Hypothesis-based research on the causes of sick building symptoms: A design for Phases 2 and 3 of the California Healthy Building Study

Phase 2 of the California Healthy Building Study: A status report

“…After listing each hypothesis, we provide background information justifying the hypothesis, describe the Phase 2 activities, and then summarize the findings to date. A document describing the designs of Phase-2 and a potential Phase 3 of the CHBS (Fisk, et al, 1992) provides more detailed information on the procedures employed.…”

“…During the period of Phase-2 data collection, research activities were completed on a subset of the set of hypotheses discussed in Fisk, et al (1992). Consequently, this document only discusses research activities connected to hypotheses 1,2,8, and 9.…”

“…The 27 air handling units serving the study spaces within the twelve buildings were inspected using the protocol and inspection forms described in Appendices 2 and 3 of Fisk, et al (1992). During the inspections, the presence or lack of internal duct liner was noted on the inspection forms and the surface area of duct liner was estimated when possible.…”

“…A sample of each type of duct liner, approximately 10 cm by 10 cm in area, was collected, placed in a sealed container, and stored in a freezer. Plans for subsequent analyses of VOC emissions from these samples are described in Fisk, et al 1992. The building operators were asked about the presence of fiberglass-lined duct and fiberglass duct in the building.…”

“…The 27 air handling units serving the study spaces within the twelve buildings were inspected using the protocol and inspection forms described in Appendices 2 and 3 of Fisk, et al, (1992). The inspectors received training from a microbiologist in the visual identification of microbiological contamination and were instructed to collect samples of suspected fungal or bacterial contamination for analyses in the laboratory.…”