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Diurnal Variation, Vertical Distribution and Source Apportionment of Carcinogenic Polycyclic Aromatic Hydrocarbons (PAHs) in Chiang-Mai, Thailand
Abstract
Diurnal variation of particulate polycyclic aromatic hydrocarbons (PAHs) was investigated by collecting PM10 at three different sampling altitudes using high buildings in the city center of Chiang-Mai, Thailand, during the relatively cold period in late February 2008. At site-1 (12 m above ground level), B[a]P concentrations ranged from 30.3 -1,673 pg m-3 with an average of 506±477 pg m-3, contributing on average, 8.09±8.69% to ?PAHs. Ind and B[b]F concentrations varied from 54.6 to 4,579 pg m-3 and from 80.7 to 2,292 pg m-3 with the highest average of 1,187±1,058 pg m-3 and 963±656 pg m-3, contributing on average, 19.0±19.3% and 15.4±12.0% to ?PAHs, respectively. Morning maxima were predominantly detected in all observatory sites, which can be described by typical diurnal variations of traffic flow in Chiang-Mai City, showing a morning peak between 6 AM. and 9 AM. Despite the fact that most monitoring sites might be subjected to specific-site impacts, it could be seen that PAH profiles in Site-1 and Site-2 were astonishingly homogeneous. The lack of differences suggests that the source signatures of several PAHs become less distinct possibly due to the impacts of traffic and cooking emissions from ground level.
... 32 Currently, most studies have highlighted the behavior of particulate PAHs in tropical countries and in northern Thailand. [33][34][35][36][37][38][39][40][41] Despite countless measurements of PAH compositions in coarse and fine particles around the world, there is inadequate information focusing on the characterization of particulate PAHs in tropical atmospheres. Most studies have targeted estimations of source apportionment. ...
... There has been an increasing number of articles related to air quality in northern Thailand. 36,49 These can be correlated with the PM 2.5 levels, which are caused by large-scale 'hot spot' locations. The pollutant sources can be identified, for example, pollutants from forest fires, burning of agriculture waste, and trans-boundary haze pollution. ...
... 115,116 Over the past few decades, numerous studies concerned with source identifications, quantitative source apportionments, and ecological risk assessments of PAHs in the ambient air of Thailand have conducted intensive investigations. 35,36,39,40 In the northern part of Thailand, agricultural waste and biomass burning during cold periods have released large amounts of particulate matter, especially ultra-fine particles, including PM 2.5 -bound PAHs, into the atmosphere. There are a number of recent studies that use PAHs data to obtain inferences of particulate pollution sources. ...
PM2.5 is widely regarded as a major air pollutant due to its adverse health impacts and intimate relationship with the climate system. This study aims to characterize the chemical components (e.g., organic carbon (OC), elemental carbon (EC), water soluble ionic species (WSIS) and polycyclic aromatic hydrocarbons (PAHs) in PM2.5 collected at Doi–Inthanon in Chiang-Mai, Thailand, the highest mountain in Thailand. All samples (n = 50) were collected by MiniVolTM portable air samplers from March 2017 to March 2018. In this study we found the average PM2.5 concentration was 100 ± 48.6 μg m⁻³. The OC/EC ratio was 6.8 ± 3.0, and the decreasing order of the WSIS concentrations was SO4²⁻>Na⁺>Ca²⁺>NH4⁺>NO3⁻>K⁺>Cl⁻>NO2⁻>Mg²⁺> F⁻. The total concentrations of nineteen PAHs were defined as the sum of Ace, Fl, Phe, Ant, Fluo, Pyr, B[a]A, Chry, B[b]F, B[k]F, B[a]F, B[e]P, B[a]P, Per, Ind, B[g,h,i]P, D[a,h]A, Cor, and D[a,e]P. The concentration of total PAHs was 2.361 ± 2.154 µg m⁻³. Principal component analysis (PCA) highlights the importance of vehicular exhaust, biomass burning, diesel emissions, sea-salt aerosols and volatilization from fertilizers as the five dominant potential sources that accounted for 51.6%, 16.2%, 10.6%, 5.20% and 3.70% of the total variance, respectively. The rest of the 12.7% variance probably is associated with unidentified local and regional sources such as incinerators, joss paper/incense burning, and domestic cooking. Interestingly, the results from the source estimations from the PCA underlined the importance of vehicular exhaust as the major contributor to the PM2.5 concentrations in the ambient air of Don-Inthanon, Chiang-Mai province. However, it is crucial to emphasize that the impacts of agricultural waste burning, fossil fuel combustion, coal combustion and forest fires on the variations of OC, EC and WSIS contents were not negligible.
... Although PM air pollution shows considerable spatial variation in three dimensions among and within cities, most studies only evaluated spatial variability of PM in two dimensions (i.e., horizontally) [10][11][12][13][14]. Nonetheless, investigating vertical variation of PM concentrations is also important because the vertical distribution of pollutants can be affected by the microenvironment of buildings [15][16][17], particularly around high-rise buildings that are now common in modern-day urban areas. Some studies have found declining concentrations of ground-level PM emissions at higher altitudes [18][19][20][21][22]. ...
... However, others have reported that variations in concentrations of PM with altitude depend on particle sizes and building-specific attributes [23][24][25][26]. In addition, differences in concentrations among PM species (e.g., sulfate, nitrate, and PAHs) at altitude indicate that the types of emitters and distances from them could also be responsible for variations in vertical distributions [16,17,20,27,28]. Quantifying the vertical distribution could help determine whether the PM is generated locally or is being transported from more distant locations [29]. ...
Receptor models have been widely used for identifying and quantifying source-specific contributions from mixtures of air pollutants. Nonetheless, our knowledge is still limited on how various components of air pollution are vertically distributed and the sources of such pollutants. In this study, we collected 135 samples of PM2.5 (particles with aerodynamic diameter less than or equal to 2.5 µm) from building balconies at three altitudes in the metropolis of Taipei (Taiwan) and analyzed the samples for elements and polycyclic aromatic hydrocarbons that could be used to identify the sources of those pollutants. We used positive matrix factorization (PMF) to identify seven likely sources, including combustion, sulfur-rich aerosol, fresh traffic, industry/Cr-rich, oil combustion/vehicle, dust, and traffic. Although PM2.5 mass differed significantly between low-level and mid-level sites, the largest contributor to PM2.5 mass (sulfur-rich aerosol, 35.2%) showed nonsignificant variation in the vertical distribution. In contrast, oil combustion/vehicle, which exhibited significant difference between mid-level sites and the other two altitudes, might be a determinant in the vertical variation of PM2.5. We also observed negative trends with sampling height for combustion and traffic emissions.
... The study of PM behaviour in relation to their vertical distance from the ground, is complicated due to different physicochemical characteristics of fuels used (e.g., natural gas, gasoline, diesel) and to additional factors such as i) the prevailing local meteorology, ii) the percentage of heavy polluters, iii) the driving habits, as well as iv) the maintenance, quality and control measures of vehicles. As a result, information about the variability of the vertical characteristics of traffic originated PM pollution with respect to its concentration levels and chemical composition is limited (Pakkanen et al., 2003;Chrysikou et al., 2009;Gao et al., 2011;Pongpiachan, 2013). ...
... This work was financially supported by the EnTeC FP7 Capacities programme (REGPOT-2012-2013. ...
https://authors.elsevier.com/c/1XS4eB8ccgceu
In an attempt to investigate the traffic-impacted vertical aerosols profile and its relationship with potential carcinogenicity and/or mutagenicity, samples of different sized airborne particles were collected in parallel at the 1st and 5th floor of a 19 m high building located next to one of the busiest roads of Athens. The maximum daily concentrations were 65.9, 42.5 and 38.5 μg/m3, for PM10, PM2.5 and PM1, respectively. The vertical concentration ratio decreased with increasing height verifying the role of the characteristics of the area (1st/5th floor: 1.21, 1.13, 1.09 for PM10, PM2.5 and PM1, respectively). Chemically, strengthening the previous hypothesis, the collected particles were mainly carbonaceous (68%–93%) with the maximum budget of the polyaromatic hydrocarbons being recorded near the surface (1st/5th floor: 1.84, 1.07, 1.15 for PM10, PM2.5 and PM1, respectively). The detected PM-bound PAHs along with the elements as well as the carbonaceous and ionic constituents were used in a source apportionment study. Exhaust and non-exhaust emissions, a mixed source of biomass burning and high temperature combustion processes (natural gas, gasoline/diesel engines), sea salt, secondary and soil particles were identified as the major contributing sources to the PM pollution of the investigated area. With respect to the health hazards, the calculation of the Benzo[a]Pyrene toxicity equivalency factors underlined the importance of the height of residence in buildings for the level of the exposure (1st/5th floor: B[a]PTEQ: 1.82, 1.12, 1.10, B[a]PMEQ: 1.85, 1.13, 1.09 for PM10, PM2.5 and PM1, respectively). Finally, despite its verified significance as a surrogate compound for the mixture of the hydrocarbons (its contribution up to 72%, 79% on the level of the 1st and 5th floor, respectively), the importance of the incorporation of PAH species in addition to B[a]P when assessing PAH toxicity was clearly documented.
... To identify paddy grain samples, the Shimadzu GCMS-QP2010 Ultra was configured for both qualitative and quantitative analysis of 12 PAHs, including phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, and chrysene; benzo [b] Pongpiachan et al. (2013aPongpiachan et al. ( , 2013bPongpiachan et al. ( , 2015Pongpiachan et al. ( , 2017 and Deelaman et al. (2021) have provided detailed descriptions of these settings. ...
Rice is a staple meal for the majority of Asians. However, human exposure to polycyclic aromatic hydrocarbons from paddy grain is largely unknown in Thailand and Laos. Therefore, information on the quantitative measurement and assessment of the health problems caused by PAHs was analyzed. The results showed that the concentrations of total PAHs in paddy grain in Thailand and Laos were 38.86 ± 5.13 and 11.35 ± 1.96 ng g⁻¹, respectively. The highest concentration of PAHs in Thailand was B[k]F, whereas D[a,h]A was found to be the highest in Laos. A p-value less than 0.05 was defined, which showed B[b]F and B[k]F from Thailand and Laos were significant, which indicated that they could be from a different pollutant source. The main finding of this study, which was supported by the diagnostic ratios of PAHs and HCA, was that the primary source of PAHs was assumed to be incomplete combustion of petroleum products, which was caused by the burning of industrial fuels or vehicle exhausts, as well as open burning. The findings suggest that these two nations have similar PAH origins. Agricultural waste burning and transportation emissions are well-known sources of PAHs in Thailand and Laos. The cancer risk assessment method was based on the accumulation of PAHs from paddy grains. An ILCR of 1.0E-06 to 1.0E-04 was considered a tolerable limit of cancer risk, while a risk > 1.0E-04 was considered a concern in terms of cancer risk. The findings indicated that while PAH emissions exist, their contribution to global toxicity may be anticipated to be low in inhalation exposure. The higher values of ingestion and dermal risk estimated were regarded as the tolerable limit of cancer risk in children and adults from both countries, indicating that cancer risk in both nations falls within the “acceptable level” range.
... Previous research has underlined air quality deterioration episodes in Southeast Asian countries as a consequence of hotspot numbers [1][2][3][4][5]. Geographic information system ...
Previous studies have determined biomass burning as a major source of air pollutants in the ambient air in Thailand. To analyse the impacts of meteorological parameters on the variation of carbonaceous aerosols and water-soluble ionic species (WSIS), numerous statistical models, including a source apportionment analysis with the assistance of principal component analysis (PCA), hierarchical cluster analysis (HCA), and artificial neural networks (ANNs), were employed in this study. A total of 191 sets of PM2.5 samples were collected from the three monitoring stations in Chiang-Mai, Bangkok, and Phuket from July 2020 to June 2021. Hotspot numbers and other meteorological parameters were obtained using NOAA-20 weather satellites coupled with the Global Land Data Assimilation System. Although PCA revealed that crop residue burning and wildfires are the two main sources of PM2.5, ANNs highlighted the importance of wet deposition as the main depletion mechanism of particulate WSIS and carbonaceous aerosols. Additionally, Mg2+ and Ca2+ were deeply connected with albedo, plausibly owing to their strong hygroscopicity as the CCNs responsible for cloud formation.
... These substances which are classified as semi-volatile compounds, can be liberated as solid or vapour that can stick to the surface of other particles (Jones and de Voogt, 1999;Dachs and Eisenreich, 2000), that may lead to an increased environmental pollution as well as heath impacts (Bach et al., 2003;Dan et al., 2004;Unwin et al., 2006;Harrison and Yin, 2008;Campo et al., 2010;Diggs et al., 2011;Zhao et al., 2013;Pongpiachan et al., 2014a;Irei et al., 2016;Tsay et al., 2016;Chen et al., 2017;Pani et al., 2018). Moreover, These substances have been widely used as geochemical tracers to identify potential sources of PM 2.5 , based on the receptor model (Boonyatumanond et al., 2007;Dvorská et al., 2012;Hu et al., 2012;Pongpiachan, et al., 2013aPongpiachan, et al., ,b, 2015ChooChuay et al., 2020). ...
