Search

Byline: J. Han, P. Kanchanapiya, T. Sakano, T. Mikuni, M. Furuuchi, G. Wang The effect of the combustion atmosphere and the additives (CaO and HCl) on the behaviour of phosphorus and heavy metals during sewage sludge combustion was investigated. The results demonstrated that the reduction combustion promoted the vapourisation of phosphorus and heavy metals during sewage sludge combustion. Moreover, the concentrations of phosphorus and heavy metals in the bottom ash decreased with increasing HCl ratio, and the addition of CaO can stabilise heavy metals and phosphorus. It was also observed that phosphorus and heavy metals increased with increasing CaO ratio. Lastly, the difference of the TG-DTA curves with and without additives is discussed.

This study investigated seasonal fluctuations in particulate matter (PM) concentrations, including carbon and polycyclic aromatic hydrocarbon (PAH) components, in Phnom Penh, Cambodia, focusing on ultrafine particles (UFPs or ≤ 100 nm). UFP levels were notably higher during the dry season, averaging 23.73 ± 3.7 µg/m 3 compared to 19.64 ± 3.4 µg/m 3 in the wet season, attributed to increased emissions from vehicles and agricultural burning. In contrast, lower concentrations during the wet season were due to scavenging effect of rain. When compared to other Southeast Asian cities, UFP levels in Phnom Penh were significantly higher during the dry season, surpassing those in cities like Bangkok and Kuala Lumpur. Seasonal variations in carbonaceous components showed higher elemental carbon (EC) and total carbon (TC) during the dry season, with EC/TC ratios suggesting substantial influence from vehicular emissions and biomass burning. PAH analysis revealed seasonal disparities, with higher concentrations of benzo[b]fluoranthene (BbF) and benzo[k]fluoranthene (BkF) during the wet season, whereas fluoranthene (Flu) and pyrene (Pyr) were consistently present, indicating diverse PAH sources. The Flu/(Flu + Pyr) ratios, indicative of biomass burning, were higher in the dry season. Correlations between PAHs and carbon components confirmed combustion as a significant source of PAHs, aligning with global trends. This emphasizes the need to address distinct PM sources during various season in Phnom Penh., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Air pollution, especially particulate matter (PM), is a significant environmental pollution worldwide. Studying the chemical, environmental, and life-related cellular physical characteristics of size-fractionated PMs is important because of their different degrees of harmful effects on human respiratory tracts and organ systems, causing severe diseases. This study evaluates the chemical components of size-fractionated PMs down to PM 0.1 collected during a biomass-burning episode, including elemental/organic carbon and trace elements. Single particle sizes and distributions of PM 0.1 , PM 0.5-0.1 , PM 1.0-0.5 , and PM 2.5-1.0 were analyzed by scanning electron microscopy and Zeta sizer. Two commonly used cell lines, e.g., HeLa and Cos7 cells, and two respiratory-related cell lines including lung cancer/normal cells were utilized for cell cytotoxicity experiments, revealing the key effects of particle sizes and concentrations. A high-speed scanning ion conductance microscope explored particle-stimulated subcellular physical characteristics for all cell lines in dynamics, including surface roughness (SR) and elastic modulus ( E ). The statistical results of SR showed distinct features among different particle sizes and cell types while a E reduction was universally found. This work provides a comprehensive understanding of the chemical, environmental, and cellular physical characteristics of size-fractionated PMs and sheds light on the necessity of controlling small-sized PM exposures.

