• Title/Summary/Keyword: Toxicity equivalency factors

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Day and Night Distribution of Gas and Particle Phases Polycyclic Aromatic Hydrocarbons (PAHs) Concentrations in the Atmosphere of Seoul (서울 대기 중 기체 및 입자상 다환방향족탄화수소 (PAHs)의 낮·밤 분포 특성)

  • Lim, Hyung Bae;Kim, Yong Pyo;Lee, Ji Yi
    • Journal of Korean Society for Atmospheric Environment
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    • v.32 no.4
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    • pp.408-421
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    • 2016
  • Day and night sampling for gas and particle phases PAHs were carried out in Seoul to characterize gas and particle phases PAHs concentrations in day and night times. There was no significant difference between day and night time for particle phase PAHs concentrations and phase distribution of PAHs, while, gas phase PAHs concentrations in daytime were about 1/2 of nighttime concentrations in both summer and winter due to photochemical reaction of gas phase PAHs during daytime. A high fraction of cancer risk for PAHs was attributed to particle phase PAHs and the excess cancer risk in winter was higher than in summer. The excess cancer risk level of total(gas+particle) PAHs in summer was partially observed when both gas and particle phase PAHs concentrations were considered as risk assessment. Based on the diagnostic ratios and factor analysis of PAHs concentrations, combustion(coal and natural gas) and vehicular emission might be the most significant contributors of PAHs and major factors for determining of PAHs concentration were different between day and night times.

Characteristics of Gas- and Particle-phase Polycyclic Aromatic Hydrocarbon (PAH) Distribution in Tunnels (터널 내 기체 및 입자상 다환방향족탄화수소(PAH) 분포 특성)

  • Lee, Ji Yi;Lee, Seung-Bok;Kim, Jin Young;Jin, Hyoun Cher;Lim, Hyung Bae;Bae, Gwi-Nam
    • Journal of Korean Society for Atmospheric Environment
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    • v.30 no.6
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    • pp.519-530
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    • 2014
  • Twenty four individual polycyclic aromatic hydrocarbon (PAH) compounds both in gas- and particle-phase were quantified in three tunnels (Namsan Tunnel 3, Jeongneung Tunnel, Bukak Tunnel) to characterize vehiculate emission of PAHs. Gas phase PAHs were dominant in tunnels which consisted of 85% of total PAHs concentrations. Naphthalene and 2-methyl naphthalene were the most abundant gas phase PAH compounds, while the concentrations of fluoranthene and pyrene were highest in the particle phase. Most (96%) of the gas phase PAH compounds consisted of two- and three-aromatic rings whereas most of the particle phase PAHs were in four and five-rings (67%) in tunnels. Average BaP-eq concentrations of PAHs in the particle phase ($20.8{\pm}11.6ngm^{-3}$) was about twenty fold higher than that in the gas phase ($1.6{\pm}0.6ngm^{-3}$). It means that the particle phase PAHs has more adverse health effect than the gas phase PAHs even though the concentrations of the particle phase PAHs were lower than those of the gas phase PAHs. Compared to previous studies reporting diagnostic ratios for specific PAH compounds, the profile of individual PAH compounds measured in this study reflected well for the vehiculate emissions. We reported, for the first time, on the results of the profile of individual PAH compounds measured in tunnels for both gas and particle phases.