Spatio-seasonal Concentrations, Source Apportionment and Assessment of Associated Human Health Risks of PM_(2.5)-bound Polycyclic Aromatic Hydrocarbons in Delhi, India

Anurag Yadav ； Sailesh N. Behera ； Pavan K. Nagar ； Mukesh Sharma

《Aerosol and Air Quality Research》 20卷12期 (2020/12) Pp. 2805-2825+ap0-7

https://doi.org/10.4209/aaqr.2020.04.0182

摘要

To characterize the polycyclic aromatic hydrocarbons (PAHs) in PM_(2.5) (particles with an aerodynamic diameter ≤ 2.5 μm) in Delhi, the national capital of India and one of the most polluted megacities in the world, we conducted a comprehensive field campaign at six sampling sites in different areas during winter and summer. Both the PM_(2.5) and PAH concentrations exhibited seasonal variations, with higher values during winter (356 ± 136 μg m^(-3) and 75.1 ± 50.2 ng m^(-3) for the PM_(2.5) and PAHs, respectively) than summer (268 ± 94 μg m^(-3) and 10.4 ± 8.5 ng m^(-3), respectively). Additionally, the maximum winter concentrations were found in the urban industrial-cum-residential area (430 ± 104 μg m^(-3) and 124.5 ± 70.7 ng m^(-3) for the PM_(2.5) and PAHs, respectively). Among the PAHs, benzo[ghi]perylene displayed the highest ambient concentration (14.3 ± 7.4 ng m^(-3) during winter), followed by indeno[1,2,3-cd]pyrene (13.1 ± 7.3 ng m^(-3) during winter), at the majority of the sampling sites. Additionally, based on the benzo[a]pyrene-equivalent concentrations at the six sites, we estimated the PAH-associated incremental lifetime cancer risk (ILCR) in the entire study area to be 423 per 1 million persons, which exceeds the World Health Organization (WHO) limit. Source apportionment performed with the Chemical Mass Balance Model version 8.2 (CMB8.2) revealed that emissions from vehicles, municipal waste burning and biomass burning contributed 62%, 15% and 11% to the total PAH mass, respectively. Our results indicate that PM_(2.5)-bound PAHs in Delhi will continue to pose serious health risks without collective initiatives for pollution control from scientific, policy-making and regulatory bodies.

關鍵字

Total benzo[a]pyrene-equivalent concentration ； Incremental lifetime cancer risk (ILCR) ； Chemical Mass Balance Model version 8.2 (CMB8.2) ； Biomass burning ； Municipal solid waste burning