空气中多环芳烃的研究进展

介绍了国内对大气中气态,颗粒态ＰＡＨｓ的研究概况,室内外空气中ＰＡＨｓ污染与城市交通间的相关性,ＰＡＨｓ总量代表物,硝基ＰＡＨｓ及人体接触ＰＡＨｓ的生物指标。     

Sources and patterns of polycyclic aromatic hydrocarbons pollution in kitchen air,China

Twelve polycyclic aromatic hydrocarbons, multi-ringed compounds known to be carcinogenic in air of six domestic kitchens and four commercial kitchens of China were measured in 1999-2000. The mean concentration of total PAHs in commercial kitchens was 17 microg/m3, consisting mainly of 3- and 4-ring PAHs, and 7.6 microg/m3 in domestic kitchens, where 2- and 3-ring PAHs were predominant, especially naphthalene. The BaP levels in domestic kitchens were 0.0061-0.024 microg/m3 and 0.15- 0.44 microg/m3 in commercial kitchens. Conventional Chinese cooking methods were responsible for such heavy PAHs pollution. The comparative study for PAH levels in air during three different cooking practices: boiling, broiling and frying were conducted. It was found that boiling produced the least levels of PAHs. For fish, a low-fat food, frying it produced a larger amount of PAHs compared to broiling practice, except pyrene and anthracene. In commercial kitchens, PAHs came from two sources, cooking practice and oil-fumes, however the cooking practice had a more predominant contribution to PAHs in commercial kitchen air. In domestic kitchens, except for cooking practice and oil-fumes, there were other PAHs sources, such as smoking and other human activities in the domestic houses, where 3-4 ring PAHs mainly came from cooking practice. Naphthalene (NA, 2-ring PAHs) was the most predominant kind, mostly resulting from the evaporation of mothball containing a large quantity of NA, used to prevent clothes against moth. A fingerprint of oil-fumes was the abundance of 3-ring PAHs. Heating at the same temperature, the PAHs concentrations in different oil-fumes were lard > soybean oil > rape-seed oil. An increase in cooking temperature increased the levels of PAHs, especially acenaphthene.     

Size distribution of polycyclic aromatic hydrocarbons in urban and suburban sites of Beijing, China

PAHs in five-stage size segregated aerosol particles were investigated in 2003 at urban and suburban sites of Beijing. The total concentration of 17 PAHs ranged between 0.84 and 152 ng m(-3), with an average of 116 ng m(-3), in urban area were 1.1-6.6 times higher than those measured in suburban area. It suggested a serious pollution level of PAHs in Beijing. PAHs concentrations increased with decreasing the ambient temperature. Approximately 68.4-84.7% of PAHs were adsorbed on particles having aerodynamic diameter 2.0 microm. Nearly bimodal distribution was found for PAHs with two and three rings, more than four rings PAHs, however, followed unimodal distribution. The overall mass median diameter (MMD) for PAHs decreased with increasing molecular weight. Diagnostic ratios and normalized distribution of PAHs indicated that the PAHs in aerosol particles were mainly derived from fossil fuel combustion. Coal combustion for domestic heating was probably major contributor to the higher PAHs loading in winter, whereas PAHs in other seasons displayed characteristic of mixed source of gasoline and diesel vehicle exhaust. Biomass burning and road dust are minor contributors to the PAHs composition of these aerosol particles. Except for source emission, other factors, such as meteorological condition, photochemical decay, and transportation from source to the receptor site, should to be involved in the generation of the observed patterns.     

Biomonitoring seasonal variation of urban air polycyclic aromatic hydrocarbons (PAHs) using Ficus benghalensis leaves

Temporal and seasonal variations of polycyclic aromatic hydrocarbons (PAHs) concentrations in leaves of Ficus benghalensis were investigated in Varanasi city (India). Leaf samples were collected from six sites from urban area of Varanasi and from a control site. PAH extraction was done by sonication in dichloromethane-acetone and quantification by GC-MS. In January total leaf PAHs concentrations at all the urban sites were twice higher as compared to other season's viz. summer and rainy. In contrast, at the control site leaf PAHs concentrations showed lower values than urban sites. The maximum concentrations of total PAHs in winter were due to the medium molecular weight PAHs which increases with respect to both low and high molecular weight PAHs. The temporal variation of medium molecular weight PAHs was similar both at the urban and remote sites. These results support biomonitoring ability of Ficus benghalensis leaves to temporal variations in PAHs contamination.     

