1. Carcinogenic profile, toxicity and source apportionment of polycyclic aromatic hydrocarbons accumulated from urban road dust in Tokyo, Japan.
- Author
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Khanal, Rajendra, Furumai, Hiroaki, Nakajima, Fumiyuki, and Yoshimura, Chihiro
- Subjects
POLYCYCLIC aromatic hydrocarbons ,PARKING facilities ,ORGANIC compounds ,BIOMASS ,PETROLEUM - Abstract
Abstract Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in urban environments. Urban road dust (URD) generated by traffic is an important PAH accumulator. Twelve priority PAHs in < 2000 µm fraction of ten URD samples from Tokyo, Japan were characterized based on profile distributions, carcinogenicity, toxicity, and source apportionment by cluster analysis, biplot and diagnostic ratios. PAH concentrations (mg/kg dry weight) in arterial roads, highways, highway parking, highway drainage pit and residential area URD samples were 2.06–4.24, 0.25–3.37, 3.44, 4.94, and 5.26 respectively, dominated by the ∑4 rings (average 46%) and ∑5 + 6 rings (average 41%) PAHs. Biplot analysis revealed that the antecedent dry weather period, vehicle frequency and organic matter content were the dominant environmental factors governing PAH profiles of different road types. The total amount of carcinogenic PAHs in the residential URD (2.12 mg/kg) was higher than those in the arterial road (0.60–2.00 mg/kg) and highway (0.10–1.84 mg/kg) URD. Toxic equivalent concentrations (TECs) of residential, arterial road and highway URD were 0.54, (0.12–0.57), and (0.02–0.51) mg/kg, respectively. The dominant PAH sources were found to be petrogenic combustion in arterial road and highway URD, and pyrogenic combustion consisting of a mix of biomass, petroleum and traffic-related sources in the residential and highway drainage pit samples. This is also the first study to find that TEC-based toxicity should not be taken as a measure of URD toxicity. Highlights • PAH is characterized based on carcinogenicity, toxicity and source apportionment. • Antecedent dry weather period, vehicles frequency and organic matter governs PAH profile. • PAH source was petrogenic combustion in arterial and highway road dust. • PAH source was pyrogenic combustion in residential and drainage pit road dust. • Toxic equivalent concentration is not a measure of toxicity of road dust. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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