Search

Asthmatics may suffer harmful health effects from air pollution. This year-long study, which was conducted from November 2015 till October 2016 and resulted in 12,045 data points from 33 participants, assessed the relationships (with a 95% confidence interval [CI]) between measured air pollutant (CO, NO2, O3, SO2, PM2.5 and PM10) concentrations and peak expiratory flow rates (PEFRs) among adults with asthma in the district of Mae Moh in Lampang, Thailand. A positive correlation was found between the mean daily concentration of NO2 from 4 days prior (“lag 4”) and the PEFR upon waking (“morning PEFR”), with an increase of 1 ppb in the former being associated with an increase of 1.34 L min–1 (95% CI: 0.25, 2.44) in the latter. Also, the interaction between NO2 (lag 4) and PM10 (lag 6) was multiplicatively associated with a decrease of –0.015 L min–1 in the morning PEFR, which was also negatively associated with the maximum daily concentration (“max”) of NO2 (lag 2) and that of PM10 (lag 6), with coefficients of –0.07 and –0.013, respectively. Furthermore, when including PM2.5 max in the generalized estimating equation model, only NO2 max (lag 2) and CO max (lag 6) were negatively associated with the morning PEFR, displaying coefficients of –0.08 and –1.71, respectively. O3 max (lag 3) and PM2.5 max exhibited positive relationships with the PEFR before sleeping (“evening PEFR”), with coefficients of 0.078 and 0.029, respectively. Additionally, the average daily PEFR was positively associated with the average daily concentration of NO2 (lag 4), with a coefficient of 0.15, but negatively associated with that of SO2, with a coefficient of –0.47. We also observed a negative relationship between the average daily PEFR and NO2 max (lag 2), with a coefficient of –0.05, but a positive one between the former and O3 max (lag 3), with a coefficient of 0.06. Our results indicate that the delayed—and, in some cases, negative—effects of these pollutants on PEFRs must be considered in health forecasting and that preventative measures should be implemented to control certain emissions at the source.

A rotating filtration device (RFD) that is filled with porous media is developed for sampling particulate matter with a diameter of 1 μm or less (PM1). An experiment is conducted on a test system using corn oil as a test aerosol. The RFD was evaluated using an aerodynamic particle sizer. The results yielded cutoff sizes of 1.68 μm and 1.04 μm at rotational speeds of 0 rpm and 9000 rpm, respectively, with foam with 80 pores per inch (ppi), a thickness of 80 mm, and a face velocity of 13.5 cm/s. When the foam was replaced with 94 ppi nickel mesh, the cutoff size decreased from 1.45 μm to 0.98 μm as the thickness increased from 17 to 68 mm. As the face velocity of the RFD increased from 13.5 to 108.3 cm/s, the cutoff size declined from 1.04 μm to 0.77 μm. Most of the changes in the cutoff sizes of the RFD were statistically significant (p

Size-segregated aerosol samples collected from a rural site (Rajim: 20˚59′N and 81˚55′E) in eastern central India during the winter of 2011 were analyzed for anhydrosugars, sugar alcohols and primary sugars to better understand their potential sources and formation. Anhydrosugars showed the predominance of levoglucosan, whereas sugar alcohol showed the predominance of mannitol, with glucose as a major primary sugar in the sub-micron (Da 1.1 μm). Levoglucosan gave a bimodal size distribution pattern with a major peak at 0.43–0.65 μm in the sub-micron mode during period 2 and period 3, suggesting its origin from biomass burning, whereas during period 1 the major peak was found at 4.4–5.8 μm in super-micron mode that may be due to the mixing of biomass burning derived particles with soil dust particles. Sugar alcohols (arabitol and mannitol) and primary sugars (glucose and trehalose) showed bimodal size distribution trend with a major peak at 4.4–5.8 μm in super-micron mode during all periods, perhaps due to fungal activity and soil dust re-suspension, respectively. The potential ingress of biomass burning derived particles into the lungs was calculated to be high whereas fungal spores and soil particles were more likely found in the upper respiratory tract. Principal component analysis and correlation analysis showed that biomass burning was a major source in the sub-micron mode whereas fungal spores and vegetative soil were dominant sources for quantified sugars in super-micron mode.

Light-absorbing organic carbon (or brown carbon, BrC) has been recognized as a critical driver in regional-to-global climate change on account of its significant contribution to light absorption. BrC sources vary from primary combustion processes (burning of biomass, biofuel, and fossil fuel) to secondary formation in the atmosphere. This paper investigated the light-absorbing properties of BrC such as site-specific mass absorption cross-section (MACBrC), absorption Angstrom exponent (AAEBrC), and the absorbing component of the refractive index (kBrC) by using light absorption measurements from a 7-wavelength aethalometer over an urban environment of Chiang Mai, Thailand in northern peninsular Southeast Asia (PSEA), from March to April 2016. The contribution of BrC to total aerosol absorption (mean ± SD) was 46 ± 9%, 29 ± 7%, 24 ± 6%, 20 ± 4%, and 15 ± 3% at 370, 470, 520, 590, and 660 nm, respectively, highlighting the significant influence of BrC absorption on the radiative imbalance over northern PSEA. Strong and significant associations between BrC light absorption and biomass-burning (BB) organic tracers highlighted the influence of primary BB emissions. The median MACBrC and kBrC values at 370 nm were 2.4 m2 g−1 and 0.12, respectively. The fractional contribution of solar radiation absorbed by BrC relative to BC (mean ± SD) in the 370–950 nm range was estimated to be 34 ± 7%, which can significantly influence the regional radiation budget and consequently atmospheric photochemistry. This study provides valuable information to understand BrC absorption over northern PSEA and can be used in model simulations to reassess the regional climatic impact with greater accuracy.

Water-soluble organic compounds are important constituents of atmospheric aerosols and have been recognized as unique fingerprints to identify atmospheric processes. Fine aerosol samples (PM2.5) were collected at Ambikapur (23.1°N and 83.2°E) in eastern central India from March to June 2017. The samples were analyzed for water-soluble dicarboxylic acids (C2–C12), glyoxylic acid (ωC2), glyoxal (Gly), methylglyoxal (MeGly), organic carbon (OC), elemental carbon (EC) and water-soluble OC (WSOC). Oxalic acid (C2) was detected as the most abundant species, followed by succinic (C4) and malonic (C3) acids. Temporal variation in concentrations of C2 diacid and related compounds was pronounced from early to late April when biomass burning (BB) was dominant in eastern central India. Strong positive correlations of C2 diacid and related compounds with levoglucosan (r = 0.83–0.99) further demonstrate that organic aerosols (OAs) were affected by BB in eastern central India. Strong positive correlations of C2 with saturated diacids (C3–C9: r = 0.78–0.97), ωC2 (r = 0.98), Gly (r = 0.96) and MeGly (r = 0.84) suggest that their sources and formation processes were similar and oxalic acid might be produced via the photochemical degradation of precursor compounds. The relatively high ratios of WSOC to OC (avg. 0.69) and C3 to C4 diacid (avg. 0.95) suggest that water-soluble OAs were photochemically processed during the campaign. The total water-soluble organic compounds detected in Ambikapur PM2.5 samples accounted for an average of 1.9% (1.1–3.1%) of OC. Our results demonstrate that BB and photochemical processing caused high levels of water-soluble organic compounds over eastern central India.