Distributions and concentrations of PAHs in Hong Kong soils

Surface soil (0-10 cm) samples from 53 sampling sites including rural and urban areas of Hong Kong were collected and analyzed for 16 EPA priority polycyclic aromatic hydrocarbons (PAHs). Total PAH concentrations were in the range of 7.0-410 microg kg(-1) (dry wt), with higher concentrations in urban soils than that in rural soils. The three predominant PAHs were Fluoranthene, Naphthalene and Pyrene in rural soils, while Fluoranthene, Naphthalene and Benzo(b + k)fluoranthene dominated the PAHs of urban soils. The values of PAHs isomer indicated that biomass burning might be the major origin of PAHs in rural soils, but vehicular emission around the heavy traffic roads might contribute to the soil PAHs in urban areas. A cluster analysis was performed and grouped the detectable PAHs under 4 clusters, which could be indicative of the PAHs with different origins and PAHs affected by soil organic carbon contents respectively.     

Historical deposition behaviors of PAHs in the Yangtze River Estuary: Role of the sources and water currents

Historical profiles and sources of PAHs at two typical sediment cores (i.e., the shipping route site and the shoal site) were fully compared to probe the controlling factors, specifically the water currents, for the PAHs deposition processes in the Yangtze River Estuary. Compared with ocean water currents, river runoff affected by the water impoundment of the Three Gorges Dam greatly affected the PAHs levels and percent contribution of PAHs sources in the two cores. River runoff hindered the PAHs deposition in shoal site, while a contrary phenomenon was observed for the shipping route site. Though the PAHs in the estuary were mainly from river catchment, only low ring PAHs in the shipping route site were mainly from the upper reach of the river. Coarse sediments with higher organic carbon content also accounted for the higher deposition levels of PAHs in the shipping route site.     

中国南方某城市自来水厂处理工艺对多环芳烃的去除效果研究

讨论了中国南方某城市自来水厂饮用水中的多环芳烃残留规律以及现有净水工艺对多环芳烃的去除效果。研究结果表明,该自来水厂饮用水中检出多环芳烃以2~4环芳烃为主,强致癌性高环数多环芳烃均在检出限以下,且多环芳烃总量未超出中国供水行业标准(2000年)的相关限值。各处理工艺段中,砂滤过程对多环芳烃的去除效果最好,相较于原水对多环芳烃总量的去除率可达64%。     

The characterisation of polycyclic aromatic hydrocarbons emissions from burning of different firewood species in Australia

Four kinds of woods used for residential heating in Australia were selected and burned under two burning conditions in a domestic wood heater installed in a laboratory. The selected wood species included pine (Pinus radiata), red gum (Eucalvptus camaldulensis), sugar gum (Eucalyptus cladocalyx) and yellow box (Eucalyptus melliodora). The two different burning conditions represented fast burning and slow burning, with the air inlet of the combustion chamber respectively 'full open' and 'half open'. By sampling and analysing particulate and gaseous emissions from the burning of each load of wood under defined experimental conditions, PAHs emissions and their profiles in the particulate and gaseous phases were obtained. 16 species out of the 18 selected PAHs were detected. Of these, seven species were detected in the gaseous phase and most were lower molecular weight compounds.Similarly, more than 10 species of PAHs were detected in the particulate phase and these were mostly heavier molecular weight compounds. Under both burning conditions, emission levels for total PAHs and total genotoxic PAHs were the highest for pine and lowest for sugar gum, with red gum being the second highest, followed by yellow box. Using the specific sampling method, gaseous PAHs accounted for above 90% mass fraction of total PAHs in comparison to particulate PAHs (10%). The majority of the genotoxic PAHs were present in the particulate phase. PAHs emission levels in slow burning conditions were generally higher than those in fast burning conditions.     

