Polycyclic Aromatic Hydrocarbons In PM2 Research Articles

加熱脱着―GC/MSによるPM<sub>2.5</sub>中多環芳香族炭化水素類の直接分析と熊本における日内変動・季節変動や野焼きの解析

加熱脱着―GC/MSによるPM<sub>2.5</sub>中多環芳香族炭化水素類の直接分析と熊本における日内変動・季節変動や野焼きの解析

Source apportionment of polycyclic aromatic hydrocarbons in PM2.5 using positive matrix factorization modeling in Shanghai, China.

Providing quantitative information on the sources of PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) in urban regions is vital to establish effective abatement strategies for air pollution in a megacity. In this study, based on a year data set from October 2011 to August 2012, the sources of PM2.5-bound 16 USEPA priority PAHs (16 PAHs) in Shanghai, a megacity in China, were apportioned by positive matrix factorization (PMF) modeling. The average concentrations (in ng m(-3)) of 16 PAHs in PM2.5 in the fall, winter, spring and summer were 20.5 ± 18.2, 27.2 ± 24.0, 13.7 ± 7.7 and 6.4 ± 8.1, respectively, with an annual average of 16.9 ± 9.0. The source apportionment by PMF indicated that coal burning (30.5%) and gasoline engine emission (29.0%) were the two major sources of PAHs in the PM2.5 in Shanghai, followed by diesel engine emission (17.5%), air-surface exchange (11.9%) and biomass burning (11.1%). The highest source contributor for PAHs in the fall and winter was gasoline engine emission (36.7%) and coal burning (41.9%), respectively; while in the spring and summer, it was diesel engine emission that contributed the most (52.1% and 43.5%, respectively). It was suggested that there was a higher contribution of PAHs from engine emissions in 2011-2012 compared with those in 2002-2003. The major sources apportioned by PMF complemented well with this of using diagnostic ratios, suggesting a convincing identification of sources for the PM2.5-bound 16 PAHs in a megacity.

PAHs in PM2.5 in Zhengzhou: concentration, carcinogenic risk analysis, and source apportionment.

Ambient air samples were collected at two different locations between 2011 and 2012 in Zhengzhou, China in order to assess the concentration level, health risks, as well as the sources of polycyclic aromatic hydrocarbons (PAHs) in particulate matter (PM2.5). The mean annual levels of PM2.5 observed at industry site and residential site were 172 ± 121 and 160 ± 72μgm(-3), respectively, which were about five times the annual value of proposed PM2.5 standard (35μgm(-3)) in China. The PM2.5 in all daily samples (n = 47) exceeds the proposed PM2.5 standard in China (75μgm(-3)) at both industrial and residential sites. Seasonal variations of PM2.5 showed a clear trend of winter > autumn > spring > summer at both sites. The total concentrations of 16PM2.5-associated PAHs ranged from 61 ± 51 to 431 ± 281 and 38 ± 25 to 254 ± 189ngm(-3), with mean value of 176 ± 233 and 111 ± 146ngm(-3) at industry and residential sites, respectively. The major species were fluoranthene, pyrene, chrysene, benzo[b]fluoranthene and benzo[k]fluoranthene, and the concentration levels of PAHs in PM2.5 were higher in winter than those of other seasons at both sites. The annual mean values of toxicity equivalency concentrations of ∑16PAHs in PM2.5 were 22.8 and 13.5ngm(-3) in industry and residential area, respectively. In this study, the risk level of adult citizens through inhalation exposure to PAHs was calculated. The average estimates of lifetime inhalation cancer risks were approximately 8.9 × 10(-7) and 6.3 × 10(-7) for industry and residential sites, respectively. The main sources of 16 PAHs from both diagnostic ratios and principle component analysis identified as vehicular emissions and coal combustion.