A cascade impactor type sampler equipped with an inertial filter was used to collect size-segregated particles down to ultrafine particles (UFPs or PM 0.1 ) on Batam Island in Sumatra, Indonesia, bordered by Singapore and Malaysia during a wet and the COVID-19 pandemic season in 2021. Carbonaceous species, including organic carbon (OC) and elemental carbon (EC), were analyzed by a thermal/optical carbon analyzer to determine the carbon species and their indices. The average UFP was 3.1 ± 0.9 μg/m 3 , which was 2-4 times lower than in other cities in Sumatra during the same season in the normal condition. The PMs mass concentration was largely affected by local emissions but long-range transportation of particles from Singapore and Malaysia was also not negligible. The air mass arrived at the sampling site passed the ocean, which introduced out clean air with a low level of PMs. The backward trajectory of the air mass and the largest fraction of OC2 and OC3 in all sizes was identified as being transported from the 2 above countries. OC is the dominant fraction in TC and the ratio of carbonaceous components indicated that origin of all particle sizes was predominantly vehicle emissions. UFPs were dominantly emitted from vehicles exhaust emission, while coarser particles (>10 μm) were influenced by the non-exhaust emissions, such as tire wear. Other particles (0.5-1.0; 1.0-2.5; and 2.5-10 μm) were slightly affected by biomass burning. The effective carbon ratio (ECR) and inhalation dose (ID) related EC indicated that finer particles or UFPs and PM 0.5-1 contributed more to human health and global warming., Competing Interests: The authors declare no competing interests.The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Many of the current atmospheric environmental problems facing Thailand are linked to air pollution that is largely derived from biomass burning. Different parts of Thailand have distinctive sources of biomass emissions that affect air quality. The main contributors to atmospheric particulate matter (PM), especially the PM 2.5 fraction in Thailand, were highlighted in a recent study of PM derived from biomass burning. This review is divided into six sections. Section one is an introduction to biomass burning in Thailand. Section two covers issues related to biomass burning for each of the four main regions in Thailand, including Northern, Northeastern, Central, and Southern Thailand. In northern Thailand, forest fires and the burning of crop residues have contributed to air quality in the past decade. The northeast region is mainly affected by the burning of agricultural residues. However, the main contributor to PM in the Bangkok Metropolitan Region is motor vehicles and crop burning. In Southern Thailand, the impact of agoindustries, biomass combustion, and possible agricultural residue burning are the primary sources, and cross-border pollution is also important. The third section concerns the effect of biomass burning on human health. Finally, perspectives, new challenges, and policy recommendations are made concerning improving air quality in Thailand, e.g., forest fuel management and biomass utilization. The overall conclusions point to issues that will have a long-term impact on achieving a blue sky over Thailand through the development of coherent policies and the management of air pollution and sharing this knowledge with a broader audience., Competing Interests: The authors declare no competing interests., (© 2023 The Authors.)

The health risk of schoolchildren who were exposed to airborne fine and ultrafine particles (PM 0.1 ) during the COVID-19 pandemic in the Jambi City (a medium-sized city in Sumatra Island), Indonesia was examined. A questionnaire survey was used to collect information on schoolchildren from selected schools and involved information on personal profiles; living conditions; daily activities and health status. Size-segregated ambient particulate matter (PM) in school environments was collected over a period of 24 h on weekdays and the weekend. The personal exposure of PM of eight selected schoolchildren from five schools was evaluated for a 12-h period during the daytime using a personal air sampler for PM 0.1 particles. The schoolchildren spent their time mostly indoors (~88%), while the remaining ~12% was spent in traveling and outdoor activities. The average exposure level was 1.5~7.6 times higher than the outdoor level and it was particularly high for the PM 0.1 fraction (4.8~7.6 times). Cooking was shown to be a key parameter that explains such a large increase in the exposure level. The PM 0.1 had the largest total respiratory deposition doses (RDDs), particularly during light exercise. The high level of PM 0.1 exposure by indoor sources potentially associated with health risks was shown to be important.

Distribution of PM 0.1 , PM 1 and PM 2.5 particle- and gas-polycyclic aromatic hydrocarbons (PAHs) during the 2019 normal, partial and strong haze periods at a background location in southern Thailand were investigated to understand the behaviors and carcinogenic risks. PM 1 was the predominant component, during partial and strong haze periods, accounting for 45.1% and 52.9% of total suspended particulate matter, respectively, while during normal period the contribution was only 34.0%. PM 0.1 concentrations, during the strong haze period, were approximately 2 times higher than those during the normal period. Substantially increased levels of particle-PAHs for PM 0.1 , PM 1 and PM 2.5 were observed during strong haze period, about 3, 5 and 6 times higher than those during normal period. Gas-PAH concentrations were 10 to 36 times higher than those of particle-PAHs for PM 2.5 . Average total Benzo[a]Pyrene Toxic Equivalency Quotients (BaP-TEQ) in PM 0.1 , PM 1 and PM 2.5 during haze periods were about 2-6 times higher than in the normal period. The total accumulated Incremental Lifetime Cancer Risks (ILCRs) in PM 0.1 , PM 1 and PM 2.5 for all the age-specific groups during the haze effected scenario were approximately 1.5 times higher than those in non-haze scenario, indicating a higher potential carcinogenic risk. These observations suggest PM 0.1 , PM 1 and PM 2.5 were the significant sources of carcinogenic aerosols and were significantly affected by transboundary haze from peatland fires. This leads to an increase in the volume of smoke aerosol, exerting a significant impact on air quality in southern Thailand, as well as many other countries in lower southeast Asia., (Copyright © 2021. Published by Elsevier B.V.)