Despite the extensive use of the Internet, printed newspapers remain a primary information source. In this study, reading a newspaper in a relatively confined or poorly ventilated indoor space was simulated to determine the profile of particles released from the newspaper into the air. The consecutive simulated conditions were reading without agitation of the newspaper (NoAg), followed by reading with agitation of the newspaper (Ag) and post-reading absent the newspaper (PostR), repeated with four newspapers. We found that particle number concentration (ΣN) fell during Ag owing to electroadhesion of ultrafine particles (200 nm) caused by static charges created by friction between the paper surface and the air as a result of newspaper agitation. Conversely, particle surface area concentrations (ΣA) and particle volume concentrations (ΣV) increased significantly during Ag. This was because the larger, fine (1-2.5 μm) and coarse mode (2.5-10 μm), particles were detached from the newspaper during agitation due to inertial detachment - the release of even a small number of these particles contributing greatly to ΣA and ΣV. The critical particle number diameter (CPND) occurred at 207-310 nm. Particles smaller than this were subject to electroadhesion during Ag. The critical particle volume diameter (CPVD) occurred at 130-497 nm. Particles larger than this were subject to inertial detachment during Ag. These observations indicate that the electroadhesion of smaller particles and the inertial detachment of larger particles occur simultaneously. Particle mass concentrations were found to be as high as 168.7-534.3 μg m

Cooking oil fumes (CF) coming from night market stalls exhaust contain substantial amounts of air pollutants such as carbonyl compounds that may contribute to outdoor air pollution and may have adverse health effects on the Taiwanese population. Carbonyl emission characteristics depend on several factors, which include but are not limited to, the cooking style and food material being used. The current study evaluated carbonyl compound emissions from two scenarios: a standard kitchen cooking classroom with a stack gas tunnel and night market food stalls. The different cooking styles and food types cooked using a liquefied petroleum gas (LPG) stove, such as grilled chicken with (GCS) and without sauce (GC), mixed barbecue with sauce (MBS), grilled vegetables with sauce (GVS), stir-fried oyster omelet (OM), fried Taiwanese chicken nuggets (FN) in the kitchen cooking classroom, and grilled chicken with (GCS) and without sauce (GC), stir-fried oyster omelet (OM), grilled vegetables with sauce (GVS), and fried steak (FS) in the night market were evaluated for carbonyl carbon emissions. OM from the kitchen classroom and GCS from the night market showed the highest mean total carbonyl compound concentrations (1850 ± 682 ppb and 1840 ppb). Formaldehyde was found to be the most predominant carbonyl compound, with contribution percentages ranging from 70.9–99.58% of the total carbonyl emission factors in CFs. Grilled vegetables with sauce had the highest emission factor magnitude of 274 µg kg–1 wt. Factors such as the addition of sauce and grilling were also observed to increase carbonyl compound emissions. Corresponding health risks of carbonyl compounds in CFs for the night market vendors were also assessed. All values for cancer risk (R) were above the standard R value for workplace exposure, and HQ values were all greater than 1, suggesting a high risk for adverse health effects. Although our reported values were relatively high due to our sampling conditions, our study was first to be conducted in Taiwan and holds an important contribution to the global existing data of carbonyl compound emissions.

Carcinogenic polycyclic aromatic hydrocarbons (cPAHs) in ambient PM

Taiwan's rivers dry during the winter, exposing large areas of river bed and leading to airborne aeolian river dust. This study used PM10 and windspeed data taken from monitoring stations local to the Zhuoshui River (the river with the largest exposed area in Taiwan) to investigate the relationship between airborne river dust and air quality, and subsequently to estimate river dust emissions. During river dust events, PM10 concentrations were significantly and positively correlated with wind speeds exceeding 5 m/s (the critical wind speed). FPG Lunbei station, located downwind (south of the river) and the closest station to the river, recorded an average hourly PM10 concentration of 189 ± 193 μg/m3 an average correlation coefficient (r) of 0.94 between hourly PM10 concentration and average hourly wind speed, an average annual dust occurrence rate of 15%, and a maximum PM10 concentration exceeding 1000 μg/m3. PM2.5 increased with PM10, albeit at a disproportional rate. When hourly PM10 concentration exceeded 200 μg/m3, most of the particulates in the dust were coarse particulates (PM2.5–10). An hourly PM2.5/PM10 ratio of

This study systemically investigated the ambient PM2.5 (n=108) with comprehensive analyses of the chemical composition, identification of the potential contributors, and estimation of the resultant respiratory physician visits in the residential regions near energy-consuming and high-polluting industries in central Taiwan. The positive matrix fraction (PMF) model with chemical profiles of trace metals, water-soluble ions, and organic/elemental carbons (OC/EC) was applied to quantify the potential sources of PM2.5. The influences of local sources were also explored using the conditional probability function (CPF). Associations between the daily PM2.5 concentration and the risk of respiratory physician visits for the elderly (≥65years of age) were estimated using time-series analysis. A seasonal variation, with higher concentrations of PM2.5, metals (As, Cd, Sb, and Pb), OC/EC and ions (i.e., NO3-, SO42- and NH4+) in the winter than in the spring and summer, was observed. Overall, an increase of 10μgm-3 in the same-day PM2.5 was associated with an ~2% (95% CI: 1.5%-2.5%) increase in respiratory physician visits. Considering the health benefits of an effective reduction, we suggest that the emission from coal combustion (23.5%), iron ore and steel industry (17.1%), and non-ferrous metallurgy (14.4%), accounting for ~70% of the primary PM2.5 in the winter are prioritized to control.

This study investigated allergenic terpenol compounds in incense powder and smoke. The powder of two Thai brands contained higher concentrations of terpenols up to 6.15 times higher than those of two Taiwanese brands. Consequently, Thai incense makers face a higher potential risk of contact dermatitis than Taiwanese incense makers do. d -Limonene was the primary terpenol compound in the powder of Thai B (64.0%) and Thai Y (31.5%), sold in Thailand. By contrast, anisyl alcohol was the primary terpenol compound in the powder of LST (40.3%) and SC (37.7%), sold in Taiwan. After the four brands of incense were ignited, their mean PM 2.5 emission factor was 18.02 ± 6.20 mg g − 1 incense. The PM 2.5 mass emission factors of the Taiwanese brands were far higher than those of the Thai brands, and so were the PM 2.5 terpenol emission factors, showing that the smokes of the Taiwanese incense were potentially more allergenic than those of the Thai incense. Geraniol, the most allergenic terpenol compound, was 2.8%–10.7% of total terpenol compounds in the powder of the four brands, yet was the main contributor to PM 2.5 , constituting 66.3%–83.5% of terpenol compounds in the smokes of the four brands. Furthermore, geraniol exhibited an IP ratio, defined as the incense/powder (IP) ratio of terpenol-related species, > 1 in all four brands, and > 5 in the Taiwanese brands, suggesting a greater health risk with the smoke from the Taiwanese incense. The IP ratios of other terpenol species were all 1, meaning that the generation of PM 2.5 terpenol compounds was potentially enhanced by indoor lighting.

