Effects of Toxic Exposure to Molds and Mycotoxins in Building-Related Illnesses

The authors studied 100 patients who had been exposed to toxic molds in their homes. The predominant molds identified were Alternaria, Cladosporium, Aspergillus, Penicillium, Stachybotrys, Curvularia, Basidiomycetes, Myxomycetes, smuts, Epicoccus, Fusarium, Bipolaris, and Rhizopus. A variety of tests were performed on all, or on subgroups of, these patients. Sensitivities and exposures were confirmed in all patients by intradermal skin testing for individual molds (44-98% positive), and by measurement of serum antibodies. Abnormalities in T and B cells, and subsets, were found in more than 80% of the patients. The findings of trichothecene toxin and breakdown products in the urine, serum antibodies to molds, and positive intradermal skin tests confirmed mycotoxin exposure. Respiratory signs (e.g., rhinorrhea, sinus tenderness, wheezing) were found in 64% of all patients, and physical signs and symptoms of neurological dysfunction (e.g., inability to stand on the toes or to walk a straight line with eyes closed, as well as short-term memory loss) were identified in 70% of all patients. Objective abnormal autonomic nervous system tests were positive in all 100 patients tested. Brain scans, conducted using triple-head single photon emission computed tomography, were abnormal in 26 (86%) of 30 (subgroup of the 100) patients tested. Objective neuropsychological evaluations of 46 of the patients who exhibited symptoms of neurological impairment showed typical abnormalities in short-term memory, executive function/judgment, concentration, and hand/eye coordination.

Evaluation of individual-based and group-based exposure estimation of microbial agents in health effects associated with a damp building

We evaluated attenuation in linear associations between microbial exposure and respiratory symptoms occurring when individual measurements of microbial agents were used for estimating employees' exposure compared with group means. Symptoms, which improved when away from the building (building-related, BR), and measurements of culturable fungi, ergosterol, and endotoxin in floor dust were obtained between 2001 and 2007 from four cross-sectional studies on occupants of a water-damaged building. We compared odds ratios from longitudinal health effect models using individual measurements at employees' workstations with those using floor (group) means. Estimated odds for BR respiratory symptoms in group-based analyses increased by 2 to 5 times compared with those from individual-based analyses for culturable fungi and ergosterol, although they were less precise. For endotoxin, we found substantially increased and significant odds in group-based analyses, while we found no associations in individual-based analyses for various symptoms. Our study suggested that the building floor was useful in constructing exposure groups for microbial agents in this water-damaged building for epidemiologic analysis. Our study showed that group-average exposure estimation provides less attenuated associations between exposures to microbial agents and health in damp indoor environments where measurement error and intrinsic temporal variability are often large.

Size-resolved emission rates of airborne bacteria and fungi in an occupied classroom

The role of human occupancy as a source of indoor biological aerosols is poorly understood. Size-resolved concentrations of total and biological particles in indoor air were quantified in a classroom under occupied and vacant conditions. Per-occupant emission rates were estimated through a mass-balance modeling approach, and the microbial diversity of indoor and outdoor air during occupancy was determined via rDNA gene sequence analysis. Significant increases of total particle mass and bacterial genome concentrations were observed during the occupied period compared to the vacant case. These increases varied in magnitude with the particle size and ranged from 3 to 68 times for total mass, 12-2700 times for bacterial genomes, and 1.5-5.2 times for fungal genomes. Emission rates per person-hour because of occupancy were 31 mg, 37 × 10(6) genome copies, and 7.3 × 10(6) genome copies for total particle mass, bacteria, and fungi, respectively. Of the bacterial emissions, ∼18% are from taxa that are closely associated with the human skin microbiome. This analysis provides size-resolved, per person-hour emission rates for these biological particles and illustrates the extent to which being in an occupied room results in exposure to bacteria that are associated with previous or current human occupants.

PRACTICAL IMPLICATIONS

Presented here are the first size-resolved, per person emission rate estimates of bacterial and fungal genomes for a common occupied indoor space. The marked differences observed between total particle and bacterial size distributions suggest that size-dependent aerosol models that use total particles as a surrogate for microbial particles incorrectly assess the fate of and human exposure to airborne bacteria. The strong signal of human microbiota in airborne particulate matter in an occupied setting demonstrates that the aerosol route can be a source of exposure to microorganisms emitted from the skin, hair, nostrils, and mouths of other occupants.

Influence of various growth parameters on fungal growth and volatile metabolite production by indoor molds

A Penicillium polonicum, an Aspergillus ustus and a Periconia britannica strain were isolated from water-damaged environments and the production of microbial volatile organic compounds (MVOCs) was investigated by means of headspace solid-phase microextraction followed by GC-MS analysis. The most important MVOCs produced were 2-methylisoborneol, geosmin and daucane-type sesquiterpenes for P. polonicum, 1-octen-3-ol, 3-octanone, germacrene D, δ-cadinene and other sesquiterpenes for A. ustus and the volatile mycotoxin precursor aristolochene together with valencene, α-selinene and β-selinene for P. britannica. Different growth conditions (substrate, temperature, relative humidity) were selected, resembling indoor parameters, to investigate their influence on fungal metabolism in relation with the sick building syndrome and the results were compared with two other fungal strains previously analyzed under the same conditions. In general, the range of MVOCs and the emitted quantities were larger on malt extract agar than on wallpaper and plasterboard, but, overall, the main MVOC profile was conserved also on the two building materials tested. The influence of temperature and relative humidity on growth and metabolism is different for different fungal species, and two main patterns of behavior could be distinguished. Results show that, even at suboptimal conditions for growth, production of fungal volatiles can be significant.