In this study, PM2.5-bound carbonaceous compounds, including organic carbon (OC), elemental carbon (EC), water-soluble ionic species (WSIS), and polycyclic aromatic hydrocarbons (PAHs) in the ambient air of Bangkok were analysed. The mean PM2.5 concentration was 77.0 ± 21.2 μg m⁻³, while the average concentrations of OC, and EC were 8.03 ± 4.02, and 2.62 ± 1.49 μg m⁻³, respectively. The relatively high OC/EC ratio (3.52 ± 1.41) coupled with a strong positive correlation between K⁺ and carbonaceous compounds (K⁺ vs. OC (r = 0.86), K⁺ vs. EC (r = 0.87), K⁺ vs. Char-EC (r = 0.82)) suggest that biomass burning are one of the major contributors to PM2.5 in the sampling area. A comparatively high abundance of both B[g,h,i]P and Ind guides that vehicular exhausts, industrial combustion, and burning of waste might reflect the sources of these PAHs in Bangkok's atmosphere. Interestingly, hierarchical cluster analysis (HCA) indicated that the main source of PM2.5 was a mixture of various combustion activities (e.g. biomass burning, vehicular exhaust, fossil fuel, coal, and industrial emissions). Principal Component Analysis (PCA) successfully classified five principal sources of PM2.5, including vehicular exhaust, biomass burning, sea salt aerosol, power plant, and industrial emissions, which accounted for 43.7%, 24.0%, 10.5%, 6.48%, and 4.46%, respectively. These results indicated that the effects of vehicular exhausts and biomass burning played an important role in governing the PM2.5 level in ambient air of Bangkok. The findings of this study aid policymakers in launching effective air quality control strategies based on the source apportionment analysis.
... Over the last few decades there has been increasing interest in the adverse public health impacts of exposure to ambient toxic chemicals, principally in relation to carcinogenicity and mutagenicity [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. Another central concern of ambient air quality studies is the chemical compositions of particular matter High-volume air samplers (TE-6001; Graseby-Andersen, Atlanta, GA, USA) were used to obtain unmanned 24 h samples for PM10 at the four sampling sites, yielding volumes of approximately 1632 m 3 for each 24 h sample. ...
Bonfire night is a worldwide phenomenon given to numerous annual celebrations characterised by bonfires and fireworks. Since Thailand has no national ambient air quality standards for metal particulates, it is important to investigate the impacts of particulate injections on elevations of air pollutants and the ecological health impacts resulting from firework displays. In this investigation, Pb and Ba were considered potential firework tracers because their concentrations were significantly higher during the episode, and lower than/comparable with minimum detection limits during other periods, indicating that their elevated concentrations were principally due to pyrotechnic displays. Pb/Ca, Pb/Al, Pb/Mg, and Pb/Cu can be used to pin-point emissions from firework displays. Air mass backward trajectories (72 h) from the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model indicated that areas east and north-east of the study site were the main sources of the airborne particles. Although the combined risk associated with levels of Pb, Cr, Co., Ni, Zn, As, Cd, V, and Mn was far below the standards mentioned in international guidelines, the lifetime cancer risks associated with As and Cr levels exceeded US-EPA guidelines, and may expose inhabitants of surrounding areas of Bangkok to an elevated cancer risk.
... The levels of S 15 EPA-PAHs in Lijiang are one to three orders of magnitude higher than PAH concentrations in remote regions of the Arctic (Ding et al., 2007b), the Antarctic (Cabrerizo et al., 2014), and the Tibetan Plateau (Ren et al., 2017) (Table S4), but are one to two orders of magnitude lower than those in megacities in Asia [such as Beijing (Ma et al., 2011), Guangzhou (Li et al., 2006), and Delhi (Sharma et al., 2007)]. The levels of PAHs in Lijiang are comparable to those in small cities in Thailand (Pongpiachan, 2013), Pakistan (Kamal et al., 2016), Southwest China (Lv et al., 2009), and the Tibetan Plateau (Gong et al., 2011) (Table S4). Relatively infrequent anthropogenic activities and atmospheric input may have led to the moderate contamination levels of PAHs for a small city like Lijiang (Ma et al., 2013). ...
Lijiang is a high-altitude city located on the eastern fringe of the Tibetan Plateau, with complex seasonal atmospheric circulations (i.e. westerly wind, Indian Monsoon, and East Asia Monsoon). Very few previous studies have focused on seasonal variations and sources of organic pollutants in Lijiang. In this study, a four-year air campaign from June 2009 to July 2013 was conducted to investigate the temporal trends and the sources of polycyclic aromatic hydrocarbons (PAHs) and organochlorine compounds [including organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs)]. The atmospheric PAH concentrations in winter are 2-3 times of those in summer, probably because of the combined result of enhanced local emission and long-range atmospheric transport (LRAT) during winter. Traffic pollution was the primary local source of PAHs, while biomass burning is the dominant LRAT source. OCPs and PCBs also mainly underwent LRAT to reach Lijiang. The peak concentrations of most of OCPs occurred in pre-monsoon season and winter, which were carried by air masses from Myanmar and India through westerly winds. As compared with other sites of the Tibetan Plateau, without the direct barrier of the Himalaya, Lijiang is easily contaminated by the incursion of polluted air masses.
... Polycyclic aromatic hydrocarbons (PAHs), usually acknowledged as a group of persistent organic pollutants (POPs), have been comprehensively investigated in the past decades because these congeners have a profound association with a wide range of adverse health effects and other respiratory diseases [1][2][3]. PAHs are widely detected in various types of environmental compartments including marine organisms [4][5][6][7][8][9]. It is well known that PAHs can be generated from both anthropogenic and natural sources [10][11][12][13]. ...
Identification of Tsunami deposits has long been a controversial issue among geologists. Although there are many identification criteria based on the sedimentary characteristics of unequivocal Tsunami deposits, the concept still remains ambiguous. Apart from relying on some conventional geological, sedimentological, and geoscientific records, geologists need some alternative “proxies” to identify the existence of Tsunami backwash in core sediments. Polycyclic aromatic hydrocarbons (PAHs) are a class of very stable organic molecules, which can usually be presented as complex mixtures of several hundred congeners; one can assume that the “Tsunami backwash deposits” possess different fingerprints of PAHs apart from those of “typical marine sediments.” In this study, three-dimensional plots of PAH binary ratios successfully identify the Tsunami backwash deposits in comparison with those of global marine sediments. The applications of binary ratios of PAHs coupled with HCA are the basis for developing site-specific Tsunami deposit identification criteria that can be applied in paleotsunami deposits investigations.
... Recent study also highlights the bioaccumulation of PAHs in agricultural products (soybean) (Pongpiachan, 2015). The importance of PAH emission sources in tropical environment have been well demonstrated (Pongpiachan, 2013a(Pongpiachan, , 2013bPongpiachan et al., 2013;Pongpiachan et al., 2015). Moreover high levels of PAHs in PM 2.5 were often obtained while the places suffered from severe air pollution, particularly in wintertime regularly. ...
Polycyclic aromatic hydrocarbons (PAHs) and its oxygenated derivatives (OPAHs) are toxins in PM2.5. Little information has been known for their transformation in the ambient airs. In this study, PM2.5 samples were collected at 19 sampling sites in Xi’an, China during the heating period, which is classified into: urban residential, university, commercial area, suburban region, and industry. Organic compounds including PAHs, OPAHs, hopanes and cholestanes were quantified. The average of total quantified PAHs and OPAHs concentrations were 196.5 ng/m3 and 29.4 ng/m3, respectively, which were consistent with other northern cities in China. Statistical analyses showed that there were significant differences on the distributions of PAHs between urban and suburban regions. The industry also had distinguishable profiles compared with urban residential and commercial area for OPAHs. The greater diversity of OPAHs than PAHs might be due to different primary emission sources and transformation and degradation pathways. The ratios of OPAHs to the corresponding parent PAHs, including 9-fluorenone/fluorene, anthraquinone/anthracene, benz[_a_]anthracene-7,12-dione/benzo[_a_]anthracene were 6.2, 12.7, and 1.4, respectively, which were much higher than those for the fresh emissions from coal combustion and biomass burning. These prove the importance of secondary formation and transformation of OPAHs in the ambient airs. Biomarkers such as retene, cyclopenta[CD]pyrene and αα-homohopane were characterized for the source apportionment. With Positive Matrix Factorization (PMF) model analysis, biomass burning was recognized as the most dominant pollution sources for PAHs during the heading period, which accounted for a contribution of 37.1%. Vehicle emission (22.8%) and coal combustion (22.6%) were also contributors in Xi’an.
... The principal reasons for investigating environmental concentrations of PAHs relate to their adverse effects on health, such as their potential to disrupt the endocrine system (Annamalai and Namasivayam, 2015), increase anxiety-related behaviour and decrease regional brain metabolism in adult male rats (Crépeaux et al., 2012), and cause adverse reproductive outcomes (Šrám et al., 1999), DNA damage to lungs (Müller et al., 2004), the development of solid tumours in mice (Wang and Xue, 2015), and increased risks of coupled lung and breast cancers (Venkatachalam et al., 2014;Moorthy et al., 2015). As a consequence of the numerous adverse health effects, several studies have used receptor models, including principal component analysis (Pongpiachan, 2013b), positive matrix factorisation (Jang et al., 2013), and a chemical mass balance model (Hanedar et al., 2011), to quantitatively identify potential sources of atmospheric PAHs. ...
The reliability of using diagnostic binary ratios of particulate carcinogenic polycyclic aromatic hydrocarbons (PAHs) as chemical tracers for source characterisation was assessed by collecting PM10 samples from various air quality observatory sites in Thailand. The major objectives of this research were to evaluate the effects of day and night on the alterations of six different PAH diagnostic binary ratios: An/(An + Phe), Fluo/(Fluo + Pyr), B[a]A/(B[a]A + Chry), B[a]P/(B[a]P + B[e]P), Ind/(Ind + B[g,h,i]P), and B[k]F/Ind, and to investigate the impacts of site-specific conditions on the alterations of PAH diagnostic binary ratios by applying the concept of the coefficient of divergence (COD). No significant differences between day and night were found for any of the diagnostic binary ratios of PAHs, which indicates that the photodecomposition process is of minor importance in terms of PAH reduction. Interestingly, comparatively high values of COD for An/(An + Phe) in PM10 collected from sites with heavy traffic and in residential zones underline the influence of heterogeneous reactions triggered by oxidising gaseous species from vehicular exhausts. Therefore, special attention must be paid when interpreting the data of these diagnostic binary ratios, particularly for cases of low-molecular-weight PAHs.
... Depending on the volatility of the individual compound and meteorological conditions, they are transported either in gaseous form or bound to particles of different sizes over long distances in the atmosphere (Ma et al., 2011; Yan et al., 2015). PAHs are released to ambient air during incomplete combustions from various sources such as vehicular road transport, power plants, coal burning, waste treatment, and shipping emissions (Hanedar et al., 2014; Lu et al., 2008; Pongpiachan et al., 2015a, b; Slezakova et al., 2013a, b). The main indoor sources include ...
This work characterizes levels of polycyclic aromatic hydrocarbons (PAHs) in indoor and outdoor air of preschool environments, and assesses the respective risks for 3-5-years old children. Eighteen gaseous and particulate (PM1 and PM2.5) PAHs were collected indoors and outdoors during 63 days at preschools in Portugal. Gaseous PAHs accounted for 94-98% of total concentration (ΣPAHs). PAHs with 5-6 rings were predominantly found in PM1 (54-74% particulate ΣPAHs). Lighter PAHs originated mainly from indoor sources whereas congeners with 4-6 rings resulted mostly from outdoor emissions penetration (motor vehicle, fuel burning). Total cancer risks of children were negligible according to USEPA, but exceeded (8-13 times) WHO health-based guideline. Carcinogenic risks due to indoor exposure were higher than for outdoors (4-18 times).
... capillary column of Agilent JW Scientific DB-5 GC columns). The analytical procedure used in this study and relevant information has been explained in previous publications [19][20][21]. Table 1, in terms of their mean values with the corresponding standard deviations. : 3,667 ± 4,456 pg m -3 ) were significantly (p < 0.05) much higher than those of samples collected at NNP-I and NNP-II (Table 1). ...
In Northern Thailand, wildland fires during the cold period release large amounts of smoke and fine particles into the atmosphere. The fine particles include several persistent organic compounds such as PAHs. In this study, PM2.5-bound PAH concentrations in the air of nine administrative provinces, namely Chiang-Mai, Chiang-Rai, Nan, Phayao, Mae Hong Son, Phrae, Lampang, Lamphun, Uttaradit (northern Thailand), were determined during the wildland fire and non-wildland fire seasons. The monitoring strategy comprised two campaigns in each season. PM2.5 was collected using MiniVolTM portable air samplers (Airmetrics) with quartz fibre filters. Both PAHs and their B[α]P equivalent concentrations of other urban cities around the world were significantly higher than those of northern provinces for both seasons. The average cancer risks observed at nine administrative provinces were 8.525×10-4±3.493±10-3 and 2.558×10-3±6.986× 10-3 for ingestion rate of 50 and 100 mg day-1, respectively. The excess cancer risks of world cities for ingestion rate of 50 and 100 mg day-1 were much higher than those of northern Thailand for 851 and 567 times in that order. Dust ingestion was exceedingly critical to non-dietary PAH exposure in comparison with PM2.5 inhalation. These results are in good agreement with those of previous studies, underlining the significance of indoor air quality on long-term adverse respiratory diseases in Asian cities.
... The toxicity equivalent concentration (TEQ) equation is broadly used for assessing the risk of exposure to PAHs, which can be calculated as described bellows (Yang et al., 2007; Yu et al., 2008; Pongpiachan et al., 2013b): ...