This study evaluated the impact on persistent organic pollutant (POP) emissions from a diesel engine when deploying a diesel oxidation catalyst (DOC) combined with an uncatalyzed diesel particulate filter (DPF), as well as fueling with conventional diesel (B2) and waste cooking oil-based (WCO-based) biodiesel blends (B10 and B20). When the engine was fueled with WCO-based biodiesel blends (B10 and B20) in combination with deploying DOC+A-DPF, their levels of the chlorine and potassium contents could not stimulate the formation of chlorinated POPs (PCDD/Fs and PCBs), although previous studies had warned that happened on diesel engines fueled with biodiesel and deployed with iron-catalyzed DPFs. In contrast, the WCO-based biodiesel with a lower aromatic content reduced the precursors for POP formation, and its higher oxygen content compared to diesel promoted more complete combustion, and thus using WCO-based biodiesel could reduce both PM 2.5 and POP emissions from diesel engines. This study also evaluated the impact of DPF conditions on the POP emissions from a diesel engine; that is, the difference in POP emissions before and just after the regeneration of the DPF. In comparison to the high soot-loaded DPF scenario, the regeneration of the DPF can drastically reduce the formation potential of POPs in the DPFs. An approach was developed to correct the effects of sampling artifacts on the partitioning of gas- and particle-phase POPs in the exhaust. The gas-phase POPs are highly dominant (89.7–100%) in the raw exhausts of diesel engines, indicating that the formation mechanism of POPs in diesel engines is mainly through homogeneous gas-phase formation, rather than de novo synthesis.

A rotating filtration device (RFD) that is filled with porous media is developed for sampling particulate matter with a diameter of 1 μm or less (PM

Incense burning produces potentially harmful particulate matter. In this study we investigated the emissions of PM2.5 and gaseous acetic acid from four brands of traditional incense; Liao and Shang Lao Shan (SLS), sold in Taiwan, and Thai Yellow (Thai Y) and Thai Black (Thai B), sold in Thailand. Additionally, photochemical reactions of PM2.5 carboxylates emitted from incense burning were studied via a simulated light experiment. The average PM2.5 mass emission factor of each incense type was inversely correlated with the ash production of that incense. The Thailand incense carboxylate emissions were markedly higher than the Taiwan incense. Acetate accounted for 87.46% of total carboxylate emissions, with acetate emitted from the Thailand incense 1.26 times higher than from the Taiwan incense. Phthalate was detected in the PM2.5, indicating the presence of plasticizer. Concentrations of PM2.5 acetate, formate, pyruvate, glutarate, succinate, fumarate and tartarate were reduced in simulated light (51.5%–97.1% of those under dark), indicating that these seven types of carboxylate are easily photodegradable. In contrast, malonate, maleate, oxalate and phthalate concentrations in light were 1.17–1.84 times higher than in darkness, indicating photochemical reactions contribute to the formation of these species. The formation of the low-molecular weight dicarboxylates oxalate and malonate was most noticeable. Acetic acid, highly irritating to the respiratory system and skin, was present at high levels for all four incense types, as shown by the gaseous acetic acid/PM2.5 acetate ratios of 1.03–3.61. Burning incense indoors can generate high concentrations of PM2.5 acetate that increases the risks of respiratory and contact irritation, particularly when burning the Thailand incense. Moreover, burning incense in poorly ventilated, dimly lit indoor areas (e.g., temples and homes) can markedly increase the risk of irritation because the gaseous acetic acid is not degraded as it would be in light.

Carcinogenic polycyclic aromatic hydrocarbons (cPAHs) in ambient PM2.5 and a specific molecular marker of biomass burning, levoglucosan, are used to investigate the influence on public health of biomass burning. In this work, we present an effective method for one-time analysis of cPAHs and levoglucosan by GC-MS without derivatization. The method was applied for the analysis of PM2.5 samples (64.3 ± 17.6 μg m−3, n = 57) collected during a smoke haze period in Chiang Mai, Thailand. Levoglucosan was analyzed by using both the developed method (GC-MS) and a reference method (HPAEC-PAD) for comparison. Its average concentration obtained from GC-MS (0.31 ± 0.21 μg m−3) was about 4 times less than the concentration obtained from the reference method (1.22 ± 0.76 μg m−3). Therefore, a correcting factor (CF = 4) was used as a multiplying factor, to obtain a comparative value (1.23 ± 0.86 μg m−3). The average concentration of cPAHs found in PM2.5 samples was 5.88 ± 1.97 ng m−3 with the highest value of 10.86 ng m−3 indicating medium to high cancer risk due to PAHs exposure when referring to values of toxicity equivalence and inhalation cancer risk. Diagnostic ratios of BaA/(BaA + CHR) (0.48 ± 0.04) and IND/(IND + BPER) (0.58 ± 0.04) and strong correlations between PM2.5, levoglucosan and cPAHs concentrations implied that the major source of air pollution in the study period was biomass burning. PM2.5 concentration as a pollution indicator was labelled as BB-low, BB-medium, BB-high or BB-extreme; 100 μg m−3, respectively. The levoglucosan and cPAHs concentration during BB-extreme pollution was 4.3 times and 2.34 times, respectively, that during BB-low pollution, and the correlation coefficient (r) between the concentrations of levoglucosan and cPAHs was as high as 0.987, indicating that the more intense the burning of biomass, the higher the carcinogenic risk in the urban air.

An open-system combustion chamber was designed and constructed for simulation of burning of various biomass types to estimate emission factors of pollutant gases, fine particulate matters and their composition to find out significant tracers. Rice straw (RS), maize residues (MR) and forest leaf litters (FLL) from mixed deciduous forest (MDF) and dry dipterocarp forest (DDF) were collected from various places in Northern Thailand based on land-use types. Approximately 1 kg of air-dried biomass sample was burned in the chamber, PM2.5 were collected. CO2 dominated during the flaming state while CO is predominant in the smoldering state. The highest EFPM2.5 was obtained from MDF burning (4.38 ± 2.99 g kg−1), while the lowest value was from MR burning (2.15 ± 0.95 g kg−1). Among water soluble ions, K+ (biomass burning (BB) tracer) was the most abundant species in PM2.5 followed by Cl− and SO42−. The average EFK+ from the burning of agricultural biomass was significantly higher than the burning of FLL. Scatter plot of K+/SO42− versus K+/Cl− can be used to distinguish between agricultural crop residues and FLL burning. Levoglucosan (BB tracer) was a dominant species among anhydrosugars and also a major component found in FLL burning. The ratios of levoglucosan/K+ and levoglucosan/mannosan obtained from forest and agricultural waste burnings were significantly different, therefore they can be used for BB source identification.

Two portable, battery powered particle size distribution analyzers, TSI NanoScan scanning mobility particle sizer (TSI NanoScan SMPS 3910, USA) and Kanomax Portable Aerosol Mobility Spectrometer (Kanomax PAMS 3300, Japan), have been recently introduced to the market. Both are compact and allow researchers to rapidly measure and monitor ambient or indoor ultrafine and nanoparticles in real time. In addition, both instruments apply the SMPS measuring scheme, utilizing a corona charger in place of a radioactive neutralizer, and are integrated with a hand-held condensation particle counter (CPC). In this study, the different designs, flow schemes, and operational settings of both instruments have been summarized based on the information released by the manufacturers and the available published literature. The performance characteristics and monitoring capability of these two portable ultrafine to nanoparticle sizers were investigated and compared to a reference TSI 3936 lab-based SMPS under identical conditions. Reasonable agreement was found between the three instruments in terms of their efficiency in sizing and counting polydispersed particles. Of the two portable analyzers, PAMS was able to provide a higher sizing resolution for monodispersed particle measurements than NanoScan, when operated under the High Mode (higher sheath to aerosol flow ratio).

