Cite this article: Wang, J., Guinot, B., Dong, Z., Li, X., Xu, H., Xiao, S., Ho, S.S.H., Liu, S. and Cao, J. (2017). PM2.5-Bound Polycyclic Aromatic Hydrocarbons (PAHs), Oxygenated-PAHs and Phthalate Esters (PAEs) inside and outside Middle School Classrooms in Xi’an, China: Concentration, Characteristics and Health Risk Assessment.
Aerosol Air Qual. Res.
17: 1811-1824. https://doi.org/10.4209/aaqr.2017.03.0109
PM2.5 bound 19PAHs, 3OPAHs, and 7PAEs were monitored in a middle school in Xi’an.
PAHs were mostly influenced by outdoor air; PAEs were mainly from indoor emissions.
Students’ activities affected the indoor and outdoor distributions.
Inhalation cancer risks assessment of PAHs and PAEs for students were determined.
In China, the exposure of children to particulate toxics, like organics, has been poorly investigated mainly due to the technical challenges in sampling and analysis. This article reports indoor and outdoor concentrations of PM2.5-bound polycyclic aromatic hydrocarbons (PAHs), oxygenated-PAHs (OPAHs) and phthalate esters (PAEs) monitored for 13 days in May 2012 in two classrooms, A and B, of a middle school at Xi’an, China. Outdoors, the average PM2.5 mass was 96.9 µg m–3, while indoor concentrations ranged between 154.7 µg m–3 (A) and 120.2 µg m–3 (B). Total PAEs, dominated by bis(2-ethylhexyl)phthalate (DEHP) and di-n-butyl phthalate (DBP), were found at much higher concentrations than PAHs and OPAHs, and their outdoor versus indoor distribution followed that of PM2.5, ranging from 622.0 ng m–3 outdoors, to 808.6 (A) and 864.7 ng m–3 (B) indoors. Concentrations of total PAHs were about 50 ng m–3 outdoors and indoors, while OPAHs were observed at concentrations of 17.7 outdoors and 15.9 (A) and 19.8 ng m–3 (B) indoors. High molecular weight PAHs (i.e., 4-ring, 5-ring and 6-ring) generally accounted for about 80%. Variations of PAHs levels indoors were closely associated with the ventilation and the occupancy rate of the classrooms. Activities on the playground also influenced the indoor organic pollutant concentrations. Intense PAEs sources were evidenced, but outdoor sources also influenced the I/O ratios. Both the PAHs and PAEs inhalation risk estimations demonstrated that there is a non-negligible potential cancer risk for children in their school environment.
Keywords: PM2.5; Indoor/Outdoor; PAHs/OPAHs/PAEs; Schoolchildren; Health risks