Abstract

This study uses a health-centered approach to quantify and compare the chronic harm caused by indoor air contaminants using the Disability-Adjusted Life-Year (DALY). The aim is to understand the chronic harm caused by airborne contaminants in office buildings and identify the most harmful. Harm intensities (HI) are a metric of chronic harm per unit of contaminant concentration. Starting with a broad range of 342 organic and inorganic gases and particulate matter, uncertainty is evaluated in the concentrations of 90 indoor air contaminants commonly found in offices. Chronic harm is estimated from the harm intensities and the concentrations. The most harmful contaminants in offices are fine particulate matter (PM2.5), formaldehyde (HCHO), ozone (O3), and coarse particulates (PM10−2.5), accounting for over 99% of the estimated median time-weighted chronic harm of 300 DALYs/105 person/year (geometric standard deviation of 3.5). © 2025 The Authors