Three biodiesels and two aftertreatments were tested on a heavy-duty diesel engine under the US FTP transient cycle and additional four steady engine loads. The objective was to examine their effects on the gaseous and particulate emissions, with emphasis given to the organic and elemental carbon (OC and EC) in the total particulate matter. Negligible differences were observed between the low-sulfur (B1S50) and ultralow-sulfur (B1S10) biodiesels, whereas small reductions of OC were identified with the 10% biodiesel blend (B10). The use of diesel oxidation catalyst (DOC1) showed moderate reductions of EC and particularly OC, resulting in the OC/EC ratio well below unity. The use of DOC plus diesel particulate filter (DOC2+DPF) yielded substantial reductions of OC and particularly EC, resulting in the OC/EC ratio well above unity. The OC/EC ratios were substantially above unity at idle and low load, whereas below unity at medium and high load. The above changes in particulate OC and EC are discussed with respect to the fuel content, pollutant removal mechanisms and engine combustion conditions. Overall, the present study shows that the carbonaceous composition of PM could change drastically with engine load and aftertreatments, and to a lesser extent with the biodiesels under study.

The Mid-Autumn Festival (MAF), or Moon Festival, is a harvest festival in Taiwan, celebrated by families across the island with evening barbecues outside. This study investigated the potential impact of these activities on the air quality in Tainan, a city in southern Taiwan. Fine particulate matter (PM2.5) was examined in the period leading up to the MAF (pre-MAF), during the Festival (MAF), after the Festival (post-MAF), and in the period after this (a period of moderate air quality: MAQ). Gaseous pollutants in PM2.5 were, from highest to lowest mean concentration, NH3, SO2, HCl, HNO3, HNO2, and oxalic acid, while inorganic salts were mainly in the form of the photochemical products SO4(2-), NH4(+), and NO3(-). These inorganic salts accounted for 37.6%-44.5% of the PM2.5 mass concentration, while a further 26.3%-42.8% of the PM2.5 mass was total carbon (TC). TC was mostly composed of organic carbon (OC) produced by photochemical reactions. Of this, 9.8%-14.9% was carboxylates, of which oxalate was the most abundant compound, accounting for 22.8%-31.9% of carboxylates. The presence of phthalates in the PM2.5 indicated emissions from the plastics industry. Although a noticeable amount of aerosol was produced by festival activities and burning of softwood and hardwood, onshore air currents during the festival prevented potential high aerosol loading. During the moderate air quality period following post-MAF, the concentration of total carbohydrates was 1.44-2.64 times the amount during the festival. Levoglucosan and myo-inositol accounted for 81.7%-89.6% of the total carbohydrate concentration. The average Levo/Manno ratio was 18.64 ± 5.24. The concentration of levoglucosan was closely related to that of PO4(3-), erythritol, and galactose. Backward trajectories indicated that biomass burning in China affected the air quality of Tainan City.

The impact of biomass burning in atmospheric aerosols load is poorly known. We investigated the impact of biomass burning through molecular markers on the concentration of PM2.5 aerosol samples collected from a rural site in eastern central India during three episodic periods from October to November 2011. The collected PM2.5 samples were chemically quantified for potassium as well as sugars and dicarboxylic acids using ion chromatography. Levoglucosan and glucose were found as the most abundant sugar compounds and sugar-alcohols showed the predominance of mannitol whereas oxalic acid was the most abundant diacid followed by maleic acid in PM2.5 aerosols. Substantially enhanced concentrations of K+ as well as levoglucosan and glucose were observed in eastern central India. Analysis of the source specific molecular markers and ratios of sugars and diacids infer that combustion of biomass was the major emission sources of organic compounds associated with PM2.5 aerosols over eastern central India. We applied Spearman correlation analysis and principal component analysis to further investigate the sources of measured sugars and diacids. The concentrations of K+ and levoglucosan were significantly correlated with sugars and diacids that verifying their common sources from biomass burning emission. This study demonstrates that biomass burning for domestic heating and cooking purposes and agricultural activities significantly influence the air quality of eastern central India during the investigation period. The obtained data in this research is helpful for the global scientific community to assessments and remedial of air quality parameters in rural areas of developing countries under similar atmospheric circumstances.

We investigated the emission characteristics of the allergenic aromatics eugenol and related compounds and vanillin from the incense powder and the PM2.5 emitted from burning Hsin Shan (HSIN), Shang Chen (SC), Shang Lao Shan (SLS) and Lao Shang Tou (LST) incense sticks. The powder produced 590.7–72.5 μg of fragrant compounds g−1 of incense powder, ranking HSIN >> SLS > LST ∼ SC, with vanillin representing 65.83–71.46% of the total, while the PM2.5 produced a higher 870.8–593.7 μg of fragrant compounds g−1 of incense, ranking HSIN >> SC >> LST > SLS, with methyl isoeugenol the most prevalent compound, at 48.13–56.59% of the total, followed by vanillin. Burning caused some transformation of isoeugenol and methyl isoeugenol into the cis-type and hence both trans and cis types were present in the PM2.5. The ratio of total fragrant compounds in smoke PM2.5 to the content per gram of incense powder (IPt ratio) in the four types of incense ranged from 1.153 (SLS) to 1.507 (SC), indicating that incense powder produces a substantial amount of total fragrant compounds when burned. The ratio of fragrant emission factors in smoke PM2.5 to the content per gram of incense powder (IPs ratio) of methyl eugenol, vanillin, and eugenol was

In spring 2013 air samples were collected from a coastal site in the sparsely populated far south-west of Taiwan and analysed for ambient gases, inorganic salts, carboxylates, and saccharides. Concentration of ambient gases was in the order SO_2 ＞ HCl ＞ HNO_3 ＞ NH_3 ＞ HNO_2. Day-night variation in concentrations indicated that photochemical conversion of HNO_2 to HNO_3 occurs during the day. PM_(2.5) (16.16 ± 5.30 μg m^(-3)) accounted for 61.1% of PM10 mass concentrations. The main inorganic salts were SO_4 ^(2-), NH_4 ^+, Na^+, NO_3 ^-, and Cl^-, collectively accounting for 48.8 ± 27.4% of the PM_(2.5). Cldepletion during the day was higher than during the night due to the presence of reactive photochemical products. The average Cl-depletion of PM_(2.5) (53.1%) was markedly higher than that of PM_(2.5-10) (26.0%), indicating that in PM_(2.5), a high amount of Cl^- reacts with acidic gases to form HCl, which then escapes into the atmosphere. The carboxylate concentration in PM_(2.5) was 0.50 ± 0.24 μg m^(-3). It was found that low-molecular-weight carboxylates formed more readily in the open coastal region than in urban regions of southern Taiwan. Additionally, the daily mean ratio of Oxalate/non-seasalt SO_4 ^(2-) (6.15 ± 2.28%) in the coastal region was higher than that in the urban regions in southern Taiwan. The most prevalent saccharide in PM_(2.5) was myo-inosital (333 ± 300 μg m^(-3)), a type of soil fungus metabolite. Emissions of arabitol and mannitol, emitted through lichen and fungal activity, were markedly higher during the day. Only a trace amount (8.92 ± 16.92 μg m^(-3)) of Levoglucosan (Levo), an indicator of biomass burning, was detected. The mean Levo/organic carbon ratio was 5.04 ± 8.72‰, suggesting that biomass burning contributed slightly to aerosols in the study area. An analysis of air mass backward trajectories showed that the products of biomass burning in Southeast Asia and southern China may be transported to the study area through long-range transport. This effect is more noticeable during the day when onshore breezes support the transport of particles sourced from the west of Taiwan.

