We assessed relationships between health symptoms in office workers and risk factors related to moisture and contamination, using data collected from a representative sample of U.S. office buildings in the U.S. EPA BASE study. Analyses assessed associations between three types of weekly, work-related symptoms--lower respiratory, mucous membrane, and neurologic and risk factors for moisture or contamination in these office buildings. Multivariate logistic regression models were used to estimate the strength of associations for these risk factors as odds ratios (ORs) adjusted for personal-level potential confounding variables related to demographics, health, job, and workspace.