Nanoparticles (NPs), nanoaerosols (NAs), ultrafine particles (UFPs), and PM0.1 (diameters ≤ 0.1 µm or 100 nm) are used interchangeably in the field of atmospheric studies. This review article ...summarizes recent research on PM0.1 in Thailand. The review involved peer-reviewed papers that appeared in the Scopus and the Web of Science databases and included the most recently published articles in the past 10 years (2013–2022). PM0.1 mainly originate from combustion processes such as in motor vehicles. The highest mass concentration of PM0.1 occurs during the dry season, in which open fires occur in some regions of Thailand. The northern area of the country has higher PM0.1 mass concentrations, followed by the central and southern areas. Carbonaceous nanoaerosols are produced during normal periods, and the proportions of organic to elemental carbon and char to soot suggest that these originate from motor vehicles. However, in haze periods, biomass fires can also produce carbon-containing particles. PM0.1 pollution from local and cross-border countries also needs to be considered. The overall conclusions reached will likely have a beneficial long-term impact on achieving a blue sky over Thailand through the development of coherent policies and managing new air pollution challenges and sharing knowledge with a broader audience.
For the appropriate hygienic management of workplaces where workers handled nano-TiO2 products, the status of the personal exposure of workers to respirable dust (PM4) and nanoparticles (PM0.1) was ...investigated. Using a cyclone sampler for PM4 and a personal sampler for PM0.1, PM4 and PM0.1 exposure levels were evaluated to discuss them in relation to worker’s duties. The number of particles of 0.01–10 µm was also monitored online in order to examine the short-term fluctuation in the concentration and size distribution of particles. The 8h-time-weighted average (TWA) and 95% upper limit for respirable dust exposure were below the occupational exposure limit specified by the Japan Society for Occupational Health and the recommended exposure limits for TWA by NIOSH. The action level was exceeded during the filling of a flexible container bag. More than 70% of particles in the breathing zone was coarse agglomerates of > 1 µm, while it may be influenced by powder properties and the handling process as well as the management of local ventilation. The maximum PM0.1 concentration (31.3 µg m–3) occurred in a powder filling booth without air ventilation. The operation of a gasoline powered forklift temporarily increased the concentration of ultrafine particles. Most of TiO2 powder was suspended as micron-order agglomerates in the breathing zone. However, since PM0.1 exposure was much larger than those in outdoor environment particularly under insufficient cares to aerosolized powder and air ventilation, PM0.1 exposure should also be monitored.
Ribbed Smoked Sheet (RSS) is one of the leading primary rubber products and is used as a raw material for tire production. An emission inventory (EI) analysis was conducted for the production and ...transportation of RSS in Thailand following the Life Cycle Inventory (LCI) methodology in order to highlight improvements needed to render the processes more environmentally friendly. The air emission inventory focussed on CO2, NOx, SOx, particulate matters (PM) and particle-bound polycyclic aromatic hydrocarbons (PAHs) using available databases, reports and previously published papers. Data was also obtained from a small-scale RSS factory, known as a cooperative, in Songkhla province, Thailand. Upstream para-rubber industries start from RSS in Thailand. Instead, downstream industries operate under tire production in Japan. There are high exported of RSS from Thailand to tire production in Japan. The material flow during the production and export of the amount of RSS produced and transported and the distances travelled were investigated. The results suggest that the tire production in Japan contributes more than 80% of the CO2 and 90% of the SOx emissions arising during the period from latex tapping to tire production. Conversely, 60% of PM and more than 90% of the PAHs were released from the drying process involving the wood-fuel burning without any pollution control devices. These results indicate that the environmental load due to hazardous air pollutants such as PAHs and smoke particles is serious in Thailand and has to be reduced to achieve environmentally sustainable tire production.
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•Emission Inventory from RSS production in Thailand and Tire production in Japan.•PAHs and smoke particles is serious in Thailand.•60% of PMs and more than 90% of the PAHs involving the burning of wood-fuel.•Japan contributes more than 80% of the CO2 and 90% of the SOx emissions.
