Development of Spatial Decision Support System for Management of Contaminated Urban Subsurface Environment Based on Vapor Intrusion Risk

Spatial Decision Support Systems (SDSS) are essential for addressing complex spatial problems, particularly in environmental health risk management in urban settings. This study presents the development and application of the Risk Assessment Program for Vapor Intrusion (RAPVI), a novel web-based SDSS designed to assess and manage human health risks associated with vapor-phase contamination from subsurface sources. RAPVI integrates preprocessing of site-specific environmental data, spatial data processing, tiered health risk assessment and GIS-based visualization. The system incorporates conceptual site modeling (CSM) to simulate source-pathway-receptor linkages across various environmental scenarios. The health risk from subsurface VOC contamination in urban area was assessed focusing on the vapor intrusion pathway using Johnson and Ettinger Model (JEM). The applicability of RAPVI was demonstrated by a case study for an urban area with legacy petroleum contamination. This system allowed for the identification of high-risk areas, spatial mapping of indoor air exposure risks, and prioritization of remediation targets based on visualized outputs and automated risk classification. The system’s web-based architecture and intuitive interface allow for real-time interaction with spatial data and support transparent decision-making processes. This novel web-based SDSS could facilitate consistent and reproducible risk evaluations, while improving data management and communication among stakeholders. RAPVI is expected to support decisions for early-stage environmental management, such as selecting investigation points and establishing risk management plans, thereby contributing to proactive and sustainable urban environmental health management.