This article summarizes the review by Seppänen et al. (1999) of current literature on the relationship of ventilation rates and carbon dioxide concentrations in non-residential and non-industrial buildings (primarily offices) with the health of the building's occupants and with the occupants' perceptions of indoor air quality (IAQ). While ventilation rates do not directly affect occupant health or perception outcomes, they affect indoor environmental conditions including air pollutant concentrations that, in turn, may modify the occupants' health or perceptions. The review aims to provide a better scientific basis for setting health-related ventilation standards. Space constraints prohibit a detailed description of both ventilation rate and carbon dioxide concentration studies; therefore, this summary focuses primarily on the ventilation rate studies.