Impact of Atmospheric Conditions and Source Identification of Gaseous Polycyclic Aromatic Hydrocarbons (PAHs) during a Smoke Haze Period in Upper Southeast Asia.

Gaseous polycyclic aromatic hydrocarbons were measured in northern Thailand. No previous studies have provided data on gaseous PAHs until now, so this study determined the gaseous PAHs during two sampling periods for comparison, and then they were used to assess the correlation with meteorological conditions, other pollutants, and their sources. The total concentrations of 8-PAHs (i.

Contrasting compositions of PM in Northern Thailand during La Niña (2017) and El Niño (2019) years.

There have been a very limited number of systematic studies on PM compositions and their source contribution in Southeast Asia. This study aims to explore the characteristics of PM composition collected in Chiang Mai (Thailand) during La Niña and El Niño years and to apportion their sources during smoke haze and non-haze periods. The average PM concentration of smoke haze episode in 2019 (El Niño) was much higher than in 2017 (La Niña).

Fresh and aged PM and their ion composition in rural and urban atmospheres of Northern Thailand in relation to source identification.

This study aims to investigate ion composition of PM in various sites and seasons and to identify the main sources on spatial and temporal basis. PM compositions of two urban and two rural areas in Northern Thailand in 2019 were investigated to distinguish urban traffic and rural open burning sources. During the burning season, average PM concentrations in rural areas (104 ± 45 μg m) were slightly higher than those in urban areas (94 ± 39 μg m).