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1.
Environmental Science and Pollution Research - Commuters are exposed to high air pollution levels daily, especially in areas with dense traffic. This study examines the commuter’s exposure to...  相似文献   

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The concentrations of polycyclic aromatic hydrocarbons in the atmosphere were measured simultaneously at Tzu Yun Yen temple and Tung Hai University pastureland in Taichung, central Taiwan. At both sites, 24 h samplings were performed between August 2001 and December 2001. The results indicated that high molecular mass polycyclic aromatic hydrocarbons are predominant at the Tzu Yun Yen temple sampling site. Moreover, the PM2.5 (fine particulate) fraction of total polycyclic aromatic hydrocarbons was higher than that of the PM2.5-10 (coarse particulate) fraction by a factor of about 1.48 at the temple sampling site. This ratio was 1.24 for the pastureland environment.  相似文献   

4.
The concentrations of trace metals and polycyclic aromatic hydrocarbons (PAHs) adsorbed to total suspended particulate (TSP) and finer fractions of airborne particulate matter (PM) were determined from a site in the centre of Athens (Greece), which is characterized by heavy local traffic and is densely populated, during the winter and summer periods in 2003-2004. Also, we collected and analyzed samples of diesel and gasoline exhaust particles from local vehicles (buses, taxis and private cars) and from chimney exhaust of residential central heating appliances. A seasonal effect was observed for the size distribution of aerosol mass, with a shift to larger fine fractions in winter. The most commonly detected trace metals in the TSP and PM fractions were Fe, Pb, Zn, Cu, Cr, V, Ni and Cd and their concentrations were similar to levels observed in heavily polluted urban areas from local traffic and other anthropogenic emissions. Analysis of 16 PAHs bound to PM showed that they are mostly traffic related. In general, the fine particulate PAHs concentrations were higher than coarse particles. The most common PAHs in PM(10.2) and PM(2.1) were pyrene, phenanthrene, acenapthylene and fluoranthene, which are associated with diesel and gasoline exhaust particles. The results of this study underlined the importance of local emission sources, especially vehicular traffic, central heating and other local anthropogenic emissions. Compared with other big cities, Athens has much higher levels of airborne particles, especially of the finer fractions PM(10) and PM(2.5), correlated with traffic-related air pollution.  相似文献   

5.
On-road mobile sources contribute substantially to ambient air concentrations of the carcinogens 1,3-butadiene, benzene, and polycyclic aromatic hydrocarbons (PAHs). The current study measured benzene and 1,3-butadiene at the Baltimore Harbor Tunnel tollbooth over 3-hr intervals on seven weekdays (n = 56). Particle-bound PAH was measured on a subset of three days. The 3-hr outdoor 1,3-butadiene levels varied according to time of day and traffic volume. The minimum occurred at night (12 a.m.-3 a.m.) with a mean of 2 microg/m3 (SD = 1.3, n = 7), while the maximum occurred during the morning rush hour (6 a.m.-9 a.m.) with a mean of 11.9 microg/m3 (SD = 4.6, n = 7). The corresponding traffic counts were 1413 (SD = 144) and 16,893 (SD = 692), respectively. During the same intervals, mean benzene concentration varied from 3 microg/m3 (SD = 3.1, n = 7) to 22.3 microg/m3 (SD = 7.6, n = 7). Median PAH concentrations ranged from 9 to 199 ng/m3. Using multivariate regression, a significant association (p < 0.001) between traffic and curbside concentration was observed. Much of the pollutant variability (1,3-butadiene 62%, benzene 77%, and PAH 85%) was explained by traffic volume, class, and meteorology. Results suggest > 2-axle vehicles emit 60, 32, and 9 times more PAH, 1,3-butadiene, and benzene, respectively, than do 2-axle vehicles. This study provides a model for estimating curbside pollution levels associated with traffic that may be relevant to exposures in the urban environment.  相似文献   

