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

Abstract

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.

Health hazard evaluation report: HETA-2001-0445-3141, evaluation of respiratory health among employees in a water-damaged office building - Connecticut.

“…This finding was also supported by results from the qualitative analysis of fungal species that the fraction of hydrophilic to total fungal concentrations was lowest in 2004, increased again in 2005 and was highest in 2007 ( Figure 11). The average fungal level in 2007 was ten-fold higher than those in previous surveys (Cho et al 2011). * GMs of microbial agents estimated using regression models for repeated measurements: a random effect of workstation and fixed effects of survey, floor, remediation, and remediation by survey interaction.…”

“…All the workstations on the 19 th and 20 th floors directly underneath the roof were considered "remediated" when the roof was replaced or repaired. We used a linear regression model that accounted for correlation of repeated measurements within the same sampled workstations across the surveys to examine remediation effectiveness on total and hydrophilic levels of culturable fungi, including the fraction of hydrophilic fungi, as well as endotoxin and cat and dog allergens (Cho et al 2011).…”

“…Remediation activities considered in this analysis included work related to eliminating sources of water and replacing damaged building materials. For the repeated measurement analysis, we used more complex regression models to account for a random effect of employees' workstations with environmental samples (Cho et al 2011). …”

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

“…The building has had a long history of water incursion since being built in 1985. The exterior walls, especially around terraces and windows on the upper floors (17)(18)(19), and the roof were the main sources of water leaks. Current tenants first occupied the building in 1994, and, on average, 1240 employees occupied 15 floors.…”

“…Detailed information on respiratory illnesses and environmental changes in relation to remediation of water damage are reported elsewhere. 3,[14][15][16][17] Not all health survey participants had individual exposure measurements. On the basis of the results of the four surveys, we identified 513 occupants who participated in one or more health questionnaire surveys and had individual exposure measurements in one or more environmental surveys ( Figure 1).…”