Developing human response and exposure criteria for evaluating indoor environments
Current building codes and standards may not be adequate to assure occupant wellbeing or to prevent problems such as the Sick Building Syndrome (SBS). As building codes and standards are based at least implicitly on human response criteria, the objective of this dissertation was to define human response criteria and measures, and to identify links with exposure parameters, exogenous factors and methodological effects.
A characterization, consisting of four domains based on two objects of evaluation: environment and personal state, and two aspects of evaluation: perceptual and affective, was used as a framework for identifying human response criteria. Through a literature review and evaluation synthesis of ten published studies, a hierarchy of exogenous factors that can be linked to the four domains was identified. Potential methodological effects associated with three types of methodologies were identified and linked to one or more domains. Then, links between human responses and exposures were identified from the literature.
A conceptual model, synthesizing the combined impacts of exposures, exogenous factors and methodological effects on human response was developed. A selected portion of the conceptual model was tested empirically in two open-plan, non-industrial work spaces.
The empirical study showed that for the selected spaces, exogenous factors explained more of the variation in human responses than did exposure parameters. Based on the empirical study, the major conclusions of the dissertation were that: (1) the concept of the four domains is useful in specifying criteria, (2) a hierarchy of exogenous factors is linked to the four human response domains, (3) control of exogenous factors such as the social environment and adaptive factors may all be needed to achieve healthy buildings, or to resolve problems associated with the Sick Building Syndrome, (4) occupant characteristics must be considered in developing exposure criteria, and (5) for levels of exposures typically found in indoor environments, it is necessary to consider their multifactorial impacts rather than the impacts of individual stressors.