Polycyclic aromatic hydrocarbons (PAHs) in atmospheric PM2.5 and PM10 at a coal-based industrial city: Implication for PAH control at industrial agglomeration regions, China

Eighteen polycyclic aromatic hydrocarbons (PAHs) in PM2.5 and PM10 are identified and quantified at five sites of E'erduosi in 2005 by GC–MS. Total PAH concentrations in PM2.5 and PM10 are in the ranges of 0.58–145.01ngm−3 and 5.80–180.32ngm−3 for the five sites, decreasing as coal-chemical base site (ZGE)>heavy industrial site (QPJ)>residential site with heavy traffic (DS)>suburban site surrounded by grassland (HJQ)>background site (QGN) for both PM2.5 and PM10. PAH concentrations in the coal-chemical base site are 250 and 31.1 times of those in the background site. Flu, Pyr, Chr, BbF, BeP, IND and BghiP are abundant for the coal-chemical base site, totally accounting for 75% of the PAH concentrations. 4, 5 and 6 rings PAHs are dominant, accounting for 88.9–94.2% and 90.5–94.1% of PAHs in PM2.5 and PM10, respectively. Combustion-derived PAH concentrations cover 42%–84% and 75%–82% of PAHs in PM2.5 and PM10, indicating large amounts of combustion sources existed for them in E'erduosi. PAH compositions between PM2.5 and PM10 are quite different from each other for sites with few human activities (HJQ and QGN) by coefficient of divergence analysis. Results obtained from principal component analysis and diagnostic ratios indicate that coal combustion, vehicle emission, wood combustion and industrial processes are the main sources for PAHs in E'erduosi. According to BaP equivalent concentration, the potential health risk of PAHs in PM2.5 at the two industrial sites ZGE and QPJ are 537 and 460 times of those for the background site. And they are 4.3 and 3.7 times of those for the residential site. The potential PAH pollution in particles at other industrial agglomeration regions that occurred in China in recent years should be paid attention by the local government.

Sources of polycyclic aromatic hydrocarbons in PM2.5 over the East China Sea, a downwind domain of East Asian continental outflow

A receptor site in the East China Sea (ECS), ∼66 km off the shore of Shanghai, was used to investigate the seasonally atmospheric transport of land-based PAHs. Positive matrix factorization (PMF) modeling and back trajectories were performed to apportion the sources of the 16 USEPA priority PAHs (16 PAHs). In the process, three episodes were observed in all seasons except summer. These episodes provided additional insight to the transport mechanisms of these air pollutants in this most developed region of China. The average concentrations (in ng/m3) of PAHs in PM2.5 in fall, winter, spring and summer were 5.26 ± 5.36, 10.41 ± 8.58, 3.93 ± 2.31 and 0.97 ± 0.25, respectively, and with an annual average of 5.24 ± 5.81. Low molecular weight (LMW) PAHs (i.e., 2 ∼ 3-ring) was a dominant contributor for the 16 PAHs in PM2.5 over the ECS (36.2%), especially in summer (55.6%). The source apportionment by PMF analysis indicated that, based on yearly average, vehicular emission (27.0%) and coal combustion (24.5%) were the two major sources of PAHs, followed by biomass burning (16.5%), petroleum residue (16.3%) and air–surface exchange (15.7%). The highest source contributor for PAHs in fall and winter was coal combustion (30.5%) and vehicular emission (34.5%), respectively; while in spring and summer, the air–surface exchange contributed the most (27.1% and 59.5%, respectively). The specific composition patterns of 16 PAHs and PMF modeling results manifested that the air–sea exchange could be a potential source for the LMW PAHs in PM2.5 over the ECS, especially in warm season.