6.
In an effort to assess the occurrence and sources of polycyclic aromatic hydrocarbons (PAHs) in the ambient air of Riyadh, Saudi Arabia, PM10 samples were collected during December 2010. Diagnostic PAH concentration ratios were used as a tool to identify and characterize the PAH sources. The results reflect high PM10 and PAH concentrations (particulate matter (PM)?=?270–1,270 μg/m3). The corresponding average PAH concentrations were in the range of 18?±?8 to 1,003?±?597 ng/m3 and the total concentrations (total PAHs (TPAHs) of 17 compounds) varied from 1,383 to 13,470 ng/m3 with an average of 5,871?±?2,830 ng/m3. The detection and quantification limits were 1–3 and 1–10 ng/ml, respectively, with a recovery range of 42–80 %. The ratio of the sum of the concentrations of the nine major non-alkylated compounds to the total (CPAHs/TPAHs) was 0.87?±?0.10, and other ratios were determined to apportion the PM sources. The PAHs found are characteristic for emissions from traffic with diesel being a predominant source.  相似文献   

7.
Recent results from field studies in the Los Angeles air basin which focused on the nature and concentrations of mononitroarenes in the gaseous and particulate states in polluted ambient air are reviewed. Relative concentrations in organic extracts of ambient particulate polycyclic organic matter (POM) were found to be, in decreasing order, 2-NO2-fluoranthene > 1-NO2-pyrene ≳ 2-NO2-pyrene; this is in sharp contrast to primary emissions of diesel soot, where 1-NO2-PY > 3-NO2-FL > 8-NO2-FL. Since light and heavy duty diesel motor vehicle emissions are a significant source of sub-μm particles in the Los Angeles area, the relatively high abundance of 2-NO2-FL suggests that a significant fraction of the 2-NO2-FL in southern California may be formed via atmospheric reactions. In a wintertime 1986 study of a high-NOx episode ~ 20 km east of the Los Angeles International Airport, high concentrations of 1- and 2-nitronaphthalenes, much of which could have been in the gaseous state, were collected on a polyurethane backup ‘plug,’ along with lesser amounts of 2-NO2-FL (and 1- and 2-NO2-PY) adsorbed on the particles collected by a Hi-vol prefilter.Two gas phase mechanisms are proposed for the formation of adsorbed 2-NO2-fluoranthene and gaseous 2-NO2-naphthalene in urban air
  • 1.(a) during daylight, attack on gaseous FL by OH radicals followed by NO2 addition, loss of H2O and condensation of 2-NO2-FL on particle surfaces
  • 2.(b) reaction with N2O5 at night under ambient conditions during which the gaseous NO3 radical and NO2 are present, in equilibrium with N2O5. Chamber experiments with simulated polluted atmospheres support both of these mechanisms for the formation of 2-NO2-FL and 2-NO2-naphthalene; only the OH mechanism seems valid for 2-NO2-PY. Environmental and health implications of these studies are briefly discussed.
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8.
Lung SC  Hu SC 《Chemosphere》2003,50(5):673-679
The generation rates and emission factors of particulate matter and associated polycyclic aromatic hydrocarbons (PAHs) from incense burning were assessed in a laboratory setting. The differences among different segments of the same stick, among different sticks of the same kind of incense, and between two kinds of manually made Chih-Chen incense sticks (A and B) were evaluated. Joss sticks were burned inside a 44 cm long elutriator; personal environmental monitors fitted into the top of the elutriator were used to take PM2.5 and PM10 samples of incense smoke. Samples were analyzed for PAHs by gas chromatography-flame ionization Detector. It was found that particle and associated PAHs were generated approximately at 561 microg/min (geometric standard deviation (GSD) = 1.1) and 0.56 microg/min (GSD = 1.1) from Incense A, and at 661 microg/min (GSD = 1.7) and 0.46 microg/min (GSD = 1.3) from Incense B, respectively. One gram of Incense A emitted about 19.8 mg (GSD = 1.1) particulate matter and 17.1 microg (GSD = 1.2) particulate-phase PAHs, while one gram of Incense B produced around 43.6 mg (GSD = 1.1) of particles and 25.2 microg (GSD = 1.2) of particle-bound PAHs. There were significant differences in emissions between Incenses A and B, although they belong to the same class of incense. A 10-20% variability in emissions was observed in the main part of the manually produced stick, and a larger variation was found at both tips of the combustible part.  相似文献   

