http://hkadtmk.org/wcac2019/files/downloads/WCAC2019-Proceedings.pdf

East Asia-Nanoparticle Monitoring Network (EA-Nanonet) was found based on the air quality status in East Asia that experiences smoke and haze problem. The campaigns have been conducted to discuss the status and characteristics of PM0.1, or, nanoparticles in 10-countries in East and South-East Asia with Japan, South Korea, China, Taiwan, Thailand, Cambodia, Vietnam, Indonesia, Malaysia and Singapore. Current ongoing activities are continuous monitoring of air pollutants such as Particulate Matter especially, nanoparticles, Black Carbon (BC), and others. The PM was collected by Nano-samplers for size-segregated ambient particles. The Nano-sampler can be used to sample a greater amount of nanoparticles at ambient pressure. The used sampler consisted of 4 impactors stages (including >10, 2.5-10, 1-2.5, 0.5-1 μm), an inertial filter stage (0.1-0.5 μm) as well as a backup filter (<0.1 μm ). Carbon components (Organic Carbon (OC) plus Elemental Carbon (EC) in PM collected on quartz fiber filter were investigated by the Interagency Monitoring of Protected Visual Environment using Thermal/Optical Reflectance (IMPROVE_TOR) technique. Nanoparticles were collected from 11 sites in East Asian countries during March 28th to April 3rd, 2016 with flow rate 40 L/min. Organic carbon (OC) and elemental carbon (EC) concentrations were measured. OC originates from primary sources and formation of secondary organis carbon (SOC) by photochemical activity in the air. The concentrations of OC were higher than EC in every sites. The OC/EC ratios in PM0.1 at the sampling sites ranged from 1.91 to 9.06. The highest of OC/EC ratios were observed at Hat Yai, sounthern Thailand (9.06). High OC/EC ratios might be attributed to OC-rich source emissions (i.e. biomass burning) and secondary organic aerosol (SOA) formation. The lowest OC fractions was Bangkok, Thailand (1.91). Overall, this result indicates that emission sources are soot emissions of open burning, industrial and coal combustion, as well as aged traffic emissions transported.

In this study, atmospheric particles smaller down to ultrafine (PM_0.1) particles (PM_0.1) were investigated at selected sites; Chiang Mai, Bangkok and Hat Yai city in Thailand. The sampling was conducted during 1 year period using Nano-samplers with a PM_0.1 stage. The carbonaceous aerosols (CA) including elemental carbon (EC) and organic carbon (OC) were quantified with the thermal/optical transmittance (TOT) method. Furthermore, the CA namely, black carbon (BC) and brown carbon (BrC) were also investigated by the optical integrating sphere (IS) method. The study provides an interesting result that particle-bound BC, BrC and OC have spatio-temporal variations dependent on weather conditions. The carbon material in PMs is highest concentration in finer particle especially, PM_0.5-1.0. In the northern part of Thailand (Chiang Mai), the forest fires located upwind of the monitoring site were found to be the largest contributor of CA. In Bangkok, CA was better accounted for diesel engine emissions and open biomass burning from the provinces in Bangkok and its surrounding provinces, where the agricultural residue burning are extensive. In southern part of Thailand is more complex emission source of CA, including motor vehicle, wood biomass burning and transported plumes from Indonesian forest fires. This result indicates the importance of focusing emission control strategies on different PM particle sizes in Thailand.