Single nucleotide polymorphism ?617 C/A in the Nrf2 gene promoter modifies gene expression-air pollution relationships in subjects with coronary artery disease

Background: We previously found positive associations between traffic-related air pollution exposures and gene expression in Nrf2-mediated antioxidant response genes and other genes. We hypothesize that genetic variation in NRF2 will alter relationships between pollutant exposure and expression of Nrf2-mediated genes. Aims: We aimed to determine if the -617C>A SNP in the Nrf2 promoter, a polymorphism shown to decrease binding and promoter activity, modifies our prior pollutant-gene expression relations. Methods: We measured whole blood gene expression levels weekly (12 weeks) in 40 subjects with coronary heart disease living in retirement communities in the Los Angeles area. We measured outdoor air pollutants: size-fractionated PM (including quasi-ultrafine PM<0.25?m), elemental and organic carbon (EC, OC), black carbon (BC), polycyclic aromatic hydrocarbons in PM (PAH), and gases (NOx, O3). We estimated primary and secondary OC (OCpri, SOC) from total OC. We genotyped the -617 position of NRF2 by sequencing. We used mixed effects regression models to test effect modification with pollutant*genotype interaction terms. We tested informative genes from our prior analysis: NRF2, HMOX1, SOD2, NQO1, GCLC, GCLM, CAT, GSTP1, CYP1B1, IL1B and SELP. Results: We identified 8 carriers of the risk allele (8AC, 0AA) and 32 non-carriers (CC). We found pollutant-genotype interactions for NRF2, SOD2, CYP1B1, NQO1, IL1B and SELP. In 617A carriers, NRF2 expression was lower in association with several pollutants. For SOD2, carriers had higher expression with exposure to traffic pollutants including: qUFP, PAH, EC, BC, OCpri, and NOx; as well as OC and SOC. Among carriers, we found increased IL1B and SELP, and decreased CYP1B1 with exposure. Conclusion: Overall, we found complex relationships with possible support for both a direct (CYP1B1) and an indirect role (SOD2, IL1B and SELP) of Nrf2 in mediating the gene expression changes associated with air pollution exposure.

Emission and profile characteristic of polycyclic aromatic hydrocarbons in PM2.5 and PM10 from stationary sources based on dilution sampling

The mass concentrations and profile characteristic for 18 kinds of polycyclic aromatic hydrocarbons (PAHs) in PM2.5 and PM10 from stack gases for six types of stationary sources in Shandong Province, China were studied by a dilution sampling system and GC–MS analysis method from February to March in 2010. The mass concentrations of PM2.5 and PM10 from the six types of stationary sources varied in 8.2–79.4 mg m−3 and 23.3–156.7 mg m−3, respectively. The total mass concentrations of analyzed PAHs in PM2.5 and PM10 were in the ranges of 0.40–94.35 μg m−3 and 9.16–122.91 μg m−3. The most toxic ashes were from sinter and coke oven for both PM2.5 and PM10 with high carcinogenic PAHs concentrations. BbF, Phe, NaP, BghiP, Pyr, BaP and BeP were abundant which was different from formers and one of the key reasons may be the differences of sampling methods. Diversities in PAHs compositions existed between fly ashes within PM2.5 and PM10 fractions for coke oven according to coefficient of divergence (CD) values. PAHs profiles for PM10 emitted from coke oven were different from those of other stationary sources (with CD values higher than 0.35) and for PM2.5, it was the same for sinter (with most CD values close to 0.30). There existed similar PAHs markers for fine particles emitted from stationary sources excepted for the sinter. For PM10, PAHs markers were primary 3-ring PAHs except for the coke oven with BbF, IND and BghiP as its signatures. Diagnostic ratios of BaA/(BaA + Chr), Flu/(Flu + Pyr), BaP/(BaP + BeP), BeP/BghiP and IND/(IND + BghiP) could be not well distinguished for the six types of stationary sources with the maximum/minimum ratios lower than 2 for both PM2.5 and PM10 of fly ashes which should be not used for source identification studies. The mass concentrations and source profiles of PAHs should be updated timely for size-differentiated fly ashes from various stationary sources by dilution sampling method.

