BUILDING-RELATED SYMPTOMS AMONG U.S. OFFICE WORKERS AND RISK FACTORS FOR MOISTURE AND CONTAMINATION

Abstract

Introduction Moisture and other risks for indoor microbiologic growth have been associated with increased prevalence of symptoms in many studies. 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 100 U.S. office buildings in the U.S. EPA BASE study. Methods Analyses assessed associations between three types of buildingrelated symptoms (defined as occurring at least weekly and improving when away from the building)-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. Results A number of risk factors were associated significantly (e.g., 95% confidence limits excluded 1.0) in adjusted models with small to moderate increases in one or more symptom outcomes. Significantly elevated ORs for mucous membrane symptoms were associated with the following risk factors: presence of humidification system in good condition versus no system present (OR = 1.4); air handler inspection annually versus daily (OR = 1.6); current water damage in the building (OR = 1.2); and less than daily vacuuming in study space (OR = 1.2). Significantly elevated ORs for lower respiratory symptoms were associated with: air handler inspection annually versus daily (OR = 2.0); air handler inspection less than daily but at least semi-annually (OR = 1.6); less than daily cleaning of offices (1.7); and less than daily vacuuming of the study space (OR = 1.4). Only two statistically significant risk factors for neurologic symptoms were identified: presence of any humidification system versus none (OR = 1.3); and less than daily vacuuming of the study space (OR = 1.3). Dirty cooling coils, dirty or poorly draining drain pans, and standing water near outdoor air intakes were not identified as risk factors in these analyses, despite predictions based on previous findings elsewhere, except that very dirty cooling coils were associated with a statistically nonsignificant increase (OR = 1.3, 95% confidence interval = 0.9–2.1) in lower respiratory symptoms Conclusions These preliminary findings suggest that some factors indicating risks for moisture or contamination in office buildings may have adverse effects on respiratory or neurologic health of office workers. Expanded analyses are underway that will include in multivariate models additional potential confounders and risk factors, such as ventilation rate and indoor temperature. Future analyses will also assess risk in susceptible sub-groups such as previously diagnosed asthmatics.