Simultaneous N- and Pt-doped TiO 2 powders are usually synthesized via multi-stage processes. In this study, Pt/N-doped (sample Pt/N-TiO 2 ), Pt-doped (sample Pt-TiO 2 ), N-doped (sample N-TiO 2 ), and without doping (sample TiO 2 ) TiO 2 in the form of spherical nano to micro-particles are rapidly synthesized in a single-step process by spraying clear Ti- and Pt-containing nano aerosols into an atmospheric-pressure microwave plasma torch. The anatase modified Pt/N-TiO 2 powders were produced in about 0.12 s. After the collection of 14-stage impactors, the size distribution showed that the most of the particles by number were in the 2 , Pt-TiO 2 , and Pt/N-TiO 2 powders, respectively, although the mass distribution of the powders was mainly in the 1–2.5 μm range. Chemical composition analysis showed that the N doped contents were 0.47, 0.21, and 0.41 at.% in the N-TiO 2 , Pt-TiO 2 , and Pt/N-TiO 2 powders, respectively, levels higher than that of the TiO 2 sample (0.12 at.%). As a result, the photocatalytic activities of N-containing (N-TiO 2 and Pt/N-TiO 2 samples) powders are significantly higher than those of TiO 2 and P25 under visible light degradation. The rapid production of N- and/or Pt-TiO 2 powders by using a simple plasma process can thus be achieved successfully for use in photocatalytic applications.

This study investigated the chemical properties and composition sources of dicarboxylic organic acids and inorganic salts in dry plus wet deposition (DWD) and wet-only deposition at a coastal suburban area in southern Taiwan in 2008. DWD is the accumulation of dry deposition and wet deposition from the beginning of each new rain event, while wet-only deposition is the wet deposition from the beginning of each new rain event only. A total of 60 samples were collected during the period of study. The wet-only deposition samples were slightly more acidic (pH 5.01–5.50) than the DWD samples (pH 5.51–6.00). The total volume-weighted mean (VWM) equivalent ionic concentration of 784.3 ± 431.1 μeq L−1 in DWD was higher than that of 682.2 ± 392.4 μeq L−1 in wet-only deposition. In both types of deposition the major cation species were Ca2+, Na+ and NH 4 + , and the major anion species were HCO 3 − , Cl− and non-sea salt (nss) nss- SO 4 2 − . Total dicarboxylic acids contributed only 0.60% and 0.45% of the total ionic equivalent concentration in DWD and wet-only deposition, respectively, and oxalic and malonic acids were the major dicarboxylic acid species. DWD to wet-only deposition species concentration ratios (DWD/W ratios) were always higher than 1.0. DWD contained more water-soluble inorganic salts and dicarboxylic acids than wet-only deposition, with DWD/W ratios of the dust-bound species K+, Mg2+ and Ca2+ as large as 1.6–1.8 and those from photochemical species nss- SO 4 2 − and NH 4 + of 1.36 and 1.29, respectively. These ratios show that the dry deposition flux of dust is greater than that of photochemical particles. In addition, the 1.81 ratio for oxalic acid shows that oxalic acid is easier to remove from the atmosphere via dry deposition than malonic and succinic acids. Probable deposition composition sources for both DWD and wet-only deposition, investigated using principal component analysis, were marine spray, photochemical inorganic products, and terrestrial origin and photochemical organic products. As the study site is close to the coast, marine spray deposits as dry deposition, and the anthropogenic dicarboxylic acids deposit together with resuspended crustal materials.

The manufacture of water-containing butanol diesel blends requires no excess dehydration and surfactant addition. Therefore, compared with the manufacture of conventional bio-alcohols, the energy consumption for the manufacture of water-containing butanol diesel blends is reduced, and the costs are lowered. In this study, we verified that using water-containing butanol diesel blends not only solves the tradeoff problem between nitrogen oxides (NOx) and particulate matter emissions from diesel engines, but it also reduces the emissions of persistent organic pollutants (POPs), including polycyclic aromatic hydrocarbons, polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls, polychlorinated diphenyl ethers, polybrominated dibenzo-p-dioxins and dibenzofurans, polybrominated biphenyls and polybrominated diphenyl ethers. After using blends of B2 with 10% and 20% water-containing butanol, the POP emission factors were decreased by amounts in the range of 22.6%-42.3% and 38.0%-65.5% on a mass basis, as well as 18.7%-78.1% and 51.0%-84.9% on a toxicity basis. The addition of water-containing butanol introduced a lower content of aromatic compounds and most importantly, lead to more complete combustion, thus resulting in a great reduction in the POP emissions. Not only did the self-provided oxygen of butanol promote complete oxidation but also the water content in butanol diesel blends could cause a microexplosion mechanism, which provided a better turbulence and well-mixed environment for complete combustion.

Evidence shows a strong association among air pollution, oxidative stress (OS), deoxyribonucleic acid (DNA) damage, and diseases. Recent studies indicated that the aging, human neurodegenerative diseases and cancers resulted from mitochondrial dysfunction and OS. The purpose of this study is to provide a probabilistic risk assessment model to quantify the atmospheric diesel exhaust particles (DEP)-induced pre-cancer biomarker response and cancer incidence risk for residents in south Taiwan. We conducted entirely monthly particulate matter sampling data at five sites in Kaohsiung of south Taiwan in the period 2002e2003. Three findings were found: (i) the DEP dose estimates and cancer risk quantification had heterogeneously spatiotemporal difference in south Taiwan, (ii) the pre-cancer DNA damage biomarker and cancer incidence estimates had a positive yet insignificant association, and (iii) all the estimates of cancer incidence in south Taiwan populations fell within and slight lower than the values from previous cancer epidemiological investigations. In this study, we successfully assessed the tumor incidence for residents posed by DEP exposure in south Taiwan compared with the epidemiological approach. Our approach provides a unique way for assessing human health risk for residences exposed to atmospheric DEP depending on specific combinations of local and regional conditions. Our work implicates the importance of incorporating both environmental and health risk impacts into models of air pollution exposure to guide adaptive mitigation strategies.

This study describes a method for reducing the emissions of toxic organic pollutants from heavy duty diesel engines fueled by biodiesel produced from waste cooking oil (WCO). An analytical method was developed to simultaneously measure five pollutants from one exhaust sample, namely polycyclic aromatic hydrocarbons (PAHs), polychlorined dibenzo- p -dixins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated dibenzo- p -dioxins and dibenzofurans (PBDD/Fs) and polybrominated diphenyl ethers (PBDEs). As yet, no data regarding PBDD/F emissions from mobile sources has been reported in the literature. The mass concentrations in the exhaust, in order, were PAHs ≫ PBDEs ≫ PBDD/Fs > PCBs > PCDD/Fs, while for the pollutants having dioxin-like toxicity, their toxicity concentrations, in order, were PCDD/Fs > PBDD/Fs > PCBs. These concentrations were two to four orders higher than those in the atmosphere. Even though the chlorine content in the WCO-based biodiesel was five times higher than that of fossil diesel, the reduction in the emission factors of the aforesaid pollutants increased along with the percentage of biodiesel. For example, B20 achieved a 49–73% and 61–83% reduction in mass and toxicity, respectively. In conclusion, the use of WCO-based biodiesel not only solves the problem of waste oil disposal, but also reduces the toxic organic pollutant emissions from diesel engines.

The carboxylic acid component of autumn aerosol and wet deposition (fog water and rainwater) in a broad-leaved forest in central Taiwan was investigated. High levels of low molecular weight carboxylic acids (LMWCAs) were noted in all deposition types. Acetic acid, oxalic acid and formic acid were the most prevalent carboxylic acids, together accounting for 72.2% (fog water), 86.7% (rain water), 77.2% (PM 2.5 ) and 88.3% (PM 2.5–10 ) of total carboxylic acid. The forest fog water contained 2453.9 ± 1030.5 ng mL −1 of carboxylic acid, 2.71 times more than was contained in forest rainwater. In PM, most carboxylic acid existed in the fine PM 2.5 aerosol (576.6 ± 254.1 ng m −3 or 6.28 times more than was contained in PM 2.5–10 . Most carboxylic acids in PM had higher concentrations during the day. Pyruvic acid concentration was higher during the night (2.97 times), however, owing to its rapid photodegradation during the day. Citric acid accounted for 9.1% of the total carboxylic acid in fog water compared with just 1.8% in rainwater, confirming its origin from emissions from leaves. Raman spectroscopy was used to observe the photochemical conversion of citric acid into intermediate products and this observation confirmed that the carboxylic acids identified in the forest dry and wet depositions originated directly from biological emissions in the forest environment.

