Vertical distribution of polycyclic aromatic hydrocarbons in atmospheric boundary layer of Beijing in winter (original) (raw)
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Atmospheric particulate and gaseous polycyclic aromatic hydrocarbons (PAHs) samples were collected from an urban area in Dokki (Giza) during the summer of 2007 and the winter of 2007-2008. The average concentrations of PAHs were 1429.74 ng/m 3 in the particulate phase, 2912.56 ng/m 3 in the gaseous phase and 4342.30 ng/m 3 in the particulate + gaseous phases during the period of study. Dokki has high level concentrations of PAH compounds compared with many polluted cities in the world. The concentrations of PAH compounds in the particulate and gaseous phases were higher in the winter and lower in the summer. Total concentrations of PAHs in the particulate phase and gaseous phase were 22.58% and 77.42% in summer and 36.97% and 63.03% in winter of the total (particulate + gaseous) concentrations of PAHs, respectively. The gaseous/particulate (G/P) ratios of PAHs concentration were 3.43 in summer and 1.71 in winter. Significant negative correlation coefficients were found between the ambient temperature and concentrations of the total PAHs in the particulate and gaseous phases. The distribution of individual PAHs and different categories of PAHs based on aromatic ring number in the particulate and gaseous phases during the summer and winter were nearly similar, indicating similar emission sources of PAHs in both two seasons. Benzo(b)fluoranthene in the particulate phase and naphthalene in the gaseous phase were the most abundant compounds. Diagnostic concentration ratios of PAH compounds indicate that these compounds are emitted mainly from pyrogenic sources, mainly local vehicular exhaust emissions. Health risks associated with the inhalation of individual PAHs in particulate and gaseous phases were assessed on the basis of its benzo(a)pyrene equivalent concentration (BaP eq). Dibenzo(a,h)anthracene and benzo(a)pyrene in the particulate phase and benzo(a)pyrene and benzo(a)anthracene in the gaseous phase were the greatest contributors to the total health risks. The mean contributions of the total carcinogenic activity of all PAHs to the total concentrations of PAHs were 29.37% and 25.15% in the particulate phase and 0.76% and 0.92% in the gaseous phase during the summer and winter, respectively. These results indicate that PAHs in the particulate phase in the ambient air of Dokki may pose a potential health risk.
Journal of Hazardous Materials, 2010
Twenty-three polycyclic aromatic hydrocarbons (PAHs) were measured simultaneously in indoor and outdoor environment of ten homes at urban and roadside sites in the north central part of India during winter season (November 2006 to February 2007. The average concentration of total PAH (TPAH) was 1946.84 ng/m 3 in kitchen, 1666.78 ng/m 3 in living room and 1212.57 ng/m 3 in outdoors at urban site, whereas at roadside site it was 2824.87 ng/m 3 , 2161.26 ng/m 3 , and 3294.28 ng/m 3 in kitchen, living room and outdoors respectively. The two, three and four ring PAHs were predominant in vapour phase, while the five, six ring PAHs were primarily associated with the particulate phase. The concentration trends of the PAHs in present study were naphthalene > 2-methylnaphthalene > 1methylnaphthalene > biphenyl > acenaphthylene in indoor and outdoor environment of both the sites. The spatial trend of total PAHs concentrations in the house located at urban sites, was kitchen > living room > outdoors whereas at roadside site, the trend was outdoors > kitchen > living room. Correlation analysis has been used to identify the sources of PAHs. The correlation between CO 2 and ratio of living room/outdoors (L/O) and kitchen/outdoor (K/O) of total PAHs concentration for two sites was found to be significant.