In Northern Thailand, wildland fire during cold period releases large amounts of smoke and fine particles into the atmosphere. The fine particles include several persistent organic compounds such as PAHs. In this study, PM 2.5-bound PAH concentrations in the air of nine administrative provinces, namely Chiang-Mai, Chiang-Rai, Nan, Phayao, Mae Hong Son, Phrae, Lampang, Lamphun, Uttaradit (N Thailand) were determined during the wildland fire and non-wildland fire seasons. The monitoring strategy comprised two campaigns in each season. PM 2.5 was collected using MiniVolTM portable air samplers (Airmetrics) with quartz fibre filters. Both PAHs and their B[a]P Equivalent concentrations of other urban cities around the world were significantly higher than those of northern provinces for both seasons. The average cancer risks observed at nine administrative provinces were 8.525 × 10 –4 ± 3.493 × 10 –3 and 2.558 × 10 –3 ± 6.986 × 10 –3 for ingestion rate of 50 and 100 mg day –1 , respectively. The excess cancer risks of world cities for ingestion rate of 50 and 100 mg day –1 were much higher than those of Northern Thailand for 851 and 567 times in that order. Dust ingestion was exceedingly critical to non-dietary PAH exposure in comparison with PM 2.5 inhalation. These results are in good agreement with those of previous studies, underlining the significance of indoor air quality on long-term adverse respiratory diseases in Asian cities.
... The toxicity equivalent concentration (TEQ) equation is widely used for estimating the risk of exposure to PAHs and it can be calculated as follows (Pongpiachan et al., 2013b; Yang et al., 2007; Yu et al., 2008): ...
... Carbonaceous aerosols, particularly elemental carbon (EC), have been considered as factors affecting climate system due to its atmospheric radiative forcing capability (Badarinath and Latha, 2006;Panicker et al. 2010;Cheng and Wu, 2011;Das and Jayaraman, 2011). Apart from its impacts on climate system, the role of carbonaceous particles on gas-particle partitioning of persistent organic pollutants (POPs) such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), pesticides and dioxins, has been extensively evaluated in different countries during the past few years (Hayakawa et al., 2004;Tasdemir et al., 2004;Scheyer et al., 2008;Pongpiachan et al., 2009;Marcosa et al., 2010;Gaga and Ari, 2011;Yang et al., 2012;Pongpiachan, 2013a;2013b). Since POPs are widely considered as carcinogenic and mutagenic compounds (Binelli and Provini, 2004;Abas and Mohamad, 2011;Guo et al., 2012), it is therefore crucial to understand the behavior of OC/EC compositions in atmospheric environment. ...
Carbonaceous compositions, water-soluble ionic species and trace gaseous
species were identified and quantified in Hat-Yai city, Thailand. All samples
were collected every three hours consecutively from 21:00 h December 17th to
21:00 h December 20th at Site 1 (30 m agl), Site 2 (60 m agl) and Site 3
(125 m agl). The averaged concentration of OC was significantly higher at Site 1
than those detected at Site 2 and Site 3 suggesting that anthropogenic activities at
ground level might play a major role in governing air quality at ground level.
The main objective of this study is to investigate the vertical distribution of
carbonaceous aerosols in Hat-Yai’s atmosphere for the first time by using
IMPROVE TOC (Interagency Monitoring to Protect Visual Environments Total
Organic Carbon) protocol. The morning peak of carbonaceous compositions
observed during the sampling period of 06:00–09:00 emphasized the main
contribution of traffic emissions on OC/EC contents in Hat-Yai city. In this
study, we found that aged maritime aerosols from long-range transportation
and/or biomass burning particles overwhelmed carbonaceous aerosols at the top
of building. Whilst hierarchical cluster analysis and Pearson correlation analysis
show some considerable influences of night-time tourism activities on
carbonaceous contents at ground level, principal component analysis highlights
the impacts of maritime aerosols, biomass burning and possibly agricultural
waster burning particles at a higher atmospheric layer.
... Polycyclic aromatic hydrocarbons (PAHs), usually acknowledged as a group of persistent organic pollutants (POPs), have been comprehensively investigated in the past decades because these congeners have a profound association with a wide range of adverse health effects and other respiratory diseases [1][2][3]. PAHs are widely detected in various types of environmental compartments including marine organisms [4][5][6][7][8][9]. It is well known that PAHs can be generated from both anthropogenic and natural sources [10][11][12][13]. ...
Identification of Tsunami deposits has long been a controversial issue among geologists. Although there are many identification criteria based on the sedimentary characteristics of unequivocal Tsunami deposits, the concept still remains ambiguous. Apart from relying on some conventional geological, sedimentological, and geoscientific records, geologists need some alternative "proxies" to identify the existence of Tsunami backwash in core sediments. Polycyclic aromatic hydrocarbons (PAHs) are a class of very stable organic molecules, which can usually be presented as complex mixtures of several hundred congeners; one can assume that the "Tsunami backwash deposits" possess different fingerprints of PAHs apart from those of "typical marine sediments. " In this study, three-dimensional plots of PAH binary ratios successfully identify the Tsunami backwash deposits in comparison with those of global marine sediments. The applications of binary ratios of PAHs coupled with HCA are the basis for developing site-specific Tsunami deposit identification criteria that can be applied in paleotsunami deposits investigations.
... Carbonaceous aerosols, particularly elemental carbon (EC), have been considered as factors affecting climate system due to its atmospheric radiative forcing capability (Badarinath and Latha, 2006;Panicker et al. 2010;Cheng and Wu, 2011;Das and Jayaraman, 2011). Apart from its impacts on climate system, the role of carbonaceous particles on gas-particle partitioning of persistent organic pollutants (POPs) such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), pesticides and dioxins, has been extensively evaluated in different countries during the past few years (Hayakawa et al., 2004;Tasdemir et al., 2004;Scheyer et al., 2008;Pongpiachan et al., 2009;Marcosa et al., 2010;Gaga and Ari, 2011;Yang et al., 2012;Pongpiachan, 2013a;2013b). ...
To assess environmental contamination with carcinogens, carbonaceous compounds, water-soluble ionic species and trace gaseous species were identified and quantified every three hours for three days at three different atmospheric layers at the heart of Chiang-Mai, Bangkok and Hat-Yai from December 2006 to February 2007. A DRI Model 2001 Thermal/Optical Carbon Analyzer with the IMPROVE thermal/optical reflectance (TOR) protocol was used to quantify the organic carbon (OC) and elemental carbon (EC) contents in PM10. Diurnal and vertical variability was also carefully investigated. In general, OC and EC mass concentration showed the highest values at the monitoring period of 21.00-00.00 as consequences of human activities at night bazaar coupled with reduction of mixing layer, decreased wind speed and termination of photolysis at nighttime. Morning peaks of carbonaceous compounds were observed during the sampling period of 06:00-09:00, emphasizing the main contribution of traffic emission in the three cities. The estimation of incremental lifetime particulate matter exposure (ILPE) raises concern of high risk of carbonaceous accumulation over workers and residents living close to the observatory sites. The average values of incremental lifetime particulate matter exposure (ILPE) of total carbon at Baiyoke Suit Hotel and Baiyoke Sky Hotel are approximately ten times higher than those air samples collected at Prince of Songkla University Hat-Yai campus corpse incinerator and fish-can manufacturing factory but only slightly higher than those of rice straw burning in Songkla province. This indicates a high risk of developing lung cancer and other respiratory diseases across workers and residents living in high buildings located in Pratunam area. Using knowledge of carbonaceous fractions in PM10, one can estimate the gas-particle partitioning of polycyclic aromatic hydrocarbons (PAHs). Dachs-Eisenreich model highlights the crucial role of adsorption in gas-particle partitioning of low molecular weight PAHs, whereas both absorption and adsorption tend to account for gas-particle partitioning of high molecular weight PAHs in urban residential zones of Thailand. Interestingly, the absorption mode alone plays a minor role in gas-particle partitioning of PAHs in Chiang-Mai, Bangkok and Hat-Yai.
The intense light of synchrotron radiation, with the assistance of infrared spectroscopy, allows for the measurement of extremely low levels of organic functional groups. In this study, PM10 samples (n = 84) were collected at three air quality observatory sites strategically situated on the periphery of the seaport, residential zone, and industrial area of Laem Chabang, Thailand from May 27 to June 23, 2020. Aliphatic carbons, carbonyl species, organo-nitrates, aromatic nitro compounds, ammonium ions, carbonate, nitrate ions, sulfate species, and calcium carbonate were successfully characterised in all PM10 samples. Sulfate and aliphatic carbons were the two dominant chemical species detected at all monitoring sites. Sulfate and bisulfate ions were two major ionic species with the percentage contribution of 64%, 74% and 46% to the port area, the urban background and the industrial area, respectively. Aliphatic carbons were the most abundant organic functional groups, contributing 27% and 15% to the industrial area and the port area, respectively. While aliphatic carbons, organo-nitrates, and aromatic nitro compounds were closely related to shipping activities, sea salt aerosols and fertiliser dust can be considered as two potential sources of sulfate and ammonium, respectively.
This manuscript provides some comprehensive technical insights regarding the application of polycyclic aromatic hydrocarbons (PAHs) characterized by using Gas-Chromatography Mass Spectrometry. Although numerous chemical species such as water soluble ionic species (e.g. Na þ , K þ , Cl À , Ca 2þ , Mg 2þ) and acid leachable heavy metal fractions (e.g. Fe, Cd, Al, Mo, Sb, As, Cu, Zn, Pb, and Mn) can be used to characterize tsunami deposits, the knowledge of PAH congeners as alternative chemical species for identifying tsunami backwash deposits is strictly limited. This manuscript is exclusive because it aims to find some alternative chemical proxies in order to distinguish tsunami backwash deposits from typical marine sediments. A wide range of diagnostic binary ratios of PAH congeners have been selected in order to characterize Typical Marine Sediments (TMS), Tsunami backwash deposits (TBD), Onshore Tsunami Deposits (OTD) and Coastal Zone Soils (CZS). The state of the art and future perspectives coupled with both advantages and disadvantages of above mentioned chemical tracers will be critically reviewed and further discussed.
There are limited source apportionment studies conducted to assess vertical distributions of fine particulate matter (PM2.5) and its contributing sources in urban regions. Additionally, none of these vertical studies used inorganic and organic tracers simultaneously. The present study aimed to explore the vertical variation of source-specific contributions to PM2.5 by modeling with both inorganic and organic markers in vertically stratified samples in the Taipei metropolis (Taiwan). One hundred and five samples were collected from three floor-levels at one building and analyzed for trace elements and nonpolar organic compounds (NPOCs). Seven source factors, i.e., industrial emission, biomass burning, PAH related, oil combustion, soil dust, traffic related, and environmental tobacco smoke (ETS)/lubricant, were retrieved by positive matrix factorization (PMF). The major contributors, including industrial emission (29%), biomass burning (23%), and oil combustion (22%), could be involved with regional transported aerosols and showed non-significant variation in the vertical distribution. In contrast, both traffic related and ETS/lubricant factors could be the contributors to the statistically significant difference of PM2.5 concentrations between floor-levels.
Research has focused on the impacts of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere due to their potential carcinogenicity. In this study, we investigated the seasonal variation, sources, incremental lifetime cancer risks (ILCRS), and vitro DNA oxidative damage of PAHs in Urumqi in NW China. A total of 72 atmospheric samples from Urumqi were collected over a year (September 2017–September 2018) and were analyzed for 16 PAHs that are specifically prioritized by the U.S Environmental Protection Agency (U·S EPA). The highest PAHs concentrations were in winter (1032.66 ng m⁻³) and lowest in spring (146.00 ng m⁻³). Middle molecular weight PAHs with four rings were the most abundant species (45.28–61.19% of the total). The results of the diagnostic ratio and positive matrix factorization inferred that the major sources of atmospheric PAHs in Urumqi were biomass burning, coking, and petrogenic sources (52.9%), traffic (30.1%), coal combustion (8.9%), and the plastics recycling industry (8.1%). ILCRS assessment and Monte Carlo simulations suggested that for all age groups PAHs cancer risks were mainly associated with ingestion and dermal contact and inhalation was negligible. The plasmid scission assay results showed a positive dose-response relationship between PAHs concentrations and DNA damage rates, demonstrating that toxic PAHs was the primary cause for PM2.5-induced DNA damage in the air of Urumqi.
Levoglucosan, as a biomass tracer, and sixteen polycyclic aromatic hydrocarbons (PAHs) in PM2.5 ambient air samples collected from Tak Province during smoke and non-smoke episodes were analyzed. The average PM2.5, levoglucosan and total PAHs concentrations in the smoke episode were 61.64 ± 22.85, 1.00 ± 0.41 μg/m³ and 6.32 ± 2.26 ng/m³, respectively. This figures were significantly higher than those recorded during the non-episode (13.76 ± 5.58, 0.12 ± 0.03 μg/m³ and 2.59 ± 0.15 ng/m³, respectively). The predominant PAHs proportions were comprised of Phenanthrene and Benzo[ghi]perylene and levoglucosan concentrations revealed a strong correlation with PM2.5 concentrations, which indicated the source of PM2.5 from biomass burning. Toxicity equivalent (TEQBaP) and the mutagenic equivalent (MEQBaP) levels during the smoke episode were significantly higher than those in the non-smoke episode. Furthermore, lifetime lung cancer risk recorded during smoke episode exceeded the acceptable cancer risk that has been recommended by US-EPA. These results suggest that this area was not only exposed to PAHs that originated from traffic combustion, but was also exposed from biomass burning emissions, particularly during biomass burning season when there is an increased risks of cancer and mutation. Although the exposure time in this area is relatively short, the high dose period of exposure occurs repetitively every year. In addition, backward trajectories showed that most of the air mass was generated from western region of Thailand and they were throughout the burning region not only emitted from local areas, but also from outside the country during the smoke episode.