Autumn and Wintertime Polycyclic Aromatic Hydrocarbons in PM2.5 and PM2.5-10 from Urumqi, China

Concurrent sampling of PM2.5 and PM2.5–10 aerosols on a rooftop (15 m above ground) was conducted at a location in urban Urumqi (Xinjiang University 43°77'N, 87°61'E) during September 2010 to March 2011. These filters were analyzed for fifteen polycyclic aromatic hydrocarbons (PAHs). The ΣPAHs (sum of 15 PAHs) ranged from 0.11 to 1058.08 ng/m3 in PM2.5 and 0.01 to 90.89 ng/m3 in PM2.5–10, respectively. 90% of the ΣPAHs existed in PM2.5. In the autumn the ΣPAHs ranged from an undetectable level to 10.93 ng/m3 in PM2.5 and 2.10 ng/m3 in PM2.5–10, and in the winter from an undetectable level to 54.11 ng/m3 in PM2.5 and 5.12 ng/m3 in PM2.5–10. Benzo(a)pyrene-equivalent carcinogenic potency (BaPeq) was calculated to evaluate the cancer risk of carcinogenic PAHs to the public. The level of BaPeq in PM2.5 was an average of 5.97 ng/m3, significantly higher than the value recommended by the WTO (1 ng/m3). This suggests that it is important to control regional combustion sources to reduce air pollution-related health risks in urban Urumqi.

Chemical composition and source identification of PM2.5 in the suburb of Shenzhen, China

In this study, PM2.5 has been measured in the suburb of Shenzhen. The mean mass concentration of PM2.5 was 101.6±27.5μgm−3 in winter and 32.7±19.7μgm−3 in summer. The high PM2.5 concentration level is probably due to the serious emissions from the Pearl River Delta where Shenzhen is located. The sum contribution of water-soluble ions was an average of 53.1±7.6% in winter and 56.3±15.2% in summer, while the sum contribution of polycyclic aromatic hydrocarbons was an average of 7.5±1.4% in winter and 20.5±7.0% in summer. Obvious seasonal variations of PM2.5 and chemical composition were partly because of the different origins of air mass reaching Shenzhen. SO42−, NH4+ and NO3− were the major water-soluble ions and fluorene and pyrene were the major polycyclic aromatic hydrocarbons in PM2.5. Additionally, six factors including combustion emission factor, fresh sea-salt factor, secondary nitrate factor, airborne dust factor, secondary aerosol factor and aged sea-salt factor were identified by EPA positive matrix factorization.

Tracer-based source apportionment of polycyclic aromatic hydrocarbons in PM2.5 in Guangzhou, southern China, using positive matrix factorization (PMF)

From 28 November to 23 December 2009, 24-h PM2.5 samples were collected simultaneously at six sites in Guangzhou. Concentrations of 18 polycyclic aromatic hydrocarbons (PAHs) together with certain molecular tracers for vehicular emissions (i.e., hopanes and elemental carbon), coal combustion (i.e., picene), and biomass burning (i.e., levoglucosan) were determined. Positive matrix factorization (PMF) receptor model combined with tracer data was applied to explore the source contributions to PAHs. Three sources were identified by both inspecting the dominant tracer(s) in each factor and comparing source profiles derived from PMF with determined profiles in Guangzhou or in the Pearl River Delta region. The three sources identified were vehicular emissions (VE), biomass burning (BB), and coal combustion (CC), accounting for 11 ± 2%, 31 ± 4%, and 58 ± 4% of the total PAHs, respectively. CC replaced VE to become the most important source of PAHs in Guangzhou, reflecting the effective control of VE in recent years. The three sources had different contributions to PAHs with different ring sizes, with higher BB contributions (75 ± 3%) to four-ring PAHs such as pyrene and higher CC contributions (57 ± 4%) to six-ring PAHs such as benzo[ghi]perylene. Temporal variations of VE and CC contributions were probably caused by the change of weather conditions, while temporal variations of BB contributions were additionally influenced by the fluctuation of BB emissions. Source contributions also showed some spatial variations, probably due to the source emission variations near the sampling sites.