Objectives: Gas sampling tubes are essential tools for the evaluation of air quality in work environments. It adsorbs toxic gaseous matters onto the surface of various granular adsorbents, such as silica gel or activated carbon packed in a thin glass tube, for quantitative analysis by gas chromatography. Currently, most of the semi-volatile matters are evaluated via aerosol filtration or solid-phase gas adsorption depending on the main phase of the substances; however, only a few substances have a sampling protocol regarding both solid and gaseous phases. Therefore, semi-volatile components evaluated by the solid-phase adsorption may result in the underestimation of the component concentrations due to particulate components passing through and remaining in the adsorbent. To highlight issues on sampling of semi-volatile matters by the solid-phase adsorption method, the collection efficiency of aerosol particles by 17 commercial gas sampling tubes were measured via pressure drop., Methods: To measure the particle collection efficiency of the gas collection tubes, precise control and dilution of the aerosol particle monitors are essential. However, we cannot apply typical filter test methods at a lower filtration flow rate than that of the aerosol particles monitors. Therefore, we developed a new experimental method that considers flow adjustment between the aerosol monitors. By assuming two specific particle size distributions and five inlet conditions, the collection efficiencies of total mass particles are estimated. From the gas-particle partitioning ratio of 16 polycyclic aromatic hydrocarbons (PAHs) in a coal tar pitch manufacturing industry, the underestimation of the concentration of semi-volatile matters using the gas collection tubes has been discussed., Results: The aerosol particles were collected in all kinds of layers in the gas sampling tubes, such as in the glass wool cap, gas adsorbent granular bed, and polyurethane foam. Furthermore, the collection efficiency curve of all 17 gas sampling tubes tested showed similar trends; a valley around particle sizes ranging from 0.2-0.3 μm between high collection zones below 0.1 μm and above 1 μm was observed. The observations suggested granular bed filters collection mechanisms such as inertial impaction, Brownian diffusion, gravity, and interception as same as air filters., Conclusions: Solid-phase collection can underestimate the concentrations of multi-phase matters. Thus, we wish to highlight the importance of solid-phase collection methods along with filtration collection methods to collect all phases of semi-volatile matters.

Ambient nanoparticles, or PM 0.1 and thirteen trace elements (Al, Ba, K, Fe, Cr, Cu, Ni, Na, Mn, Mg, Ti, Pb, and Zn) were studied in Hat Yai, Thailand during the year 2018. The annual average PM 0.1 mass concentration was 8.45 ± 1.93 µg/m 3 . The PM 0.1 levels in Hat Yai were similar to those in large cities in South East Asia, such as Hanoi and North Sumatra, but lower than other cities in Thailand. The sum of thirteen trace elements was 207.83 ± 17.06 ng/m 3 and was dominated by Na, Zn, K, Mg, and Al. The highest concentration of elements occurred in the pre-monsoon season followed by the dry and monsoon seasons. A principal component analysis (PCA) indicated that PM 0.1 comes from motor vehicles, crustal dust, industrial and biomass burning. The PM 0.1 was dominated in the pre-monsoon season, suggesting that biomass burning from the southwest direction could cause an increase in the levels of Cr, Ti, and Ni. The total cancer risk from all the carcinogenic elements was 1.98 × 10 -6 in adults, indicating that the carcinogenic risk is in a tolerable risk assessment range. The increasing levels of PM 0.1 during transboundary haze pollution and local source emissions are a concern., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Atmospheric nanoparticles (PM < 0.1 µm) are a major cause of environmental problems and also affect health risk. To control and reduce these problems, sources identification of atmospheric particulates is necessary. Combustion of bituminous coal and biomass including rubber wood, palm kernel, palm fiber, rice stubble, rice straw, maize residue, sugarcane leaves and sugarcane bagasse, which are considered as sources of air quality problems in many countries, was performed. Emissions of particle-bound chemical components including organic carbon (OC), elemental carbon (EC), water-soluble ions (NH 4 + , Cl - , NO 3 - , SO 4 2- ), elements (Ca, K, Mg, Na) and heavy metals (Cd, Cr, Ni, Pb) were investigated. The results revealed that PM < 0.1 µm from all samples was dominated by the OC component (>50%) with minor contribution from EC (3%-12%). The higher fraction of carbonaceous components was found in the particulates with smaller sizes, and lignin content may relate to concentration of pyrolyzed organic carbon (PyOC) resulting in the differences of OC/EC values. PM emitted from burning palm fiber and rice stubble showed high values of OC/EC and also high PyOC. Non-carbonaceous components such as Cl - , Cr, Ca, Cd, Ni, Na and Mg may be useful as source indicators, but they did not show any correlation with the size of PM., (Copyright © 2021. Published by Elsevier B.V.)

