Levels of microbial agents in floor dust during remediation of a water-damaged office building

We examined the effects of remediation on loads of culturable fungi in floor dust collected from a large water-damaged office building during four cross-sectional surveys (2002, 2004, 2005, and 2007, respectively). We created a binary remediation variable for each year for each sampled workstation using information on remediation associated with water damage obtained from building management and used generalized linear mixed-effects models. We found significantly lower levels of culturable total and hydrophilic fungi at remediated workstations than at non-remediated workstations in 2004 and 2005 after completion of major remediation. The remediation effect, however, disappeared in 2007. The fraction of hydrophilic to total fungal concentrations was lowest in 2004, increased in 2005, and was highest in 2007. Our results indicate that the 2003 remediation lowered dust indices of dampness temporarily, but remediation was incomplete, consistent with a building assessment report of water infiltration. This study demonstrates the utility of longitudinal evaluation of microbial indices during remediation of water damage in this building, in which elimination of sources of moisture was not fully addressed. Our findings indicate that the fraction of hydrophilic fungi derived from concentrations of fungal species may be a useful index for assessing the long-term effectiveness of remediation. PRACTICAL IMPLICATIONS: This study demonstrates the utility of longitudinal evaluation of microbial indices during remediation of water damage in this building, in which elimination of sources of moisture was incomplete. Our findings indicate that the fraction of hydrophilic fungi derived from concentrations of fungal species may be a useful index for assessing the long-term effectiveness of remediation.     

Rhinosinusitis and mold as risk factors for asthma symptoms in occupants of a water-damaged building

Abstract Mold exposure in damp buildings is associated with both nasal symptoms and asthma development, but the progression of building-related (BR) rhinosinusitis symptoms to asthma is unstudied. We examined the risk of developing BR-asthma symptoms in relation to prior BR-rhinosinusitis symptoms and microbial exposure among occupants of a damp building. We conducted four cross-sectional health and environmental surveys among occupants of a 20-story water-damaged office building. We defined BR-rhinosinusitis symptom (N?=?131) and comparison (N?=?361) groups from participants' first questionnaire responses. We compared the odds for the development of BR-asthma symptoms between these two groups over the subsequent surveys, using logistic regression models adjusted for demographics, smoking, building tenure, and first-survey exposures to fungi, endotoxin, and ergosterol. The BR-rhinosinusitis symptom group had higher odds for developing BR-asthma symptoms [odds ratio (OR)?=?2.2; 95% confidence interval (CI)?=?1.3-3.6] in any subsequent survey compared to those without BR-rhinosinusitis symptoms. The BR-rhinosinusitis symptom group with higher fungal exposure within the building had an OR of 7.4 (95% CI?=?2.8-19.9) for developing BR-asthma symptoms, compared to the lower fungal exposure group without BR-rhinosinusitis symptoms. Our findings suggest that rhinosinusitis associated with occupancy of water-damaged buildings may be a sentinel for increased risk for asthma onset in such buildings. PRACTICAL IMPLICATIONS: Exposure to mold is associated with the development of asthma in damp building occupants, and rhinitis is known to be a risk factor for asthma. However, there is little information about the degree of risk for the progression of rhinosinusitis to asthma owing to mold exposures in damp buildings. Our study of damp building occupants demonstrates that building-related (BR) rhinosinusitis symptoms were a risk factor for the development of BR asthma symptoms and that exposure to mold (fungi) or other dampness-related agents augments risk for the development of BR asthma symptoms among those with BR rhinosinusitis symptoms. Our findings suggest that occurrence of BR upper respiratory illness in water-damaged buildings may presage future endemic asthma.     

Changes of symptoms, tear film stability and eosinophilic cationic protein in nasal lavage fluid after re-exposure to a damp office building with a history of flooding