Polycyclic aromatic hydrocarbons in PM2.5 in Guangzhou, southern China: Spatiotemporal patterns and emission sources

Fine particulate samples were simultaneously collected at six sites in Guangzhou in November–December 2009. Eighteen polycyclic aromatic hydrocarbons (PAHs) and tracers, i.e. hopanes, elemental carbon, picene and levoglucosan were measured. Three high level episodes were observed during the sampling period, likely due to accumulation effects. Back trajectory analysis revealed that the air masses for the three episodes were from eastern inland Pearl River Delta (PRD) region. There was no obvious concentration gradient for total and 5–6 ring PAHs such as benzo[g,h,i]perylene (BghiP) from urban to rural sites. However, 4-ring PAHs such as pyrene (Pyr) exhibited significantly higher levels at rural site than that at urban/suburban sites (p<0.01). BghiP correlated well with hopanes, elemental carbon and picene, indicating vehicular emissions and coal combustion were the sources of 5–6 ring PAHs, which were further confirmed by comparing the four tracers/BghiP ratios and IcdP/BghiP ratios in ambient samples with those from source profiles. Results indicated that vehicular emissions were no longer the dominant sources in winter season in Guangzhou.

Characterization of polycyclic aromatic hydrocarbons in PM2.5 and PM10 in Tanggu District, Tianjin Binhai New Area, China

Particulate matter (PM10 and PM2.5) concentrations were monitored during the November 2008 by using the filter samples collected day and night from three sites in Tanggu District at Tianjin Binhai New Area, China. The mean concentrations of PM2.5 and PM10 rank in the order of urban (150 μg/m3 for PM2.5 and 197 μg/m3 for PM10)>industrial (32 μg/m3 for PM2.5 and 170 μg/m3 for PM10)>suburb area (27 μg/m3 for PM2.5 and 59 μg/m3 for PM10). Sixteen polycyclic aromatic hydrocarbons (PAHs) were analyzed in PM10 and PM2.5 samples. Concentrations of total PAHs in PM2.5 and PM10 are in the range of 8.47–113.94 ng/m3 with average of 62.88 ng/m3 and 21.07–118.23 ng/m3 with average of 73.42 ng/m3, respectively. The light ring PAHs (2–4 rings) are dominant in both PM2.5 and PM10 during sampling time compares with the heavy ring (5–6 rings) PAHs. The relationship of PAHs and PM2.5 (r = 0.689, p<0.05) is stronger than PAHs and PM10 (r = 0.570, p<0.05), illustrating PAHs tend to adsorb in PM2.5. In addition, principal component analysis was applied to find the source of PAHs. Three principal factors representing three types of PAHs sources in Tanggu District are extracted, which were coke production, pyrogenic sources and vehicular source.

Modern and Fossil Contributions to Polycyclic Aromatic Hydrocarbons in PM2.5 from North Birmingham, Alabama in the Southeastern U.S.

Analyzing the radiocarbon ((14)C) content of polycyclic aromatic hydrocarbons (PAHs) in atmospheric particulate matter can provide estimates on the source contributions from biomass burning versus fossil fuel. The relative importance of these two sources to ambient PAHs varies considerably across regions and even countries, and hence there is a pressing need to apportion these sources. In this study, we advanced the radiocarbon analysis from bulk carbon to compound class specific radiocarbon analysis (CCSRA) to determine Δ(14)C and δ(13)C values of PAHs in PM(2.5) samples for investigating biomass burning and fossil fuel source contributions to PAHs from one of the Southeastern Aerosol Research and Characterization (SEARCH) sites in North Birmingham (BHM), Alabama during winter (December 2004-February 2005) and summer (June-August 2005) by accelerator mass spectrometry. To compare our ambient samples to known sources, we collected and analyzed fenceline samples from the vicinity of a coke plant in BHM. As expected, PAHs from the coke plant fenceline samples had very low radiocarbon levels. Its Δ(14)C varied from -990 to -970‰, indicating that 97 to 99% were of fossil source. PAHs in the ambient PM(2.5) had Δ(14)C from -968 to -911 ‰, indicating that 92-97% of PAHs were from fossil fuel combustion. These levels indicated the dominance of fossil sources of ambient PAHs. The radiocarbon level of ambient PAHs was higher in winter than in summer. Winter samples exhibited depleted δ(13)C value and enriched Δ(14)C value because of the increased contribution of PAHs from biomass burning source. However, biomass burning contributed more to heavier PAHs (modern source accounting for 6-8%) than lighter ones with a modern contribution of 3%.

