Size distributions of polycyclic aromatic hydrocarbons in urban atmosphere: sorption mechanism and source contributions to respiratory deposition
| Autor: | Y. Lv, X. Li, T. T. Xu, T. T. Cheng, X. Yang, J. M. Chen, Y. Iinuma, H. Herrmann |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | Atmospheric Chemistry and Physics, Vol 16, Pp 2971-2983 (2016) |
| Druh dokumentu: | article |
| ISSN: | 1680-7316 1680-7324 |
| DOI: | 10.5194/acp-16-2971-2016 |
| Popis: | In order to better understand the particle size distribution of polycyclic aromatic hydrocarbons (PAHs) and their source contribution to human respiratory system, size-resolved PAHs have been studied in ambient aerosols at a megacity Shanghai site during a 1-year period (2012–2013). The results showed the PAHs had a bimodal distribution with one mode peak in the fine-particle size range (0.4–2.1 µm) and another mode peak in the coarse-particle size range (3.3–9.0 µm). Along with the increase in ring number of PAHs, the intensity of the fine-mode peak increased, while the coarse-mode peak decreased. Plotting of log(PAH / PM) against log(Dp) showed that all slope values were above −1, suggesting that multiple mechanisms (adsorption and absorption) controlled the particle size distribution of PAHs. The total deposition flux of PAHs in the respiratory tract was calculated as being 8.8 ± 2.0 ng h−1. The highest lifetime cancer risk (LCR) was estimated at 1.5 × 10−6, which exceeded the unit risk of 10−6. The LCR values presented here were mainly influenced by accumulation mode PAHs which came from biomass burning (24 %), coal combustion (25 %), and vehicular emission (27 %). The present study provides us with a mechanistic understanding of the particle size distribution of PAHs and their transport in the human respiratory system, which can help develop better source control strategies. |
| Databáze: | Directory of Open Access Journals |
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