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-PM 10 , 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&#95;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/m 3 , 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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Data for source apportionment estimation was obtained from combustion of 11 types of biomass (rubber wood, palm kernel, palm fiber, sugarcane bagasse, sugarcane leaves, maize residue, rice stubble, rice straw, Xylocarpus moluccensis, Avicennia alba Blume and Rhizophora mucronata) and bituminous coal. Combustion was carried out in a tube furnace and emitted particulate matter (PM) was collected using a nanosampler that segregated particle sizes down to 0.1 μm. Emission factors of PM < 0.1 μm were in the range of 0.11-0.28 g kg -1 (∼1-8% of total PM), except in the case of Rhizophora mucronata, which had an emission factor of 0.071 ± 0.004 g kg -1 (∼18% of total PM). The dominant polycyclic aromatic hydrocarbons (PAHs) found on PM < 0.1 μm were chrysene from combustion of rubber wood, palm kernel, palm fiber, maize residue, Xylocarpus moluccensis, Avicennia alba Blume, Rhizophora mucronata and bituminous coal; benzo[b]fluoranthene from combustion of rice straw, sugarcane bagasse and sugarcane leaves; and benzo[k]fluoranthene from rice stubble combustion. The emission factors of PAHs bound to PM < 0.1 μm from biomass combustion ranged from 0.005 to 0.044 mg kg -1 and the emission factor from bituminous coal combustion was 0.1411 ± 0.0004 mg kg -1 . The carcinogenic potency equivalent or benzo[a]pyrene equivalent was highest from bituminous coal combustion (0.1252 mg kg -1 ) and between 0.0019 and 0.0192 mg kg -1 from biomass combustion. However, emission factors of both PM and particle-bound PAHs from biomass combustion were affected by moisture content of biomass and moisture contents of biomass used in this study were quite low, ranging from 0.165 to 0.863%., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Transboundary haze from biomass burning is one of the most important air pollutions in Southeast Asia. The most recent serious haze episode occurred in 2015. Southern Thailand was affected by the haze during September to October when the particulate matter concentration hit a record high. We investigated physical and chemical characteristics of aerosols, including concentration and aerosol size distribution down to sub-micron sizes during haze episodes in 2013 and 2015 and, for reference, an insignificant haze period in 2017. The highest total suspended particulates and PM 10 levels in Hat Yai city were 340.1 and 322.5 µg/m 3 . The mass fractions were nanoparticles (< 100 nm) 3.1%-14.8% and fine particles (< 1 µm) 54.6%-59.1%. Polycyclic aromatic hydrocarbon size distributions in haze periods peaked at 0.75 µm and the concentrations are 2-30 times higher than the normal period. High molecular weight (4-6 ring) PAHs during the haze episode contribute to about 56.7%-88.0% for nanoparticles. The average values of benzo(a)pyrene toxic equivalency quotient were 3.34±2.54ng/m 3 in the 2015 haze period but only 0.89±0.17 ng/m 3 in 2017. It is clear that particles smaller than 1 µm, were highly toxic. Nanoparticles contributed 19.4%-26.0% of total BaP-TEQ, whereas the mass fraction is 13.1%-14.8%. Thus the nanoparticles were more carcinogenic and can cause greater health effect than larger particles. The fraction of BaP-TEQ for nanoparticles during 2017 non-haze period was nearly the same, while the mass fraction was lower. This indicates that nanoparticles are the significant source of carcinogenic aerosols both during haze and non-haze periods., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020. Published by Elsevier B.V.)

In this study, size-fractionated particulate matters (PM) down to ultrafine (PM 0.1 ) particles were collected using a cascade air sampler with a PM 0.1 stage, in Hat Yai city, Songkhla province, southern Thailand during the year 2018. The particle-bound carbonaceous aerosols (CA) as elemental carbon (EC) and organic carbon (OC) were quantified with the thermal/optical reflectance method following the IMPROVE&#95;TOR protocol. The concentrations of different temperature carbon fractions (OC1-OC4, EC1-EC3 and PyO) in the size-fractionated PM were evaluated to discern OC and EC correlations as well as those between char-EC and soot-EC. The results showed that biomass burning, motor vehicle, and secondary organic aerosols (SOC) all contributed to the size-fractionated PM. The OC/EC ratios ranged from 2.90 to 4.30 over the year, with the ratios of PM 2.5-10 being the highest, except during the open biomass burning period. The concentration of CA was found to increase during the pre-monsoon season and had its peak value in the PM 0.5-1.0 fraction. The long-range transport of PMs from Indonesia, southwest of Thailand toward southern Thailand became more obvious during the pre-monsoon season. Transported plumes from biomass burning in Indonesia may increase the concentration of OC and EC both in the fine (PM 0.5-1.0 and PM 1.0-2.5 ) and coarse (PM 2.5-10 and PM >10 ) fractions. The OC fraction in PM 0.1 was also shown to be significantly affected by the transported plumes during the pre-monsoon season. Good OC and EC correlations (R 2  = 0.824-0.915) in the fine particle fractions indicated that they had common sources such as fossil fuel combustion. However, the lower and moderate correlations (R 2  = 0.093-0.678) among the coarser particles suggesting that they have a more complex pattern of emission sources during the dry and monsoon seasons. This indicates the importance of focusing emission control strategies on different PM particle sizes in southern Thailand., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Size-segregated ambient particles down to particles smaller than 0.1 μm (PM 0.1 ) were collected during the year 2014-2015 using cascade air samplers with a PM 0.1 stage, at two cities in Thailand, Bangkok and Chiang Mai. Their characteristics and seasonal behavior were evaluated based on the thermal/optical reflectance (IMPROVE&#95;TOR) method. Diagnostic indices for their emission sources and the black carbon (BC) concentration were assessed using an aethalometer and related to the monthly emission inventory (EI) of particle-bound BC and organic carbon (OC) in order to investigate the contribution of agricultural activities and forest fires as well as agro-industries in Thailand. Monthly provincial EIs were evaluated based on the number of agricultural crops produced corresponding to field residue burning and the use of residues as fuel in agro-industries, and also on the number of hot spots from satellite images corresponding to the areas burned by forest fires. The ratio of char-EC/soot-EC describing the relative influence of biomass combustion to diesel emission was found to be in agreement with the EI of BC from biomass burning in the size range <1 μm. This was especially true for PM 0.1 , which usually tends to be indicative of diesel exhaust particles, and was shown to be very sensitive to the EI of biomass burning. In Chiang Mai, the northern part of Thailand, the forest fires located upwind of the monitoring site were found to be the largest contributor while the carbon behavior at the site in Bangkok was better accounted for by the EI of provinces in central Thailand including Bangkok and its surrounding provinces, where the burning of crop residues and the cultivation of sugarcane for sugar production are significant factors. This suggests that the influence of transportation of polluted air masses is important on a multi-provincial scale (100-200 km) in Thailand., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