Distribution and sources of polycyclic aromatic hydrocarbons in the middle and lower reaches of the Yellow River, China

In this study, concentrations, distribution between different phases, transition along the Middle and Lower reaches of the Yellow River and possible sources of PAHs were assessed. Results demonstrated that the relative proportions of 15 PAHs in all stations of the main River were similar, with concentrations of benzo[a]pyrene all above drinking water standards in most of the stations sampled. PAHs concentrations in tributaries were higher than those in the corresponding sites in the main River. PAHs concentrations of suspended particles were mainly correlated with contents of total organic carbon. However, PAHs concentrations in sediments were mainly correlated to the volume of particles with size smaller than 0.01 mm. The distribution of PAHs in all media sampled indicated that sediments could act as a sink/source for PAHs in different sections and source analysis revealed that PAHs mainly originated from coal burning, although in some tributaries PAH inputs could come from combustion of petroleum.     

Distribution,source, and ecological risk assessment of PAHs among size and density fractions in contaminated sediments from the Yellow River of Henan section

This study investigated particle size and density distributions of polycyclic aromatic hydrocarbons (PAHs) in two surface sediments (JZ and KF), collected from the Yellow River of Henan section, China. The concentrations of Σ₁₅PAHs ranged from 35.6 to 45862?ng g^?1 dry wt, which were greatly elevated in coarse particles and low-density fractions. The Σ₁₅PAHs concentrations in low-density fractions were 533 (JZ) and 996 (KF) times higher than those in the corresponding high-density fractions. However, due to relatively less quantities of low-density fractions (0.27–2.33%), most of the PAHs were contributed by the high-density components. For both sediments, the influence factors of PAHs source in the environment were very complex, more so than the level of TOC and BC content. JZ sediment was dominated by 4-ring to 6-ring PAHs (61.5–75.1%), while, 2-ring to 3-ring PAHs were abundant in KF samples (39.8–72.6%). Ratios of specific PAHs reflected PAHs among the size- and density-fraction of each sediment may be contaminated by mixed of pyrolytic and petrogenic origin. Additionally, ecological risk assessment of PAHs suggested that total toxic equivalent values of PAHs in the low-density fractions were much higher than those of the corresponding high-density fractions in the studied area.     

Experimental study on the removal of PAHs using in-duct activated carbon injection

This paper presents the incineration tests of municipal solid waste (MSW) in a fluidized bed and the adsorption of activated carbon (AC) on polycyclic aromatic hydrocarbons (PAHs). An extraction and high performance liquid chromatography (HPLC) technique was used to analyze the concentrations of the 16 US EPA specified PAHs contained in raw MSW, flue gas, fly ash, and bottom ash. The aim of this work was to decide the influence of AC on the distribution of PAHs during the incineration of MSW. Experimental researches show that there were a few PAHs in MSW and bottom ash. With the increase of AC feeding rate, the concentrations of three- to six-ring PAHs in fly ash increased, and the concentration of two-ring PAH decreased. The total-PAHs in flue gas were dominated by three-, and four-ring PAHs, but a few two-, five-ring PAHs and no six-ring PAHs were found. PAHs could be removed effectively from flue gas by using in-duct AC injection and the removal efficiencies of PAHs were about 76-91%. In addition, the total toxic equivalent (TEQ) concentrations of PAH in raw MSW, bottom ash, fly ash, and flue gas were 1.24 mg TEQ kg-1, 0.25 mg TEQ kg-1, 6.89-9.67 mg TEQ kg-1, and 0.36-1.50 microg TEQ Nm-3, respectively.     

Distribution,transfer, and health risks of polycyclic aromatic hydrocarbons (PAHs) in soil-wheat systems of Henan Province,a typical agriculture province of China

In order to investigate the distribution, transfer, and human health risks of polycyclic aromatic hydrocarbons (PAHs) in the soil-wheat systems, soil samples from 20 farmlands and corresponding wheat tissues were collected from selected regions of Henan Province in June 2013 and were analyzed to estimate the concentration of PAHs. The total concentrations of 15 PAHs (∑₁₅ PAHs) in soils from Henan Province varied from 6.91 to 72.4 ng/g. Moreover, two-ring to three-ring PAHs (1.59–29.1 ng/g) were the major species in soils, occupying 56.2% of total PAHs. Principal component analysis (PCA)-multiple linear regression (MLR) revealed that fossil fuel burning dominated the input of PAHs in agricultural soils of Henan Province. The range of ∑₁₅ PAHs concentrations in wheat tissues was 13.9–50.9 ng/g, which decreased along the root-straw-grain. Positive correlation among PAHs of soil and wheat tissues showed that PAHs in wheat mainly came from soil and then migrated along root-straw-grain. Moreover, PAHs were accumulated highest in root and lowest in grain. Two-ring to three-ring PAHs were easier to transfer from soil to wheat than five-ring to six-ring PAHs. Consumption of wheat grain created potential risk of cancer in Henan Province.