9.
A PAH contaminated river floodplain soil was separated according to grain size and density. Coal and coal-derived particles from coal mining, coal industry and coal transportation activities were identified by organic petrographic analysis in our samples. Distinct concentrations of PAHs were found in different grain size and density fractions, however, similar distribution patterns of PAHs indicated similar sources. In addition, although light fractions had the mass fraction by weight of less than 5%, they contributed almost 75% of the total PAHs in the soil. PAH concentrations of all sub fractions showed positive correlation with their TOC contents. Altogether, coal and coal-derived particles that were abundant in light fractions could be the dominant geosorbents for PAHs in our samples.  相似文献   

10.
To obtain the characteristic factors or signatures of particulate polycyclic aromatic hydrocarbons (PAHs) to help identify the sources of particulate PAHs in the atmosphere, different carbonaceous aerosols were generated by burning different fossil fuels and biomass under different conditions in the laboratory, and the chemical characteristics of 14 PAHs were studied in detail. The results showed that (1) carbonaceous aerosols derived from domestic burning of coal, diesel fuel, and gasoline have much higher concentrations of PAHs than those derived from domestic burning of biomass; (2) carbonaceous aerosols derived from domestic burning of diesel fuel/gasoline have similar PAH components as those derived from high-temperature combustion of diesel fuel/gasoline, although the former have much higher concentrations of PAHs than the latter, suggesting that the burning temperature obviously affects the emitting amount of particulate PAHs, but only slightly influences the PAHs components; and (3) the ratios of benzo[b]fluoranthene/acenaphthylene, benzo[b]fluoranthene/fluorene, dibenzo[a,h]anthracene/acenaphthylene, dibenzo[a,h]anthracene/fluorine, and benzo[b]fluoranthene/benzo[k]fluoranthene in carbonaceous aerosols are sensitively dependent on their sources, indicating that these ratios are suitable for use as characteristic factors or signatures of particulate PAHs in the atmosphere.  相似文献   

11.
为研究西南岩溶地区城市近郊型地下河沉积物中多环芳烃(PAHs)的污染特征及来源,选择南宁市清水泉地下河进行分析,沿地下河流动方向共采集8个表层沉积物样品,并检测16种PAHs的含量。结果表明,地下河表层沉积物中总PAHs为257.7~609.5ng/g(基于表层沉积物干质量计算),整体浓度处于中等污染水平;从PAHs组成来看,16种PAHs均被检出,且含量表现为4环PAHs5~6环PAHs2~3环PAHs;空间分布规律呈下游中游上游的趋势,且2~3环PAHs占比先增大后降低,而4~6环PAHs占比变化则相反;不同区域的PAHs来源各不相同,上游地区PAHs为燃烧来源,中游地区PAHs为石油来源,下游地区为混合来源,燃烧来源、石油来源与混合来源对PAHs的贡献率分别为28.4%、16.5%和55.1%。  相似文献   

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The effects of the herbicide atrazine on the gill of the freshwater fish Prochilodus lineatus were evaluated after exposure of fish to 2, 10 and 25 μg L−1 atrazine during 48 h (acute exposure) and 14 d (subchronic exposure). Ions and osmolality were measured in plasma and gill samples were taken to determine the Na+/K+-ATPase (NKA) and carbonic anhydrase (CA) activities and for morphological analysis. Plasma osmolality and Na+ and Cl ions changed depending on atrazine concentration, but atrazine exposure had no effect on the Na+/Cl ratio. NKA activity did not change after atrazine exposure, but CA activity decreased in fish exposed to 25 μg L−1 for 14 d. Gill MRC density decreased after acute exposure but did not change in fish exposed to the subchronic treatment. The MRC density at the epithelial surface increased in fish exposed to 25 μg L−1, and the MRC fractional area (MRCFA) increased in fish exposed to 10 μg L−1. The changes in MRCs provide evidence of morphological adjustments to maintain ionic homeostasis in spite of the inhibition of CA activity at the highest atrazine concentration.  相似文献   

