Carbonaceous aerosols affect air quality adversely,affect global warming,and human health.However,our understanding of the impact of ultrafine(PM_(0.1))carbonaceous particulate matter is incomplete,particularly the ef...Carbonaceous aerosols affect air quality adversely,affect global warming,and human health.However,our understanding of the impact of ultrafine(PM_(0.1))carbonaceous particulate matter is incomplete,particularly the effects during haze episodes.This study monitored diurnal variations in PM_(0.1) in Chiang Mai,Thailand,from March to April 2020.We investigated carbonaceous PM_(0.1) collected by an ambient nano-sampler and evaluated their effect by using a carbon analyzer(IMPROVE_TOR).The results showed that burning large open areas in the dry season was crucial for increasing the particle mass concentration because of the large open burnings that occurred in this area.The majority of biomass fires near the sampling site occurred during the night,which would allow more particles to be released thus resulting in higher concentrations of PM_(0.1).Hence,the release of PM_(0.1) during the night would obviously result in higher concentrations than that during the day.In the eight carbon profiles,organic carbon 3(OC3)was predicted to be a marker of biomass fires.The carbon indices displayed that PM_(0.1) was influenced by biomass burning both daytime and nighttime.The findings reported herein should be of great impor-tance in terms of establishing biomass burning control policies for mitigating heavy haze pollution in Thailand and elsewhere.展开更多
This study reports on an investigation of fine and coarse carbonaceous particulate matters(PM)in Tachileik,eastern Myanmar,during the dry and wet seasons of 2022.The carbon compositions,including organic carbon(OC)and...This study reports on an investigation of fine and coarse carbonaceous particulate matters(PM)in Tachileik,eastern Myanmar,during the dry and wet seasons of 2022.The carbon compositions,including organic carbon(OC)and elemental carbon(EC),in each size(PM10-2.5,PM2.5-1.0,and PM1.0-0.5)were determined by a carbon analyzer.The average total mass concentration of the three fractions of particle samples during the dry season was higher(51.23±23.86μg/m3)than that of the wet season(14.00±5.26μg/m3).The results indicate that OC and EC levels were highest for PM1.0-0.5 during the dry season and the sizes were similar for both seasons.The OC/EC ratios varied in different seasons,from 1.93 to 4.40 and 4.13 to 5.25 in the dry and wet seasons,respectively.EC was sub-divided into char-EC and soot-EC;the char-EC/soot-EC in the dry season was higher than in the wet season,signifying that biomass burning is the main particle source during the dry season.However,vehicle emissions dominated during the wet season.The effective carbon ratio(ECR)suggested that finer particles contributed more to global warming.This information is important in terms of air quality control and mitigation in Myanmar and elsewhere.展开更多
Atmospheric nanoparticles(PM<0.1μm)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.Combu...Atmospheric nanoparticles(PM<0.1μm)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 includ-ing 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 includ-ing organic carbon(OC),elemental carbon(EC),water-soluble ions(NH4^(+),Cl^(-),NO_(3)^(-),SO_(4)^(2-)),elements(Ca,K,Mg,Na)and heavy metals(Cd,Cr,Ni,Pb)were investigated.The results re-vealed that PM<0.1μm 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 emit-ted 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.展开更多
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 investigate...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.PM1 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 periodswere 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 nonhaze 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.展开更多
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 ...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 SO2, 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.展开更多
Transboundary and domestic aerosol transport during 2018–2019 affecting Bangkok air quality has been investigated.Physicochemical characteristics of size-segregated ambient particles down to nano-particles collected ...Transboundary and domestic aerosol transport during 2018–2019 affecting Bangkok air quality has been investigated.Physicochemical characteristics of size-segregated ambient particles down to nano-particles collected during 2017 non-haze and 2018–2019 haze periods were analyzed.The average PM2.5 concentrations at KU and KMUTNB sites in Bangkok,Thailand during the haze periods were about 4 times higher than in non-haze periods.The highest average organic carbon and elemental carbon concentrations were 4.6±2.1μg/m3 and 1.0±0.4μg/m3,respectively,in PM0.5–1.0 range at KU site.The values of OC/EC and charEC/soot-EC ratios in accumulation mode particles suggested the significant influence of biomass burning,while the nuclei and coarse mode particles were from mixed sources.PAH concentrations during 2018–2019 haze period at KU and KMUTNB were 3.4±0.9 ng/m3 and 1.8±0.2 ng/m3,respectively.The PAH diagnostic ratio of PM2.5 also suggested the main contributions were from biomass combustion.This is supported by the 48-hrs backward trajectory simulation.The higher PM2.5 concentrations during 2018–2019 haze period are also associated with the meteorological conditions that induce thermal inversions and weak winds in the morning and evening.Average values of benzo(a)pyrene toxic equivalency quotient during haze period were about 3–6 times higher than during non-haze period.This should raise a concern of potential human health risk in Bangkok and vicinity exposing to fine and ultrafine particulate matters in addition to regular exposure to traffic emission.展开更多
基金supported by the Office of the Permanent Secretary,Ministry of Higher Education,Science,Research and Innovation,Thailand (Grant No.RGNS 63-253)Moreover,this research work was partially supported by JICA-JST SATREPS (Grant No.JPMJSA2102)JSPS KAKENHI 21H03618。
文摘Carbonaceous aerosols affect air quality adversely,affect global warming,and human health.However,our understanding of the impact of ultrafine(PM_(0.1))carbonaceous particulate matter is incomplete,particularly the effects during haze episodes.This study monitored diurnal variations in PM_(0.1) in Chiang Mai,Thailand,from March to April 2020.We investigated carbonaceous PM_(0.1) collected by an ambient nano-sampler and evaluated their effect by using a carbon analyzer(IMPROVE_TOR).The results showed that burning large open areas in the dry season was crucial for increasing the particle mass concentration because of the large open burnings that occurred in this area.The majority of biomass fires near the sampling site occurred during the night,which would allow more particles to be released thus resulting in higher concentrations of PM_(0.1).Hence,the release of PM_(0.1) during the night would obviously result in higher concentrations than that during the day.In the eight carbon profiles,organic carbon 3(OC3)was predicted to be a marker of biomass fires.The carbon indices displayed that PM_(0.1) was influenced by biomass burning both daytime and nighttime.The findings reported herein should be of great impor-tance in terms of establishing biomass burning control policies for mitigating heavy haze pollution in Thailand and elsewhere.