This research aims to investigate the effects of irradiation energy and residence time of soft X-ray irradiation in the decomposition of sixteen polycyclic aromatic hydrocarbons (PAHs) in smoke particles emitted from the Para rubber wood burning. The burning process was carried out in a tube furnace and the soft X-ray radiation used had a wave length of 0.13-0.41 nm. The irradiated (IR) and non irradiated (N-IR) smoke particles were collected simultaneously using a 10-stage Andersen sampler equipped with an inertial-filter stage (ANIF), in order to determine the physicochemical characteristic of both IR and N-IR smoke particles, including particle size distribution and concentration, and particle-bound PAHs concentration. Results show that the nano-size smoke particles contained the highest amount of PAHs and of carcinogenic potency equivalent (BaP-TEQ). About 75% of PAH compounds on the total smoke particles were decomposed at the highest irradiation energy. Moreover, 4-6 ring PAHs in nanoparticles (<70 nm) were decomposed of up to about 91% at the highest irradiation energy. The decomposition efficiency of PAHs was influenced by particle size, PAHs boiling temperature and irradiation energy. It was higher for PAHs with lower boiling temperature and smaller size particles, while the effect of residence time was not significant., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Annual and monthly-based emission inventories in northern, central and north-eastern provinces in Thailand, where agriculture and related agro-industries are very intensive, were estimated to evaluate the contribution of agricultural activity, including crop residue burning, forest fires and related agro-industries on air quality monitored in corresponding provinces. The monthly-based emission inventories of air pollutants, or, particulate matter (PM), NOx and SO 2 , for various agricultural crops were estimated based on information on the level of production of typical crops: rice, corn, sugarcane, cassava, soybeans and potatoes using emission factors and other parameters related to country-specific values taking into account crop type and the local residue burning period. The estimated monthly emission inventory was compared with air monitoring data obtained at monitoring stations operated by the Pollution Control Department, Thailand (PCD) for validating the estimated emission inventory. The agro-industry that has the greatest impact on the regions being evaluated, is the sugar processing industry, which uses sugarcane as a raw material and its residue as fuel for the boiler. The backward trajectory analysis of the air mass arriving at the PCD station was calculated to confirm this influence. For the provinces being evaluated which are located in the upper northern, lower northern and northeast in Thailand, agricultural activities and forest fires were shown to be closely correlated to the ambient PM concentration while their contribution to the production of gaseous pollutants is much less., (Copyright © 2016. Published by Elsevier B.V.)

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 characteristics of the particles of the smoke that is emitted from the burning of biomass fuels were experimentally investigated using a laboratory-scale tube furnace and different types of biomass fuels: rubber wood, whole wood pellets and rice husks. Emitted amounts of particles, particle-bound polycyclic aromatic hydrocarbons (PAHs) and water-soluble organic carbon (WSOC) are discussed relative to the size of the emitted particles, ranging to as small as nano-size (<70nm), and to the rate of heating rate during combustion. differential thermal analysis (DTA) and thermogravimetric analysis (TG) techniques were used to examine the effect of heating rate and biomass type on combustion behaviors relative to the characteristics of particle emissions. In the present study, more than 30% of the smoke particles from the burning of biomass fuel had a mass that fell within a range of <100nm. Particles smaller than 0.43μm contributed greatly to the total levels of toxic PAHs and WSOC. The properties of these particles were influenced by the fuel component, the combustion conditions, and the particle size. Although TG-DTA results indicated that the heating rate in a range of 10-20°C did not show a significant effect on the combustion properties, there was a slight increase in the decomposition temperature as heating rate was increased. The nano-size particles had the smallest fraction of particle mass and particle-bound PAHs, but nonetheless these particles registered the largest fraction of particle-bound WSOC., (Copyright © 2014. Published by Elsevier B.V.)

