EXPOSURE ASSESSMENT OF BTEX COMPOUNDS AMONG SAFEGUARDS IN UNDERGROUND PARKING GARAGES IN HIGH BUILDINGS IN HANOI

Abstract

Multi – storey parking structures have potentially high concentrations of benzene (B), toluene (T), ethyl benzene (E) and xylene (X),  as known BTEXs, which could have adverse effects on human health  This study aims to estimate BTEX levels and sources and to assess the occupational health risk for safeguards in underground parking garages in high buildings in Hanoi. 27 samples were conducted using active diffusion monitors and analyzed by a GC/FID device. Health risk assessment was conducted using chronic daily intake (CDI) and slope factor (SF). Benzene, toluene and xylene were detected in all selected parking lots. In contrast, those of ethyl benzene were not detected. The mean concentrations were 16.99 µg/m³, 200.36 µg/m³ and 625.22 µg/m³ for benzene, toluene and xylene, respectively. Petroleum vapor and vehicle emission were two main sources to contribute to BTEX compounds. Non- carcinogenic risks from toluene and xylene were low when values of hazard quotient (HQ) were lower than 1. Benzene showed upper-bound lifetime cancer risks that exceeded the US. EPA benchmark of one per million, exposing the moderate risk.