     

Vapor-phase and fine particulate matter concentrations of polycyclic aromatic hydrocarbons measured during the winter months in a northern Rocky Mountain urban airshed

A fine particulate matter (PM2.5) sampling program was conducted in Missoula, MT, to investigate both the particle and vapor phases of PM2.5-associated polycyclic aromatic hydrocarbons (PAHs) found in a northern Rocky Mountain urban airshed. Twenty-four-hour samples were collected during the cold winter months of January through April 2002, when many of the more volatile organic components of PM2.5 were expected to be found in the condensed particle form. To meet analytical detection limits, each of the 12 individual sample days were aggregated into four total filter and polyurethane foam (PUF) samples, respectively, with each aggregate containing 3 sample days. Quartz filter (particle-phase PAHs) and PUF (vapor-phase PAHs) aggregates were analyzed separately for 18 individual PAHs and phenolics by gas chromatography/mass spectrometry. Results showed that 87% of the PM2.5-associated phenolics and PAHs measured in this study were found in the vapor phase. PM2.5-associated gas/particle partition coefficients (Kp,2.5) ranged from 0 for the lighter phenolics and PAHs to approximately 0.1 for some of the heavier PAHs, such as fluoranthene and pyrene. Calculating Kp,2.5 for the heaviest measured PAHs was not feasible because of low or undetectable concentrations in the vapor phases of these compounds. Phenolics and two-ringed and three-ringed PAHs were found almost exclusively in the vapor phase. Four-ringed PAHs were distributed between the particle and vapor phases, with more mass measured in the vapor phase. Very little five-ringed and higher PAHs were measured from either the filter or PUF sampling medium. These results provide information on both the concentrations and different phases of PM2.5-associated PAHs measured during the winter months in a northern Rocky Mountain urban airshed, when concentrations of PM2.5 are generally at their highest compared with the rest of the year.     

Polycyclic aromatic hydrocarbons in soils in the vicinity of Nanjing, China

The occurrence and distribution of polycyclic aromatic hydrocarbons (PAHs) in vegetable soils from five vegetable fields (including: Liuhe, Xixia, Pukou, Jianye and Yuhua districts) in Nanjing outskirt were investigated with high performance liquid chromatography (HPLC) equipped with fluorescence detector. The total concentrations of 15 priority PAHs in 126 soil samples ranged from 21.91 to 533.84ngg(-1) dry weight, and the sum of seven carcinogenic PAHs concentrations varied from 1.48 to 236.19ngg(-1) dry weight. Statistical analysis of the PAHs concentrations showed that the highest PAHs concentration was observed in Liuhe, and the lowest PAHs concentrations were found in Xixia among the five districts. The ratios of fluoranthene to sum of fluoranthene and pyrene concentrations (Flt/(Flt+Pyr)) were more than 0.5 in 99% of vegetable soil samples, showing that the PAHs in soils were generally derived from straw and coal combustion sources. The results from principal component analysis (PCA) further indicated that extensive combustion activities affected the PAHs distribution in Nanjing vegetable soils.     

Polycyclic aromatic hydrocarbons in weathered bottom ash from incineration of municipal solid waste

Polycyclic aromatic hydrocarbons (PAHs) were analysed in weathered bottom ash from different municipal solid waste incinerators. The sum of the 16 "USEPA" PAHs was found to vary from 480 to 3590 microg/kg. The amounts of carcinogenic PAHs were between 89 and 438 microg/kg ash. The maximum levels of carcinogenic PAHs exceed the Swedish generic guidelines for sensitive land use. The results showed that the amount of PAHs in fresh and weathered bottom ash are similar, indicating that the PAHs are strongly bound to the ash and only limited amounts are released to the surroundings.     