Relationships between mite allergen levels, mold concentrations, and sick building syndrome symptoms in newly built dwellings in Japan

This study investigated the possible relationships between exposures to mite allergen and airborne fungi with sick building syndrome (SBS) symptoms for residents living in newly built dwellings. We randomly sampled 5709 newly built dwellings in six prefectures from northern to southern Japan. A total of 1479 residents in 425 households participated in the study by completing questionnaire surveys and agreeing to environmental monitoring for mite allergen (Der 1), airborne fungi, aldehydes, and volatile organic compounds. Stepwise logistic regression analyses adjusted for confounders were used to obtain odds ratios (OR) of mite allergen and fungi for SBS symptoms. Der 1 had a significantly high OR for nose symptoms. Rhodotorula had a significantly high OR for any symptoms, and Aspergillus had significantly high OR for eye symptoms. However, the total colony-forming units had a significantly low OR for throat and respiratory symptoms. Eurotium had a significantly low OR for skin symptoms. In conclusion, dust-mite allergen levels and indoor airborne Rhodotorula and Aspergillus concentrations may result in SBS symptoms in newly built dwellings.

PRACTICAL IMPLICATIONS

Various factors can cause sick building syndrome symptoms. This study focused on biologic factors such as dust-mite allergen and airborne fungi in newly built dwellings in Japan. Dust-mite allergen levels were significantly associated with higher rates of nose symptoms, airborne Rhodotorula concentrations were significantly associated with higher rates of any symptoms, and Aspergillus concentrations were significantly associated with higher rates of eye symptoms. Measures should be taken to reduce mite allergen levels and fungal concentrations in these dwellings.

The possible role of fungal contamination in sick building syndrome

The following is a review of some of the work that we have done since 2007 regarding the importance of molds in the phenomenon of sick building syndrome (SBS). In these studies we first examined mold contamination in air handling units (AHU). Our results showed that Cladosporium sp. were commonly recovered in AHU as growth sites and free spores. They were found mainly on the blower wheel fan blades, the ductwork, and cooling coil fans. Our results showed that the presence of species of molds other than Cladosporium in locations other than the blower wheel blades indicated that the AHU condition was not optimal. In a series of three papers, we examined growth and mycotoxin production by Chaetomium globosum (CG). In these studies we showed that CG produces two potent mycotoxins, chaetoglobosin A (Ch-A) and chaetoglobosin C (Ch-C) when grown on building material. We discovered that these toxins break down when exposed to temperatures in excess of 75 degrees C. We also showed that growth and mycotoxin production by CG is favored at a neutral pH. In another study, we showed that mycotoxins can be detected in body fluids and human tissues from patients exposed to mycotoxin producing molds, and we showed which human tissues or fluids were the most likely to give positive results for detection of these compounds. Finally, we showed that the macrocyclic trichothecene mycotoxins (MTM) produced by Stachybotrys chartarum (SC) are detectable in experimental animals soon after exposure and we described the dynamics of MTM tissue loading.

[Fungal contamination of dwelling and public buildings: hygienic aspects]

Dwelling and public buildings underwent comprehensive hygienic studies for fungal contamination. Human allergization associated with fungal contamination within the building envelopes and with the viable fungal spores in the air of enclosed spaces was found to be prevalent. The leading factors determining the extent to which the internal environment of premises was exposed to fungal contamination: their increased air humidity due to leakages and inlets, the affected area of building envelopes, and a temperature factor were revealed. The criteria showing it necessary to undertake specific measures to optimize the living conditions of the population were defined.

Respiratory inflammatory responses among occupants of a water-damaged office building

The National Institute for Occupational Safety and Health (NIOSH) received a request for evaluation of a water-damaged office building which housed approximately 1300 employees. Workers reported respiratory conditions that they perceived to be building related. We hypothesized that these symptoms were associated with airways inflammation. To test this hypothesis, we assessed airways inflammation in employees using exhaled breath condensate (EBC) and the fraction of exhaled nitric oxide (FENO). In September 2001, a health questionnaire was offered to all employees. Based on this questionnaire, NIOSH invited 356 symptomatic and asymptomatic employees to participate in a medical survey. In June 2002, these employees were offered questionnaire, spirometry, methacholine challenge test, allergen skin prick testing, EBC and FENO. FENO or EBC were completed by 239 participants. As smoking is highly related to the measurements that we used in this study, we included only the 207 current non-smokers in the analyses. EBC interleukin-8 (IL-8) levels, but not nitrite, were significantly higher among workers with respiratory symptoms and in the physician-diagnosed asthmatic group. Of the analyses assessed, EBC IL-8 showed the most significant relationship with a number of symptoms and physician-diagnosed asthma.