14.
Particle-associated polycyclic aromatic hydrocarbon (PAH) concentrations were investigated at six sampling sites in the heating (February to March 2001) and nonheating (August to September 2001) periods in an industrial city in Northern China. Thirteen PAHs were measured. The total average concentrations (nanograms per meter cubed) of PAHs ranged between 78.93 and 214.63 during the heating period and from 31.48 to 102.26 in the nonheating period. Benzo(a)pyrene occurred at the highest level at a site near an industrial area but occurred at low concentrations far from the city center and industrial areas. In addition, ambient PAH profiles were studied. The five and six-ring species occurred in high fractions at the sampling site. By diagnostic ratio analysis, the major source at each sampling site in the city was coal combustion in the heating period; in the nonheating period, the major sources were relatively complex. Finally, the similarities among the six regions were assessed by principal component analysis, cluster analysis, and coefficient of divergence. These multivariate statistical analyses produced similar results, which agreed with the results from the diagnostic ratio analysis.  相似文献   

15.
Investigations have been undertaken at two integrated steelworks in the UK to characterise airborne organic micro-pollutants and to assess the contribution of iron ore sintering and coke making operations on the air quality. Concentrations of volatile organic compounds (VOCs), namely benzene, toluene and p-xylene, were measured continuously within the boundary of a coking plant using for the first time differential optical absorption spectrometry (DOAS) between 2004 and 2006. Concentrations were obtained along two monitoring paths surrounding the coke plant and the average benzene concentration measured along both paths over the campaign was 28 μg m?3. Highest benzene concentrations were associated with winds downwind of the coke oven batteries. Concentrations of polycyclic aromatic hydrocarbons (PAHs) in ambient air were measured during 27 consecutive days in 2005 at three different locations on an integrated steelworks. PAH profiles were determined for each sampling point and compared to coke oven and sinter plant emission profiles showing an impact from the steelworks. The mean benzo [a] pyrene concentration determined in the immediate vicinity of the coke ovens downwind from the battery was 19 ng m?3, whereas for the two other sites average benzo [a] pyrene concentrations were much lower (around 1 ng m?3). Data were analysed using principal components analysis (PCA) and results showed that coke making and iron ore sintering were responsible for most of the variation in the PAH concentrations in the vicinity of the investigated plant.  相似文献   

16.
Water, suspended particulate matter (SPM), and sediment samples were collected from ten rivers in Tianjin and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs), dissolved organic carbon (DOC), particulate organic carbon (POC) in SPM and total organic carbon (TOC) in sediment. The behavior and fate of PAHs influenced by these parameters were examined. Generally, organic carbon was the primary factor controlling the behavior of the 16 PAH species. Partitioning of PAHs between SPM and water phase was studied, and K(OC) for some PAH species were found to be significantly higher than the predicted values. The source of PAHs contamination was diagnosed by using PAH isomer ratios. Coal combustion was identified to be a long-term and prevailing contamination source for sediment, while sewage/wastewater source could reasonably explain a short-term PAHs contamination of SPM.  相似文献   

