Building-related symptoms among U.S. office workers and risks factors for moisture and contamination: Preliminary analyses of U.S. EPA BASE Data

Abstract

Background: 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.Methods: Analyses assessed associations between three types of weekly, workrelated 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.Results: A number of risk factors were associated (e.g., 95% confidence limits excluded 1.0) significantly 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 none (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, evaluated by inspection, 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 nonsignificant increase in lower respiratory symptoms Conclusions: These preliminary findings suggest that some factors that indicate risks for moisture or contamination in office buildings may have adverse effects on respiratory or neurologic health of office workers. More refined analyses are underway that will include these risk factors in simultaneous multivariate models along with additional risk factors that may be confounders, such as ventilation rate and indoor temperature. Future analyses will also use more refined metrics for both health outcomes and environmental risks, as well as assess risk in susceptible sub-groups.

Summary of human responses to ventilation

“…from 80 complaint office buildings, controlling for many more confounders, and only debris in the outdoor air intake and poor drainage in cooling drain pans remained significant predictors of symptoms. A similar analysis, but in 100 non‐complaint office buildings (Mendell & Cozen 2003b), found that less frequent air‐handler inspection was associated with increased symptoms; however, dirty cooling coils, dirty drain pans with poor drainage, and standing water near outdoor intakes were not associated with significant increases in symptoms.…”

Mold exposure and respiratory health in damp indoor environments

“…In a nationwide study of 100 buildings not known to have indoor air quality complaints, current water damage was documented in 43% (11). Although the prevalence of indoor dampness is variable depending on the country, continent, and climate zone, the World Health Organization (WHO) estimated that from 10% to 50% of indoor environments are affected by damp conditions in Europe, North America, Australia, India, and Japan (12).…”