文摘This study reports on an investigation of fine and coarse carbonaceous particulate matters(PM)in Tachileik,eastern Myanmar,during the dry and wet seasons of 2022.The carbon compositions,including organic carbon(OC)and elemental carbon(EC),in each size(PM10-2.5,PM2.5-1.0,and PM1.0-0.5)were determined by a carbon analyzer.The average total mass concentration of the three fractions of particle samples during the dry season was higher(51.23±23.86μg/m3)than that of the wet season(14.00±5.26μg/m3).The results indicate that OC and EC levels were highest for PM1.0-0.5 during the dry season and the sizes were similar for both seasons.The OC/EC ratios varied in different seasons,from 1.93 to 4.40 and 4.13 to 5.25 in the dry and wet seasons,respectively.EC was sub-divided into char-EC and soot-EC;the char-EC/soot-EC in the dry season was higher than in the wet season,signifying that biomass burning is the main particle source during the dry season.However,vehicle emissions dominated during the wet season.The effective carbon ratio(ECR)suggested that finer particles contributed more to global warming.This information is important in terms of air quality control and mitigation in Myanmar and elsewhere.
基金jointly funded by the Thailand Science Research and Innovation (TSRI) and the Electricity Generating Authority of Thailand (EGAT) under grant number RDG60D0002partially supported by the Graduate School,Prince of Songkla University,Thailandsupported by Scholarship Awards Thai PhD students under Thailand’s Education Hub for Southern Region of ASEAN Countries.
文摘Atmospheric nanoparticles(PM<0.1μm)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 includ-ing 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 includ-ing organic carbon(OC),elemental carbon(EC),water-soluble ions(NH4^(+),Cl^(-),NO_(3)^(-),SO_(4)^(2-)),elements(Ca,K,Mg,Na)and heavy metals(Cd,Cr,Ni,Pb)were investigated.The results re-vealed that PM<0.1μm 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 emit-ted 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.
基金financially supported by Thailand Science Research and Innovation (TSRI) and Electricity Generating Authority of Thailand (EGAT) under grant number RDG60D0002supported by the Interdisciplinary Graduate School of Energy Systems,Prince of Songkla University via student scholarships under grant number IGS-Energy 1-2018/09Equipment support from the East Asia Nanoparticle Monitoring Network (EA-Nano Net)
文摘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.PM1 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 periodswere 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 nonhaze 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.
基金supported by the Japan Society for the Promotion of Science(JSPS)KAKENHI,253030003
文摘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 SO2, 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.
基金financially supported by the Biodiversity-based Economy Development Office of Thailand under grant#ENG6205126S。
文摘Transboundary and domestic aerosol transport during 2018–2019 affecting Bangkok air quality has been investigated.Physicochemical characteristics of size-segregated ambient particles down to nano-particles collected during 2017 non-haze and 2018–2019 haze periods were analyzed.The average PM2.5 concentrations at KU and KMUTNB sites in Bangkok,Thailand during the haze periods were about 4 times higher than in non-haze periods.The highest average organic carbon and elemental carbon concentrations were 4.6±2.1μg/m3 and 1.0±0.4μg/m3,respectively,in PM0.5–1.0 range at KU site.The values of OC/EC and charEC/soot-EC ratios in accumulation mode particles suggested the significant influence of biomass burning,while the nuclei and coarse mode particles were from mixed sources.PAH concentrations during 2018–2019 haze period at KU and KMUTNB were 3.4±0.9 ng/m3 and 1.8±0.2 ng/m3,respectively.The PAH diagnostic ratio of PM2.5 also suggested the main contributions were from biomass combustion.This is supported by the 48-hrs backward trajectory simulation.The higher PM2.5 concentrations during 2018–2019 haze period are also associated with the meteorological conditions that induce thermal inversions and weak winds in the morning and evening.Average values of benzo(a)pyrene toxic equivalency quotient during haze period were about 3–6 times higher than during non-haze period.This should raise a concern of potential human health risk in Bangkok and vicinity exposing to fine and ultrafine particulate matters in addition to regular exposure to traffic emission.
