Leah Mickelson

Project title: Comparison of Fungal Exposure Methods, Using Ergosterol Concentrations, Viable and Non-viable Fungal Spore Counts and Questionnaire Based Exposure Assessments, As Used in the Seattle Healthy Homes Projects

Degree: MS | Program: Industrial Hygiene & Safety (IH&S) | Project type: Thesis/Dissertation
Completed in: 2003 | Faculty advisor: Timothy K. Takaro


The purpose of this study was to evaluate sampling and analysis methods for ergosterol (an indicator of the biomass of fungi), viable fungi, and non-viable fungi from settled dust and to compare these results with questionnaire data used to assess exposure to mold and dampness in the home. Study subjects were enrolled in the Public Health Seattle-King County Healthy Homes II Project (HH-II), an on-going community-based randomized controlled trial, focused on reducing exposures to indoor asthma triggers in the homes of low-income families with asthmatic choldren (Krieger 2000). Viable and non-viable fungal analyses were completed on the floor dust in addition to ergosterol analysis for comparisons between thee laboratory-based methods. Additional floor dust samples were collected and analyzed to look at the reliability of collecting a single floor dust sample from the subject's bedroom. This project was a quality assurance measure for HH-II.

Specific Aims:
1. Compare the laboratory-based (ergosterol levels, non-viable, and viable fungi spore counts) and observational (questionnaire) method used to assess fungal exposures in Public Health Seattle & King County Healthy Homes Projects.
2. Compare ergosterol with non-viable and viable fungi spore count methods.
3. Determine the level of reliability of floor dust samples collected within a subject's bedroom for the Public Health Seattle-King County Healthy Homes II Project.