By modulating the Earth-atmosphere energy, hydrological and biogeochemical cycles, and affecting regional-to-global weather and climate, biomass burning is recognized as one of the major factors affecting the global carbon cycle. However, few comprehensive and wide-ranging experiments have been conducted to characterize biomass-burning pollutants in Southeast Asia (SEA) or assess their regional impact on meteorology, the hydrological cycle, the radiative budget, or climate change. Recently, BASE-ASIA (Biomass-burning Aerosols in South-East Asia: Smoke Impact Assessment) and the 7-SEAS (7-South-East Asian Studies)/Dongsha Experiment were conducted during the spring seasons of 2006 and 2010 in northern SEA, respectively, to characterize the chemical, physical, and radiative properties of biomass-burning emissions near the source regions, and assess their effects. This paper provides an overview of results from these two campaigns and related studies collected in this special issue, entitled “Observation, modeling and impact studies of biomass burning and pollution in the SE Asian Environment”. This volume includes 28 papers, which provide a synopsis of the experiments, regional weather/climate, chemical characterization of biomass-burning aerosols and related pollutants in source and sink regions, the spatial distribution of air toxics (atmospheric mercury and dioxins) in source and remote areas, a characterization of aerosol physical, optical, and radiative properties, as well as modeling and impact studies. These studies, taken together, provide the first relatively complete dataset of aerosol chemistry and physical observations conducted in the source/sink region in the northern SEA, with particular emphasis on the marine boundary layer and lower free troposphere (LFT). The data, analysis and modeling included in these papers advance our present knowledge of source characterization of biomass-burning pollutants near the source regions as well as the physical and chemical processes along transport pathways. In addition, we raise key questions to be addressed by a coming deployment during springtime 2013 in northern SEA, named 7-SEAS/BASELInE (Biomass-burning Aerosols & Stratocumulus Environment: Lifecycles and Interactions Experiment). This campaign will include a synergistic approach for further exploring many key atmospheric processes (e.g., complex aerosol–cloud interactions) and impacts of biomass burning on the surface–atmosphere energy budgets during the lifecycles of biomass-burning emissions.

PM10 aerosol was collected between February and April 2010 at an urban site (CMU) and an industrial site (TOT) in Chiang Mai, Thailand, and characteristics and provenance of water-soluble inorganic species, carboxylates, anhydrosugars and sugar alcohols were investigated with particular reference to air quality, framed as episodic or non-episodic pollution. Sulfate, a product of secondary photochemical reactions, was the major inorganic salt in PM10, comprising 25.9% and 22.3% of inorganic species at CMU and TOT, respectively. Acetate was the most abundant monocarboxylate, followed by formate. Oxalate was the dominant dicarboxylate. A high acetate/formate mass ratio indicated that primary traffic-related and biomass-burning emissions contributed to Chiang Mai aerosols during episodic and non-episodic pollution. During episodic pollution carboxylate peaks indicated sourcing from photochemical reactions and/or directly from traffic-related and biomass burning processes and concentrations of specific biomarkers of biomass burning including water-soluble potassium, glutarate, oxalate and levoglucosan dramatically increased. Levoglucosan, the dominant anhydrosugar, was highly associated with water-soluble potassium (r = 0.75–0.79) and accounted for 93.4% and 93.7% of anhydrosugars at CMU and TOT, respectively, during episodic pollution. Moreover, levoglucosan during episodic pollution was 14.2–21.8 times non-episodic lows, showing clearly that emissions from biomass burning are the major cause of PM10 episodic pollution in Chiang Mai. Additionally, the average levoglucosan/mannosan mass ratio during episodic pollution was 14.1–14.9, higher than the 5.73–7.69 during non-episodic pollution, indicating that there was more hardwood burning during episodic pollution. Higher concentrations of glycerol and erythritol during episodic pollution further indicate that biomass burning activities released soil biota from forest and farmland soils.

Spherical TiO2 nano- to microparticles are rapidly synthesized by spraying clear stock solution as a nano aerosol into an atmospheric-pressure microwave plasma torch at 550–600°C. The stock solution was prepared by an initial H2O/TiCl4 (titanium tetrachloride) volume ratio of 8. At about 0.15 s, anatase TiO2 powders were produced and collected by 14-stage impactors. The size distribution shows that 98.47% of the particles in number were in the < 10-nm impactor, with the normalized particle number percentage (dn'/dlogDp) of 327.1, although the mass distribution of the powders was mainly in the size range of 2.5–6.2 μm. Scanning electron microscopy and transmission electron microscopy images show that most of the spherical TiO2 particles had a primary particle size of about 10 nm. Moreover, larger secondary particles (several μm), likely aggregated small particles were also presented. The chemical composition and elemental analyses show that the structure of the powders is mainly composed of TiO2 with traces of TiO2-xNx. Hence, the total reaction pathway is proposed as Ti(OH)xCl4-x + H2O + N2 + O2 → TiO2 nuclei + HCl + other byproducts. Moreover, the ultraviolet-visible absorption spectrum and photocatalytic performance of the synthesized powders during exposure to ultraviolet or visible light are comparable to those of commercial TiO2 powders.

This study systemically investigated the ambient PM

This study investigated allergenic terpenol compounds in incense powder and smoke. The powder of two Thai brands contained higher concentrations of terpenols up to 6.15 times higher than those of two Taiwanese brands. Consequently, Thai incense makers face a higher potential risk of contact dermatitis than Taiwanese incense makers do. d-Limonene was the primary terpenol compound in the powder of Thai B (64.0%) and Thai Y (31.5%), sold in Thailand. By contrast, anisyl alcohol was the primary terpenol compound in the powder of LST (40.3%) and SC (37.7%), sold in Taiwan. After the four brands of incense were ignited, their mean PM

Size-segregated aerosol samples were collected continuously from July 2009 to June 2010 at urban area of Raipur, the eastern central India. The collected samples were analyzed for PM10 mass and its water-soluble dicarboxylate species and major inorganic ions. Results showed that the annual mean PM10 concentration was 270.5 µg/m3, which varied from 109.8 to 455.6 µg/m3. The higher concentration of PM10 mass was found during winter season followed by spring and summer, and lower during monsoon season. High PM10 mass concentration in Raipur could be attributed to the anthropogenic activities which may include high rate of construction activities, biomass combustion and mechanical erosion from road dusts. The concentrations of total dicarboxylates (TDCs) ranged from 325.3 to 1537.7 ng/m3 with an average of 904.0 ng/m3 constituting only 0.3% of PM10 mass. The oxalate (C2) and malonate (C3) were the dominant DCs followed by succinate (C4) and phthalate (Ph). The water-soluble major inorganic ions constituted 10.0% of PM10 mass with SO42– and NO3– being the dominant species followed by Cl– and Ca2+. The concentrations of dicarboxylates and major inorganic ions also showed maxima in winter and spring than summer and monsoon seasons. The ratio of malonate to succinate was used to distinguish primary sources from secondary sources of these dicarboxylates. The average C3/C4 ratio in spring and summer was 1.6 and 2.1, respectively, which suggested a large contribution of secondary sources to particulate dicarboxylates formation. Correlation analysis of DCs with SO42– and K+ was investigated to interpret their possible secondary formation pathways. Source identification study by principal component analysis (PCA) revealed that photochemical, secondary sources and vehicular emissions were the main sources contributing to overall PM10 mass with minor contribution from paved road dust and explained almost 95.5% variance of total aerosol data set.