Thailand has been facing increasing levels of air pollution, resulting in adverse health consequences. One of the most serious pollutants is airborne particulate matter (PM). PM contains many inorganic and organic hazardous compounds. Among them, polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) are of great concern because of their severe toxicity (carcinogenicity and/or mutagenicity and/or teratogenicity) to humans. This chapter reviews ambient and indoor concentrations of PAHs and NPAHs with a focus on Chiang Mai, Thailand, and discusses their possible emission sources and health risks. In addition, concerning human intake, the concentrations of individual urinary hydroxyPAHs (OHPAHs) were measured in different Thai subjects in order to estimate their PAH exposure. Understanding PAH and NPAH distributions can be useful in order to understand their sources, sinks, and exposure risks to Thai citizens.
Among Southeast Asian countries, Thailand has gradually accustomed to extremely prompt urbanization, motorization, and industrialization. Chonburi and Rayong provinces are two provinces involved in "eastern seaboard" industrial zones, which is an emerging economic region that plays a key role in Thailand's economy. The 2013 Rayong oil spill did not only cause damages to the coastal and maritime environment, but also undermine trust in the overall safety system and negatively affect the investor confidence. In this study, 69 coastal soils collected around Koh Samed Island were chemically extracted and analyzed for 15 PAHs by using a Shimadzu GCMS-QP2010 Ultra system comprising a high-speed performance system with ASSP function. In this study, numerous diagnostic binary ratios were applied to identify potential sources of PAHs. Advanced statistical techniques such as hierarchical cluster analysis coupled with principal component analysis were also conducted for further investigations of source identifications.
Smoke from agricultural waste burning causes hazardous haze pollution in Southeast Asian countries every year. Besides traces of a few toxic gases several persistent organic pollutants, natural, and anthropogenic emissions are released, resulting in adverse health effects. The study focuses on identification of sources of PM 2.5-bound polycyclic aromatic hydrocarbons (PAHs) during the non-haze and haze seasons and investigates the concentration and toxicity of fine particulate matter, especially in the middle of biomass burning period. Totally, 12 fine particulate PAH congeners were selected and analysed at air quality observatory sites located in nine administrative provinces of Northern Thailand during four different sampling periods from 7th December 2012 to 27th March 2015. Nisbet and Lagoy's toxicity equivalent concentration (TEQ) equation revealed that the B[a]P Equivalent value for 2014e2015 roughly surpassed the value of 2012e2013 by a factor of 17. This can be attributed to the significant rise in five-to six-ring PAHs levels in the past two years. Diagnostic binary ratios and linear regression analysis highlight the roles of vehicular exhausts and biomass burning as two major contributors of PM 2.5-bound PAHs. Interestingly, principal component analysis (PCA) reveals similar loading patterns for PC1 during the non-haze and haze periods, indicating that agricultural waste burning cannot be considered as the sole contributor of particulate PAHs in Northern Thailand.
The " Loy Krathong " festival is a major annual Thai event that includes firework displays. It takes place on the evening of the full moon in the 12th month of the traditional Thai lunar calendar. Since fireworks are widely considered a major source of PAHs, it is considered reasonable to expect a significant increase in PAH levels during this event. The overall PAH profile at the six air quality observatories operated by the Pollution Control Department (PCD), Ministry of Natural Resources and Environment (MNRE), showed that the Kingdom of Thailand's atmosphere was dominated by 5e6-ring PAHs during the firework display period. A significant increase in SPAHs (153%) was observed during firework displays. A statistical analysis coupled with the application of diagnostic binary PAH ratios was conducted to determine whether the detected increase in PAH congeners during the festival period was due to firework combustion or whether it was a coincidental effect caused by vehicular exhausts, long-range atmospheric transportation, photolysis and chemical degradation. The average incremental lifetime cancer risk (ILCR) values of adults and children living in Bangkok as estimated by three different TEQs for ingestion, dermal contact, and inhalation exposure pathways were greatly lesser than the US EPA baseline, further highlighting that the cancer risk of bonfire night falls into the ''acceptable level'' range.
This study aims to conduct a quantitative ecological risk assessment of human exposure to polycyclic aromatic hydrocarbons (PAHs) in terrestrial soils of King George Island, Antarctica. Generally, the average PAH concentrations detected in King George Terrestrial Soils (KGS) were appreciably lower than those of World Marine Sediments (WMS) and World Terrestrial Soils (WTS), highlighting the fact that Antarctica is one of the most pristine continents in the world. The total concentrations of twelve probably carcinogenic PAHs (ΣPAHs: a sum of Phe, An, Fluo, Pyr, B[a]A, Chry, B[b]F, B[k]F, B[a]P, Ind, D[a,h]A and B[g,h,i]P) were 3.21 ± 1.62 ng g⁻¹, 5749 ± 4576 ng g⁻¹, and 257,496 ± 291,268 ng g⁻¹, for KGS, WMS and WTS, respectively. In spite of the fact that KGS has extremely low ΣPAHs in comparison with others, the percentage contribution of Phe is exceedingly high with the value of 50%. By assuming that incidental ingestion and dermal contact are two major exposure pathways responsible for the adverse human health effects, the cancer and non-cancer risks from environmental exposure to PAHs were carefully evaluated based on the “Role of the Baseline Risk Assessment in Superfund Remedy Selection Decisions” memorandum provided by US-EPA. The logarithms of cancer risk levels of PAH contents in KGS varied from −11.1 to −7.18 with an average of −7.96 ± 7.73, which is 1790 times and 80,176 times lower than that of WMS and WTS, respectively. All cancer risk levels of PAH concentrations observed in KGS are significantly (p < 0.001) lower than those of WMS and WTS. Despite the Comandante Ferraz Antarctic Station fire occurred in February 25th, 2012, both the cancer and non-cancer risks of environmental exposure to PAHs were found in “acceptable level”.
Estimating the atmospheric concentrations of PM10-bounded selected metals in urban air is crucial for evaluating adverse health impacts. In the current study, a combination of measurements and multivariate statistical tools was used to investigate the influence of anthropogenic activities on variations in the contents of 18 metals (i.e., Al, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Sb, Ba, La, Ce and Pb) in ambient air. The concentrations of PM10-bounded metals were measured simultaneously at eight air quality observatory sites during a half-year period at heavily trafficked roads and in urban residential zones in Bangkok, Thailand. Although the daily average concentrations of Al, V, Cr, Mn and Fe were almost equivalent to those of other urban cities around the world, the contents of the majority of the selected metals were much lower than the existing ambient air quality guidelines and standard limit values. The sequence of average values of selected metals followed the order of Al > Fe > Zn > Cu > Pb > Mn > Ba > V > Sb > Ni > As > Cr > Cd > Se > Ce > La > Co > Sc. The probability distribution function (PDF) plots showed sharp symmetrical bell-shaped curves in V and Cr, indicating that crustal emissions are the predominant sources of these two elements in PM10. The comparatively low coefficients of divergence (COD) that were found in the majority of samples highlight that site-specific effects are of minor importance. A principal component analysis (PCA) revealed that 37.74, 13.51 and 11.32 % of the total variances represent crustal emissions, vehicular exhausts and the wear and tear of brakes and tires, respectively.
The aims of this study were to investigate the impact of meteorological parameters and trace gas concentrations on daily hospital walk-ins and admissions in Chiang-Mai province, Thailand, during 2007–2013. Advanced statistical models, including t-tests, Analysis of Variance (ANOVA), Multiple Linear Regression Analysis (MLRA) and Incremental Lifetime Particulate Matter Exposure (ILPE), were constructed using meteorological data from the Pollution Control Department (PCD), Ministry of Natural Resources and Environment (MNRE), Thailand, and the Thai Meteorological Department at Chiang-Mai Province Air Quality Observatory Site (TMCS) as well as the number of walk-in and admitted patients at Nakornping Hospital, Chiang-Mai (NHCM). The results showed that all trace gaseous species and PM10 were significantly higher during the “haze episode” than during the “non-haze period.” The FTIR spectra highlight the relatively homogeneous organic functional compositions of PM2.5 collected from urban, suburban and rural observatory sites, indicating that agricultural waste burning plays an important role in air quality during the “haze episode.” The effect of age on susceptibility to respiratory diseases was investigated by separating the dataset into four groups (i.e., < 15 years, 15–59 years, 60–74 years and ≥ 75 years). The ANOVA results revealed a significant increase in hospital walk-ins and admissions for both genders in the < 15 years group (p < 0.005). MLRA revealed the significantly highest impacts of CO on hospital walk-ins for both genders. The predicted ILPE of PM10 showed the highest values for both genders during the “haze-episode” in 2007, with average values of 3.338 ± 0.576 g and 1.838 ± 0.317 g for male and female outdoor workers, respectively, over an exposure duration of 25 years.
Four Organic Carbon (OC) compositions and three Elemental Carbon (EC) fractions in PM10 collected monthly from February to December 2007 at eight PCD air quality observatory sites were analysed by using a DRI Model 2001. Since both OC and EC play a major role in governing the gas-particle partitioning of carcinogenic Polycyclic Aromatic Hydrocarbons (PAHs), it is therefore, important to investigate the spatial and temporal distributions of carbonaceous fractions in Bangkok. The sum of OC (ΣOC) and EC (ΣEC) collected at eight PCD sites were 71.4±19.3 μg m-3 and 74.9±32.7 μg m-3, correspondingly. The relatively low OC/EC ratios observed in Bangkok highlight the influence of transportation sector in governing carbonaceous aerosols, particularly in heavy traffic congestion area. Three-dimensional plots of Principal Components (PCs) successfully discriminate "traffic emission" group from those of "urban residential background" group. In addition, the estimated Incremental Lifetime Particulate Exposure (ILPE) of carbonaceous compositions were constantly highest at heavy traffic congestion area in both genders with the average values of 1,130±457 and 622±252 mg for TC accumulated in male and female, respectively.
To investigate the potential cancer risk resulting from biomass burning, polycyclic aromatic hydrocarbons (PAHs) bound to fine particles (PM2.5) were assessed in nine administrative northern provinces (NNP) of Thailand, before (N-I) and after (N-II) a haze episode. The average values of Σ3,4-ring PAHs and B[a]PEquivalent concentrations in world urban cities were significantly (p<0.05) much higher than those in samples collected from northern provinces during both sampling periods. Application of diagnostic binary ratios of PAHs underlined the predominant contribution of vehicular exhaust to PM2.5-bound PAH levels in NNP areas, even in the middle of the agricultural waste burning period. The proximity of N-I and N-II values in three-dimensional (3D) principal component analysis (PCA) plots also supports this conclusion. Although the excess cancer risk in NNP areas is much lower than those of other urban area and industrialized cities, there are nevertheless some concerns relating to adverse health impacts on preschool children due to non-dietary exposure to PAHs in home environments.
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To investigate the potential cancer risk resulting from biomass burning, polycyclic aromatic hydrocarbons (PAHs) bound to fine particles (PM2.5) were assessed in nine administrative northern provinces (NNP) of Thailand, before (N-I) and after (N-II) a haze episode. The average values of Σ3,4-ring PAHs and B[a]PEquivalent concentrations in world urban cities were significantly (p b 0.05) much higher than those in samples collected from northern provinces during both sampling periods. Application of diagnostic binary ratios of PAHs underlined the predominant contribution of vehicular exhaust to PM2.5-bound PAH levels in NNP areas, even in the middle of the agricultural waste burning period. The proximity of N-I and N-II values in three-dimensional (3D) principal component analysis (PCA) plots also supports this conclusion. Although the excess cancer risk in NNP areas is much lower than those of other urban area and industrialized cities, there are nevertheless some concerns relating to adverse health impacts on preschool children due to non-dietary exposure to PAHs in home environments.
Organic functional groups of alcohol, alkane, alkene, alkyl halide, alkyne, amine, aromatic, ether, nitrile and nitro in PM2.5 were qualitatively identified by using FTIR techniques with the assistances of IRAffinity-1 Shimadzu. PM2.5 were collected at the city center, sub-urban, and rural area of Chiang-Mai city, Thailand during the haze episode in March 2012. The measured concentrations of PM2.5 at three air quality observatory sites were relatively high in comparison with those of other cities around the world during the agricultural waste-burning period. The predicted probabilistic incremental lifetime cancer risk (ILCR) of PM2.5 were consistently highest at the city center in both genders with the average values of 418 ± 180 y-1 and 228 ± 98 y-1 for PM2.5 accumulated in male and female outdoor workers over exposure duration of 25 years respectively. This indicates the influences of vehicular exhausts on the enhanced contents of PM2.5 irrespective of the “Haze Episode”. The results are in good agreement with those obtained from FTIR technique.
Polycyclic Aromatic Hydrocarbons (PAHs) are a class of very stable organic molecules made up of only carbon and hydrogen and contain two to eight fused aromatic rings. PAHs are formed during incomplete combustion of organic materials such as fossil fuels, coke and wood. PAHs can be found in environment, the atmosphere, surface water, sediment, soil, food and in lipid tissues of both aquatic and terrestrial organisms. Natural emission sources of PAHs into the atmosphere include emissions from forest fires and volcanoes. Anthropogenic emission sources include combustion and industrial production. Incomplete combustion from motor vehicles, domestic heating and forest fires are major sources of PAHs in the atmosphere. Assuming that each region has different types of PAH emission sources, it seems rationale to hypothesize that the fingerprint of PAHs in agricultural products has its own unique locality characteristic. Since the food traceability is extremely crucial for food business, one can use PAH profile extracts from agricultural products to identify the originality. Three groups of soybean were classified according to the planting areas. In conclusion, soybean from three different countries (i.e. Thailand, Taiwan, Indonesia) can successfully be identified with the assistance of ANOVA and three-dimensional plots of binary diagnostic ratios of PAHs.