The aim was to study health effects in office workers (N = 18) in a medical case book archive with dampness caused by flooding. They were first investigated in a building without dampness (exposure free for 10 days). Then all returned to the damp building, and were re-investigated after 2 days. We measured tear film break up time (BUT), nasal patency, biomarkers in nasal lavage (NAL), and dynamic spirometry. Both buildings had low CO(2) (380-600 ppm), low levels of respirable particles (8-10 microg/m(3)), and formaldehyde (5-7 microg/m(3)). The flooded building had slightly higher (149 ng/m(3) vs. 94 ng/m(3)) levels of microbial volatile organic compounds (MVOC). After 2 days of re-exposure, there was an increase of ocular (P < 0.001), nasal (P = 0.002), and throat symptoms (P < 0.001), dyspnea (P = 0.006), headache (P = 0.002), nausea (P = 0.04), and tiredness (P = 0.01). The median BUT decreased from 16 to 8 s (P = 0.003), and eosinophilic cationic protein (ECP) in NAL increased slightly (P = 0.04). A separate test of the weekday effect showed slight improvements, or no change of symptoms and signs from Monday to Wednesday. In conclusion, subjects previously exposed to building dampness had an increase of symptoms, reduced tear film stability, and signs of eosinophilic inflammation in the nasal mucosa after 2 days of re-exposure. PRACTICAL IMPLICATIONS: The study is in agreement with previous cross-sectional studies, suggesting that building dampness may cause mucosal irritation, general symptoms such as headache and tiredness, impaired tear film stability, and eosinophilic inflammation in the airway mucosa. From a preventive point of view, health consequences of water leakage and flooding should not be neglected. The measurements of molds and microbial volatile organic compounds could not identify any obvious exposure contrast between the damp building and the dry control building. This illustrates the limitations of air measurements of microbial exposures in damp buildings.     

Bacteria in a water‐damaged building: associations of actinomycetes and non‐tuberculous mycobacteria with respiratory health in occupants

We examined microbial correlates of health outcomes in building occupants with a sarcoidosis cluster and excess asthma. We offered employees a questionnaire and pulmonary function testing and collected floor dust and liquid/sludge from drain tubing traps of heat pumps that were analyzed for various microbial agents. Forty‐nine percent of participants reported any symptom reflecting possible granulomatous disease (shortness of breath on exertion, flu‐like achiness, or fever and chills) weekly in the last 4 weeks. In multivariate regressions, thermophilic actinomycetes (median = 529 CFU/m²) in dust were associated with FEV₁/FVC [coefficient = ?2.8 per interquartile range change, P = 0.02], percent predicted FEF_25–75% (coefficient = ?12.9, P = 0.01), and any granulomatous disease‐like symptom [odds ratio (OR) = 3.1, 95% confidence interval (CI) = 1.45?6.73]. Mycobacteria (median = 658 CFU/m²) were positively associated with asthma symptoms (OR = 1.5, 95% CI = 0.97?2.43). Composite score (median = 11.5) of total bacteria from heat pumps was negatively associated with asthma (0.8, 0.71?1.00) and positively associated with FEV₁/FVC (coefficient = 0.44, P = 0.095). Endotoxin (median score = 12.0) was negatively associated with two or more granulomatous disease‐like symptoms (OR = 0.8, 95% CI = 0.67?0.98) and asthma (0.8, 0.67?0.96). Fungi or (1→3)‐β‐D‐glucan in dust or heat pump traps was not associated with any health outcomes. Thermophilic actinomycetes and non‐tuberculous mycobacteria may have played a role in the occupants' respiratory outcomes in this water‐damaged building.     

Prevalence and risk factors associated with nonspecific building‐related symptoms in office employees in Japan: relationships between work environment,Indoor Air Quality,and occupational stress

A nationwide cross‐sectional study of 3335 employees was conducted in 320 offices in Japan to estimate the prevalence of building‐related symptoms (BRSs) and determine the risk factors related to work environment, Indoor Air Quality, and occupational stress. Data were collected through self‐administered questionnaires. The prevalences of general symptoms, eye irritation, and upper respiratory symptoms were 14.4%, 12.1%, and 8.9%, respectively. Multiple logistic regression analyses revealed that eye irritation was significantly associated with carpeting [odds ratio (OR), 1.73; 95% confidence interval (CI), 1.24–2.41], coldness perception (OR, 1.28; 95% CI, 1.13–1.45), and air dryness perception (OR, 1.61; 95% CI, 1.42–1.82). General symptoms were significantly associated with unpleasant odors (OR, 1.37; 95% CI, 1.13–1.65), amount of work (OR, 1.24; 95% CI, 1.06–1.45), and interpersonal conflicts (OR, 1.44; 95% CI, 1.23–1.69). Upper respiratory symptoms were significantly associated with crowded workspaces (OR, 1.36; 95% CI, 1.13–1.63), air dryness perception (OR, 2.07; 95% CI, 1.79–2.38), and reported dustiness on the floor (OR, 1.39; 95% CI, 1.16–1.67). Although psychosocial support is important to reduce and control BRSs, maintaining appropriate air‐conditioning and a clean and uncrowded workspace is of equal importance.