Long-range Transboundary Atmospheric Transport of Polycyclic Aromatic Hydrocarbons, Carbonaceous Compositions, and Water-soluble Ionic Species in Southern Thailand

Abstract

This study investigated atmospheric particulate matter (PM) with an aerodynamic diameter of < 2.5 µm (PM 2.5 ) observed at the Prince of Songkla University (Phuket Campus) in southern Thailand. All samples (n = 75) were collected using MiniVol™ portable air samplers from March 2017 to February 2018. Carbonaceous aerosol compositions, i.e., organic carbon (OC) and elemental carbon (EC), water-soluble ionic species (WSIS), and polycyclic aromatic hydrocarbons (PAHs) in the PM 2.5 samples were identified and quantified. We found that the average PM 2.5 concentration was 42.26 ± 13.45 µg m -3 , while the average concentrations of OC and EC were 3.05 ± 1.70 and 0.63 ± 0.58 µg m -3 , respectively. The OC/EC ratio was in the range of 2.69-16.9 (mean: 6.05 ± 2.70), and the average concentration of 10 selected ions was 6.91 ± 3.54 µg m -3 . The average concentration of SO 4 2was the highest throughout the entire study period (2.33 ± 1.73 µg m -3 ); the average contribution of SO 4 2to the major ionic components was 34%. Surprisingly, the average concentrations of NO 3and NH 4 + were relatively low. The mean ratio of [NO 3 -]/[SO 4 2-] was 0.33 ± 0.24. Strong positive correlation was found between K + and both OC and EC (r = 0.90 and r = 0.93, respectively). It is also precious to highlight that biomass burning (BB) is the major source of OC, EC and K + , which multiple studies have confirmed that the role of K + as a biomass marker. Results showed that BB episodes might play a major role in producing the observed high levels of OC. The relatively high abundance of both B[g,h,i]P and Ind suggests that motor vehicles, petroleum/oil combustion, and industrial waste burning are the primary emission sources of PAHs in the ambient air of Phuket. Interestingly, principal component analysis (PCA) indicated that vehicular exhausts are the main source of carbonaceous aerosol compositions found in the ambient air of Phuket, whereas the contributions of biomass burning, diesel emissions, sea salt aerosols and industrial emissions were also important.

Discrimination of the geographical origins of rice based on polycyclic aromatic hydrocarbons

“…Alternatively, it appears rationale to interpret the comparatively high contribution of 5-6 ring PAHs as a consequence of unique distribution and compositional fingerprints detected in rice samples of this region. This interpretation is in good accordance with previous studies highlighting that HMW PAHs are significantly prominent ([ 70%) compared to LMW PAHs in PM 2.5 collected in Southeast Asian countries (ChooChuay et al, 2020a(ChooChuay et al, , 2020b(ChooChuay et al, , 2020cKhan et al, 2015;Oanh et al, 2020;Pongpiachan et al, 2015;Sulong et al, 2019). In addition, there are even further factors in operation including gas-particle partitioning, atmospheric transport, and biotransformation that could contribute to compositional alteration of PAH congeners in rice samples (Jariyasopit et al, 2014;Pongpiachan et al, 2013c;Singer et al, 2003;Sun et al, 2018).…”

Simultaneous Measurements of PM2.5- and PM10-bound Benzo(a)pyrene in a Coastal Urban Atmosphere in Poland: Seasonality of Dry Deposition Fluxes and Influence of Atmospheric Transport

“…In order to investigate the sources of PAH congeners in PM2.5 and PM10 over Gdynia, the air mass trajectory analysis was performed. The air mass transport models have been widely used in many aerosol-oriented studies (Forster et al 2001, Chang et al 2011, Halse et al, 2011, Aalto et al, 2015, Moroni et al, 2015, ChooChuay et al, 2020. In the present study, 24-h backward trajectories (BTs) were computed using a three-dimensional kinematic FLEXTRA air mass trajectory model (NILU and Institute of Meteorology and Geophysics, Vienna) with numerical meteorological data provided by European Centre for Medium Range Weather Forecast (ECMWF).…”

Influence of Meteorological Conditions and Fire Hotspots on PM0.1 in Northern Thailand during Strong Haze Episodes and Carbonaceous Aerosol Characterization

“…Southeast Asia (SEA) is strongly affected by atmospheric haze pollution (Wiriya et al, 2013;(Li and Shao, 2009;Pongpiachan et al, 2014a;Pongpiachan et al, 2015;Chuang et al, 2016;Li et al, 2016;Chomanee et al, 2020;Dejchanchaiwong et al, 2020;ChooChuay et al, 2020a;ChooChuay et al, 2020b;ChooChuay et al, 2020c;Dejchanchaiwong and Tekasakul, 2021). In the upper SEA, the haze is observed during a quarter of every year and studied, mostly in Thailand (Wiriya et al, 2013;Wiriya et al, 2016;Thepnuan et al, 2019;Pani et al, 2019), but recently, air quality affected by PM10 and PM2.5 was studied in Laos (Nguyen et al, 2019), Myanmar (Sricharoenvech et al, 2020) and Vietnam (Le, 2020).…”