Tsunamis symbolize one of the most harmful natural disasters for low-lying coastal zones and their residents, due to both its destructive power and irregularity. The 2004 Boxing Day tsunami, which attack the Andaman Sea coast of Thailand, resulted 5,395 of deaths and inestimable casualties, interrupted economies and social well-being in numerous coastal villages and caused in extreme alterations of both onshore and offshore coastal morphology. The Great Indian Ocean tsunami also highlighted that there are many missing jigsaw puzzle pieces in scientific knowledge, starting from the generating of tsunamis offshore to the countless influences to the marine ecosystems on the continental shelf, coastal areas and on land and to the economic and social systems consequences. As with all deposits that do not have a direct physical link to their causative sources, marine tsunami deposits must be distinguished from other deposits through regional correlation, dating and criteria for recognition within the deposits themselves. This study aims to provide comprehensive reviews on using Polycyclic Aromatic Hydrocarbons (PAHs) as a chemical proxy to discriminate tsunami related Vol. 32, No. 4, page 236 (2013) deposits from typical marine sediments. The advantages and disadvantages of this chemical tracer will be critically reviewed and further discussed.
The total concentrations of twelve, likely carcinogenic, polycyclic aromatic hydrocarbons (PAHs) (i.e., phenanthrene (Phe), anthracene (An), fluoranthene (Fluo), pyrene (Pyr), benz[a]anthracene (B[a]A), chrysene (Chry), benzo[b]fluoranthene (B[b]F), benzo[k]fluoranthene (B[k]F), benzo[a]pyrene (B[a]P), indeno[1,2,3-cd]pyrene (Ind), dibenz[a,h]anthracene (D[a,h]A), and benzo[g,h,i]perylene (B[g,h]P) in backwash deposits of the 2004 Khao Lak tsunami were carefully investigated and compared with the concentrations of world marine sediments (WMS). In general, ∑12PAHs in this study (i.e., 69.43±70.67ngg(-1)) were considerably lower than those values observed in marine sediments from Boston (54,253ngg(-1)), coastal sediments from Barcelona Harbour (15,069ngg(-1)), and riverine sediment from Guangzhou Channel (12,525ngg(-1)), but were greater than values from coastal sediments in Rosas Bay (12ngg(-1)), Santa Ponsa Bay (26ngg(-1)) and Le Planier (34ngg(-1)). The total toxic benzo[a]pyrene equivalent (TEQ(Carc)) values calculated for Khao Lak coastal sediments (KCS), Khao Lak terrestrial soils (KTS), and Songkhla Lake sediments (SLS) were 10.3±12.2ngg(-1), 16.0±47.7ngg(-1), and 5.67±5.39ngg(-1), respectively. Concentrations of PAHs at all study sites resulted in risk levels that fell into the "acceptable" range of the US EPA model and were much lower than those of other WMS. The cancer risk levels of PAH content in KCS ranged from 7.44×10(-8) to 2.90×10(-7), with an average of 1.64×10(-7)±8.01×10(-8); this value is 119 times lower than that of WMS. In addition, soil cleanup target levels (SCTLs) for both non-carcinogens (i.e., Phe, An, Fluo and Pyr) and carcinogens (i.e., B[a]A, Chry, B[b]F, B[k]F, B[a]P, Ind, D[a,h]A and B[g,h,i]P) in the KTS samples were estimated for all target groups, with an average value of 115,902±197,229ngg(-1).
Along with rapid economic growth and enhanced agricultural productivity, particulate matter emissions in the northern cities of Thailand have been increasing for the past two decades. This trend is expected to continue in the coming decade. Emissions of particulate matter have brought about a series of public health concerns, particularly chronic respiratory diseases. It is well known that lung cancer incidence among northern Thai women is one of the highest in Asia (an annual age-adjusted incidence rate of 37.4 per 100,000). This fact has aroused serious concern among the public and the government and has drawn much attention and interest from the scientific community. To investigate the potential causes of this relatively high lung cancer incidence, this study employed Fourier transform infrared spectroscopy (FTIR) transmission spectroscopy to identify the chemical composition of the PM2.5 collected using Quartz Fibre Filters (QFFs) coupled with MiniVolTM portable air samplers (Airmetrics). PM2.5 samples collected in nine administrative provinces in northern Thailand before and after the "Haze Episode" in 2013 were categorised based on three-dimensional plots of a principal component analysis (PCA) with Varimax rotation. In addition, the incremental lifetime exposure to PM2.5 of both genders was calculated, and the first derivative of the FTIR spectrum of individual samples is here discussed.
It is well known that increased incidences of lung, skin, and bladder cancers are associated with occupational exposure to PAHs. Animal studies show that certain PAHs also can affect the hematopoietic and immune systems and can produce reproductive, neurologic, and developmental effects. As a consequence, several studies have been attempted to investigate the fate of PAHs in atmospheric environment during the past decades. However, there is still a lack of information in regard to the atmospheric concentration of PAHs during the "Bon Fire Night". In this study, twenty-three polycyclic aromatic hydrocarbons and twenty-eight aliphatics were identified and quantified in the PM10 and vapour range in Birmingham (27th November 2001-19th January 2004). The measured concentrations of total particulate and vapour (P+V) PAHs were consistently higher at the BROS in both winter and summer. Arithmetic mean total (P+V) PAH concentrations were 51.04±47.62 ng m-3 and 22.30±19.18 ng m-3 at the Bristol Road Observatory Site (BROS) and Elms Road Observatory Site (EROS) respectively. In addition arithmetic mean total (P+V) B[a]P concentrations at the BROS were 0.47±0.39 ng m-3 which exceeded the EPAQS air quality standard of 0.25 ng m-3. On the other hand, the arithmetic mean total (P+V) aliphatics were 81.80±69.58 ng m-3 and 48.00±35.38 ng m-3 at the BROS and EROS in that order. The lowest average of CPI and Cmax measured at the BROS supports the idea of traffic emissions being a principle source of SVOCs in an urban atmosphere. The annual trend of PAHs was investigated by using an independent t-test and one- way independent ANOVA analysis. Generally, there is no evidence of a significant decline of heavier MW PAHs from the two data sets, with only Ac, Fl, Ph, An, 2-MePh, 1+9-MePh, Fluo and B[b+j+k]F showing a statistically significant decline (p<0.05). A further attempt for statistical analysis had been conducted by dividing the data set into three groups (i.e. 2000, 2001-2002 and 2003-2004). For lighter MW compounds a significant level of decline was observed by using one-way independent ANOVA analysis. Since the annual mean of O3 measured in Birmingham City Centre from 2001 to 2004 increased significantly (p<0.05), it may be possible to attribute the annul reduction of more volatile PAHs to the enhanced level of annual average O3. By contrast, the heavier MW PAHs measured at the BROS did not show any significant annual reduction, implying the difficulties of 5- and 6-ring PAHs to be subject to photochemical decomposition. The deviation of SVOCs profile measured at the EROS was visually confirmed during the "Bonfire Night" festival closest to the 6th November 2003. In this study, the atmospheric PAH concentrations were generally elevated on this day with concentrations of Fl, Ac, B[a]A, B[b+j+k]F, Ind and B[g,h,i]P being particularly high.
The chemical mass balance (CMB) receptor model was applied to the chemically speciated diurnal particulate matter samples acquired at nine locations in California's South Coast Air Basin (SoCAB) during the summer and fall of 1987 as part of the Southern California Air Quality Study (SCAQS). Source profiles applicable to the Los Angeles area were used to apportion PM 2.5 and PM 10 (particles with aerodynamic diameters < 2.5 and 10 m, respectively) to primary paved road dust, primary construction dust, primary motor vehicle exhaust, primary marine aerosol, secondary ammonium nitrate, and secondary ammonium sulfate. Suspended dust was the major contributor to PM 10 during the summer, whereas secondary ammonium nitrate and primary motor vehicle exhaust contributions were high during the fall. Secondary ammonium sulfate contributions were uniform across the SoCAB, with average contributions during the fall less than half those found during the summer. Marine aerosol contributions were lower during the fall than during the summer, and were substantially lower at the inland sites relative to the sites near the coast.
Organic carbon (OC) and elemental carbon (EC) are operationally defined by the analysis methods, and different methods give in different results. The IMPROVE Iinteragency Monitoring of protected Visual Environments) and NIOSH (National Institute of Occupational Safety and Wealth) thermal evolution protocols present different operational definitions. These protocols are applied to 60 ambient and sonrce samples from different environments using the same instrument to quantify differences in implemented protocols on the same instrument. The protocols are equivalent for total carbon sampled on quartz-fiber filters. NIOSH EC was typically less than half of IMPROVE EC. The primary difference is the allocation of carbon evolving at the NIOSH 850 degrees C temperature in a helium atmosphere to the OC rather than EC fraction. increasing light transmission and reflectance during this temperature step indicate that this fraction should he classified as EC. When this portion of NIOSH OC is added to NIOSH EC, the IMPROVE and NIOSH analyses are in good agreement. The most probable explanation is that mineral oxides in the complex particle mixture on the filter are supplying oxygen to neighboring carbon particles at this high temperature. This has been demonstrated by the principle of the thermal manganese oxidation method that is also commonly used to distinguish OC from EC, For both methods, the optical pyrolysis adjustment to the EC fractions was always higher for transmittance than for reflectance. This is a secondary cause of differences between the two methods, with transmittance resulting in a lower EC loading than reflectance. The difference was most pronounced for very black filters on which neither reflectance nor transmittance accurately detected further blackening due to pyrolysis.
This study retrospectively analyzes the daily results of relative response factors (RRFs) of polycyclic aromatic hydrocarbons detected by gas chromatography–mass spectrometry (GC-MS). Although instrumental routine maintenance can enhance the reliability of measurement, there is no quantitative study to investigate the effects of glass liner contamination, manifold temperature drop, and column degradation on deteriorating sensitivities and stabilities of RRFs. This study demonstrates that by removing the contribution of outliners to the background level, great reductions of RRFs were achieved. Although several factors potentially undermined the analyzer’s confidence on data reliability, there were no significant differences on the relative sensitivities of RRFs.
The Polycyclic aromatic hydrocarbons PAHs (naphthalene, acenaphthylene, acenaphthene, phenanthrene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene and benzo(ghi)perylene) concentrations in fine (PM2.5) and coarse (PM2.5–10) atmospheric particulate matter were measured at São Paulo city, Brazil. The dominant PAH compounds were indeno(1,2,3-cd)pyrene, benzo(ghi)perylene and benzo(b)fluoranthene for both the fractions. The calculated ratios of some specific PAHs were in close agreement with those attributed to direct emissions of car exhaust. The factor analysis for PM2.5 produced four factors: Factor 1 was attributed to diesel emissions, Factor 2 was attributed to stationary combustion source, Factor 3 was attributed to vehicular emissions and Factor 4 to natural gas combustion and biomass burning. For PM2.5–10, Factor 1 was attributed to vehicular emissions and Factor 2 was attributed to a mixture of combustion sources such as natural gas combustion, incineration emissions and oil combustion. Also, vehicular emissions were assumed to be the major source of PAHs in the São Paulo city atmosphere.
Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in urban air samples of Konya, Turkey between August 2006 and May 2007. The concentrations of pollutants in both the gas and particulate phase were separately analysed. The average total (gas + particulate) concentrations of PAHs, PCBs and OCPs were determined as 206 ng m− 3, 0.106 ng m− 3, 4.78 ng m− 3 respectively. All of the investigated target compounds were dominantly found in the gas phase except OCPs. Higher air concentrations of PAHs were found at winter season while the highest concentrations of PCBs were determined in September. The highest OCPs were detected in October and in March. In urban air of Konya, PCB 28 and PCB 52 congeners represent 46% and 35% of total PCBs while Phenanthrene, Fluoranthene, Pyrene accounted for 29%, 13%, 10% of total PAHs. HCH compounds (α + β + γ + δ-HCH), total DDTs (p,p′-DDE, p,p′-DDD, p,p′-DDT), Endosulfan compounds (Endosulfan I, Endosulfan II, Endosulfan sulfate) were dominantly determined as 30%, 21%, 20% of total OCPs respectively. Considering the relation between these compounds with temperature, there was no significant correlation observed. Despite banned/restricted use in Turkey, some OCPs were determined in urban air. These results demonstrated that they are either illegally being used in the course of agricultural activity and gardens in Konya or they are residues of past use in environment. According to these results, it can be suggested that Konya is an actively contributing region to persistent organic pollutants in Turkey.
This work focuses on the determination of PCB source profiles and their contributions to sediments in the Milwaukee Harbor Estuary by a principal component analysis (PCA) model. The model was recently developed and, for the first time, applied to apportion pollutant sources in sediments. Factor loadings and scores were computed, rotated via nonnegative constraints, and matched with candidate Aroclor profiles. Contamination by Aroclors 1016, 1242, 1254, and 1260 were identified for cores VC 6, 9, and 12 based on a log Q2 criterion. The majority of PCB contribution was from a combination of Aroclors 1016 and 1242. Similarity between Aroclors 1016 and 1242 obscured resolution between the two profiles. Results from a chemical mass balance (CMB) model with known Aroclor profiles were in good agreement with the prediction from the PCA model.
