Scholarlink

<p>Air pollution, particularly biomass burning (BB)–derived particulate matter (PM), remains a major challenge in Southeast Asia, affecting atmospheric processes, climate, human health, and socio-economic systems. This study presents the chemical characterization and source contributions of PM<sub>0.49</sub> at a rural site along the Thailand–Myanmar border in 2023. PM<sub>0.49</sub> concentrations showed pronounced temporal variability, with smoke-haze (SH) concentrations (67.9 ± 46.0&#xa0;µg/m<sup>3</sup>) nearly six times higher than those during non-haze periods (non-SH; 10.9 ± 4.4&#xa0;µg/m<sup>3</sup>). Organic carbon (OC) dominated during SH, accounting for 46% of PM<sub>0.49</sub> mass, followed by secondary inorganic aerosols (SO<sub>4</sub><sup>2−</sup>, NO<sub>3</sub><sup>−</sup>, NH<sub>4</sub><sup>+</sup>; 13%) and BB tracers such as K<sup>+</sup> (1.4%) and levoglucosan (2.7%), indicating strong BB influence. K⁺ exhibited strong correlations with levoglucosan (<i>r</i> = 0.95) and major anions (<i>r</i> = 0.52–0.94), highlighting its dual role as both a neutralizing cation and a BB tracer in both fresh and aged BB aerosols. Elevated OC to elemental carbon ratios (OC/EC; 13.4 ± 4.6) and char-EC/soot-EC ratios (9.68 ± 4.82) indicate smoldering BB as the principal source. Positive matrix factorization attributed 57% of PM<sub>0.49</sub> to BB during SH (up to 69% during peak phase), whereas soil dust dominated during non-SH conditions (70%). Backward trajectories and fire hotspot analyses suggest substantial cross-border transport from Myanmar. Furthermore, the seasonal shift in the effective carbon ratio (ECR), from 0.63 (SH) to 1.13 (non-SH), indicates a transition from light-absorbing to light-scattering aerosol dominance, underscoring the role of PM<sub>0.49</sub> in aerosol transformation under BB influence. These findings suggest air quality and potential climate implications, supporting coordinated mitigation.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Chemical signatures, source characteristics, and transboundary transport of PM0.49 in Thailand–Myanmar border region

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年7月30日

查看全文
  • Radshadaporn Janta,
  • Nuttipon Yabueng,
  • Sarana Chansuebsri,
  • Supattarachai Saksakulkrai,
  • Pavidarin Kraisitnitikul,
  • Ta-Chih Hsiao,
  • Yu-Chieh Ting,
  • Somporn Chantara

摘要

Air pollution, particularly biomass burning (BB)–derived particulate matter (PM), remains a major challenge in Southeast Asia, affecting atmospheric processes, climate, human health, and socio-economic systems. This study presents the chemical characterization and source contributions of PM0.49 at a rural site along the Thailand–Myanmar border in 2023. PM0.49 concentrations showed pronounced temporal variability, with smoke-haze (SH) concentrations (67.9 ± 46.0 µg/m3) nearly six times higher than those during non-haze periods (non-SH; 10.9 ± 4.4 µg/m3). Organic carbon (OC) dominated during SH, accounting for 46% of PM0.49 mass, followed by secondary inorganic aerosols (SO42−, NO3−, NH4+; 13%) and BB tracers such as K+ (1.4%) and levoglucosan (2.7%), indicating strong BB influence. K⁺ exhibited strong correlations with levoglucosan (r = 0.95) and major anions (r = 0.52–0.94), highlighting its dual role as both a neutralizing cation and a BB tracer in both fresh and aged BB aerosols. Elevated OC to elemental carbon ratios (OC/EC; 13.4 ± 4.6) and char-EC/soot-EC ratios (9.68 ± 4.82) indicate smoldering BB as the principal source. Positive matrix factorization attributed 57% of PM0.49 to BB during SH (up to 69% during peak phase), whereas soil dust dominated during non-SH conditions (70%). Backward trajectories and fire hotspot analyses suggest substantial cross-border transport from Myanmar. Furthermore, the seasonal shift in the effective carbon ratio (ECR), from 0.63 (SH) to 1.13 (non-SH), indicates a transition from light-absorbing to light-scattering aerosol dominance, underscoring the role of PM0.49 in aerosol transformation under BB influence. These findings suggest air quality and potential climate implications, supporting coordinated mitigation.