PAHs in organic film on glass window surfaces from central Shanghai, China: distribution, sources and risk assessment

Abstract

Polycyclic aromatic hydrocarbons (PAHs) concentrations were analysed in the organic film on the glass surfaces of different functional areas in central Shanghai. Concentration levels of total PAHs in the organic film ranged from 1,348.5 to 4,007.9 ng m(-2). The concentration of PAHs was lowest in parks and green spaces (1,348.5 ng m(-2)) and highest in traffic zones (4,007.9 ng m(-2)). A concentration gradient of total PAHs was observed as follows: traffic zones > commercial areas > cultural and educational areas > parks and green spaces. The distribution of PAHs was characterised by 3-4 ring PAHs in the study areas. The most abundant PAHs were phenanthrene (20.5 %), fluorene (16.7 %), pyrene (12.4 %) and chrysene (Chry) (11.2 %). The mass of the bulk film was composed of organic and inorganic compounds and ranged from 246 to 1,288 mg m(-2). The bulk film thickness varied from 144 to 757 nm in the different functional areas. The ratios of An/178 and Fl/202 and principal component analysis suggested that PAHs came mainly from the mixed sources of fossil fuel, coal and incomplete combustion of biomass. Benzo[a]anthracene (BaA)/Chry is not suitable for use as a tracer for the transmission process of PAHs because of the rapid depletion of BaA in the organic film by photooxidation during daylight hours. The concentration of benzo[a]pyrene equivalent (BaPeq) varied from 21 to 701 ng g(-1), and the major carcinogenic contributors of the 16 PAHs were BaP, DahA, B[b/k]F and InP, accounting for 83 % of BaPeq.

Modeling the formation and growth of organic films on indoor surfaces

“…13,14 Understanding SVOC behavior in the indoor environment and associated human exposure pathways requires identification of their sources, characterization of their physicochemical properties, and knowledge of their transport mechanisms ( Figure 1). 4 Several studies have experimentally characterized film growth and composition, [18][19][20] finding them to contain high concentrations of PBDEs, PCBs, PAHs, and some phthalates, which makes them major constituents of the organic fraction of the film. 2,15 The formation of a thin organic film or "grime layer" on these surfaces therefore represents a sink for SVOCs, forming a reservoir that may subsequently re-emit SVOCs over long periods of time.…”

“…2,16,17 Thin films of deposited material are ubiquitous on impervious indoor surfaces such as window glass and walls. 4 Several studies have experimentally characterized film growth and composition, [18][19][20] finding them to contain high concentrations of PBDEs, PCBs, PAHs, and some phthalates, which makes them major constituents of the organic fraction of the film. [20][21][22][23][24] Additional constituents are water, water-soluble salts, other inorganic species, and elemental carbon, which collectively account for about 15% to 30% of the total mass of the film.…”

Source and Ecological Risk Characteristics of PAHs in Sediments from Qinhuai River and Xuanwu Lake, Nanjing, China

“…Factor 2 ( 2 ) is predominately composed of PAHs with 3-6 rings, including Flu, Phe, Pyr, Chr, BkF, BaP, and BghiP, which mainly come from biomass and coal combustion [75]. Some researches showed that Phe, Ant, Fla, and Pyr were indicative of coal combustion [76]. According to Khalili et al, gasoline combustion was shown to predominantly produce Nap, Flu, Acy, and Pyr [77].…”

“…Existing research showed that Ace and acenaphthylene (Acy) are the foremost product of coke burning [78]. And Phe, Ant, Fla, and Chr were indicative of coal combustion [71,76]. Therefore, factor 3 ( 3 ) was identified as petroleum source > coal combustion [79,80].…”

Vertical Distribution of Polycyclic Aromatic Hydrocarbons in Window Organic Films Formed in an Urban Street Canyon

“…Totally 48 samples were collected during one year. Details of the sampling method are presented in detail elsewhere [8]. Briefl y organic fi lm on windows was sampled by wiping.…”