A series of 68 duplicate aerosol samples was collected in the fall of 1986 in Ghent, Belgium, by means of two cyclone/filter combinations, set up on parallel. The filters, containing the less than 5 mu m particle size fraction, were analyzed for 23 elements by particle induced X-ray emission analysis. The data set, consisting of concentrations for 15 elements in 64 sampling periods, was subjected to varimax rotated principal component analysis. The use of this multivariate technique, combined with some simple matrix algebra, allowed us to indicate the major sources of the atmospheric trace elements, to extract the relative source profiles, and to calculate the contribution of the various sources to the observed elemental concentrations.
The causes of lung cancer in northern Thailand have not been completely understood, but it is strongly believed that they are multi-factorial. The environmental and occupational factors have played a significant role on lung cancer. They can be categorized as physical, chemical, and biological. In the northern region of Thailand, specifically Chiang Mai province, it has been recognized that the incidence of lung cancer is among the highest in Thailand. For example, in the year 2007, the age-standardized incidence rate in males was 31.3 and that in female was 22.9 per 100,000 population. The district ranked the highest was Muang district, Chiang Mai. The previous studies showed that, apart from smoking, the indoor radon, air pollution and genetic factors might be the causes.
Comprehensive measurements of atmospheric aerosols were made in Phimai, central Thailand (15.183°N, 102.565°E, elevation: 206 m) during the BASE-ASIA field experiment from late February to early May in 2006. The observed aerosol loading was sizable for this rural site (mean aerosol scattering: 108 ± 64 Mm−1; absorption: 15 ± 8 Mm−1; PM10 concentration: 33 ± 17 μg m−3), and dominated by submicron particles. Major aerosol compounds included carbonaceous (OC: 9.5 ± 3.6 μg m−3; EC: 2.0 ± 2.3 μg m−3) and secondary species (SO42−: 6.4 ± 3.7 μg m−3, NH4+: 2.2 ± 1.3 μg m−3). While the site was seldom under the direct influence of large forest fires to its north, agricultural fires were ubiquitous during the experiment, as suggested by the substantial concentration of K+ (0.56 ± 0.33 μg m−3). Besides biomass burning, aerosols in Phimai during the experiment were also strongly influenced by industrial and vehicular emissions from the Bangkok metropolitan region and long-range transport from southern China. High humidity played an important role in determining the aerosol composition and properties in the region. Sulfate was primarily formed via aqueous phase reactions, and hygroscopic growth could enhance the aerosol light scattering by up to 60%, at the typical morning RH level of 85%. The aerosol single scattering albedo demonstrated distinct diurnal variation, ranging from 0.86 ± 0.04 in the evening to 0.92 ± 0.02 in the morning. This experiment marks the first time such comprehensive characterization of aerosols was made for rural central Thailand. Our results indicate that aerosol pollution has developed into a regional problem for northern Indochina, and may become more severe as the region's population and economy continue to grow.
Thirty re-suspended dust samples were collected from building surfaces in an oilfield city, re-suspended and sampled through PM2.5, PM10 and PM100 inlets and analyzed for 18 PAHs by GC–MS technique. PAHs concentrations, toxicity and profiles characteristic for different districts and size were studied. PAHs sources were identified by diagnostic ratios and primary component analysis. Results showed that the total amounts of analyzed PAHs in re-suspended dust in Dongying were 45.29, 23.79 and 11.41 μg g−1 for PM2.5, PM10 and PM100, respectively. PAHs tended to concentrate in finer particles with mass ratios of PM2.5/PM10 and PM10/PM100 as 1.96 ± 0.86 and 2.53 ± 1.57. The old district with more human activities and long oil exploitation history exhibited higher concentrations of PAHs from both combustion and non-combustion sources. BaP-based toxic equivalent factor and BaP-based equivalent carcinogenic power exhibited decreasing sequence as PM2.5 > PM10 > PM100 suggesting that the finer the particles, the more toxic of the dust. NaP, Phe, Flu, Pyr, BbF and BghiP were the abundant species. Coefficient of divergence analysis implied that PAHs in different districts and size fractions had common sources. Coal combustion, industrial sources, vehicle emission and petroleum were probably the main contributions according to the principal component analysis result.
Polycyclic aromatic hydrocarbons (PAHs) were measured in pine needles (passive sampling) and on high-volume particulate matter (PM) filters (active sampling) over a period of eight to ten months at two separate sites in the Dayton, Ohio, USA metropolitan area: Moraine and Yellow Springs. Total PAH concentrations for PM ranged from 77.4 μg g−1 to 837 μg g−1 (dry wt.) at both sites with high molecular weight PAHs being the predominant form that tended to be higher in concentration during the colder months. Total PAH concentrations for pine needles varied by tree species and location. With an average concentration of 4187 ng g−1, Austrian pine (Pinus nigra) needles in Moraine ranged from 2543 ng g−1to 6111 ng g−1 (dry wt.) with the lowest and highest concentrations occurring in October and August, respectively. The amount of phenanthrene was extremely high for August, 4200 ± 112, which could have resulted from the close proximity of the tree to the parking lot at a firehouse. White pine (Pinus strobus) needles in Yellow Springs had an average concentration of 384 ng g−1and ranged from 127 ng g−1 to 589 ng g−1 (dry wt.) with September and November, respectively, having the lowest and highest PAH concentrations. The 2- and 3-ring PAHs were the predominant form in P. nigra, while the 4-ring PAHs predominated in P. strobus. Total PAH concentrations in P. nigra were an order of magnitude greater than for P. strobus. A bivariate plot of BaA/(BaA + Chry) versus Flt(Flt + Pyr) allowed the PM and pine needle data to be included in the same source analysis and indicated sources of PM at both sites were biomass and/or coal combustion. This plot also suggested PAHs in Yellow Springs P. strobus originated from petroleum combustion sources, whereas PAHs in Moraine P. nigra originated from petroleum combustion with some sources more aged or remote.
To investigate the intraurban spatial variability of air toxics associated with respirable particulate matter (PM), ambient PM2.5 and 16 polycyclic aromatic hydrocarbons (PAH) species (vapour phase plus 2.5 μm particle phase) were sampled over a dense network of sites in Hamilton, Ontario, Canada in June/July 2009 and December 2009. PM2.5 levels ranged from 2.46 to 11.0 μg m−3 in the summer campaign and 6.52 to 13.4 μg m−3 in the winter campaign. Total sampled PAH (Σ16PAH) levels ranged from 10.2 to 83.7 ng m−3 in the summer campaign and 8.31 to 52.1 ng m−3 in the winter campaign. Ambient PM2.5 and PAH concentrations were greater below the city's escarpment with a below/above escarpment difference in concentration much greater for PAH than for PM2.5 in both summer and winter sampling campaigns. Elevated levels of both pollutants were observed to occur near or downwind of the central business district and industrialized harbourfront area, suggesting the contribution of local sources. Ambient PAH exhibited a substantially greater degree of intraurban variability than PM2.5 (coefficient of variation approximately three times greater in summer campaign, four times greater in winter campaign) both above and below the escarpment, particularly for heavy MW species found predominantly in the particle phase. Benzo(a)Pyrene-equivalent toxicity (BaP-TEQ) associated with ambient PAH showed a generally similar spatial distribution to Σ16PAH; however, several sites with relatively low Σ16PAH had high BaP-TEQ (enriched in more toxic heavy MW species), indicating potential hotspots for elevated PAH exposures and local source contributions. Co-located field sampling data showed that central site monitoring was a poor proxy for PM2.5 and particularly for PAH and associated toxicity (BaP-TEQ) across the urban centre, underestimating levels at many sites, likely due to the significant number of locally distributed sources and mixed land use. The much greater intraurban variability of PAH relative to PM2.5, particularly for toxic heavy MW species predominantly in particle phase, demonstrated variability in PM2.5 composition and confirmed the importance of the local scale for PAH exposure health risk assessment.
Motor vehicles are significant sources of polycyclic aromatic hydrocarbon (PAH) emissions to the urban atmosphere. Improved understanding of PAH emission profiles in mobile sources is the key to determining the viable approach for reducing PAH emissions from motor vehicles. Very limited data is available on the levels of PAH emissions in the urban atmospheres in Syria and no data are currently available on the level of PAH emissions from different combustion sources in the country. The aim of this study was to determine the profile and concentration of PAH in exhaust emissions of light and heavy-duty vehicles running on the roads of Damascus city. Three different types of vehicles (passenger cars, minivans and buses) were selected along with different age groups. Vapor- and particulate-phase PAH were collected from the vehicular exhausts of six in-service vehicles (with/without catalytic converters). High-performance liquid chromatography system, equipped with UV–Visible and fluorescence detectors, was used for the identification and quantification of PAH compounds in the cleaned extracts of the collected samples. The mean concentration of total PAH emissions (sum of 15 compounds) from all types of studied vehicles ranged between 69.28 ± 1.06 μg/m3 for passenger cars equipped with catalytic converters and 2169.41 ± 5.17 μg/m3 for old diesel buses without pollution controls. Values of total benzo(a)pyrene equivalent (∑ B[a]Peq) ranged between 1.868 μg/m3and 37.652 μg/m3. The results obtained in this study showed that the use of catalytic converters resulted into cleaner exhaust compositions and emissions with characteristics that are distinct from those obtained in the absence of catalytic converters.
Organic aerosols are important atmospheric components, and their formation and sources represent important aspects of urban air quality and health effects. Asia, including India, is the largest global source of aerosol particles due to regional natural advection (e.g. desert and soil dust) and anthropogenic activities (e.g. emissions from traffic, industry and burning of coal, biomass and agricultural waste) that generate vast amounts of particulate matter (PM) significantly contributing to climate change. This article reports on the distributions, concentrations, and sources of organic compounds (i.e., alkanes, carboxylic acids, carbonyl compounds, alcohols, plasticizers, PAHs, biomarkers) of PM in the ambient atmosphere of an extensively industrialized area of central India (Raipur, Chhattisgarh, a coal mega-burning region). The dominant components are emissions from fossil fuel utilization, burning of biomass and plastics, and fugitive sources. Speciation and variations of potential new tracer compounds identified are also described.
Total suspended particle (TSP) samples were collected during January to December in 2005 at urban and rural sites in Guiyang, and were analyzed for 14 particulate-phase polycyclic aromatic hydrocarbons (P-PAHs) using High Performance Liquid Chromatography (HPLC) with fluorescence detection. The total concentration of the P-PAHs ranged from 6.0–29.1 ng/m3 at monitoring sites, and 1.2–84.8 ng/m3 in and around Guiyang. P-PAHs concentration in samples collected from Guiyang possesses distinct seasonal variation with a higher concentration in winter and lower concentration in summer. PAHs with 5-ring were found to have the most distinct seasonal variation among other target PAHs. Correlations between the TSP concentration, ambient temperature (T), relative humidity (RH), and the P-PAHs concentrations were evaluated.It was found that the TSP had significant influence on the P-PAHs concentration with correlation coefficients of 0.69 (P < 0.01, n = 180). In addition, the P-PAHs concentration showed negative correlation with RH (r = − 0.28, P < 0.01, n = 180), and a moderate negative correlation with T (r = − 0.17, P < 0.05 n = 180). Diagnostic ratios and Principal Component Analysis suggest that the main pollution sources identified were coal combustion emission (52.5%), traffic gasoline (21.4%) and other miscellaneous sources (14.2%).
A set of 16 priority polycyclic aromatic hydrocarbons (PAH) associated with particulate matter (PM), emitted by a diesel engine fueled with petroleum diesel and a 15%-vol. palm oil methyl ester blend with diesel (B15), were determined. PM was filtered from a sample of the exhaust gas with the engine running at a steady speed and under no load. PAH were extracted from the filters using the Soxhlet technique, with dichloromethane as solvent. The extracts were then analyzed by gas chromatography using a flame ionization detector (FID). No significant difference was found between PM mass collected when fueled with diesel and B15. Ten of the 16 PAH concentrations were not reduced by adding biodiesel: Benz(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, chrysene, dibenz(a,h)anthracene, fluoranthene, fluorene, indeno(1,2,3-c,d)pyrene, naphthalene and phenanthrene. The acenaphthene, acenaphthylene and anthracene concentrations were 45%-80% higher when using diesel, whereas those for benzo(k)fluoranthene, benzo(g,h,i)perylene and pyrene were 30%-72% higher when using the B15 blend. Even though the 16 priority-PAH cumulative concentration increased when using the B15 blend, the total toxic equivalent (TEQ) concentration was not different for both fuels.
Positive matrix factorization (PMF) was applied on a large dataset of polycyclic aromatic hydrocarbon (PAH) concentrations determined in air at the central European background monitoring site Košetice, Czech Republic. The long-term (1996–2009) PAH median concentration in Košetice is about 6 times higher during winter than summer months. As the source apportionment of these pollutants is accompanied by concerns regarding the loss of the source signature during atmospheric transport, PMF was run on two winter PAH concentration data subsets stratified according to different ambient levels of oxidants. It is suggested, that the typical ambient air PAH pattern is largely preserved on a regional transport scale in winter in central Europe. However, the allocation of PMF model factors to particular PAH source categories (e.g., road traffic, residential wood combustion, residential and industrial coal combustion) could not be achieved due to (a) a high similarity of reference PAH profiles among each other and (b) variability in ambient reference PAH profiles. It is suggested, that the commonly studied set of EPA PAHs is not source category specific and thus not suitable for source apportionment. PAH source apportionment using more specific PAH and non-PAH markers is recommended.
