Risk assessment of vapor intrusion and health hazards from chlorinated solvent-contaminated groundwater in residential area adjacent to an industrial complex

In industrial complexes and surrounding areas, chlorinated solvents may migrate via both air and groundwater, leading to potential human exposures through multiple pathways. This study quantified inhalation risks from chlorinated solvents—specifically trichloroethylene (TCE), tetrachloroethylene (PCE), dichloroethylene (DCE), and vinyl chloride (VC)—present in outdoor air and indoor air affected by vapor intrusion from contaminated groundwater. Outdoor air concentrations of TCE and PCE were highest within the industrial complex, and the estimated inhalation risks generally decreased with increasing distance from the industrial area. We also measured concentrations of TCE and PCE in air inside groundwater monitoring wells and estimated vapor intrusion risks using groundwater concentrations measured at 23 observation points distributed across the industrial complex, adjacent road, and nearby residential district. Vapor intrusion risks estimated using groundwater concentrations were generally higher within the industrial complex and lower in the adjacent residential district. However, vapor intrusion risks were estimated even at points where chlorinated solvents were not detected in outdoor air. The results suggest that human exposure to chlorinated solvents may occur through multiple exposure pathways in industrial and nearby residential areas. These findings indicate that risk-based site management should consider contaminant migration and potential exposure pathways associated with chlorinated solvent contamination.