PRACTICAL IMPLICATIONS

Implementation of exhaled breath condensate and exhaled nitric oxide in indoor air quality problems.

Symptoms, complaints, ocular and nasal physiological signs in university staff in relation to indoor environment - temperature and gender interactions

Symptoms, signs, perceptions, and objective measures were studied in university buildings. Two problem buildings with a history of dampness and complaints were compared with two control buildings. Health investigations among university staff were performed at the workplace (n = 173) including tear film stability [non-invasive break-up time (NIBUT) and self-reported break-up time (SBUT)], nasal patency (acoustic rhinometry), nasal lavage fluid analysis [NAL: eosinophil cationic protein (ECP), myeloperoxidase (MPO), lysozyme and albumin] and atopy by total serum IgE and IgE antibodies (Phadiatop). Exposure assessment included inspections, thermal and atmospheric climate at 56 points modelled for all work sites. Multiple regressions were applied, controlling for age and gender. Exposure differences between problem buildings and controls were small, and variations between rooms were greater. Workers in the problem buildings had more general and dermal symptoms, but not more objective signs than the others. Adjusted day NIBUT and SBUT increased at higher night air temperatures, with B (95% CI) 0.6 (0.04-1.2) and 1.3 (-0.02 to 2.5), respectively. Higher relative humidity at mean day air temperature <22.1 degrees C was associated with adjusted NIBUT and SBUT, with B (95% CI) 0.16 (0.03-0.29) and 0.37 (-0.01 to 0.75), respectively. Air velocity below recommended winter values and reduced relative humidity in the range of 15-30% were associated with dry air and too low temperature.

PRACTICAL IMPLICATIONS

Thermal climate in university buildings may be associated with both perceptions and physiological signs. Reduced night time air temperature, increased difference in air temperature between day and night, and fast changes in air temperature might impair indoor environment. This may have implication for energy-saving policies. It might be difficult to identify the exposure behind, and find the reason why, some buildings are defined as 'problem buildings'.

Excess dampness and mold growth in homes: an evidence-based review of the aeroirritant effect and its potential causes

Exposure to fungi produces respiratory disease in humans through both allergic and nonallergic mechanisms. Occupants of homes with excess dampness and mold growth often present to allergists with complaints of aeroirritant symptoms. This review describes the major epidemiological and biological studies evaluating the association of indoor dampness and mold growth with upper respiratory tract symptoms. The preponderance of epidemiological data supports a link between exposure to dampness and excess mold growth and the development of aeroirritant symptoms. In addition, biological and clinical studies evaluating potential causal substances for the aeroirritant effect, notably volatile organic compounds (VOCs), are examined in detail. These studies support the role of VOCs in contributing to the aeroirritant symptoms of occupants of damp and mold-contaminated homes.

A simple multiplex polymerase chain reaction assay for the identification of four environmentally relevant fungal contaminants

Historically, identification of filamentous fungal (mold) species has been based on morphological characteristics, both macroscopic and microscopic. These methods may often be time-consuming and inaccurate, necessitating the development of identification protocols that are rapid, sensitive, and precise. The polymerase chain reaction (PCR) has shown great promise in its ability to identify and quantify individual organisms from a mixed culture environment; however, the cost effectiveness of single organism PCR reactions is quickly becoming an issue. Our laboratory has developed a simple method to identify multiple fungal species, Stachybotrys chartarum, Aspergillus versicolor, Penicillium purpurogenum, and Cladosporium spp. by performing multiplex PCR and distinguishing the different reaction products by their mobility during agarose gel electrophoresis. The amplified genes include the beta-Tubulin gene from A. versicolor, the Tri5 gene from S. chartarum, and ribosomal sequences from both P. purpurogenum and Cladosporium spp. This method was found to be both rapid and easy to perform, while maintaining high sensitivity and specificity for characterizing isolates, even from a mixed culture.

[Microbiological quality of indoor air at the School of Building and Environmental Engineering at Białystok University of Technology]

The investigation of microbiological rate of indoor air pollution on Faculty of Building and Environmental Engineering at Białystok University of Technology were made by sedimentation method in accordance with Polish standards (PN-89/Z-04111/01,02,03). Six series of measurements were carried out from autumn 2002 to spring 2003. The results show bad microbiological quality of indoor air on Faculty of Building and Environmental Engineering at Białystok University of Technology. It was found that the number of Staphylococcus, Actinomycetales as well as the total count of bacteria were too high and broke the Polish regulations of the clear air. Because of the students' and other workers' safety, monitoring of microbiological pollution of the indoor air must be done and existing emergency to improve the quality of the air must be lead.