Biomass is one of the most important renewable energy sources that could help to achieve the 2020 targets set by European Directive 2009/28. This is particularly true in Italy where the government plans to replace a final energy use corresponding to 200-250 PJ through the use of small wood stoves/boilers for domestic heating (<35 kW). This corresponds to about 25% of the national target for 2020. However, this solution is under discussion because of the environmental problems that poses in terms of emissions of PM and PAHs especially in lowland areas. The study, starting from these assumptions, was focussed to better characterize, with laboratory tests, the composition of PAHs emitted by a modern pellet stove and verify their distribution in the solid, liquid and gaseous fractions of the fumes at the stack. In brief, the tests showed that about 85% of the harmful effect of PAH is associated with the PM. This confirms that special attention should be given to the control of the dust through a better design of the stoves and/or the development of abatement equipment also suitable for small devices.
To identify the ambient characteristics of a mega city in Northeast Asia, the particulate PAHs in TSP were measured for 18months at Seoul, the capital of Korea. The average concentration of the ambient particulate PAHs at Seoul for the sampling period was 26.6±28.4ngm−3 with the range from 1.57 to 166ngm−3. It showed winter maxima and summer minimum mainly due to the increased fuel consumption in winter both at Seoul and Northeast Asia. The ambient level of PAHs in Seoul was lower than the cities in China but higher than other urban areas. The stronger relationship between the ambient particulate PAHs concentrations and the inverse of the ambient temperature (1/T) at Seoul compared to Gosan, a background site in Korea and the difference of the distributions of BeP/BaP ratios at Seoul and Gosan might be due to the characteristics of Seoul which was governed by both transport from outside and local emissions. The relationship between the particulate PAHs concentration and (1/T) can be used as an indicator for those two factors for Seoul.
This work focuses on the determination of PCB source profiles and their contributions to sediments in the Milwaukee Harbor Estuary by a principal component analysis (PCA) model. The model was recently developed and, for the first time, applied to apportion pollutant sources in sediments. Factor loadings and scores were computed, rotated via nonnegative constraints, and matched with candidate Aroclor profiles. Contamination by Aroclors 1016, 1242, 1254, and 1260 were identified for cores VC 6, 9, and 12 based on a log Q2 criterion. The majority of PCB contribution was from a combination of Aroclors 1016 and 1242. Similarity between Aroclors 1016 and 1242 obscured resolution between the two profiles. Results from a chemical mass balance (CMB) model with known Aroclor profiles were in good agreement with the prediction from the PCA model.
Molecular markers, such as n-alkanes, hopanes, PAHs, n-alkanols, n-alkanals, n-alkan-2-ones and n-alkanoic acids, and atmospheric back trajectories have been conjointly used to reconcile Eastern Mediterranean marine organic aerosols with their emission sources. In the urban site, local inputs of polar and non polar lipids control the aerosol composition. In addition the presence of iso- and anteisoalkanes in the aliphatic fraction of all urban samples analysed, demonstrated the contribution of cigarette smoke to urban aerosols. The composition of the aliphatic and aromatic fractions demonstrated a clear petrogenic input. In the rural site the composition and concentrations of the PAH fraction were dependant on the origin of air masses, and showed a rather pyrolytic origin. They were higher for air masses from the north than for air masses originating from the south. Some molecular markers, such as 6,10,14-trimethylpentadecan-2-one and α,ω-dicarboxylic acids with Cn > C20, characterized rural aerosols corresponding to air masses with a pronounced marine origin.
Measurements of the principle solvent extractable organic components associated with airborne particulates were conducted at two urban sites of Algiers, Algeria, between July 2005 and June 2006 to gain information about their ambient concentration levels and source impacts. The compounds identified included n-alkanes, n-alkanoic mono- and dicarboxylic acids, polycyclic aromatic hydrocarbons (PAHs), nitrated-PAHs (N-PAHs), and nitrogen/oxygen containing polycyclic aromatic compounds (PACs). The seasonal average concentrations for these chemical groups ranged from 42–193 ng m−3, 292–2656 ng m−3, 8–629 ng m−3, 12–189 pg m−3, and 2–9 ng m−3, respectively. Maximum concentrations were recorded during the cold season for all groups except N-PAHs that peaked in summertime. Fatty acids accounted for more than 67% of total organic aerosol mass at both sites. The ratios between atmospheric concentrations of marker species as well as the evolution of the distribution of species in the chemical groups studied indicate that the organic aerosols are of vehicular origin.
The solvent-extractable organic compounds of atmospheric PM10 samples, collected over two years beginning in 2003 at urban and suburban sites of Beijing, were characterized using gas chromatography–mass spectrometry (GC–MS). The elemental carbon (EC) contents were determined and ranged from 4.3 to 42 μg m−3. Organic compounds in total extracts were identified and included unresolved complex mixture (UCM) and series of n-alkanes, n-alkanols, n-alkanoic acids, polycyclic aromatic hydrocarbons (PAHs); saccharides, alkanedioic acids, steroids, and other biomarkers and source tracers. The seasonal variations of their relative abundances are discussed. The abundance order for the major molecular classes in the particulate organic matter (POM) was the following: UCM>saccharides>n-alkanoic acids>n-alkanes>n-alkanols>PAHs>hydroxy-PAHs>other biomarker tracers. Based on the genetic significance of the molecular tracers, the dominant sources of POM are proposed for the two sampling sites. The emissions from fossil fuel use (both coal and petroleum products), biomass combustion, other pyrolysis sources, higher plant wax, and secondary products contribute >98.0% of the POM mass. The fossil fuel use (average=65% of POM) is the largest contributor and derives mainly from vehicular traffic.
During the 20th century, there has been an increased risk from environmental by-products that may be harmful to reproductive function in humans. Therefore, as the 21st century begins, it is appropriate to evaluate future directions within the field of reproductive toxicology. This commentary identifies several approaches and developing technologies that would help research continue in a meaningful direction. Four areas for development are suggested, and selected examples of research involved in those areas are discussed: (1) Translational applications: workplace exposures thought to cause infertility in men (1,2-dibromo-3-chloropropane, DBCP) and menstrual disturbances in women (2-bromopropane, 2BP) are given as examples of human effects that have prompted animal studies. (2) Exposure paradigms: extrapolating dosing in animals to exposures in humans becomes complex. Two examples of surprising findings using lower doses are cited: ovotoxicity caused by polycyclic aromatic hydrocarbons (PAHs), and disrupted sexual differentiation caused by the fungicide vinclozolin. (3) Gender differences: predicting variable risk between women and men requires investigation of the effects of reproductive toxicants in both genders. The phthalates provide a good example for this comparison. Whereas di-(2-ethylhexyl)phthalate (DEHP) is a reproductive toxicant working by similar mechanisms in males and females, di-n-butyl phthalate (DBP) produces developmental effects in males and reproductive tract effects in females. (4) Endocrine disruptors: recent research has identified environmental chemicals that disrupt reproductive processes by altering the actions of endogenous steroid hormones. The endocrine disruptor issue is discussed in terms of evaluation of the actual risk these chemicals may pose in humans.
The purpose of the present study was to evaluate the polycyclic aromatic hydrocarbons (PAHs) in fine (PM2.5) and coarse particles (PM2.5–10)inanurban andindustrialareaintheMetropolitan Area of Porto Alegre (MAPA), Brazil. Sixteen U.S. Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (PAHs) were measured. Filters containing ambient air particulate were extracted with dichloromethane using Soxhlet. Extracts were later analyzed, for determining PAH concentrations, using a gaseous chromatograph coupled with a mass spectrometer (GC-MS). The polycyclic aromatic hydrocarbons (PAHs)weremore concentrated in PM2.5 with an average of 70% of total PAHs in the MAPA. The target PAH apportionment among the main emission sources was carried out by diagnostic PAH concentration ratios, and principal component analysis (PCA). PAHs with higher molecular weight showed higher percentages in the fine particles in the MAPA. Based on the diagnostic ratios and PCA analysis, itmay be concluded that the major contribution of PAHswas fromvehicular sources (diesel and gasoline), especially inthePM2.5 fraction, aswellascoal andwoodburning. The winter/summer ratio in the PM2.5andPM2.5–10 fractions intheMAPAwas3.1 and 1.8, respectively, revealing the seasonal variation of PAHs in the two fractions. The estimated toxicity equivalent factor (TEF), used to assess the contributionof the carcinogenic potency, confirms a significant presence of the moderately active carcinogenic PAHs BaP and DahA in the samples collected in theMAPA.©
Air pollution authorities use models to develop optimal control strategies for air pollutants. According to the traditional approach, emissions inventories for various sources are used as inputs for plume, box, or grid models to predict ambient concentrations of total suspended particulate matter (TSP), SO/sub 2/, or other air pollutants. These methods, however, are inadequate for many purposes today and will be even less useful for many future needs. Even if dispersion models were accurate, the source emissions inventories upon which they rely are not. Source emission inventories, especially for sources equipped with pollution controls, usually do not include contributions from fugitive process emissions and dust. Furthermore, air quality standards are beginning to require knowledge of source of particles in certain size ranges, particles bearing certain toxic substances, or particles that have a special role in problems such as visibility degradation or climate modification.
The size distribution of elemental carbon (EC), organic carbon (OC) and particle-phase PAHs emission from a direct injection diesel engine fueled with a waste cooking biodiesel, ultra low sulfur diesel (ULSD, 10-ppm-wt), and low sulfur diesel (LSD, 400-ppm-wt) were investigated experimentally. The emission factor of biodiesel EC is 90.6mg/kWh, which decreases by 60.3 and 71.7%, compared with ULSD and LSD respectively and the mass mean diameter (MMD) of EC was also decreased with the use of biodiesel. The effect of biodiesel on OC emission might depend on the engine operation condition, and the difference in OC size distribution is not that significant among the three fuels. For biodiesel, its brake specific emission of particle-phase PAHs is obviously smaller than that from the two diesel fuels, and the reduction effect appears in almost all size ranges. In terms of size distribution, the MMD of PAHs from biodiesel is larger than that from the two diesel fuels, which could be attributed to the more effective reduction on combustion derived PAHs in nuclei mode. The toxicity analysis indicates that biodiesel could reduce the total PAHs emissions, as well as the carcinogenic potency of particle-phase PAHs in almost all the size ranges.
Air pollution represents a serious risk not only to environment and human health, but also to historical heritage. In this study, air pollution of the Oporto Metropolitan Area and its main impacts were characterized. The results showed that levels of CO, PM10 and SO2 have been continuously decreasing in the respective metropolitan area while levels of NOx and NO2 have not changed significantly. Traffic emissions were the main source of the determined polycyclic aromatic hydrocarbons (PAHs; 16 PAHs considered by U.S. EPA as priority pollutants, dibenzo[a,l]pyrene and benzo[j]fluoranthene) in air of the respective metropolitan area. The mean concentration of 18 PAHs in air was 69.9±39.7ngm−3 with 3–4 rings PAHs accounting for 75% of the total ΣPAHs. The health risk analysis of PAHs in air showed that the estimated values of lifetime lung cancer risks considerably exceeded the health-based guideline level. Analytical results also confirm that historical monuments in urban areas act as passive repositories for air pollutants present in the surrounding atmosphere. FTIR and EDX analyses showed that gypsum was the most important constituent of black crusts of the characterized historical monument Monastery of Serra do Pilar classified as “UNESCO World Cultural Heritage”. In black crusts, 4–6 rings compounds accounted approximately for 85% of ΣPAHs. The diagnostic ratios confirmed that traffic emissions were the major source of PAHs in black crusts; PAH composition profiles were very similar for crusts and PM10 and PM2.5.
The chemical mass balance model was applied to atmospheric Polycyclic Aromatic Hydrocarbons (PAHs) in Istanbul, Turkey. A total of 326 airborne samples were collected and analyzed for 16 PAHs and Total Suspended Particles (TSP) in the September 2006 December 2007 period at three monitoring stations: Yildiz, DMO (urban sites) and Kilyos (rural site). The total average PAH concentrations were 100.66 +/- 61.26, 84.63 +/- 46.66 and 25.12 +/- 13.34 ng m(-3) and the TSP concentrations were 101.16 +/- 53.22, 152.31 +/- 99.12, 49.84 +/- 18.58 mu g m(-3) for Yildiz. DMO and Kilyos stations respectively. At all the sites, the lighter compounds were the most abundant, notably Nap, AcPy and PA. The average correlation values between TSP and total heavier PAH were greater than 0.5 for Yildiz and DMO stations. The patterns of PAH and TSP concentrations showed spatial and temporal variations. PAH concentrations were evaluated for the PAH contribution from four sources (diesel engines, gasoline engines, natural gas combustion, and coal + wood burning). Vehicle emissions appear to be the major source with contributions of 61.2%, 63.3% and 54.1% for Yildiz. DMO and Kilyos stations respectively. Seasonal and yearly variations had different trends for all sites. (C) 2010 Elsevier B.V. All rights reserved.
Normal alkanes and PAHs in atmospheric PM10 aerosols collected during 2008 winter and spring in Baoji, a mid-scale inland city of China, were determined on a molecular level. Concentrations of n-alkanes ranged from 232 to 3583 ng/m3 with an average of 1733 ng/m3 in winter and from 124 to 1160 ng/m3 with an average of 449 ng/m3 in spring, while PAHs in the PM10 samples were 594 ± 405 and 128 ± 82 ng/m3 in the two seasons. Molecular compositions showed that CPI (odd/even) values of n-alkanes were close to unity for all the samples especially in winter, and diagnostic ratios of PAHs (e.g., Phe/(Phe + Ant), CPAH/ΣPAHs and IcdP/(IcdP + BghiP)) were found similar to those in coal burning smoke with a strong linear relationship (R2 ≥ 0.85) between PAHs and fossil fuel derived n-alkanes, demonstrating that coal burning is the main source of n-alkanes and PAHs in the city, especially in winter due to house heating. Concentrations of the determined compounds in Baoji are much higher than those in Chinese mega-cities, suggesting that air pollution in small cities in the country is more serious and need more attention.