Size-resolved aerosols were continuously collected by a Nano Sampler for 13 days at an urban site in Beijing during winter 2012 to measure the chemical composition of ambient aerosol particles. Data collected by the Nano Sampler and an ACSM (Aerodyne Aerosol Chemical Speciation Monitor) were compared. Between the data sets, similar trends and strong correlations were observed, demonstrating the validity of the Nano Sampler. PM₁₀ and PM₂.₅ concentrations during the measurement were 150.5 ± 96.0 μg/m³ (mean ± standard variation) and 106.9 ± 71.6 μg/m³, respectively. The PM₂.₅/PM₁₀ ratio was 0.70 ± 0.10, indicating that PM₂.₅ dominated PM₁₀. The aerosol size distributions showed that three size bins of 0.5-1, 1-2.5 and 2.5-10 μm contributed 21.8%, 23.3% and 26.0% to the total mass concentration (TMC), respectively. OM (organic matter) and SIA (secondary ionic aerosol, mainly SO₄(2-), NO₃(-) and NH₄(+)) were major components of PM₂.₅. Secondary compounds (SIA and secondary organic carbon) accounted for half of TMC (about 49.8%) in PM₂.₅, and suggested that secondary aerosols significantly contributed to the serious particulate matter pollution observed in winter. Coal burning, biomass combustion, vehicle emissions and SIA were found to be the main sources of PM₂.₅. Mass concentrations of water-soluble ions and undetected materials, as well as their fractions in TMC, strikingly increased with deteriorating particle pollution conditions, while OM and EC (elemental carbon) exhibited different variations, with mass concentrations slightly increasing but fractions in TMC decreasing., (Copyright © 2014. Published by Elsevier B.V.)

Mixed crude palm oil (MCPO), the mixture of palm fiber oil and palm kernel oil, has become of great interest as a renewable energy source. It can be easily extracted from whole dried palm fruits. In the present work, the degummed, deacidified MCPO was blended in petroleum diesel at portions of 30% and 40% by volume and then tested in agricultural diesel engines for long-term usage. The particulates from the exhaust of the engines were collected every 500 hr using a four-stage cascade air sampler. The 50% cut-off aerodynamic diameters for the first three stages were 10, 2.5 and 1 microm, while the last stage collected all particles smaller than 1 microm. Sixteen particle bounded polycyclic aromatic hydrocarbons (PAHs) were analyzed using a high performance liquid chromatography. The results indicated that the size distribution of particulate matter was in the accumulation mode and the pattern of total PAHs associated with fine-particles (< 1 microm) showed a dominance of larger molecular weight PAHs (4-6 aromatic rings), especially pyrene. The mass median diameter, PM and total PAH concentrations decreased when increasing the palm oil content, but increased when the running hours of the engine were increased. In addition, Commercial petroleum diesel (PB0) gave the highest value of carcinogenic potency equivalent (BaP(eq)) for all particle size ranges. As the palm oil was increased, the BaP(eq) decreased gradually. Therefore the degummed-deacidified MCPO blends are recommended for diesel substitute.

As a tool to evaluate the characteristics of aerosol nano-particles, a high-volume air sampler for the collection of nano-particles was developed based on the inertial filter technology. Instead of the webbed fiber geometry of the existing inertial filter, wire mesh screens alternately layered using spacing sheets with circular holes aligned to provide multi-circular nozzles were newly devised and the separation performance of the filter was investigated experimentally. The separation performance was evaluated for a single-nozzle inertial filter at different filtration velocities. A webbed stainless steel fiber mat attached on the inlet surface of the developed inertial filter was discussed as a pre-separator suppressing the bouncing of particles on meshes. The separation performance of a triple-nozzle inertial filter was also discussed to investigate the influence of scale-up on the separation performance of a multi-nozzle inertial filter. The influence of particle loading on the pressure drop and separation performance was discussed. A supplemental inlet for the nano-particle collection applied to an existing portable high-volume air sampler was devised and the consistency with other types of existing samplers was discussed based on the sampling of ambient particles. The layered-mesh inertial filter with a webbed stainless steel fiber mat as a pre-separator showed good performance in the separation of particles with a d p50 ranging from 150 to 190 nm keeping the influence of loaded particles small. The developed layered-mesh inertial filter was successfully applied to the collection of particles at a d p50∼ 190 nm that was consistent with the results from existing samplers.

