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The mean particulate polybrominated dibenzop-dioxins/furans (PBDD/Fs) levels for Guangzhou were in the range of 225-2244 fg/m 3 and showed the spatial trend of background \ suburb areas \ urban area \ industrial area, suggesting the industrial and urban sources of PBDD/ Fs. The most abundant congeners were 2,3,7,8-TBDF, 1,2,3,7,8-PeBDF and 2,3,4,7,8-PeBDF. The mean toxicity equivalency quantities (TEQs) of PBDD/Fs were in the range of 89.3-456 fg I-TEQ/m 3 for Guangzhou, which were several times higher than that of the background area (49.1 fg I-TEQ/m 3 ). The rough inhalation risk evaluation showed that the residents in Guangzhou were in relatively higher exposure levels of PBDD/Fs.

This study investigated polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins/furans (PBDD/Fs), and dechlorane plus (DP) in air around three concentrated vehicle parking areas (underground, indoor, and outdoor) in a metropolitan of South China. The parking areas showed higher concentrations of PBDEs, PBDD/Fs, and DP than their adjacent urban area or distinct congener/isomer profiles, which indicate their local emission sources. The highest PBDE and DP concentrations were found in the outdoor parking lot, which might be related to the heating effect of direct sunlight exposure. Multi-linear regression analysis results suggest that deca-BDEs without noticeable transformation contributed most to airborne PBDEs in all studied areas, followed by penta-BDEs. The statistically lower anti-DP fractions in the urban area than that of commercial product signified its degradation/transformation during transportation. Neither PBDEs nor vehicle exhaust contributed much to airborne PBDD/Fs in the parking areas. There were 68.1-100 % of PBDEs, PBDD/Fs, and DP associated with particles. Logarithms of gas-particle distribution coefficients (K p s) of PBDEs were significantly linear-correlated with those of their sub-cooled vapor pressures (p L s) and octanol-air partition coefficients (K OA s) in all studied areas. The daily inhalation doses of PBDEs, DP, and PBDD/Fs were individually estimated as 89.7-10,741, 2.05-39.4, and 0.12-4.17 pg kg −1 day −1 for employees in the parking areas via Monte Carlo simulation.

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