Particle-associated polycyclic aromatic hydrocarbons in urban air of Hong Kong
Atmospheric Environment, 2003
PM 2.5 and PM 10 samples were collected at two sampling sites in Hong Kong in wintertime from November 2000 to March 2001 and in summertime from June to August 2001. The concentrations of 16 selected polycyclic aromatic hydrocarbons (PAHs) in aerosols were quantified. Spatial and seasonal variations of PAHs were characterized. The dominated PAHs in PM 2.5 and PM 10 included benzo[b]fluoranthene, pyrene, fluoranthene, indeno[1,2,3-cd]pyrene and chrysene, accounting for 50-82% of total PAHs. The sum of 16 PAHs in PM 2.5 at roadside ranged from 3 to 330 ng/m 3 , and in PM 10 between 5 and 297 ng/m 3 , whereas at a residential/industrial/commercial site, the total PAHs in PM 2.5 was from 0.5 to 122 ng/m 3 , and 2-269 ng/m 3 in PM 10. Results indicated that most of the PAHs were in the PM 2.5 fraction. Spatial variations were predominantly due to the difference of source strength. For both PM 2.5 and PM 10 , the total PAHs at PU site was higher than that at KT site. The average concentrations of individual PAHs in aerosols at PU site were also higher than that at KT site. Higher winter PAHs concentrations and lower summer concentrations were observed at the two sites. Higher winter PAHs concentrations were mainly caused by local emission sources superimposed by highly polluted air masses from Mainland China. The lower summer PAHs concentrations were likely due to easier dispersion of air pollutants, washout effects and to a lesser extent, photo-degradation and higher percentage in the air in vapor phase. Potential sources of PAHs in aerosols were identified using the diagnostic ratios between PAHs and PCA analysis. At PU site, vehicular emissions were the main contributors of particle-associated PAHs, and stationary combustion sources may also contribute to the particulate PAHs. On the contrary, at the KT site, PAHs in aerosols were predominantly from gasoline and diesel engines.
Environmental Science & Technology, 2004
A highly sensitive analytical method for the simultaneous determination of 39 gaseous and particulate polycyclic aromatic hydrocarbons (PAHs) was used to determine the PAH composition of indoor and outdoor air in Shimizu, Japan. In both indoor and outdoor air, gaseous PAH concentrations were higher in summer than in winter, whereas particulate PAH concentrations were higher in winter than in summer. Correlation analysis indicated that indoor PAH compositions, especially the gaseous PAH composition, differed significantly from outdoor PAH compositions. Gaseous PAH concentrations indoors were significantly affected by insect repellents and heating sources. Particulate PAH concentrations indoors were significantly affected by cigarette smoking, the age and type (wood) of the house, and outdoor PAH concentrations. Inhalation risk associated with carcinogenic PAHs was estimated by using toxic equivalency factors based on the potency of benzo[a]pyrene (BaP). The carcinogenicity of the indoor PAH mixture was dominated by naphthalene followed by BaP and dibenz [a,h]anthracene.
Scientific Reports, 2021
Considered that human activities mostly occur below building heights, the objective of this study was to investigate the temporal variations of fine particular matter (PM 2.5)-associated polycyclic aromatic hydrocarbons (PAHs) and benzo[a]pyrene-equivalent (BaP eq) concentrations at four different elevations (6.1, 12.4, 18.4, and 27.1 m) in Kaohsiung City, the largest industrial city of southern Taiwan. Temperature variation was critical for the PM 2.5-associated PAH concentrations, which were dominated by benzo[g,h,i]perylene (0.27 ± 0.04 ng m −3 and 24.43% of the total concentration) and other high molecular weight (HMW) species. The PM 2.5-associated BaP eq was dominated by 5-ring PAH (36.09%). The PM 2.5-associated PAH and BaP eq concentrations at all elevations were significantly increased in winter. In the night, the correlations between the PM 2.5-associated PAH concentrations and atmospheric temperatures became negatively stronger, notably at lower elevations (r = − 0.73 ~ − 0.86), whereas the BaP eq during daytime and nighttime were not changed significantly in most months. The PAHs analysis with different PM sizes demonstrated the importance of smaller particles such as PM 2.5. The meteorological variation was more important than elevation to influence the low-elevation PM 2.5-associated PAH and BaP eq concentrations in an urban area like Kaohsiung City, as the two concentrations were dominated by the PAHs with HMWs and those 5-ring species, respectively. Polycyclic aromatic hydrocarbons (PAHs) are produced during incomplete combustion of organic compounds such as fossil fuels under anoxic conditions, as their formation was also observed during pyrolysis at high temperatures 1-3. Works of literature have confirmed that PAHs and their derivatives are carcinogenic and mutagenic to the human body and are harmful to the ecosystem in the environment 4,5. While many PAHs are present in the environment, the U.S. Environmental Protection Agency (USEPA) and the European Commission have listed 16 PAHs in their priority pollutant lists 6,7. The International Agency for Research on Cancer (IARC) has classified certain PAH species, namely benzo[a]anthracene (BaA), benzo[a]pyrene (BaP), and dibenzo[a,h] anthtracene (DBA), as probable carcinogens and benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), and indeno[1,2,3-cd]pyrene (IP) as possible carcinogens to humans 8. Particulate matter (PM) is well known as hazardous air pollutants associated with carcinogenicity and other serious health symptoms such as headaches, nausea, and damages to the liver and kidney by inhalation 9. Typically, particles with a size larger than 10 μm are deposited almost exclusively in the trachea (upper throat) or bronchi region of a human body and are excreted through coughing, sneezing, and running nose. However, particles with sizes from 5 to 10 μm can deposit in the trachea or bronchial area of a human body, as the particles from 1 to 5 μm and those less than 0.1 μm deposit in the gas exchange area of the lung and through the alveolar epithelial cells, eventually circulating throughout the bloodstream and affecting cardiovascular and respiratory systems 10,11. The occurrences of PAHs on the surface of PM have been frequently reported in previous publications 12,13. While the PAH concentration distribution and the toxicity could vary in the gas and particle phases, the challenge of identifying the authentic impact of PAH pollution becomes more complex due to PM emission 14 .