Protein translation inhibition by Stachybotrys chartarum conidia with and without the mycotoxin containing polysaccharide matrix

Recent studies have correlated the presence of Stachybotrys chartarum in structures with SBS. S. chartarum produces mycotoxins that are thought to produce some of the symptoms reported in sick-building syndrome (SBS). The conidia (spores) produced by Stachybotrys species are not commonly found in the air of buildings that have been found to contain significant interior growth of this organism. This could be due in part to the large size of the Stachybotrys spores, or the organism growing in hidden areas such as wall cavities. However, individuals in buildings with significant Stachybotrys growth frequently display symptoms that may be attributed to exposure to the organism's mycotoxins. In addition, Stachybotrys colonies produce a "slime" or polysaccharide (carbohydrate) matrix that coats the hyphae and the spores. The intent of this project was to determine whether the carbohydrate matrix and the mycotoxins embedded in it could be removed from the spores by repeated washings with either aqueous or organic solvents. The results demonstrated that the process of spore washing removed compounds that were toxic in a protein translation assay as compared to spores that were washed with an organic solution, however a correlation between carbohydrate removal during the washing process and the removal of mycotoxins from the spore surface was not observed. These data demonstrated that mycotoxins are not likely to be found exclusively in the carbohydrate matrix of the spores. Therefore, mycotoxin removal from the spore surface can occur without significant loss of polysaccharide. We also showed that toxic substances may be removed from the spore surface with an aqueous solution. These results suggest that satratoxins are soluble in aqueous solutions without being bound to water-soluble moieties, such as the carbohydrate slime matrix.

Evaluation and a Predictive Model of Airborne Fungal Concentrations in School Classrooms

Exposure to airborne fungal products may be associated with health effects ranging from non-specific irritation of the respiratory tract or mucus membranes to inflammation provoked by specific fungal antigens. While concentrations of airborne fungi are frequently measured in indoor air quality investigations, the significance of these measurements in the absence of visual mold colonization is unclear. This study was undertaken to evaluate concentrations of airborne fungal concentrations in school classrooms within a defined geographic location in British Columbia, Canada, and to build a model to clarify determinants of airborne fungal concentration. All elementary schools within one school district participated in the study. Classrooms examined varied by age, construction and presence or absence of mechanical ventilation. Airborne fungal propagules were collected inside classrooms and outdoors. Variables describing characteristics of the environment, buildings and occupants were measured and used to construct a predictive model of fungal concentration. The classrooms studied were not visibly contaminated by fungal growth. The data were evaluated using available guidelines. However, the published guidelines did not take into account significant aspects of the local environment. For example, there was a statistically significant effect of season on the fungal concentrations and on the proportional representation of fungal genera. Rooms ventilated by mechanical means had significantly lower geometric mean concentrations than naturally ventilated rooms. Environmental (temperature, outdoor fungal concentration), building (age) and ventilation variables accounted for 58% of the variation in the measured fungal concentrations. A methodology is proposed for the evaluation of airborne fungal concentration data which takes into account local environmental conditions as an aid in the evaluation of fungal bioaerosols in public buildings.

Culturability and toxicity of sick building syndrome-related fungi over time

Two experiments were conducted regarding the culturability and toxicity of fungi located on building materials over time and the efficacy of seven laboratory techniques in recovering culturable fungi from sample swabs. In the first experiment, eight sections of drywall were inoculated with Stachybotrys chartarum and stored at 25 +/- 5 degrees Celsius and 20-60% relative humidity (RH) for up to two years. Another eight sections of ceiling tile were stored at 100% RH for 1 year. Six sections of ceiling tile and 15 swabs were also inoculated with Penicillium chrysogenum and S. chartarum respectively and stored under the same conditions for 8 months and 3.3 years. All materials were tested for culturability at the end of the storage period. S. chartarum-inoculated samples were also tested for toxicity. In the second experiment (replicated twice), S. chartarum and Chaetomium globosum were inoculated onto 84 swabs each. Storage was up to 266 days at 25 +/- 5 degrees Celsius and 20-60% RH. Seven techniques were compared regarding the recovery of culturable fungi from the swabs over different time points. Results for Experiment 1 showed that all samples were culturable after the storage period and that the S. chartarum-inoculated drywall samples were toxic. In Experiment 2, all techniques showed high rates of recovery. These data show that despite being without a water source, these organisms can be culturable and toxic after long periods of time under conditions similar to human-occupied dwellings and that a number of preparation techniques are suitable for the recovery of these fungi from inoculated swabs.

Microbial contamination of indoor air due to leakages from crawl space: a field study

Mechanical exhaust ventilation system is typical in apartment buildings in Finland. In most buildings the base floor between the first floor apartments and crawl space is not air tight. As the apartments have lower pressure than the crawl space due to ventilation, contaminated air may flow from the crawl space to the apartments. The object of this study was to find out whether a potential air flow from crawl space has an influence on the indoor air quality. The results show that in most cases the concentration of fungal spores was clearly higher in the crawl space than inside the building. The size distribution of fungal spores depended on the fungal species. Correlation between the fungal spores in the crawl space and indoors varied with microbial species. Some species have sources inside the building, which confounds the possible relation between crawl pace and indoor concentrations. Some species, such as Acremonium, do not normally have a source indoors, but its concentration in the crawl space was elevated; our measurements showed also elevated concentrations of Acremonium in the air of the apartments. This consistent finding shows a clear linkage between fungal spores in the indoor air and crawl space. We conclude that a building with a crawl space and pressure difference over the base floor could be a potential risk for indoor air quality in the first floor apartments.