PM(subscript 10) samples were collected between July 2009 and June 2010 in the urban area of Durg City, India, and analyzed for water-soluble dicarboxylate species. Observed PM(subscript 10) concentrations varied from 94.0 to 432.1 μg/m^3 with an annual average of 253.5 μg/m^3. The annual average concentration of PM(subscript 10) was four times higher than the Indian Central Pollution Control Board (CPCB) National Ambient Air Quality Standard (Indian NAAQS) prescribed limit of 100 μg/m^3. The high PM(subscript 10) mass concentration in Durg City are attributed to anthropogenic activities, including a high rate of construction activities, biomass combustion and mechanical disturbance of road dusts. The highest PM(subscript 10) value was recorded during the winter, a period characterized by extensive biomass burning, especially at night, while the lowest PM(subscript 10) concentration was recorded during the monsoon, when there was significant precipitation. The highest concentrations of dicarboxylates were found during winter and spring. On average, total water-soluble dicarboxylates (966 ng/m^3) accounted for 0.39% of the PM(subscript 10) mass. Oxalate (C2), followed by malonate (C3) and succinate (C4), dominated the total mass of dicarboxylates, the sum of these three species accounting for 77.5% of the total analyzed. The malonate to succinate concentration ratio calculated in this study was higher than those reported for vehicular emissions, suggesting that in addition to vehicular exhausts, secondary formation of particulate dicarboxylates via photo-oxidation also occurred. Principal component analysis (Varimax Rotated Component Matrix) revealed that secondary aerosol formation, coal and biomass combustion, and vehicular emissions were the major sources contributing to overall PM10 mass in Durg City, India.

Diesel engine exhaust contains large numbers of submicrometer particles that degrade air quality and human health. This study examines the number emission characteristics of 10–1000 nm nonvolatile particles from a heavy-duty diesel engine, operating with various waste cooking oil biodiesel blends (B2, B10 and B20), engine loads (0%, 25%, 50% and 75%) and a diesel oxidation catalyst plus diesel particulate filter (DOC + DPF) under steady modes. For a given load, the total particle number concentrations (NTOT) decrease slightly, while the mode diameters show negligible changes with increasing biodiesel blends. For a given biodiesel blend, both the NTOT and mode diameters increase modestly with increasing load of above 25%. The NTOT at idle are highest and their size distributions are strongly affected by condensation and possible nucleation of semivolatile materials. Nonvolatile cores of diameters less than 16 nm are only observed at idle mode. The DOC + DPF shows remarkable filtration efficiency for both the core and soot particles, irrespective of the biodiesel blend and engine load under study. The NTOT post the DOC + DPF are comparable to typical ambient levels of ∼104 cm−3. This implies that, without concurrent reductions of semivolatile materials, the formation of semivolatile nucleation mode particles post the aftertreatment is highly favored.

The PM 2.5 aerosol from within an area of Pinus morrisonicola Hayata in Taiwan was collected and analyzed for its low molecular weight carboxylic acid (LMWCAs) content. Oxalic acid was the major LMWCA in the aerosol, followed by acetic, tartaric and maleic acids. This differs significantly from the LMWCA composition of PM 2.5 aerosol reported for a southern Taiwan suburban region (oxalic > succinic > malonic) [Atmospheric Environment 42, 6836–6850 (2008)]. P. morrisonicola Hayata emits oxalic, malic and formic acids and yet there was an abundance of maleic and tartaric acids in the PM 2.5 forest aerosol, indicating that tartaric acid is derived from the transformation of other P. morrisonicola Hayata emissions. Raman spectroscopy was applied and 28 species of LMWCAs and inorganic species were identified. The photochemical mechanisms of maleic and tartaric acids were studied and it was found that the abundant tartaric acid in forest aerosol is most probably the photochemical product from reactions of maleic acid. Furthermore, tartaric acid is photochemically transformed into formic acid and ultimately into CO 2 .

Rainfall samples were collected over a period of 3 years and 8 months in subtropical East Asia. They are categorized into different rainfall types and analyzed to assess the ionic composition and its effect on the acidity of wet deposition in southern Taiwan. Only 4% of samples had a pH of

Many studies have investigated the particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) emissions of burning incense on the quality of surrounding air. However, the reduction of PM and PAHs from burning incense has received little attention. In the present study, two types of incense were made in the laboratory. Five to thirty percent of nanoscale calcium carbonate (nano-CaCO3) was added to Hsing Shan and Lao Shan wood flours, which are popular incense materials. It was found that the addition of 10% nano-CaCO3 reduced PM by 7.30 mg/g and reduced particle-phase PAHs by 1.03 µg/g and benzo[a]pyreneequivalent by 0.15 µg/g. In addition, considering the total consumption of incense, weadded 10% nano-CaCO3 in incense powder. Then, it can reduce PM by 73.0 tons,particle-phase PAHs by 10.3 kg, and benzo[a]pyrene equivalent by 1.5 kg in Taiwan per year. The findings of this study may serve as a guide to producing safer and less-polluting incense. Key words: Incense, calcium carbonate, particulate matter, polycyclic aromatic hydrocarbons, benzo[a]pyrene equivalent.

This paper reports the atmospheric concentrations of PM2.5 and PM1 mass, water soluble inorganic components and their seasonal variations measured between the period of July 2009 and June 2010 in Durg city (20°23' to 22°02'N and 80°46' to 81°58'E), India. A cascade impactor sampler with Whatman 41 glass filters was used to collect aerosol samples in PM2.5 and PM1 size fractions. The results showed that the annual mean concentration of PM2.5 and PM1 were 135.0 µg/m3 and 64.7 µg/m3, respectively. Annual cycle shows highest concentration of PM2.5 and PM1 mass and water soluble ions in winter season and the lowest during rainy season. This is attributed to the enhanced production of aerosols and prevailing meteorological conditions. The higher PM1/PM2.5 ratio (0.48) during the whole campaign clearly indicates larger PM1 particle fractions were in PM2.5 at this location. Out of the total aerosol mass, water soluble constituents contributed an average of 11.57% (7.48% anions, 4.09% cations) in PM2.5 and 16.98% (11.14% anions, 5.85% cations) in PM1. The concentrations of SO42- and NO3- were highest in all size fractions and accounted for 32.76% and 13.38% of the total mass of the water soluble ions in PM2.5 and 32.78% and 12.21% in PM1 size fractions. Na+, Mg2+ and Ca2+, derived from the soil dust particles, were higher in spring and summer, as the dry weather in this season was favorable for the resuspension of soil particles. The seasonal variation of Cl-, K+ and secondary components (NH4+, NO3- and SO42-) were similar with high concentrations in winter and low concentrations in fall. Two principal components explaining 76.6% and 65.9% of the variance for PM2.5 and PM1 data set respectively were identified. Factor 1 has significant loading of species of anthropogenic origins and factor 2 showed partial associations with species of natural origins.