Polycyclic Aromatic Hydrocarbons in the Indoor and Outdoor Air of Three Cities in the U.S
Environmental Science & Technology, 2002
The indoor and outdoor concentrations of 30 polycyclic aromatic hydrocarbons (PAHs) were measured in 55 nonsmoking residences in three urban areas during June 1999-May 2000. The data represent the subset of samples collected within the Relationship of Indoor, Outdoor, and Personal Air study (RIOPA). The study collected samples from homes in Los Angeles, CA, Houston, TX, and Elizabeth, NJ. In the outdoor samples, the total PAH concentrations (∑PAH) were 4.2-64 ng m -3 in Los Angeles, 10-160 ng m -3 in Houston, and 12-110 ng m -3 in Elizabeth. In the indoor samples, the concentrations of ∑PAH were 16-220 ng m -3 in Los Angeles, 21-310 ng m -3 in Houston, and 22-350 ng m -3 in Elizabeth. The PAH profiles of low molecular weight PAHs (3-4 rings) in the outdoor samples from the three cities were not significantly different. In contrast, the profiles of 5-7-ring PAHs in these three cities were significantly different, which suggested different dominant PAH sources. The signatures of 5-7ring PAHs in the indoor samples in each city were similar to the outdoor profiles, which suggested that indoor concentrations of 5-7-ring PAHs were dominated by outdoor sources. Indoor-to-outdoor ratios of the PAH concentrations showed that indoor sources had a significant effect on indoor concentrations of 3-ring PAHs and a smaller effect on 4-ring PAHs and that outdoor sources dominated the indoor concentrations of 5-7-ring PAHs.
Polycyclic Aromatic Hydrocarbons in U.K. Urban Air
Environmental Science & Technology, 1994
of a national urban air monitoring scheme in the U.K. are presented. Urban sample sites were operated in the cities of London, Manchester, and Cardiff and in the light industrial town of Stevenage. Both the particulate and vapor phases of 15 PAHs were sampled using high-volume air samplers at roof-top level (-25 m). London, the largest urban center, had the highest annual mean CPAH concentrations of 166 ng/m3 in 1991. Phenanthrene and fluorene dominated the total PAH at each site and were present predominantly in the vapor phase throughout the year. The heavier PAHs (MW > 250) were present on the collected particulate and showed a distinct seasonal variation (winter > summer).
Stochastic Environmental Research and Risk Assessment, 2015
This study presents daily and seasonal variations of PAH concentrations in Erzurum atmosphere in summer season of 2008 and in winter seasons of 2008 and 2009. Sampling location at Erzurum urban center was selected to represent the effects of traffic (University junction). 18 PAH compounds were analyzed by GC-MS. Average total PAH concentration (gas ? particulate) of 18 PAH compounds were measured during 2008 winter (431 ngm-3) and summer (103 ngm-3) seasons at the University junction. Daily and seasonal variations of PAH compounds were investigated and compared with other urban centers in the literature. Multiple linear regression and artificial neural network (ANN) models were constructed to determine the impacts of meteorological parameters on measured individual PAH concentrations. Results of the multiple linear regression and ANN models indicated that wind speed, wind direction and intensity of total solar radiation were the most significant factors for the measured concentrations of PAH compounds.