In order to study the distribution and partitioning of heavy and alkali metals in the flue gases of a sewage sludge incinerator, an experiment was carried out in a pilot scale combustor. The results indicated that it was feasible to separate part of metals from flue gases by collecting fly ash at different temperatures. On the basis of their separation temperature, heavy and alkali metals could be divided into three groups: group A included Zn, K and P, which converted from gaseous phase to liquid or solid when temperature was above 600 degrees C. Pb and Cu were the metals of group B, with optimum transformation temperature of 400 degrees C. Na and As belonged to group C, with conversion temperatures of 300 degrees C. Moreover, the effect of temperature gradient on heavy and alkali metal gas-solid transformation was also experimentally investigated. It was observed that the temperature gradient could promote the gas-solid conversion of heavy and alkali metals. However, too high a temperature gradient would suppress the formation of fine particles. The peak of conversion rate for K, Pb and Na occurred at 434 degrees C s(-1), while that of P and Cu was 487 degrees C s(-1).

Constitutive expression of telomerase in human cells prevents the onset of senescence and crisis by maintaining telomere homeostasis. However, accumulating evidence suggests that the human telomerase reverse transcriptase catalytic subunit (TERT) contributes to cell physiology independently of its ability to elongate telomeres. Here we show that TERT interacts with the RNA component of mitochondrial RNA processing endoribonuclease (RMRP), a gene that is mutated in the inherited pleiotropic syndrome cartilage-hair hypoplasia. Human TERT and RMRP form a distinct ribonucleoprotein complex that has RNA-dependent RNA polymerase (RdRP) activity and produces double-stranded RNAs that can be processed into small interfering RNA in a Dicer (also known as DICER1)-dependent manner. These observations identify a mammalian RdRP composed of TERT in complex with RMRP.

Measurements of serum fructosamine, glycated hemoglobin, and glycated albumin (GA) are increasingly used to complement serum glucose concentration for better management of diabetes mellitus. Fructosamine tests are currently not performed in veterinary medicine in Japan. As such, the measurement of GA may serve as a replacement test. Therefore, in the current study, serum GA and fructosamine were evaluated for a positive correlation in dogs, and, depending on the correlation, a reference range of GA percentage would also be determined from healthy control dogs. The degree of glycemic control in diabetic dogs was determined by fructosamine concentration. A positive correlation between GA and fructosamine was observed with both normal and diabetic animals. In addition, the reference interval of serum GA percentage in control dogs was determined to be 11.4-11.9% (95% confidence interval). Interestingly, no significant difference in serum GA percentages was observed between samples from diabetic dogs with excellent glycemic control and control dogs. However, good, fair, and poor glycemic control diabetic dogs resulted in a significant increase in serum GA percentages in comparison with control dogs. These results suggest that serum GA may be a useful diagnostic indicator, substituting for fructosamine, to monitor glycemic control in diabetic dogs.

Background and Objective: Cathepsin S is involved in the pathogenesis of COPD in murine models overexpressing interferon (IFN)-gamma and IL-13. It is widely accepted that genetic factors partly influence susceptibility to COPD; however, the association of genetic polymorphisms in the cathepsin S gene with COPD has not been reported previously. In this study, functional polymorphisms in the 5'-flanking region of the human cathepsin S gene were identified and their association with COPD phenotypes was investigated., Methods: Genetic polymorphisms were detected by single strand conformation polymorphism analysis and direct sequencing. Genotypes and haplotypes were determined using amplification refractory mutation systems and single strand conformation polymorphism analysis. A promoter-reporter assay was used to compare transcriptional activities between the haplotypes on stimulation with IFN-gamma. Haplotype analysis was performed on 204 smoking and 104 non-smoking Japanese subjects., Results: Four novel polymorphisms were detected in the 5'-flanking region and three major haplotypes were identified. The haplotypes were associated with distinct promoter activities on stimulation with IFN-gamma and there was a trend indicating that higher transcriptional activity was linked to less pulmonary emphysema., Conclusion: Novel functional polymorphisms were identified in the cathepsin S gene, which has a possible association with pulmonary emphysema in the Japanese population.