The particle size distribution of chlorinated polycyclic aromatic hydrocarbons (ClPAHs) in particulate matter (PM) in Japan is examined for the first time. PM was collected using a PM
0.1
air sampler ...with a six-stage filter. PM was collected in October 2014 and January 2015 to observe potential seasonal variation in the atmospheric behavior and size of PM, including polycyclic aromatic hydrocarbons (PAHs) and ClPAHs. We found that the concentration of PAHs and ClPAHs between 0.5–1.0 μm and 1.0–2.5 μm markedly increase in January (i.e., the winter season). Among the ClPAHs, 1-ClPyrene and 6-ClBenzo
a
Pyrene were the most commonly occurring compounds; further, approximately 15% of ClPAHs were in the nanoparticle phase (<0.1 μm). The relatively high presence of nanoparticles is a potential human health concern because these particles can easily be deposited in the lung periphery. Lastly, we evaluated the aryl hydrocarbon receptor (AhR) ligand activity of PM extracts in each size fraction. The result indicates that PM < 2.5 μm has the strong AhR ligand activity.
The present work determines the temporal and size distribution of polycyclic aromatic hydrocarbons (PAHs) concentrations in tropical urban air in Kuala Lumpur, Malaysia. Particulate matter (PM) ...fractions were assessed using a nanosampler in accordance with the seasonal cycle in Malaysia. The 16 USEPA priority PAHs were analyzed by gas chromatography mass spectrometry (GC–MS). The health risks were quantitatively determined the exposure risk of two selected population groups based on incremental lifetime cancer risks (ILCRs). Results indicate that ∑16PAH concentration was highest during the southwest (SW) monsoon (15.8 ng m−3). The high molecular weights of PAHs dominated 65% to 85% of the total PAH. Approximately 71.7% to 80.7% of indeno(1,2,3-cd)pyrene, dibenzo(a,h)anthracene, and benzo(g,h,i)perylene were concentrated as fine particles (PM0.1–0.5, PM0.5–1.0, and PM1.0–2.5), and unimodally during the SW monsoon. Principal component analysis (PCA) and positive matrix factorization (PMF) determined that the PAH have originated mainly from vehicles and engines emission with 24.7% and 23.7%, respectively. The total percentage of benzo(a)pyrene equivalent (BaPeq) concentration in the PM<0.1 was found to contribute to more than 50% of the potential health risk. The health risk assessment further showed that the estimated ILCRs due to PM BaPeq exposure is negligible.
•PAHs in size-segregated urban air particles were studied during different monsoons.•PAHs are predominated by high molecular weight compounds.•IcP, DhA, and BgP distributed unimodally in fine particles especially during SW.•PCA and PMF show traffic emission and coal combustion are the sources of PAHs.•Health risk assessment showed insignificant incremental lifetime cancer risk.
The international regulation of persistent organic pollutants (POPs) according to the Stockholm convention started in May 2001, and is intended to regulate the production and use of hazardous ...chemicals on a global scale. PFOS is one of the newly listed emerging POPs and only one of a diverse huge group of perfluoroalkyl substances (PFASs), which are known as a ＂super set＂ of chemical tracers that include more than ninety related chemicals. The comprehensive monitoring of PFASs is necessary to develop a reliable understanding of environmental kinetics related to these pollutants. However, the extent of atmospheric pollution by PFASs is still unclear because their distribution and sources are not fully understood. Hence, a reliable analytical method for precisely measuring the levels of PFASs in particulate matter is needed. In this study, in order to investigate the levels of PFASs in atmospheric particles including PM2.5, the use of new sampling equipment was evaluated by obtaining multiple samples of air from a stable meeting room environment. Meanwhile, by simultaneously obtaining samples from a roadside environment, the characteristics of PFASs from two different types of air samples were compared.
A layered mesh inertial filter that was previously developed by the authors, was combined with an impactor, in which the collection efficiency curve overlaps that of the inertial filter, in order to ...provide a sharp-cut separation tool for aerosol nanoparticles operating at a moderate pressure drop of less than 10–15 kPa. The separation performance of the proposed “hybrid inertial filter” of the inertial filter and an impactor, such as cut-off size, steepness of the collection efficiency curve and pressure drop ΔP, was evaluated for a single nozzle type in order to confirm the proposed system. The performance of the single nozzle type, which can be used as a unit of a multi nozzle type, was compared with that of the previous type layered mesh inertial filter with a stainless steel fiber mat. The hybrid inertial filter was found to have a collection efficiency curve with a much better steepness at less ΔP compared to those of the previous type for particles with the same cut-off size: a cut-off size d_(p50) of 100 nm with steepness d_(p84)/d_(p16) = 1.7, e.g., was obtained at ΔP ~12 kPa while d_(p84)/d_(p16) = 2.4 at ~16 kPa was found for the previous type.
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