Three kinds of diesel particulate filters (DPFs) were installed on used diesel-powered vehicles to investigate their influences on air pollutant emissions. The air pollutant emissions were measured before, after and running for specific distances to assess the deterioration effect. The emission measurement was performed on a chassis dynamometer. The results show that emissions of smoke, CO and HC are all reduced after DPF installation. After 20000 km driving, the emission concentrations of the above 3 criteria air pollutants do not increase in comparison with that right after installation. When DPFs are installed, the emissions of PAHs (polycyclic aromatic hydrocarbons) are reduced by 85.6-89.4% and 69.0-89.2% for heavy-duty diesel vehicles (HDVs) and light-duty diesel vehicles (LDVs), respectively. After driving 20000 km for HDVs and 2500 km for LDVs, PAH emissions do not increase in comparison with that right after installation, indicating that the DPFs do not deteriorate after driving for the test mileages. The lower molecular weight PAHs predominates in the exhaust both before and after DPF installation. The results also show the reduction rate is higher for higher molecular weight PAHs due to their tendency to adsorb on particulate.

Aerosol from the burning two types of sandalwood-based incense, Hsing Shan and Lao Shan , was analyzed to characterize the chemical profile of total particulate matter emitted. The total particulate matter (PM) mass emission factors were 46.3 ± 2.68 mg g −1 of Hsing Shan incense and 43.7 ± 1.08 mg g −1 of Lao Shan incense. Chemical analysis of emissions from the two types of incense revealed that of the 25 components in four groups characterized, anhydrosugars formed the major group, at 46.7–52.2% w/w of the identified particulate and 1078.3–1169.8 μg g −1 of incense, followed by inorganic salts at 30.4–31.8% w/w of identified particulate and 681.6–734.0 μg g −1 of incense, carboxylic acids at 12.0–17.1% w/w of the identified particulate and 268.6–392.8 μg g −1 of incense, and sugar alcohols at 4.44–5.38% w/w of the identified particulate and 102.3–120.6 μg g −1 of incense. More anhydrosugars and sugar alcohols were emitted from Lao Shan incense than from Hsing Shan incense whereas more carboxylic acids and organic salts were emitted from Hsing Shan than from Lao Shan . These differences were due to structural and functional differences in the young sandalwood used to make Hsing Shan and the aged sandalwood used to make Lao Shan . The anhydrosugar levoglucosan, used as a marker of biomass burning, was always the most abundant species in emitted PM for both incenses ( Lao Shan 21.7 mg g −1 of PM and Hsing Shan 18.7 mg g −1 ). K + and Cl − were the second most abundant components (K + and Cl − were summed), accounting for 10.6 mg g −1 of Hsing Shan PM and 9.85 mg g −1 of Lao Shan PM. The most abundant carboxylic acids in the emissions were formic, acetic, succinic, glutaric and phthalic acid. The latter is a fragrance ingredient and a potential health hazard and was twice as prevalent in Lao Shan emissions. Xylitol was the most prevalent of the sugar alcohols at 35.7–36.6% w/w of total identified sugar alcohols. These abundant species are potential markers for incense burning. K + , levoglucosan, mannosan and xylitol are already reported in discriminator ratios for wood burning and it is proposed here that these can and should also apply to incense burning. The calculated discriminator ratios for two types of incense burning reported here are 0.229–0.288 for K/Levo, 12.5–13.5 for Levo/Manno, and 21.5–23.7 for the novel discriminator ratio Levo/Xylitol.

This study elucidates the characteristics of ambient PM2.5 (fine) and PM1 (submicron) samples collected between July 2009 and June 2010 in Raipur, India, in terms of water soluble ions, i.e. Na+, NH 4 + , K+, Mg2+, Ca2+, Cl−, NO 3 − and SO 4 2− . The total number of PM2.5 and PM1 samples collected with eight stage cascade impactor was 120. Annual mean concentrations of PM2.5 and PM1 were 150.9 ± 78.6 μg/m3 and 72.5 ± 39.0 μg/m3, respectively. The higher particulate matter (PM) mass concentrations during the winter season are essentially due to the increase of biomass burning and temperature inversion. Out of above 8 ions, the most abundant ions were SO 4 2− , NO 3 − and NH 4 + for both PM2.5 and PM1 aerosols; their average concentrations were 7.86 ± 5.86 μg/m3, 3.12 ± 2.63 μg/m3 and 1.94 ± 1.28 μg/m3 for PM2.5, and 5.61 ± 3.79 μg/m3, 1.81 ± 1.21 μg/m3 and 1.26 ± 0.88 μg/m3 for PM1, respectively. The major secondary species SO 4 2− , NO 3 − and NH 4 + accounted for 5.81%, 1.88% and 1.40% of the total mass of PM2.5 and 11.10%, 2.68%, and 2.48% of the total mass of PM1, respectively. The source identification was conducted for the ionic species in PM2.5 and PM1 aerosols. The results are discussed by the way of correlations and principal component analysis. Spearman correlation indicated that Cl− and K+ in PM2.5 and PM1 can be originated from similar type of sources. Principal component analysis reveals that there are two major sources (anthropogenic and natural such as soil derived particles) for PM2.5 and PM1 fractions.

This work focuses on size segregated atmospheric aerosol mass concentrations and water soluble inorganic components in Chhattisgarh, the eastern central India. Investigation on the monitoring of ambient air levels of atmospheric particulates were done around a large source of primary anthropogenic particulate emissions: the industrial area and coal based power plants. Chemical characterization was carried out for aerosol samples collected in urban area, Raipur, (21°14′N, 81°38′E) of Chhattisgarh region over a period of one year, using cascade impactor. Annual mean of mass concentration for coarse (PM 2.5–10 ) and fine (PM 2.5 ) aerosols were monitored to be 238.1 ± 89.9 and 167.0 ± 75.3 µg m − 3 respectively This work deals with the seasonal variation and meteorological influences of inorganic components of the aerosols viz. NO 3 − , Cl − and SO 4 2− , Mg 2+ , Na + , K + , Ca 2+ and NH 4 + . The annual mean concentration of the inorganic components were monitored to be 3.8 ± 2.5, 8.9 ± 2.7, 10.2 ± 1.5, 2.6 ± 0.6, 8.7 ± 7.2, 4.6 ± 1.8, 16.4 ± 6.9 and 0.4 ± 0.5 µg m − 3 respectively in coarse particles and 8.2 ± 7.1, 6.8 ± 3.6, 46.5 ± 32.8, 1.7 ± 0.6, 7.4 ± 3.6, 5.9 ± 3.4, 10.2 ± 2.9, and 8.8 ± 7.7 µg m − 3 respectively in fine particles, for the above ions. The average distribution of nitrate and sulphate in PM 2.5–10 were found to be 1.6 and 4.2% and in PM 2.5 were 4.9 and 27.9% respectively indicating the dominance of sulphate in both PM 2.5–10 and PM 2.5 particles. Here, industrial emission plays important role for contribution of PM 2.5 particle loading in the atmosphere. The cation–anion rational analysis indicated that the PM 2.5–10 particles were mostly neutralized and PM 2.5 particle were acidic. The major ions were mainly in the form of NaCl > CaSO 4 > K 2 SO 4 > MgSO 4 > KCl > NH 4 Cl > Ca(NO 3 ) 2 > KNO 3 > MgCl 2 > Mg(NO 3 ) 2 > NH 4 NO 3 > (NH 4 ) 2 SO 4 in coarse aerosol particles and (NH 4 ) 2 SO 4 > K 2 SO 4 > CaSO 4 > NaCl > NH 4 NO 3 > CaCl 2 > KNO 3 > MgCl 2 > Ca(NO 3 ) 2 > KCl > NH 4 Cl in fine particles.