Toward Healthy Underground Spaces: A Review of Underground Environmental Design Factors and Their Impacts on Users' Physiological and Psychological Health.

Objective: This study aims to review and synthesize what design factors are associated with the physiological and psychological health of occupants in underground spaces.

Background: The development of underground spaces offers options to global challenges, such as traffic congestion, urban overcrowding, the revitalization of dormant underground areas, disaster mitigation, and adaptation to extreme environments. Despite these advantages, concerns persist about potential adverse effects on human health in these environments.