Molds in floor dust and building-related symptoms in adolescent school children

This stratified cross-sectional epidemiological study included 1053 school children aged 13-17 years. All pupils filled in a questionnaire on building-related symptoms and other relevant health aspects. The following exposure measurements were carried out: room temperature, CO2 level, and relative humidity; building characteristics including mold infestation were assessed, and dust was collected from floors, air, and ventilation ducts during a working day. Dust was examined for endotoxin level, and cultivated for viable molds. We did not find a positive association between building-related symptoms and extent of moisture and mold growth in the school buildings. Five of eight building-related symptoms were significantly and positively associated with the concentration of colony forming units of molds in floor dust: eye irritation, throat irritation, headache, concentration problems, and dizziness. After adjusting for different potentially confounding factors in separate analyses of each symptom, the above-mentioned associations between molds in dust and symptoms were still present, except for concentration problems. However, in none of the analyses was mold exposure the strongest covariate, being secondary to either asthma, hay fever, recent airway infection, or psychosocial factors.

Fungicidal properties of Pinus sylvestris L. for improvement of air quality

Sick building syndrome is a term commonly used to describe the consequences of poor indoor air quality. It is well documented that first of all air quality depends on the chemical composition, and until now negligible attention has been paid to air pollution by microorganisms. Some species of fungi (Aspergillus flavus, A. fumigatus, A. niger, A. parasiticus, A. oryzea and other) and their toxins cause difficulty in breathing, allergic rhinitis, watery eyes, headaches, and flu-like symptoms. Over recent years considerable interest has been developed for plant extracts that would be of great use for the improvement of air quality. The biological activity of Pinus sylvestris L. has been investigated in order to find out its fungicidal activity against airborne microorganisms. It was determined, that fungi from Aspergillus and Penicillium genera dominated indoors. Antimicrobial activity of pine oil was evaluated by technique of oil diffusion to Czapek agar (for fungi), malt extract agar (for yeast and yeast-like fungi) and nutrient agar (for bacteria). Minimum inhibitory concentrations of pine oil to 13 species (8 fungi, 2 yeast-like fungi, yeast and 2 bacteria,) were determined: 1.0-2.5, 1.0-1.2, 0.5-0.75, and 0.75-1.2% (v/v), respectively. According to resistance to pine oil action, microorganisms grouped themselves as following: fungi, spore bacteria, yeast-like fungi, yeast, and bacteria (fungi being the most resistive and bacteria being the least resistive). The most active concentration of pine oil against all tested microorganisms was 2.5%, and the most sensitive fungus to volatiles was Ulocladium oudemansii.

Bioluminescent bioreporter integrated-circuit sensing of microbial volatile organic compounds

A bioluminescent bioreporter for the detection of the microbial volatile organic compound p-cymene was constructed as a model sensor for the detection of metabolic by-products indicative of microbial growth. The bioreporter, designated Pseudomonas putida UT93, contains a Vibrio fischeri luxCDABE gene fused to a p-cymene/p-cumate-inducible promoter derived from the P. putida F1 cym operon. Exposure of strain UT93 to 0.02-850 ppm p-cymene produced self-generated bioluminescence in less than 1.5 h. Signals in response to specific volatile organic compounds (VOCs) such as m- and p-xylene and styrene, also occurred, but at two-fold lower bioluminescent levels. The bioreporter was interfaced with an integrated-circuit microluminometer to create a miniaturized hybrid sensor for remote monitoring of p-cymene signatures. This bioluminescent bioreporter integrated-circuit device was capable of detecting fungal presence within approximately 3.5 h of initial exposure to a culture of p-cymene-producing Penicillium roqueforti.

Dustborne fungi in large office buildings

Fungi are ubiquitous in our daily environments. However, their effects on office workers' health are of great interest to many environmental health researchers. Dust has been considered an important reservoir of indoor fungi from which aerosolization and exposure could occur. We have examined the characteristics of dustborne fungal populations recovered from floors and chairs in office buildings. We investigated twenty-one offices in four office buildings in Boston, MA over a year beginning May 1997. We conducted intensive environmental sampling every six weeks to measure culturable dustborne fungi from floors and chairs, surface dust levels and water activity in carpeting. Carbon dioxide, temperature, and relative humidity were monitored continuously. Concentrations of total dustborne fungi recovered from floors were positively related to carbon dioxide (beta = 0.00064; p-value = 0.0002) and temperatures between 20 and 22.5 degrees C (p-value = 0.0026). Also, total fungal concentrations in floors gradually increased over the year (p-value = 0.0028). Total fungi recovered from chairs varied significantly by season (p-value < 0.0001), highest in September and lowest in March, and were positively correlated with dust loads in floors (beta = 0.25; p-value < 0.0001). We used principal component analysis (PCA) to reduce various observed fungal species to fewer factors. Six groups (PCA factors) were obtained for dustborne fungi recovered from both floors and chairs. The models of the first PCA factors for both floors and chairs were similar to those for total fungal concentrations. The results of this study provide essential information to further evaluate the effects of dustborne fungi on office workers' health.