Seasonal variation for the ratio of BaP to BeP at different sites in Great Xiamen Bay

From March 2008 to February 2009, PM(10) samples were collected and analyzed for polycyclic aromatic hydrocarbons (PAHs) at eight sampling sites in Great Xiamen Bay, China. Analyses of the seasonal and spatial variations of these compounds revealed the following results. Significantly high levels of PAHs were found in the winter compared to the summer, sometimes exceeding 100 ng m(-3), and the spatial variations were influenced most by the sampling site surroundings. Composition profiles of PAHs of an urban and a rural site were shown to be very similar with a positive correlation coefficient larger than 0.9 at the 0.01 level of significance for the same season. Diagnostic ratios, together with principal component and multiple linear regression analysis, showed that more PAHs were from grass/wood/coal combustion in winter than in other seasons. The ratios of benzo[a]pyrene to benzo[e]pyrene (BaP-BeP) in winter and fall were 0.6-1.7 times higher than those in spring and summer, suggesting the importance of local emissions of PAHs. The BaP-BeP ratios in Kinmen were generally lower than those in Xiamen, indicating that the aging degree of PAHs was higher in Kinmen than in Xiamen. The external input of PAHs from upwind urban and industrial areas was one of the key factors causing high levels of PAHs in PM(10) in Great Xiamen Bay in winter.

Roadside and rooftop measurements of polycyclic aromatic hydrocarbons in PM2.5 in urban Guangzhou: Evaluation of vehicular and regional combustion source contributions

Abstract Concurrent sampling of PM2.5 aerosol at a roadside of heavy traffic (1.2 m above ground) and on a nearby rooftop (50 m above ground) was conducted at a same location in urban Guangzhou in September, October 2006 and January 2007. The samples were analyzed for eighteen polycyclic aromatic hydrocarbons (PAHs), together with major aerosol constituents and certain organic tracers for vehicular emissions (hopanes) and biomass burning (levoglucosan). Elemental carbon (EC) and hopanes were observed to be lower by 21–38% and 28–84%, respectively, at the rooftop than the roadside, confirming vehicular emissions as a significant local PM source. On the other hand, sulfate showed little vertical gradient, consistent with its secondary origin and its regional characteristics. The roadside-rooftop sample pairs have provided an opportunity in evaluating relative contributions of vehicular emissions and regional sources to ambient PAHs in this urban location. Concentrations of the total PAHs were ∼43% lower at rooftop in the September 2006 samples while they were at similar levels between rooftop and roadside in the October 2006 and January 2007 samples. Sources of PAHs were investigated through comparing ambient data of PAH isomer pairs and PAH/EC ratios with relevant source profiles including those of Guangzhou roadway tunnel emissions, rice straw/sugarcane leave combustion, and industrial coal combustion. The 4-ring PAHs such as pyrene and fluoranthene had a shift in their dominating source from vehicular emissions in September and October to regional combustion source in January. A few major 5- and 6-ring PAHs such as benzo[ghi]perylene and indeno[1,2,3-cd]pyrene were likely heavily influenced by regional biomass burning emissions in all three sampling months. Benzo(a)pyrene-equivalent carcinogenic potency (BaPeq) was calculated to evaluate the cancer risk of carcinogenic PAHs on the public. BaPeq levels in PM2.5 were significantly higher at the roadside than those at the rooftop in September; however, levels of BaPeq at the rooftop were drastically elevated and became comparable to those at the roadside in October and January due to regional sources dominating the carcinogenic PAHs. This suggests that it is important to control regional combustion sources to reduce air pollution-related health risk in urban Guangzhou.

