Seasonal Trends of Atmospheric PAHs in Five Asian Megacities and Source Detection Using Suitable Biomarkers

Abstract

The most prevalent pollutant, polycyclic aromatic hydrocarbons (PAHs) is now plenteously distributed in the global atmosphere. We recently quantified 36 polycyclic aromatic hydrocarbons (PAHs) associated with aerosols (particulate matter: PM) in five Asian cities: Tokyo (Japan), Beijing (China), Kolkata (India), Hanoi (Vietnam), and Kuala Lumpur (Malaysia). Average atmospheric PAH concentrations (∑12 PAHs-ng m -3 ) increased in the order of Kuala Lumpur (2.99) ≈ Tokyo (3.95) < Hanoi (7.99) << Kolkata (63.5) << Beijing (142.8). The most abundant PAHs in PM samples in these cities were chrysene, benz [a]anthracene, benzofluoranthenes, benzo[a]pyrene, and benzo[e]pyrene. We used the PAH compositions, especially the relative abundances of alkylated PAHs, and hopanes to determine vehicle exhaust-derived PAHs, and levoglucosan as a tracer for biomass burning, especially from wood combustion. Vehicle exhaust contributed to atmospheric PAHs in all cities, indicated by higher ratios of (C 30 17α)/total PAHs and MPAHs/PAHs than coal and wood combustion products. Coal combustion contributed also in winter aerosols in Beijing, indicated by higher abundance of β isomers i.e., 17β21β (H)-C 30 hopane (C 30 17β) and 17β21β (H)-C 29 hopane (C 29 17β) signifying mass use of coal for heating. The ratio of levoglucosan/PAHs was high in Kuala Lumpur and Hanoi, suggesting greater inputs of PAHs from biomass burning there.

Size-specific PAHs and Associated Health Risks over a Tropical Urban Metropolis: Role of Long-range Transport and Meteorology

“…Table 3 compares the average particulate TPAH concentration over Kolkata with other urban atmospheres across the world. In case of the present study location, Kolkata, no significant changes in TPAH concentrations have been observed from 2011 (Saha et al, 2017) to 2018 (present study). This indicates that either the sources of PAH or the other regulating factors remained more or less same during the period.…”

“…Therefore, the concentration values in this study could be representing the lower limit. However, utilizing the gaseous PAH concentration from a previous measurement by Saha et al (2017), we have estimated the ILCR values for the combined gaseous and particulate PAHs. We have found that the human health is more vulnerable to particulate PAH pollution rather than gaseous PAH over Kolkata.…”

“…For the particulate PAHs, we have taken PAHs in PM 10 (summing up all the size-segregated stages) from the present study. On the other hand, because of sampling limitations, we have taken the gaseous PAHs concentrations from the study conducted by Saha et al (2017) over the similar atmospheric environment over Kolkata. We have considered the PAHs that were common in both the studies.…”

Polycyclic aromatic hydrocarbons (PAHs) in road dust collected from Quang Ninh: Contamination levels and potential sources

“…Hydrocacbon thơm đa vòng ngưng tụ (PAHs) là nhóm chất có chứa nhiều vòng benzen liên hợp trong phân tử, một số PAH được biết tới như những chất gây đột biến gen, ung thư và dị tật thai nhi [1,2]. PAHs được sinh ra chủ yếu từ các quá trình cháy cả trong tự nhiên như cháy rừng, núi lửa phun trào..., cũng như các quá trình nhân tạo đốt nhiên liệu hóa thạch, sinh khối không hoàn toàn... [ g/ml trong toluen gồm: naphthalen-d8, acenaphthylen-d10, phenathren-d10, chrysen-d12, perylene-d12; dung dịch nội chuẩn (IS) pyrene-d10 có nồng độ 200 g/ml trong isooctan.…”

Seasonal and annual changes in PAH concentrations in a remote site in the Pacific Ocean

“…PAHs emission sources are coal combustion in East Asia and biomass burning in Southeast, and South Asia. Moreover, the relative contribution of PAH emissions from motor vehicles is increasing under economic transition 3,4 .…”