott Horner, Samuel B. Lehrer

Air Quality Sciences, Inc., Atlanta, GA, and Tulane University Medical Center, New Orleans, LA; Air Quality Sciences, Inc., 1337 Capital Circle, Altanta, GA 30067, tel.: 770.933.0638, FAX 770.933.0641, aqs@mindspring.com

Introduction

It has long been axiomatic that reliable allergen extracts of fungi are more difficult to produce and work with than extracts of pollen, dander, or other allergen sources (Salvaggio, 1981; Burge, 1985; D’Amato, Spieksma, 1995; Feinberg, 1946). Features of fungi that contribute to this include their number and variety, the identification is sometimes difficult, their phenotypic plasticity, and the presence of endogenous proteases that can degrade allergens in crude extracts. All of these problems can be addressed to an extent, albeit some with difficulty. Indeed, with the few fungi with which molecular techniques are being used, recombinant allergens are readily being produced. Unfortunately, adequate resources and resolve are lacking for a concerted effort at producing well-characterized allergen extracts. Further, the extracts that are available correspond poorly with the fungi that are often a problem indoors.

FROM FUNGAL EXPOSURE TO DISEASE: A BIOLOGICAL MONITORING CONUNDRUM

Raymond E. Biagini, M.S., Ph.D.

Division of Biomedical and Behavioral Science, National Institute for Occupational Safety and Health, Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, Mailstop C-26, Cincinnati, OH 45226. Phone:513-5338196; Fax: 513-533-8494; Email: reb4@cdc.gov.

Abstract:

Biological monitoring is the estimation of exposure to an agent through the measurement of biomarker(s) resulting from an internal dose of an agent. The biomarker(s) are typically the agent or its metabolite(s) in a biologically derived specimen. For example, styrene in expired air, styrene in blood, and mandelic and phenylglyoxylic acids (metabolites of styrene) in urine. The biomarker also can be a highly specific, validated effect of the agent, such as elevated levels of zinc protoporphyrin in blood caused by exposure to lead. Due to advances in molecular biology, genetics, analytical chemistry, and other basic sciences, it is now possible to detect smaller amounts of analytes and contaminants and smaller biological changes, as well as to identify mechanisms at the cellular and molecular levels. These advances can be exploited for biological monitoring, in some cases. Legacy biological monitoring, is the measurement of a specific biological monitoring determinant which contains none of the atoms of the molecule to which the organism was exposed. The most common example of this is an antibody produced against small molecular weight molecules or altered constituitive proteins. Numerous investigators have implicated putative exposure to macrocyclic tricothecenes and other compounds from Stachybotrys chartarum as being associated with a plethora of signs and symptoms of disease. To date, no compelling biological marker for exposure to Stachybotrys chartarum mycotoxins or other metabolites has been presented. There is no doubt that exposure to Stachybotrys chartarum is associated with an increased prevalence of self-reported symptoms. However, evidence of the association of these complaints with frank disease is lacking. More biological monitoring research is needed to solidify these associations, if present.

Key words: Biological Monitoring; Legacy Biomonitoring; Stachybotrys chartarum

Comparative studies of fungal media for the recovery of Stachybotrys chartarum from environmental samples

Stella M. Tsai1, M.Sc., Chin S. Yang1, Ph.D., Patricia Heinsohn2, Ph.D., CIH

1 P&K Microbiology Services, Inc., 1950 Old Cuthbert Road, Unit L, Cherry Hill, NJ 08034, Phone: (609) 427-4044, Fax: (609) 427-0232; 2 Exponent, 149 Commonwealth Drive, Menlo Park, CA 94025

Abstract

Five commonly used fungal media were used to determine the relative recovery efficiencies of Stachybotrys chartarum (SC) by culturing sixty-five unknown environmental samples from building materials. These fungal media were cornmeal agar (CMA), Czapek cellulose agar (CCA), 2% malt extract agar (2% MEA), 1% malt extract agar (1% MEA) and rose bengal agar (RBA). The samples were first examined microscopically for the presence of SC. It was found that all five fungal media were all suitable for the recovery of SC from the environmental samples. The recovery frequency of SC from bulk samples ranged from 87.7% on 2% MEA to 95.4% on CMA. Qualitative differences of colony growth and interaction between S. chartarum and other fungi were observed on the media. CMA yielded the best sporulation and highest recovery rate of SC from the environmental samples. The other four media also supported the isolation and recovery of SC but at reduced rates.

Key words: Stachybotrys chartarum, fungal contamination, media selection.

Heteroduplex DNA fingerprinting of Penicillium brevicompactum from house dust

James A. Scott1,2, Neil A. Straus1, Bess Wong1

1Department of Botany, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Tel: 416-978-5563 Fax: 416-867-5878 E-m: jscott@sporometrics.com; 2 Sporometrics Inc., 253 College Street, Box 400, Toronto, ON, M5T 1R5

Abstract

It is widely believed that many osmotolerant microfungi, including toxigenic species of Aspergillus and Penicillium proliferate on indoor substrata such as dust and broadloom even in the absence of appreciable moisture. This hypothesis has been offered as an explanation for the disproportionate abundance of propagules of these species in indoor environments, relative to their representation in outdoor reservoirs such as air and soil.

We obtained several thousand isolates of Penicillium from 367 homes in southwestern Ontario, Canada. From these, 75 isolates of P. brevicompactum representing 54 houses were selected based on micromorphological and physiological uniformity. Sequences of PCR-amplification products of polymorphic genetic loci were compared between isolates using heteroduplex mobility assay (HMA), demonstrating two primary, genetically divergent groups which appear to be stable, clonally-reproduced lineages within the dust mycoflora. These clones are distributed throughout the sample population and co-exist at several sites, suggesting that in absence of objective moisture problems, the principal amplifiers of P. brevicompactum lie outside the building environment. It is possible that mechanical / filtration effects (e.g. differential removal of propagules by vacuum cleaning and elutriation in air conveyance systems), and the relatively long spore viabilities of trichocomaceous anamorphs play a significant role in concentrating propagules of these microfungi in homes.

Key words: Penicillium brevicompactum, population, house dust, indoor air quality, heteroduplex mobility assay

The Trichodiene Synthase Gene from Stachybotrys chartarum : A potential diagnostic indicator of indoor contamination

Neil A. Straus1 PhD, James Scott, Bess Wong MSc

Department of Botany, University of Toronto, Toronto, Ontario, Canada, 1Corresponding Author, Email: straus@botany.utoronto.ca

Abstract

The hyphomycete Stachybotrys chartarum readily grows on damp cellulosic areas in buildings producing spores that may contain highly toxic trichothecenes. Here we report the cloning, sequencing of the gene for trichodiene synthase which is the first enzyme of the pathway uniquely dedicated to the synthesis of trichothecenes. The predicted amino acid sequence shows regions of high conservation. Nucleotide sequence divergence permits the selection of PCR primers that can detect the trichodiene synthase gene of S. chartarum in DNA diagnostic strategies.

Key words: Stachybotrys chartarum, trichodiene synthase gene, DNA diagnostics