The sick building syndrome: what is it when it is?

Sick building syndrome is a commonly applied diagnosis; often abused and misinterpreted to denote headaches, dizziness, fatigue and eye irritation associated with a building.

The presence of fungi associated with sick building syndrome in North American zoological institutions

A total of 110 sites from five zoological institutions were examined to determine whether fungi associated with sick building syndrome (SBS) were prevalent in the exhibits or night-time holding facilities and to investigate whether the presence of these organisms was associated with declining breeding rates or increases in morbidity and mortality (or both). Each site was sampled with an Andersen two-stage air sampler using Sabourauds dextrose agar media and a Burkard personal volumetric air sampler. Suspect surfaces were also sampled. High levels of airborne Penicillium chrysogenum, a fungal species associated with poor indoor air quality, were recovered from 16 sites out of all five institutions. Five culturable growth sites of Stachybotrys chartarum, a species strongly associated with SBS and commonly known as "black mold," were recovered from surfaces at two institutions. A wide range of other fungal species was recovered in low numbers from all institutions. A Fisher exact test analysis showed a significant nonrandom association between high levels of P. chrysogenum and sites with records of poor animal health. This study indicated that significant numbers of airborne fungi associated with SBS and poor indoor air quality are present in zoological institutions and that they could affect animal health and reproduction rates and zoo staff.

Studies of sick building syndrome. IV. Mycotoxicosis

There has been increasing public attention to the potential health risks of mold exposure, particularly in wet buildings. A variety of molds has been isolated from both damaged homes and businesses, including agents that secrete toxigenic materials. One area that is attracting particular notice is the relative toxigenic potential of mycotoxins. Although exposure to molds can produce significant mucosal irritation, there are very few data to suggest long-term ill effects. More importantly, there is no evidence in humans that mold exposure leads to nonmucosal pathology. In fact, many of the data on toxigenic molds are derived from animal toxicity studies, and these are based primarily, on ingestion. Although every attempt should be made to improve the quality of indoor air, including avoidance of molds, the human illnesses attributed to fungal exposure are, with the exception of invasive infections and mold allergy, relatively rare. In this review we discuss selected aspects of the microbiology of mycotoxin-producing molds and their potential role in human immunopathology with respect to wet building environments.

[Fungal allergy. Part I]

Fungal spores are one of the main groups of allergens. They are present in our environment all year long. The concentration of the spores in July and August is 100-1000 higher than pollens. In contrast with the pollens there is a correlation between the spore count and higher risk of medication use, nocturnal asthma attacks, and hospitalization rates. We have presented the clinical classification of fungi, and characterized main indoor and outdoor allergens. The fungi play also an important role in the sick building syndrome. Fungal allergens are not only aeroallergens, they may also get into our body with food. They may also develop contact reactions. Antibiotic allergy is regarded as one of the classic allergic reactions caused by fungi. The id reactions are caused by the fungi from far infection focuses.

Survey of the Asp f 1 allergen in office environments

Sick Building Syndrome remains a prevalent problem with patient complaints similar to typical allergy symptoms. Unlike household allergens typically found in domestic reservoirs, the allergen from a common fungus like Aspergillus fumigatus (i.e., Asp f 1) is conceivably widespread in the work environment. This project surveyed airborne levels of the Asp f 1 allergen in office and non-industrial occupational environments, as well as the dust reservoirs of A. fumigatus believed to be responsible for those levels. Airborne and bulk dust samples were collected, extracted, and assayed for Asp f 1. Concurrently, bulk dusts collected from the same locations were selectively cultured for A. fumigatus, and mesophilic fungi and bacteria. Samples were collected during both wet and dry climatological conditions from paired wet and dry building locations to examine the possibility of Asp f 1 increases due to fungal growth blooms. Very low levels of Asp f 1 were detected but only in the airborne samples (2/120 positive samples, with 3.6 ng/m3 and 1.8 ng/m3; LOD < 1.2 ng/m3). No dust samples showed even detectable traces of the allergen (LOD = 5 ng/g dust). Although A. fumigatus counts from dusts fluctuated significantly with exterior moisture events, analysis of wet versus dry period samples showed no differences in Asp f 1 levels. These results indicate that even in the presence of measurable fungal concentrations, background levels of Asp f 1 are low. Nonindustrial office buildings devoid of indoor air quality issues were not observed to have significant levels of the Asp f 1 allergen in the geographical region studied.