Characteristics of particulate PAHs during a typical haze episode in Guangzhou, China

The concentrations of polycyclic aromatic hydrocarbons (PAHs) in PM 2.5 and TSP were measured in Guangzhou during a typical haze episode. This episode included NH (non-haze, 3 days), HFN (haze when air masses from north and northeast, 6 days) and HFS (haze when air masses from south, 4 days). The air quality in HFN was much worse than that in NH and HFS. The total average concentrations of PAHs in PM 2.5 were 13.25 ng m −3, 59.82 ng m −3 and 13.09 ng m −3 in NH, HFN and HFS, respectively. It indicated PAH pollution had been substantially aggravated by HFN. PAHs(5 + 6) were the most abundant compounds in HFN and HFS, which accounted for 55–75% of total concentration of PAHs, while PAHs(3 + 4) were the most abundant compounds in NH, which accounted for 54–67% of total concentration of PAHs. TEF (Toxic Equivalency Factors)-adjusted concentrations of 13 particulate PAHs were very high in HFN, indicating high health risks to humans for PAH exposure in HFN. The characteristic ratios of PAHs indicated coal combustion and traffic emission were the major contributors to PAHs in HFN and HFS. The concentrations of particulate PAHs in haze episode were strongly affected by wind speed and wind direction. PAHs in NH could be from long-range transport with high north wind speed, while local emission could be the main contributor of particle-associated PAHs in HFN. The transport speed of air masses was found to play an important role on PAH concentrations.

Assessment of carcinogenic risk due to inhalation of polycyclic aromatic hydrocarbons in PM 10 from an industrial city: A Korean case-study

This study investigated the effects of meteorological conditions and spatial variations on the toxicity of polycyclic aromatic hydrocarbons (PAHs) in airborne PM 10 in Ulsan, the largest industrial city in Korea. Daily PM 10 samples were collected on quartz microfiber filters using high volume samplers located in a downtown area, a residential area and an industrial area of Ulsan during spring and summer sampling periods. Sixteen individual PAHs were extracted into a mixture solution of dichloromethane and n-hexane (1:1, v/v) in an ultrasonic bath and were analyzed using a high performance liquid chromatography system with an ultra-violet detector (HPLC-UVD). The average total PAH concentrations from the three representative sampling sites of Ulsan ranged from 16.15 to 57.12 ng/m 3 in spring and from 11.11 to 34.56 ng/m 3 in summer. The toxicity equivalent concentrations (TEQs) of the PAHs in PM 10 of Ulsan ranged from 1.82 to 13.1 ng/m 3, with an average level of 4.17 ng/m 3. The highest TEQs were found in the downtown area, which had an average value of 6.30 ng/m 3 in spring and 5.52 ng/m 3 in summer. BaP and DahA were identified as the major carcinogenic PAHs that contributed to 34.8 and 59.4% of the total carcinogenic potency of PAHs in PM 10 in Ulsan. The identified TEQs were highly correlated ( r 2 = 0.73–0.90, p < 0.01) with the total PAH concentrations for each area. The TEQs showed a significant correlation ( p < 0.01) with the concentration of air pollutants, including PM 10, PM 2.5 and NO 2.

A seasonal study of polycyclic aromatic hydrocarbons in PM 2.5 and PM 2.5–10 in five typical cities of Liaoning Province, China