Polycyclic aromatic hydrocarbons (PAHs) in both gas and total suspended particles were measured at Gosan, Jeju Island in Korea, a remote background site, for 15 days (March 29-April 12, 2002). During the sampling period, a severe three-day Asian dust (AD) event originating from Mongolia and northern China was observed throughout the Korean Peninsula and Jeju Island. In addition, pollution (PO) and normal (NO) periods were also identified based on the levels of anthropogenic pollutants. Despite a large difference of PM(10) concentrations between the AD and PO periods, the levels of particulate PAHs in both periods were comparable (2.7±1.0 and 2.4±0.5 ng m(-3), respectively) since they were determined by the concentration of anthropogenic PM(2.5) transported from industrial areas of China. In the AD period, the level of gaseous PAHs, which were mostly from local sources, was the lowest due to strong winds; the gas/particle partitioning was close to equilibrium as the effect of long-range transport was manifested. The results of backward air trajectories, correlation analysis, and diagnostic ratios show that long-range transport of particulate PAHs produced by coal/biomass burning in China could strongly affect the levels and patterns of PAHs at Gosan, Korea.
This work presents the influence of sugarcane burning on PAH levels and their profiles at a residence located in Araraquara (SP, Brazil), a city surrounded by sugarcane plantations. The average concentrations of total PAHs (ΣPAHs) associated with atmospheric particulate matter were higher during the burning period (ΣPAHs 22.9 ng m(-3)) than in the non-burning period (ΣPAH 2.35 ng m(-3)). A comparison of our results with previous studies regarding PAH levels and their profiles in Araraquara outdoor air indicated that sugarcane burning was the main PAH air source in the indoor harvesting season samples. The benzo[a]pyrene equivalent (BaP(eq)) was used for cancer risk assessment, and higher average values were obtained in the harvesting season air samples (1.7 ng m(-3)) than in the non-harvesting air samples (0.07 ng m(-3)). These findings suggest that sugarcane burning during the harvesting season can represent a public health risk in affected cities.
Ambient samples of coarse and fine organic particulate matter collected from two urban sites in the city of Athens over one warm and one cold period have been solvent-extracted and quantitatively characterized by gas chromatography–mass spectrometry for their content of polycyclic aromatic hydrocarbons (PAHs) and oxidized PAHs (oxyPAHs). Variable concentrations were observed for the two distinct monthly periods representing a cold, dry period and a summer period, relating to strong local primary emissions and to lower emissions with more stable meteorological conditions, respectively. Additionally, gaseous concentrations of selected PAHs were calculated, revealing that the relative proportions between gaseous and particle phase of individual compounds may differ significantly between summer and late winter, reflecting changes in PAH emission sources and climate conditions. In fact almost all of ΣPAHs were attributed to combustion sources (82–92%), while more than half are considered as comprising of probable human carcinogens (47–62%). Traffic was confirmed as the major contributor of PAHs when appropriate diagnostic ratios and traffic marker compounds were used. This approach also led to the estimation of diesel versus petrol contribution to the atmospheric PAH burden, using the methylphenanthrene to phenanthrene ratio. The fourteen oxygenated polycyclic compounds that were quantified had greater concentrations in the colder period. Among these compounds 9,10-phenanthrenequinone, 1-pyrenecarboxaldehyde and 9H-fluoren-9-one had the highest concentrations.
The concentrations of 16 US-EPA criteria polycyclic aromatic hydrocarbons (PAHs) were monitored during various seasons at six different cities/locations in the northern part of Belgium. Pressurized liquid extraction (PLE) was used for the fast recovery of PAHs from quartz fibre filters (QFFs) and polyurethane foams (PUFs) in less than 30 min with minimum solvent consumption prior to their analysis with high-performance liquid chromatography. The concentrations of PAHs varied significantly at the studied sites and showed relation to different anthropogenic activities, such as vehicular emission (diesel/gasoline), incinerator, petroleum/oil burning, coke production, and wood/coal combustion. The annual average PAH concentration ranged from 17 (at a rural site) to 114 ng m−3 (near a petroleum harbour and industry). Most of the human carcinogenic PAHs were found to be associated with suspended particulate matter, which forms around ∼55% of the total PAH levels in aerosols. Relatively higher concentrations of PAHs were detected in aerosol samples during winter compared with other seasons, whereas no clear seasonal trend was observed for the vapour phase PAHs. This fraction is likely to be more local in origin; hence, it can be used as a site-specific characteristic. The site-specific concentrations of individual PAHs were also used in diagnostic ratio evaluations and in principal component analysis to find their relation with various anthropogenic activities. These results show that the vehicular emission is a major source of PAHs in Flanders, although other anthropogenic sources, as above, have also an impact on the total PAH levels.
The Cubatão industrial complex of southeast Brazil is sited on a coastal strip bounded on the continental side by a mountainous scarp covered with tropical forest. Four cities have developed around the complex. The metropolitan region of São Paulo is located on a plateau above the scarp. The combination of the region’s topography, the industrial installations, and an intensely trafficked road network causes widespread atmospheric pollution. In November 2004, measurements were made of the 16 polycyclic aromatic hydrocarbons designated as priority pollutants by the US Environmental Protection Agency, as well as of aerosol mass and ionic composition. Use of characteristic concentration ratios for emission sources show that tailpipe emissions from diesel vehicles was the main source of the compounds. This means that a shift from gasoline to ethanol as fuel in spark ignition engines will have only minor influence on atmospheric polycyclic aromatic hydrocarbon concentrations, despite very low emissions during ethanol combustion. On the other hand, reduction in emissions associated with increasing use of biodiesel in compression ignition engine fuel mixtures could significantly reduce atmospheric concentrations.
Polycyclic aromatic hydrocarbons (PAHs) were measured in the Baltimore and adjacent Chesapeake Bay in July 1997. Time series of 4- and 12-h samples were taken at two sites 15 km apart in order to evaluate the influence of a number of processes on the short-term variability of PAH in the Baltimore and northern Chesapeake Bay atmospheres. PAH concentrations were 2–3-fold higher in the Baltimore atmosphere than in the adjacent Chesapeake Bay atmosphere. For example, gas-phase phenanthrene and pyrene concentrations were 12.5 and 2.14 ng m−3 in the Baltimore site and 5.57 and 0.548 ng m−3 in the Chesapeake Bay, respectively. The influence of wind direction, wind speed and temperature was evaluated by multiple linear regressions which indicated that atmospheric gas-phase PAH concentrations over the Chesapeake Bay were significantly higher when the air mass was from the urban/industrial Baltimore area. Furthermore, the increase of gas-phase low-MW PAH concentrations with temperature and wind speed suggests that volatilization from the bay is an important source of pollutants to the atmosphere, at least when air masses are not influenced by the Baltimore urban and industrial area. Indeed, while on the long-term, the Chesapeake Bay is a receptor of atmospherically deposited PAHs, on the short-term and during appropriate meteorological conditions, the bay acts as a source of pollutants to the atmosphere. Aerosol-phase PAH concentrations and temporal trends showed a strong dependence on aerosol soot content due to the high affinity of PAHs to the graphitic structure of soot. These results confirm the important influence of urban areas as a source of pollution to adjacent aquatic environments and as a driving factor of the short-term variability, either directly by transport of urban-generated pollutants or by volatilization of previously deposited pollutants. Conversely, the complex diurnal trends of gas-phase PAHs at the Baltimore site suggests that degradation processes dominate the diurnal trends of PAHs in urban atmospheres. This conclusion is supported by estimated rate constants for PAH reaction with OH radicals which show good agreement with reported values within a factor of two.
Four receptor-oriented source apportionment models were evaluated by applying them to simulated personal exposure data for select volatile organic compounds (VOCs) that were generated by Monte Carlo sampling from known source contributions and profiles. The exposure sources modeled are environmental tobacco smoke, paint emissions, cleaning and/or pesticide products, gasoline vapors, automobile exhaust, and wastewater treatment plant emissions. The receptor models analyzed are chemical mass balance, principal component analysis/absolute principal component scores, positive matrix factorization (PMF), and graphical ratio analysis for composition estimates/source apportionment by factors with explicit restriction, incorporated in the UNMIX model. All models identified only the major contributors to total exposure concentrations. PMF extracted factor profiles that most closely represented the major sources used to generate the simulated data. None of the models were able to distinguish between sources with similar chemical profiles. Sources that contributed <5% to the average total VOC exposure were not identified.
Based on data obtained from the U.S. Public Health Service National Air Sampling Network for the years 1957–1961, factor analysis techniques were used to produce a pollution model for 30 U.S. cities. Orthogonal models obtained from Varimax and Quartimax solutions and an oblique solution (Oblimax) were similar. The first four principal factors were tentatively assigned to pollution from (I) heavy industry, (II) automobiles, (III) fuel burning, and (IV) petroleum refining on the basis of their chemical composition. These four factors account for about 70 per cent of the variance while another 20 per cent appears to be due to widespread use of plating materials. Regression of the derived factors (factor scores) on the 30 sampling locations indicates general agreement with the known character of the sites and with other studies of individual pollution components.
Levels of 12 PAH species, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[e]pyrene, benzo[a]pyrene, perylene, indeno[1,2,3-cd]pyrene and benzo[ghi]perylene, in atmospheric particulates from urban area of Dalian, China, were determined. The sampling was performed at 15 sites in 1998. For wintertime and summertime, the summation of the 12 PAHs (ΣPAHs) averaged 167 (53.3–561) and 17.9 (1.6–48.9) ng m−3, respectively, which were much higher than the levels in other cities worldwide. Factor analysis with nonnegative constraints was used for source apportionment, which showed that PAHs originated from coal-related sources mainly (87%) and traffic emission as a second source (13%) in wintertime, and in summertime, coal-related sources (70%), traffic-related sources (27%), and wood burning (3%). The source apportionment results agree with the actual municipal and industrial layout well. Inventory analysis estimated the total amount of the 12 PAHs emitted by regulated stationary and mobile sources was 9940 kg in 1998. Qualitatively, consistent source apportionment results were obtained from the factor analysis with nonnegative constraints and inventory analysis.
A comparative study of the real-time ambient concentrations of particle-bound polycyclic aromatic hydrocarbons (pPAHs) in the vicinity of roads in Tokyo (Japan) and in Bangkok (Thailand) in summertime was carried out by using a photoelectric aerosol sensor (PAS), which gives continuous signal in relation to the total amount of pPAHs concentration. The PAS output gave a good correlation to the total concentration of the selected PAHs determined by gas chromatography/mass spectrometry (GC/MS). This technique was then employed to observe temporal variation of total pPAHs. The measurements at roadside and general areas in Tokyo and in Bangkok were performed for seven consecutive days in August 2000, and in March 2001, respectively. The diurnal profiles of pPAHs concentrations in both cities were generally similar; explicit peak concentrations were observed in early morning in association with the traffic growth in the morning rush hours. A significant reduction occurred during the daytime was probably due to rising in the mixing zone. At roadside areas, the average pPAHs concentrations throughout the sampling period in Bangkok were significantly higher than those of Tokyo, owing to the larger contribution of vehicular traffic, especially heavy-duty vehicles, on the roads near the sampling site. Otherwise, all average concentrations in the general area in Tokyo were slightly higher than that of Bangkok. This was probably due to the percentage of road coverage in Tokyo being higher than that in Bangkok, creating a higher possibility for pPAHs evolving from road traffic, and the transportation pattern of the pPAHs in Tokyo showed a more broadly diffused profile than that of Bangkok. This suggests the widespread dispersion of pPAHs over the entire study area in Tokyo. At this study scale especially at the roadside, however, a high pPAHs concentration observed in Tokyo and in Bangkok was predominantly located at low wind speed, <1.0 and 0.4 m s−1, respectively, and along the direction from the roads.
Very high concentration of suspended particulate matter (SPM) is observed at traffic junctions in India. Factor analysis-multiple regression (FA-MR), a receptor modelling technique has been used for quantitative apportionment of the sources contributing to the SPM at two traffic junctions (Sakinaka and Gandhinagar) in Mumbai, India. Varimax rotated factor analysis identified (qualitative) five possible sources; road dust, vehicular emissions, marine aerosols, metal industries and coal combustion. A quantitative estimation by FA-MR model indicated that road dust contributed to 41%, vehicular emissions to 15%, marine aerosols to 15%, metal industries to 6% and coal combustion to 6% of the SPM observed at Sakinaka traffic junction. The corresponding figures for Gandhinagar traffic junction are 33%, 18%, 15%, 8% and 11%, respectively. Due to limitation in source marker elements analysed about 16% of the remaining SPM at these two traffic junctions could not be apportioned to any possible sources by this technique. Of the observed lead in the SPM, FA-MR apportioned 62% to vehicular emissions, 17% to road dust, 11% to metal industries, 7% to coal combustion and 3% to marine aerosols at Gandhinagar traffic junction and about a similar apportionment for lead in SPM at Sakinaka traffic junction.
Chemical characterisation has been carried out on 58 fragments of archaeological pottery from pre-classical sites in Apulia and Lucania, regions in southern Italy. Fourteen elements were determined by atomic emission spectroscopy by using inductively coupled plasma source. Statistical techniques, such as principal component analysis and clustering analysis, have been utilised to define grouping of different pottery items. Tests performed showed that the analysed shards were differentiable mainly by age and provenance.