Serum IgE specific to indoor moulds, measured by basophil histamine release, is associated with building-related symptoms in damp buildings

OBJECTIVE

To study the relationship between basophil histamine release (HRT) to indoor moulds, indicating specific IgE, and building-related symptoms (BRS), asthma, and hay fever in individuals working in damp and mouldy buildings.

METHODS

A cross-sectional study was performed among 86 school staff members, who on average had worked 143 months (range: 3-396) in moist buildings with mould growth in the constructions. A questionnaire concerning mucous membrane symptoms, facial skin symptoms, central nervous system symptoms, hay fever, and asthma was fulfilled by the participants, and blood samples were taken. Eight mould species growing on building constructions were identified and cultivated to obtain allergenic materials for testing. The presence in serum of IgE specific to moulds was verified by histamine release test (HRT) based on passive sensitization of basophil leukocytes. The validity of the method was confirmed by parallel testing of patients allergic to grass- and birch pollen and by the shift from positive to negative response after removal of serum IgE and by using sham sensitization.

RESULTS

The prevalence of most BRS was between 32% and 62%. Positive HRT, showing serum IgE specific to one or more of the moulds, was observed in 37% of the individuals. The highest frequency of positive HRT was found to Penicillium chrysogenum and then to Aspergillus species, Cladosporium sphaerospermum and Stachybotrys chartarum. A significant association was found between most BRS and positive HRT, whereas no association was observed between positive HRT to moulds and self reported hay fever or asthma.

CONCLUSION

Positive HRT to indoor moulds, showing the presence in serum of IgE specific to the fungi, was found to be related to BRS in individuals working in damp and mouldy buildings. Whether the association is of causal character is a question for further studies. The test may be useful in the evaluation and study of possible mould induced BRS.

Moulds, moisture and microbial contamination of First Nations housing in British Columbia, Canada

This paper reviews the difficulties experienced with mould growth in First Nations homes in British Columbia and to describe the team approach used in dealing with this problem. Humid, damp conditions promote the growth of bacteria, moulds, and dust mites. These organisms contribute to poor air quality and causes serious health problems. There is increasing evidence indicating an association between mould, particularly toxigenic moulds, and some diseases, notably asthma. These health problems usually improve when families are relocated to more suitable accommodation. Those particularly at risk include atopic, immunocompromised, very young and elderly individuals and those with chronic health conditions. Our experience suggests that substandard housing is a major contributor to poor health in First Nations communities.

Allergic respiratory disease and fungal remediation in a building in a subtropical climate

An outbreak of allergic respiratory disease occurred in a new building that was characterized from initial occupancy by the presence of extensive visible mold (especially Aspergillus versicolor) on interior surfaces. Epidemiological study of the occupants of both the affected building and a comparison neighboring structure indicated high rates of respiratory and other symptoms among persons working in the affected building. Subsequent clinical evaluations of some persons occupying the building for up to five years identified several cases of building-related allergic respiratory disease, including asthma and hypersensitivity pneumonitis. Based on these findings, the building was evacuated before remediation began. The mycological goal of the three-year building restoration project was to reduce concentration of non-phylloplane fungi such as A. versicolor to the lowest feasible level. All visibly colonized materials in the building were discarded and all fine dust on interior surfaces was removed by vacuuming and/or damp wiping. A medical surveillance program utilizing serial self-reported questionnaires and readily available clinical evaluations was designed to monitor the health of building occupants after re-entry. Symptom rates just prior to building reentry were substantially lower than those found before evacuation and have remained unchanged after re-occupancy was completed. No new or recrudescent cases of illness are known to have occurred after building re-entry.

[Microbiological threat from buildings and rooms and its influence on human health (sick building syndrome)]

In buildings we can observe many different strains of bacteria, over 400 species of mould fungi, many strains of fungus causing the rotting of wood and wood like materials, many species of algae, aphids, and other types of growths and seed plants and also over 30 types of mites especially those seen in house dust. Buildings, especially their interiors have a very specific microclimate. Within it areas of so called ecological lows are formed in which conditions for settlement, growth and reproduction of these organisms take place. A building, which is a hazard to the health of its residents, is called a "sick building" from the term "sick building syndrome". The incidence and development of some types of mould fungus is associated with the production of very toxic metabolites which are called secondary metabolites i.e. mycotoxins. Long term human, especially in relation to children, contact with the species producing the most potent mycotoxins like aflatoxin--Apergillus flavus, ochratoxins--Aspergillus ochraceus, rubratoxins--Penicillium rubrum or strachybotrytoxins--Strachybotrys chartarum may even be the cause of death. Mould fungus or just mould is a saprophytic fungus derived from many different systemic groups (Mucor, Aspergillus, Penicillium, Fusarinum). Fungi can produce lethal mycotoxins such as: alternariol, aflatoxins, gliotoxins, ochratoxins, nivalenol, cytinine, dicumarol, rugulosine, trichoviridine and about 200 more which considering their mutagenicity are potentially dangerous to humans, animals, flora and microorganisms. Research which was begun by Prof. Julian Aleksandrowicz and Prof. Bolesław Smyk in 1970 and 1971 showed that the so called "leukaemia houses" of leukaemia victims had an abundance of toxinogenic fungus in them, particularly the most potent fungus which turned out to be Aspergillus flavus. Toxinogenic funguses are abundant in many living spaces and cellars in older and also in new housing. Mycotoxins have been shown to be very toxic and harmful and it is no wonder that many inhabitants of these living spaces are constantly ill, mainly upper respiratory tract infections, lethargy, constant headaches, nausea and a general ill feeling. Inhabiting these living spaces for a considerable period may lead to cancer.

