title: Variations of polycyclic aromatic hydrocarbons in ambient air during haze and non-haze episodes in warm seasons in Hangzhou, China.
abstract: To investigate the characteristics of polycyclic aromatic hydrocarbons (PAHs) during haze episodes in warm seasons, daily PM2.5and gaseous samples were collected from March to September 2015 in Hangzhou, China. Daily samples were further divided into four groups by the definition of haze according to visibility and relative humidity (RH), including non-haze (visibility, >10 km), light haze (visibility, 8-10 km, RH <90 %), medium haze (visibility, 5-8 km, RH <90 %), and heavy haze (visibility, <5 km, RH <90 %). Significantly higher concentrations of PM2.5-bound PAHs were found in haze days, but the mean PM2.5-bound PAH concentrations obviously decreased with the aggravation of haze pollution from light to heavy. The gas/particle partitioning coefficients of PAHs decreased from light-haze to heavy-haze episodes, which indicated that PM2.5-bound PAHs were restricted to adhere to the particulate phase with the aggravation of haze pollution. Absorption was considered the main mechanism of gas/particle partitioning of PAHs from gaseous to particulate phase. Analysis of air mass transport indicated that the PM2.5-bound PAH pollution in haze days was largely from regional sources but also significantly affected by long-range air mass transport. The inhalation cancer risk associated with PAHs exceeded the acceptable risk level markedly in both haze and non-haze days.
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang, 310018, China. luhaozju@163.com.
authors.forename: Hao
authors.identifier: http://orcid.org/0000-0001-8151-1109
authors.initials: H
authors.lastname: Lu
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang, 310018, China.
authors.forename: Shengsheng
authors.initials: S
authors.lastname: Wang
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang, 310018, China.
authors.forename: Zuliang
authors.initials: Z
authors.lastname: Wu
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang, 310018, China.
authors.forename: Shuiliang
authors.initials: S
authors.lastname: Yao
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang, 310018, China.
authors.forename: Jingyi
authors.initials: J
authors.lastname: Han
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang, 310018, China.
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Tang
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang, 310018, China.
authors.forename: Boqiong
authors.initials: B
authors.lastname: Jiang
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002681:China; D004784:Environmental Monitoring; D006358:Hot Temperature; D052638:Particulate Matter / Q000032:analysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D012621:Seasons
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D011084:Polycyclic Aromatic Hydrocarbons
keywords: Air mass transport; Gas/particle partitioning; Haze; Inhalation cancer risk; Polycyclic aromatic hydrocarbons