17.
It has been amply demonstrated that exposure to fine particulate matter, containing polycyclic aromatic hydrocarbons (PAHs), may have adverse effects on human health, affecting especially the respiratory and cardiovascular systems. Among population, school-age children and elders present particular susceptibilities and unique exposures to environmental factors. The study presented in this paper belongs to the Project EXPAH, founded by the European (EU) LIFE+ instrument, and consists of the personal monitoring of five elementary school children and four elders during the spring and the summer/autumn of the year 2012 in the city of Rome, Italy. The average exposure, expressed as the sum of eight high-molecular-weight PAHs, resulted equal to 0.70 ng/m3 (SD?=?0.37) for children and 0.59 ng/m3 (SD?=?0.23) for the elderly people. The mean levels of gravimetric PM2.5 were equal to 23 μg/m3 (SD?=?10) and 15 μg/m3 (SD?=?4) for children and elders, respectively. During spring and summer seasons, personal BaPeq resulted well below the EU Air Quality reference value of 1 ng/m3. The personal monitoring average values were in the same order of magnitude with available indoor and outdoor environmental data in Rome during the same periods, for both PAHs and PM2.5. The results suggest that, during non-heating seasons, the personal exposure to PAHs in the city of Rome can be mainly ascribed to the urban background, especially traffic emissions and road dust resuspension; secondhand cigarette smoke can be also considered another possible source of PAHs personal exposure.  相似文献   

18.

Materials and methods  

Aliphatic and polycyclic aromatic hydrocarbons (PAHs) were determined in surficial sediments from the Aegean Sea in the Eastern Mediterranean in 2008.  相似文献   

19.
Desorption behavior of pyrene, phenanthrene and naphthalene from fullerene, single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) was examined. Available adsorption space of carbon nanotubes (CNTs) was found to be the cylindrical external surface, neither the inner cavities nor inter-wall spaces due to impurities in the CNTs and restricted spaces (0.335nm) of the MWCNTs, respectively. Desorption hysteresis was observed for fullerene but not for CNTs. Deformation-rearrangement was proposed to explain the hysteresis of polycyclic aromatic hydrocarbons (PAHs) for fullerene, due to the formation of closed interstitial spaces in spherical fullerene aggregates. However, long, cylindrical carbon nanotubes could not form such closed interstitial spaces in their aggregates due to their length, thus showing no significant hysteresis. High adsorption capacity and reversible adsorption of PAHs on CNTs imply the potential release of PAHs if PAH-adsorbed CNTs are inhaled by animals and humans, leading to a high environmental and public health risk.  相似文献   

20.
The exhaust emission of the polycyclic aromatic hydrocarbons (PAHs) considered toxic to human health were investigated on two spark ignition light duty vehicles, one being gasohol (Gasohol, in Brazil, is the generic denomination for mixtures of pure gasoline plus 20–25% of anhydrous ethyl alcohol fuel (AEAF).)-fuelled and the other a flexible-fuel vehicle fuelled with hydrated ethanol. The influence of fuel type and quality, aged lubricant oil type and use of fuel additives on the formation of these compounds was tested using standardized tests identical to US FTP-75 cycle. PAH sampling and chemical analysis followed the basic recommendations of method TO-13 (United States. Environmental Protection Agency, 1999. Compendium Method TO-13A – Determination of polycyclic Aromatic hydrocarbons (PAH) in Ambient Air Using Gas Chromatography/Mass Spectrometry (CG/MS). Center for environmental research information, Cincinnati, p. 78), with the necessary modification for this particular application.Results showed that the total PAH emission factor varied from 41.9 μg km?1 to 612 μg km?1 in the gasohol vehicle, and from 11.7 μg km?1 to 27.4 μg km?1 in the ethanol-fuelled vehicle, a significant difference in favor of the ethanol vehicle. Generally, emission of light molecular weight PAHs was predominant, while high molecular weights PAHs were not detected. In terms of benzo(a)pyrene toxicity equivalence, emission factors varied from 0.00984 μg TEQ km?1 to 4.61 μg TEQ km?1 for the gasohol vehicle and from 0.0117 μg TEQ km?1 to 0.0218 μg TEQ km?1 in the ethanol vehicle.For the gasohol vehicle, results showed that the use of fuel additive causes a significant increase in the emission of naphthalene and phenanthrene at a confidence level of 90% or higher; the use of rubber solvent on gasohol showed a reduction in the emission of naphthalene and phenanthrene at the same confidence level; the use of synthetic oil instead of mineral oil also contributed significantly to a decrease in the emission of naphthalene and fluorene. In relation to the ethanol vehicle, the same factors were tested and showed no statistically significant influence on PAH emission.  相似文献   

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