The characteristics of carbonaceous particles down to the nanoparticle range in Rangsit city in the Bangkok Metropolitan Region, Thailand

Yaowatat Boongla; Phuvasa Chanonmuang; Mitsuhiko Hata; Masami Furuuchi; Worradorn Phairuang

doi:10.1016/j.envpol.2020.115940

The characteristics of carbonaceous particles down to the nanoparticle range in Rangsit city in the Bangkok Metropolitan Region, Thailand

Environ Pollut. 2021 Mar 1:272:115940. doi: 10.1016/j.envpol.2020.115940. Epub 2020 Nov 6.

Authors

Yaowatat Boongla¹, Phuvasa Chanonmuang², Mitsuhiko Hata³, Masami Furuuchi⁴, Worradorn Phairuang⁵

Affiliations

¹ Department of Sustainable Development Technology, Faculty of Science and Technology, Thammasat University, Rangsit Campus, Pathumtani, 12121, Thailand.
² Thailand Institute of Scientific and Technological Research (TISTR), Klong-Luang, Pathumtani, 12120, Thailand.
³ Faculty of Geoscience and Civil Engineering, Institute of Science and Engineering, Kanazawa University, Kanazawa, Ishikawa, 920-1192, Japan.
⁴ Faculty of Geoscience and Civil Engineering, Institute of Science and Engineering, Kanazawa University, Kanazawa, Ishikawa, 920-1192, Japan; Faculty of Environmental Management, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand.
⁵ Faculty of Geoscience and Civil Engineering, Institute of Science and Engineering, Kanazawa University, Kanazawa, Ishikawa, 920-1192, Japan; Faculty of Environmental Management, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand; Department of Geography, Faculty of Social Sciences, Chiang Mai University, Muang, Chiang Mai, 50200, Thailand. Electronic address: worradorn.ph@cmu.ac.th.

PMID: 33189443
DOI: 10.1016/j.envpol.2020.115940

Abstract

Atmospheric size-classified particles in sizes ranging from small to nanoparticles (PM_0.1) are reported for Rangsit City in the Bangkok Metropolitan Region (BMR) of Thailand, for October 2019 (wet season) and January-February 2020 (dry season). The sampling involved the use of a PM_0.1 cascade air sampler to determine the mass concentration. The PMs consisted of six stages including TSP-PM₁₀, PM_2.5-10, PM_1.0-2.5, PM_0.5-1.0, PM_0.5-1.0 and PM_0.1. Elemental carbon (EC) and organic carbon (OC) were evaluated by a carbon analyzer following the IMPROVE_TOR protocol. The average PM_0.1 mass concentrations were found to be 13.47 ± 0.79 (wet season) and 18.88 ± 3.99 (dry season) μg/m³, respectively. The average OC/EC ratio for the rainy season was lower than that in the dry season. The char-EC/soot-EC ratios were consistently below 1 for the PM_0.1 fraction in both seasons indicating that vehicular traffic appeared to be the main emission source. However, the influence of open biomass burning on fine and coarse PM particles on local air pollution was found to be an important issue during the wet season. In addition, long-range transport from other countries may also contribute to the carbon content in the Bangkok Metropolitan Region (BMR) atmosphere during the dry season. The higher secondary organic carbon to organic carbon (SOC/OC) ratio in the dry season is indicative of the contribution of secondary sources to the formation of PM, especially finer particles. A strong correlation between OC and EC in nanoparticles was found, indicating that they are derived from sources of constant emission, likely the diesel engines. Conversely, the OC and EC correlation for other size-specific PMs decreased during the dry season, indicating that these emission sources were more varied.

Keywords: Biomass burning; Carbon; Long-range transport; PM(0.1); Traffic.

MeSH terms

Aerosols / analysis
Air Pollutants* / analysis
Carbon / analysis
Cities
Environmental Monitoring
Nanoparticles*
Particle Size
Particulate Matter / analysis
Seasons
Thailand

Substances

Aerosols
Air Pollutants
Particulate Matter
Carbon