Ju-Hyeong Park

Hydrophilic Fungi and Ergosterol Associated with Respiratory Illness in a Water-Damaged Building

Background Damp building–related respiratory illnesses are an important public health issue. Objective We compared three respiratory case groups defined by questionnaire responses [200 respiratory cases, 123 of the respiratory cases who met the epidemiologic asthma definition, and 49 of the epidemiologic asthma cases who had current physician-diagnosed asthma with post-occupancy onset] to a comparison group of 152 asymptomatic employees in an office building with a history of water damage. Methods We analyzed dust samples collected from floors and chairs of 323 cases and comparisons for culturable fungi, ergosterol, endotoxin, and cat and dog allergens. We examined associations of total fungi, hydrophilic fungi (requiring water activity ≥ 0.9), and ergosterol with the health outcomes using logistic regression models. Results In models adjusted for demographics, respiratory illnesses showed significant linear exposure–response relationships to total culturable fungi [interquartile range odds ratios (IQR-OR) = 1.37–1.72], hydrophilic fungi (IQR-OR = 1.45–2.19), and ergosterol (IQR-OR = 1.54–1.60) in floor and chair dusts. Of three outcomes analyzed, current asthma with postoccupancy physician diagnosis was most strongly associated with exposure to hydrophilic fungi in models adjusted for ergosterol, endotoxin, and demographics (IQR-OR = 2.09 for floor and 1.79 for chair dusts). Ergosterol levels in floor dust were significantly associated with epidemiologic asthma independent of culturable fungi (IQR-OR = 1.54–1.55). Conclusions Our findings extend the 2004 conclusions of the Institute of Medicine [Human health effects associated with damp indoor environments. In: Damp Indoor Spaces and Health. Washington DC:National Academies Press, 183–269] by showing that mold levels in dust were associated with new-onset asthma in this damp indoor environment. Hydrophilic fungi and ergosterol as measures of fungal biomass may have promise as markers of risk of building-related respiratory diseases in damp indoor environments.

Asthma and respiratory symptoms in hospital workers related to dampness and biological contaminants.

UNLABELLED The National Institute for Occupational Safety and Health investigated respiratory symptoms and asthma in relation to damp indoor environments in employees of two hospitals. A cluster of six work-related asthma cases from one hospital department, whose symptoms arose during a time of significant water incursions, led us to conduct a survey of respiratory health in 1171/1834 employees working in the sentinel cases hospital and a nearby hospital without known indoor environmental concerns. We carried out observational assessment of dampness, air, chair, and floor dust sampling for biological contaminants, and investigation of exposure-response associations for about 500 participants. Many participants with post-hire onset asthma reported diagnosis dates in a period of water incursions and renovations. Post-hire asthma and work-related lower respiratory symptoms were positively associated with the dampness score. Work-related lower respiratory symptoms showed monotonically increasing odds ratios with ergosterol, a marker of fungal biomass. Other fungal and bacterial indices, particle counts, cat allergen and latex allergen were associated with respiratory symptoms. Our data imply new-onset of asthma in relation to water damage, and indicate that work-related respiratory symptoms in hospital workers may be associated with diverse biological contaminants. PRACTICAL IMPLICATIONS In healthcare facilities with indoor dampness and microbial contamination, possible associations between such conditions and respiratory health effects should be considered. Good building maintenance and housekeeping procedures should lead to improvements in employee respiratory health.

Identification of Mold and Dampness-Associated Respiratory Morbidity in 2 Schools: Comparison of Questionnaire Survey Responses to National Data

BACKGROUND Dampness and mold problems are frequently encountered in schools. Approximately one third of US public schools require extensive repairs or need at least 1 building replaced. This study illustrates how national data can be used to identify building-related health risks in school employees and students. METHODS School employees (n = 309) in 2 elementary schools (schools A and B) with dampness and mold problems completed standardized questionnaires. Responses were compared with participant responses from the 3rd National Health and Nutrition Examination Survey and were indirectly standardized for gender, age, smoking status, and (for school B) race. Uncontrolled comparisons were made to responses from a study of office workers, as well as between responses from school employees in different sections of the school buildings designated by decade of construction. RESULTS Employees from both schools had excess work-related throat and lower respiratory symptoms, as well as eye, nasal, sinus, and wheezing symptoms. School B employees also had excess physician-diagnosed asthma and work-related fatigue, headache, and skin irritation. Employees in sections of the school buildings that were categorized as having greater dampness and mold contamination had more frequent upper and lower respiratory symptoms than employees working in other building sections. CONCLUSIONS This noncostly type of analysis of indoor air quality complaints can be used to motivate and prioritize building remediation in public schools where funds for building remediation are usually limited.

Lack of respiratory improvement following remediation of a water‐damaged office building

BACKGROUND Damp buildings are commonly remediated without removing employees or ongoing medical surveillance. METHODS We examined paired pulmonary function and questionnaire data from 2002 and 2005 for 97 employees in a water-damaged building during ongoing but incomplete remediation. RESULTS We observed no overall improvement in respiratory health, as reflected in symptom scores, overall medication use, spirometry abnormalities, or sick leave. Four employees went from borderline bronchial hyperresponsiveness to bronchial hyperresponsiveness; six developed abnormal spirometry; three more reported post-occupancy current asthma, and four hypersensitivity pneumonitis. The number of participants without lower respiratory symptoms decreased from 27 in 2002 to 20 in 2005. Respiratory cases relocated in the building had a decrease in medication use and sick leave in 2005. CONCLUSIONS During dampness remediation, relocation may be health protective and prevent incident building-related respiratory cases. Without relocation of entire workforces, medical surveillance is advisable for secondary prevention of existing building-related disease.

Respiratory morbidity and medical visits associated with dampness and air-conditioning in offices and homes.