Fourteen polycyclic aromatic hydrocarbons (PAHs) in PM 2.5 and PM 2.5–10 samples collected in five cities (Shenyang, Anshan, Jinzhou, Fushun and Dalian), Liaoning Province, China in 2004 and 2005 were analyzed by using a HPLC equipped with fluorescence and UV detectors. Results showed total PAHs concentrations in PM 2.5 and PM 2.5–10 were in the range of 75.32–1900.89 ng m −3 and 16.74–303.24 ng m −3, respectively. 90% of the total PAHs were in PM 2.5. PAHs in PM 2.5 had a winter to summer ratio varying from 6.5 to 125.8 while PAHs in PM 2.5–10 had a ratio ranging from 1.7 to 37.6. Total PAHs concentrations were most abundant at residential/commercial sites and were fewest at an industrial site for both PM 2.5 and PM 2.5–10. Urban background sites showed unexpected higher PAHs concentrations. Total BaP equivalent concentration (BaPeq) for PM 2.5 ranged from 7.80 to 88.42 ng m −3 in different function zones. Similarities of PAHs profiles between sampling sites and between fine and coarse fractions were compared by coefficient of divergence which indicated that remarkable differences in PAHs compositions existed. Principal component analysis (PCA) associated with diagnostic ratios revealed coal combustion and vehicle emission were the major sources for PM 2.5 and PM 2.5–10 associated PAHs.

Characterization of polycyclic aromatic hydrocarbons deposition in PM2.5 and cloud/fog water at Mount Taishan (China)

Polycyclic aromatic hydrocarbons (PAHs) in PM2.5 and cloud/fog water samples were collected at Mount Taishan in an autumn–winter period, and were analyzed by GS-MS. Higher molecular weight PAHs (4–6 rings) predominated in PM2.5 samples, whereas lighter PAH compounds contributed 61.71% of the total PAH concentration in cloud/fog samples. Particles tended to contain more PAHs and have a more intensive influence on the atmospheric environment on colder days. During cloud/fog events, the scavenging ratio based on PAHs associated with particles was estimated to be about 13.45%. PAHs in PM2.5 samples had a significant positive relationship with CO and SO 2, suggesting that PAHs, SO 2, and CO may originated from the same sources, such as residential coal combustion activities. Diagnostic ratio analysis and factor analysis indicated that the sources of PAHs were mainly from coal combustion during this period.

Influence of tobacco smoke on carcinogenic PAH composition in indoor PM 10 and PM 2.5

Because of the mutagenic and/or carcinogenic properties, Polycyclic Aromatic Hydrocarbons (PAH), have a direct impact on human population. Consequently, there is a widespread interest in analysing and evaluating the exposure to PAH in different indoor environments, influenced by different emission sources. The information on indoor PAH is still limited, mainly in terms of PAH distribution in indoor particles of different sizes; thus, this study evaluated the influence of tobacco smoke on PM 10 and PM 2.5 characteristics, namely on their PAH compositions, with further aim to understand the negative impact of tobacco smoke on human health. Samples were collected at one site influenced by tobacco smoke and at one reference (non-smoking) site using low-volume samplers; the analyses of 17 PAH were performed by Microwave Assisted Extraction combined with Liquid Chromatography (MAE–LC). At the site influenced by tobacco smoke PM concentrations were higher 650% for PM 10, and 720% for PM 2.5. When influenced by smoking, 4 ring PAH (fluoranthene, pyrene, and chrysene) were the most abundant PAH, with concentrations 4600–21 000% and 5100–20 800% higher than at the reference site for PM 10 and PM 2.5, respectively, accounting for 49% of total PAH (Σ PAH). Higher molecular weight PAH (5–6 rings) reached concentrations 300–1300% and 140–1700% higher for PM 10 and PM 2.5, respectively, at the site influenced by tobacco smoke. Considering 9 carcinogenic PAH this increase was 780% and 760% in PM 10 and PM 2.5, respectively, indicating the strong potential risk for human health. As different composition profiles of PAH in indoor PM were obtained for reference and smoking sites, those 9 carcinogens represented at the reference site 84% and 86% of Σ PAH in PM 10 and PM 2.5, respectively, and at the smoking site 56% and 55% of Σ PAH in PM 10 and PM 2.5, respectively. All PAH (including the carcinogenic ones) were mainly present in fine particles, which corresponds to a strong risk for cardiopulmonary disease and lung cancer; thus, these conclusions are relevant for the development of strategies to protect public health.