Levels, profiles and human exposure of organophosphate esters (OPEs) in dust from subway stations

Abstract

For the first time, the pollution characteristics of eight organophosphate esters (OPEs) in dust from staff workspaces of subway stations were investigated in China. Dust samples were collected from ten stations, covering six rooms at each station, including offices, meeting rooms, dressing rooms, control rooms, equipment rooms and platforms within tunnels. The detection rates for seven compounds ranged from 68 % to 97 %, indicating widespread contamination. The median concentration of ∑OPEs was 23.31 μg/g, which was higher than that found in houses but not as high as that reported for station platforms and vehicle cabins. TnBP, TDCIPP and TEHP were identified as the predominant compounds, with concentrations ranging from 2.63 to 3.65 μg/g. The spatial distribution results revealed highly comparable concentrations in control rooms and offices but different profiles. Despite spatial separation between sampling sites, correlation analysis indicated strong links between tunnels and other sections of stations, suggesting the source consistency. Principal Component Analysis (PCA) results revealed that equipment shells, insulating rubber and cable jackets were major sources for control rooms and platforms within tunnels; oil-related sources influenced equipment rooms; and plastic decorations served as the main sources for station offices, dressing and meeting rooms. The hazard quotients (HQs, or noncarcinogenic risk) of ∑OPEs via ingestion and dermal contact for staff were all in the range of 10−4-10−2. Although the HQ levels were below the USEPA threshold, the occupational exposure risks through ingestion and dermal contact were greater than those in building environments and vehicle cabins.