UNLABELLED We used data from 4345 adult US residents who were part of a 2004 national random mail survey to investigate associations between dampness and air-conditioning (AC) in homes and offices, and health outcomes, sick leave due to respiratory symptoms and medical visits during the past 12 months. We identified from this group 1396 office workers employed in professional, executive, administrative, managerial or administrative support occupations. Office workers reporting home dampness had an elevated prevalence of nasal symptoms [prevalence ratio (PR) = 1.4, P = 0.01] and constitutional symptoms (PR = 1.3, P = 0.01) in the previous year. Office workers reporting workplace dampness had an elevated prevalence of sick leave attributed to respiratory symptoms (PR = 1.3, P = 0.04) in the previous year. Office workers with home AC were more likely to have visited a medical specialist in the previous year (PR = 1.3, P = 0.02). We did not find any statistically significant associations between workplace AC and any of the health outcomes. We estimated an annual cost of US

Comparison of DNA extraction methodologies used for assessing fungal diversity via ITS sequencing

1.4 billion for excess respiratory-related sick leave among office workers with workplace dampness. Our study strengthens the evidence of a relationship between dampness and health effects, and highlights the resulting economic impact. PRACTICAL IMPLICATIONS This study adds to the literature on respiratory morbidity associated with home and office exposures to mold and dampness. Public health response to lessen these exposures will improve the health and well-being of residents and workers as well as diminish the economic burden of lost work time and medical costs.

Markers of upper airway inflammation associated with microbial exposure and symptoms in occupants of a water‐damaged building

Traditional methods of assessing fungal exposure have been confounded by a number of limiting variables. The recent utilization of molecular methods such as internal transcribed spacer (ITS) sequencing of ribosomal RNA genes has provided improved insight into the diversity of fungal bioaerosols in indoor, outdoor and occupational environments. However, ITS analyses may also be confounded by a number of methodological limitations. In this study, we have optimized this technology for use in occupational or environmental studies. Three commonly used DNA extraction methodologies (UltraClean Soil kit, High Pure PCR Template kit, and EluQuik/DNeasy kit) were compared in terms of sensitivity and susceptibility to PCR inhibitors in dust for three common fungal bioaerosols, Aspergillus versicolor, Rhizopus microsporus and Wallemia sebi. Environmental dust samples were then studied using each extraction methodology and results were compared to viable culture data. The extraction methods differed in terms of their ability to efficiently extract DNA from particular species of fungi (e.g. Aspergillus versicolor). In addition, the ability to remove PCR inhibitors from dust samples was most effective using the soil DNA extraction kit. The species composition varied greatly between ITS clone libraries generated with the different DNA extraction kits. However, compared to viable culture data, ITS clone libraries included additional fungal species that are incapable of growth on solid culture medium. Collectively, our data indicated that DNA extraction methodologies used in ITS sequencing studies of occupational or environmental dust samples can greatly influence the fungal species that are detected.

Assessment of fungal diversity in a water-damaged office building

BACKGROUND Water damage in buildings has been associated with reports of upper airway inflammation among occupants. METHODS This survey included a questionnaire, allergen skin testing, nasal nitric oxide, and nasal lavage on 153 participants. We conducted exposure assessments of 297 workstations and analyzed collected dust for fungi, endotoxin, and (1 → 3)-β-D-glucan to create floor-specific averages. RESULTS Males had higher levels of nasal inflammatory markers, and females reported more symptoms. ECP, IL-8, and MPO were significantly associated with nasal symptoms, flu-like achiness, or chills. Fungi and glucan were positively associated with blowing out thick mucus. Endotoxin was significantly associated with ECP in overall models, and with ECP, IL-8, MPO, and neutrophils among non-atopic females. CONCLUSIONS In this study, we documented an association between endotoxin and nasal inflammatory markers among office workers. The results of our study suggest that a non-allergic response may contribute to symptoms occurring among occupants in this water-damaged building.

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

ABSTRACT Recent studies have described fungal communities in indoor environments using gene sequencing-based approaches. In this study, dust-borne fungal communities were elucidated from a water-damaged office building located in the northeastern region of the United States using internal transcribed spacer (ITS) rRNA gene sequencing. Genomic DNA was extracted from 5 mg of floor dust derived from 22 samples collected from either the lower floors (n = 8) or a top floor (n = 14) of the office building. ITS gene sequencing resolved a total of 933 ITS sequences and was clustered into 216 fungal operational taxonomic units (OTUs). Analysis of fungal OTUs at the 97% similarity threshold showed a difference between the lower and top floors that was marginally significant (p = 0.049). Species richness and diversity indices were reduced in the lower floor samples compared to the top floor samples and there was a high degree of compositional dissimilarity within and between the two different areas within the building. Fungal OTUs were placed in the phyla Ascomycota (55%), Basidiomycota (41%), Zygomycota (3%), Glomeromycota (0.4%), Chytridiomycota (0.3%), and unassigned fungi (0.5%). The Ascomycota classes with the highest relative abundances included the Dothideomycetes (30%) and Eurotiomycetes (16%). The Basidiomycota consisted of the classes Ustilaginomycetes (14%), Tremellomycetes (11%), and Agaricomycetes (8%). Sequence reads derived from the plant pathogen Ustilago syntherismae were the most abundant in the analysis as were obligate Basidiomycota yeast species that accounted for 12% and 11% of fungal ITS sequences, respectively. ITS gene sequencing provides additional insight into the diversity of fungal OTUs. These data further highlight the contribution of fungi placed in the phylum Basidiomycota, obligate yeasts, as well as xerophilic species that are typically not resolved using traditional culture methods.

Pulmonary inflammation induced by office dust and the relation to 1 → 3-β-glucan using different extraction techniques

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.