Besides lowering cholesterol, statins exert multiple effects, such as anti-inflammatory activity and improvement of endothelial cell function. We examined whether simvastatin (SS) protects against the development of elastase-induced pulmonary emphysema in mice by using mean linear intercepts of alveoli (Lm) as a morphometric parameter of emphysema. After injection of intratracheal elastase on day 0, C57BL/6 mice were treated daily with SS (SS+ group) or PBS (SS- group) for 2 wk. A 21% decrease in Lm on day 7 was observed in the SS+ group vs. the SS- group. Anti-inflammatory effects of SS were observed as a decrease in percentage of neutrophils up to day 3, and in hydroxyproline concentration on day 3, in bronchoalveolar lavage fluid (BALF). SS also increased the number of proliferating cell nuclear antigen (PCNA)-positive alveolar epithelial cells between days 3 and 14. To confirm the role of statins in promoting proliferation of alveolar cells, mice were treated with SS (SS+) vs. PBS (SS-) for 12 days, starting 3 wk after elastase administration. After SS treatment, Lm decreased by 52% and PCNA-positive alveolar epithelial cells increased compared with the SS- group. Concentrations of vascular endothelial growth factor in BALF and endothelial nitric oxide synthase protein expression in pulmonary vessels tended to be higher in the SS+ group vs. the SS- group in this protocol. In conclusion, SS inhibited the development of elastase-induced pulmonary emphysema in mice. This therapeutic effect was due not only to anti-inflammation but also to the promotion of alveolar epithelial cell regeneration, partly mediated by restoring endothelial cell functions.

In order to separate and reuse heavy and alkali metals from flue gas during sewage sludge incineration, experiments were carried out in a pilot incinerator. The experimental results show that most of the heavy and alkali metals form condensed phase at temperature above 600 degrees C. With the addition of 5% calcium chloride into sewage sludge, the gas/solid transformation temperature of part of the metals (As, Cu, Mg and Na) is evidently decreased due to the formation of chloride, while calcium chloride seems to have no significant influence on Zn and P. Moreover, the mass fractions of some heavy and alkali metals in the collected fly ash are relatively high. For example, the mass fractions for Pb and Cu in the fly ash collected by the filter are 1.19% and 19.7%, respectively, which are well above those in lead and copper ores. In the case of adding 5% calcium chloride, the heavy and alkali metals can be divided into three groups based on their conversion temperature: Group A that includes Na, Zn, K, Mg and P, which are converted into condensed phase above 600 degrees C; Group B that includes Pb and Cu which solidify when the temperature is above 400 degrees C; and Group C that includes As, whose condensation temperature is as low as 300 degrees C.

A mathematical model (FPM) is presented to predict the transformation of heavy metals in the downstream of combustor or incinerator. The model accounts for the transformation of heavy metals through the combined effect of condensation, nucleation, coagulation, external force and thermophoresis force. The calculation of heavy metals is embodied in the post-processor appended to Fluent soft. Before the simulation, velocity, temperature, PbCl2 concentration and other initial parameters are obtained by experiment. In addition, the transformation of PbCl2 is also experimentally studied. The comparison of experimental and predicted results indicate that the fine particle model (FPM) is valid for predicting the transformation of heavy metals in the downstream of incinerator or combustor.

The whole gene deletion CYP2A6*4, the defect of the main nicotine oxidase, contributes to limiting lifelong and daily cigarette consumption. However, the effects on smoking habits of CYP2A6*7 and *9, two major functional polymorphisms common in Asian populations, have not been reported. The present study examined the relationship between polymorphisms *4, *7 and *9 with the smoking habits of 200 Japanese smokers who visited the Keio University Hospital (Tokyo, Japan). The allele frequencies of *1 (wild type), *4, *7 and *9 were 52, 17, 11 and 20%, respectively. When the three polymorphisms were considered simultaneously, the percentages of homozygous wild type, heterozygote, and homozygous mutants and compound heterozygotes were 26.0, 52.5 and 21.5%, respectively. Homozygous mutants and compound heterozygotes (n = 43) smoked fewer cigarettes daily than heterozygotes (n = 105) and homozygous wild-type individuals (n = 52). Smokers with *7/*7, *9/*9 or *7/*9 had lower daily cigarette consumption than smokers with *1/*1. In conclusion, polymorphisms *4, *7 and *9 of CYP2A6 were detected in approximately three out of four Japanese smokers, and their daily cigarette consumption was genetically modulated by these functional polymorphisms.

A mechanistic model to predict the capture of gas-phase mercury (Hg) species using in situ-generated titania nanosize particles activated by UV irradiation is developed. The model is an extension of a recently reported model for photochemical reactions by Almquist and Biswas that accounts for the rates of electron-hole pair generation, the adsorption of the compound to be oxidized, and the adsorption of water vapor. The role of water vapor in the removal efficiency of Hg was investigated to evaluate the rates of Hg oxidation at different water vapor concentrations. As the water vapor concentration is increased, more hydroxy radical species are generated on the surface of the titania particle, increasing the number of active sites for the photooxidation and capture of Hg. At very high water vapor concentrations, competitive adsorption is expected to be important and reduce the number of sites available for photooxidation of Hg. The predictions of the developed phenomenological model agreed well with the measured Hg oxidation rates in this study and with the data on oxidation of organic compounds reported in the literature.