Occurrence and assessment of polycyclic aromatic hydrocarbons in soils from vegetable fields of the Pearl River Delta, South China

Surface soil (0-20 cm) samples from nine representative vegetable fields located in Guangzhou, Shenzhen, Zengcheng and Huadu within the Pearl River Delta, South China were collected and analyzed for 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) using gas chromatography coupled to mass spectrometry (GC-MS). Total concentrations of 16 PAHs (Sigma(PAHs)) ranged from 160 to 3700 microg kg(-1). Large variations were observed also between concentrations of individual PAHs from different vegetable fields and within the site as well. Acenapthylene, benzo[b]fluoranthene, fluoranthene, benzo[a]pyrene and benzo[k]fluoranthene were consistently the most prevalent individual PAHs. The values of PAH isomer ratios [anthracene/(anthracene+phenanthrene) and fluoranthene/(fluoranthene+pyrene)] indicate that combustion processes are the major sources of PAHs. Concentrations of PAHs were poorly correlated with organic carbon concentrations of soils, suggesting different sources and also indicating that the PAH pollution of this area is recent. The same outcome is confirmed by the predominance of PAHs with fewer rings (相似文献   

植物混种原位修复多环芳烃污染农田土壤

通过比较实验前后土壤微生物主要类群数量、PAHs降解菌数量、土壤PAHs含量和植物不同部位PAHs含量变化,评价植物单种和混种野外原位修复多环芳烃(PAHs)污染农田土壤的效果。结果显示,150 d天生长期内,黑麦草/小麦混种及黑麦草/蚕豆混种修复效果最好,对土壤PAHs总量的降解率分别达到了59.4%和64.8%。同时,这2个混种处理土壤细菌、真菌和PAHs降解菌数量分别显著高于相应的小麦、蚕豆和黑麦草单种处理。植物不同部位PAHs含量高低次序为根部>茎叶≈籽粒。混种模式下,蚕豆和小麦不同部位PAHs含量比单种模式的不同程度降低,特别是籽粒部。植物混种模式不仅显著提高了土壤PAHs的降解率,还降低了农作物体内PAHs含量,实现了边生产边修复,在污染农田土壤修复领域有着广阔的应用前景。     

Characterization of polycyclic aromatic hydrocarbons in urban stormwater runoff flowing into the tidal Anacostia River, Washington, DC, USA

To investigate the sources, fate, and transport dynamics of PAHs (polycyclic aromatic hydrocarbons) in stormwater runoff that is a leading source of pollution in urban watersheds, storm and base flow samples were collected in six branches along the lower Anacostia River. PAHs in storm flow (1510-12,500 ng/L) were significantly enriched in the particle phase, which accounted for 68-97% of the total PAHs. It suggests that reducing particles in stormwater using post-treatment system would decrease PAHs considerably. The solid-water distribution coefficients (KD) of PAHs in the storm flow samples were up to 340 times higher than predicted values. A greater portion of high molecular weight PAHs and their distribution patterns indicate higher contribution of automobile originated pyrogenic PAHs. Total suspended solids in storm flow had a positive relationship with flow rates and exceeded benchmark level for the protection of aquatic biota in some samples.     

多环芳烃的光致毒效应

多环芳烃（ＰＡＨｓ）是一类常见的污染物,过去对其毒性的研究主要集中在生物体内代谢产物的毒效应上。但是近期研究表明紫外光的照射对多环芳烃的毒性具有显著影响,称为ＰＡＨｓ的光致毒效应。本文介绍了多环芳烃在紫外光照射下的急性光致毒作用,致毒作用发生机理及毒性预测的数学模型,同时探讨了ＰＡＨｓ对紫外光致癌性的影响。     

南京市气溶胶PM2.5中多环芳烃来源识别

对2005年7月至2006年2月采集到的南京市气溶胶Pm2.5 进行季节性初步分析,并对其中的15种优控多环芳烃(PAHs)进行分析研究,通过比值法判断南京市PAHs夏季主要来源于柴油型燃烧,冬季主要来源于柴油和煤型相结合的燃烧.对15种优控PAHs两两之间的相关性分析,发现各化合物之间显著相关,表明各化合物的来源有相似之处.