Microbiology on indoor air '99--what is new and interesting? An overview of selected papers presented in Edinburgh, August, 1999

A multidisciplinary approach to microbiological implications of indoor air is fruitful for research as well as management of health and building problems. The Finnish and the Danish mold programs are examples of such productive collaborative studies. Dust samples taken from classrooms in schools where occupants complain of building-related symptoms (BRS) demonstrated an inflammatory potential in vitro, measured as a release of cytokine interleukin (IL)-8. An increase of the metabolite NO and liberation of tumor necrosis factor (TNF)-alpha and other cytokines during exposure were obtained in vivo, was presented based on these programs and on epidemiological studies on residential fungal contamination and health conducted in Canada and The Netherlands. New methods for assessing fungal exposure are PCA analysis for the toxigenic mold Stachybotrys chartarum and EPS-Asp/Pen for detecting of Aspergillus and Penicillium in dust. Based on a limited data set it is shown that emission rates of fungal spores are inversely proportional to relative humidity (RH), directly related to flow rate and to surface loading. Poor maintenance, risk constructions and risk materials are described in several studies as the main causes of water damage in buildings.

Identification of Trichoderma strains from building materials by ITS1 ribotyping, UP-PCR fingerprinting and UP-PCR cross hybridization

To study the role of Trichoderma in sick building syndrome, it is essential to be able to accurately identify species. Forty-four strains of Trichoderma spp. isolated from Danish buildings damaged by water leaks were identified using ITS1 ribotyping and universally primed PCR, UP-PCR. Ribotyping allowed the assignment of the strains into three distinct groups. High similarity of UP-PCR banding profiles of the strains allowed species designation for almost all strains (43 out of 44) when compared with the UP-PCR banding profiles obtained from reference strains of T. atroviride, T. citrinoviride, T. harzianum, T. longibrachiatum and T. viride. However, cross hybridization of UP-PCR products showed that the latter strain had high DNA homology to the ex-type strain of T. hamatum. The combined approach is a convenient way for reliable identification of Trichoderma strains.

Sick building syndrome. III. Stachybotrys chartarum

Increasingly, physicians are being asked to evaluate patients with putative environmentally associated illnesses. These can include a variety of problems, including infectious illnesses (Legionnaire's disease), chemical exposure in the workplace, and sick building syndromes. The latter has been an issue particularly in asthma because of the association of mold and increased bronchial responsiveness. Recently, attention has been focused on the mold Stachybotrys in human disease. Stachybotrys was first identified more than 60 years ago following an epidemic of stomatitis, rhinitis, conjunctivitis, pancytopenia, neurologic disorders, and death in horses. Since then, Stachybotrys has been identified in several outbreaks of disease in animals. It has also attracted attention as a possible agent in idiopathic pulmonary hemorrhage in infants. Stachybotrys is a relatively uncommon fungus but has been isolated from a variety of sources, including contaminated grains, tobacco, indoor air, insulator foams, and water-damaged buildings with high humidity. This fungus is particularly important because it is one of a series of fungi that produces trichothecenes mycotoxins; these mycotoxins are biologically active and can produce a variety of physiological and pathologic changes in humans and animals, including modulation of inflammation and altered alveolar surfactant phospholipid concentrations. The presence of Stachybotrys in a building does not necessarily imply a cause-and-effect relationship with illness, but should alert physicians and healthcare professionals to do more vigorous environmental testing. Guidelines are presented herein for intervention measures in the maintenance of heating, ventilation, and air-conditioning systems.

Continually measured fungal profiles in sick building syndrome

Buildings with indoor air quality (IAQ) complaints frequently have high airborne concentrations of Penicillium species, while buildings with few IAQ complaints have an indoor air (IDA) fungal ecology similar to outdoor air (ODA), where Cladosporium species is usually the dominant microorganism. These studies compared fungal air profiles, measured continually over 6 h in a documented sick building, in IDA in a room experiencing IAQ problems with fungal profiles measured concurrently in ODA. The dominant species collected at both sites were Penicillium species, Cladosporium species, and Alternaria species. In the IDA, Penicillium species were always the dominant organisms, ranging from 150 to 567 cfu/m3 (89.8-100% of the total fungi). In the ODA, Cladosporium species were dominant in four samples (40.0-70.6%), while Penicillium species were dominant (52.7-79.6%) in two. These data demonstrate that, even though ODA fungal profiles are changing continuously, IDA fungal profiles in "sick" buildings tend to remain unchanged.