Continuous monitoring of ambient polycyclic aromatic hydrocarbons near open‐air burning of metal scraps

Airborne concentrations of PAH in the vicinity of the source region with open‐air burning of metal scraps were measured between February, 1992 and November, 1993. The activity of open‐air burning decreased significantly since 1993 due to prohibition regulation. Both gaseous phase and particle‐bound PAH were measured at five sampling sites, which included one reference sampling site far away from the source region. Both values of gaseous and particle‐bound PAH concentrations, which were measured in the vicinity of source region, decreased clearly during the two years monitoring period. It shows that the uncontrolled open‐air burning of metal scraps was a significant emission source of airborne PAH in the study area. The profiles of various species of PAH were also compared. A large decrease in benzo(a)pyrene was observed in the source region.     

Vertical distribution and environmental significance of PAHs in soil profiles in Beijing,China

Vertical distribution of both the concentration and composition of polycyclic aromatic hydrocarbons (PAHs) in ten profiles in Beijing has been investigated. The results showed that PAH concentrations and compositions in topsoil from different sampling sites were different. PAH concentrations were much higher in topsoil of the investigated urban area, industrial region, and paddy field with wastewater irrigation than in other areas. Moreover, PAH concentrations in topsoil were much higher than those at greater depth, where the concentrations were relatively consistent in most soil profiles. The fingerprints of PAHs in the samples from topsoil (0–30 cm) in the same profiles were similar and were obviously different from those at greater depth, suggesting that PAH sources were consistent in topsoil samples and were discriminating between topsoil and deeper soils. PAHs in topsoil mainly arose from mixed sources of combustion of liquid fuel, coal, and/or wood, as well as wastewater irrigation, while those at greater depth were derived from soil genesis and the process of soil formation.     

Lichens to distinguish urban from industrial PAHs

This paper shows that lichens can be used as biomonitors to distinguish urban from industrial polycyclic aromatic hydrocarbons (PAHs). PAHs are atmospheric pollutants originating mainly from incomplete combustion of fuels in vehicles and industry. The occurrence of PAHs in air is a serious health issue in urban areas and industrial areas because some PAHs are carcinogenic. Biomonitoring PAHs with lichens is generally applied for quantification of PAHs. However, the precise sources of PAHs are not well known. Here we use lichen to trace the source of PAHs. PAHs were analyzed in Pyxine subcinerea Stirton, a lichen species collected from twelve sites which vary from urban and industrial to periurban forest area of Haridwar, in the foothills of the Indian Himalayas. Total PAH concentration ranged between 1.25 and 187.3 μg g⁻¹. Results indicate a clear distinction between urban and industrial PAHs profile, using principal component analysis. Lichen sampled from industrial sites exhibited higher concentrations of two-, five-, and six-ringed PAHs, up to 60% of total PAHs, while samples from urban sites were dominated by four-ringed PAHs, predominantly fluoranthene and acenaphthylene. Molecular ratios indicate that combustion was the dominant source of origin of PAHs in industrial area, while urban sites showed mixed origin of PAHs, both pyro- and petrogenic.     

Polycyclic aromatic hydrocarbons in soils around Guanting Reservoir,Beijing, China

The concentrations of 16 polycyclic aromatic hydrocarbons (∑ 16PAHs) were measured by gas chromatography equipped with a mass spectrometry detector (GC-MS) in 56 topsoil samples around Guanting Reservior (GTR), which is an important water source for Beijing. Low to medium levels of PAH contamination (mean=394.2±580.7 ng g^?1 dry weight (d.w.)) was evident throughout the region. In addition, localised areas of high PAH contamination near steel and cement factories were identified, with ∑ 16PAHs concentrations as high as 4110 ng/g, dry weight (d.w.). There was a significant positive correlation (r²=0.570, p<0.01) between total organic carbon content and ∑ 16PAHs concentrations. Phenanthrene was the predominant compound, accounting for 27.2% of the ∑ PAH concentration, followed by chrysene>pyrene>benzo[a]anthracene≈ benzo[b]fluoranthene≈ benzo[a]pyrene. Four-ring PAH homologues (39%) were dominant. The higher proportion of 4–6 ring homologues, molecular indices, and the spatial distribution of PAH indicated that industrial discharges, incineration of wastes and traffic discharges were the major sources of soil PAHs around the water reservoir.     

北京东南郊大气中多环芳烃的相分配及其致癌毒性表征

采用索氏提取法提取2005年3月至2006年1月间北京市东南郊3个采样点大气总悬浮颗粒物(TSP)样品和气相样品中的多环芳烃(PAHs),利用GC/MS分析其质量浓度,对PAHs在颗粒相和气相间的分配行为进行研究。结果表明,2环组分在气相PAHs中占优势地位,全年平均在95%左右;4环组分在颗粒相PAHs中全年平均占56%左右;5~6环组分几乎全部分布在颗粒相中。引入苯并[a]芘等当量毒性因子(TEFs),探讨致癌毒性组分在2相间的分配行为,研究发现低毒高质量浓度的低环组分与高毒低质量浓度的高环组分对致癌性贡献相当;利用苯并[a]芘等效质量浓度与16种PAHs组分质量浓度进行多元线性回归,得到的回归方程用于粗略计算大气中PAHs致癌性组分的等效质量浓度;在分析PAHs分配行为的季节变化规律基础上,结合气象参数和空气污染指数分析PAHs在大气气相和颗粒相中分配系数的影响因素,并提出了分配系数与气象参数和API指数的回归方程,并利用回归方程来计算PAHs组分在大气中的分配系数。     

Dependency of polycyclic aromatic hydrocarbon concentrations on particle size distribution in Tehran atmosphere

In this work, the airborne particulate matter with an aerodynamic diameter less than 10 µm (PM₁₀) was fractionated in a six-stage high-volume cascade impactor to identify particulate size distribution in Tehran atmosphere. The study was conducted at 15 sites located in the north, south, east, west, and central parts of Tehran in 2005. Air samples were analyzed for 16 polycyclic aromatic hydrocarbons (PAHs) by HPLC. The daily PM₁₀ concentrations at the peak of traffic in roadside areas were found to be 106–560 µg m^?3. The cumulated concentration sum of PAHs, based on 16 species, was found to have an average concentration of 380 ng m^?3. Furthermore, it was found that more than 60% of PAHs belonged to the small particulate size range, having sizes of less than 0.49 µm, some containing benzo(ghi)perylene and indeno(123cd)pyrene (high molecular weight) with average concentrations of 8 and 6 ng m^?3 and fluorene, phenanthrene, and fluoranthene (low molecular weight) with average concentrations of 14, 13, and 19 ng m^?3, respectively. In addition, the results revealed that the lighter three- and four-ring PAH compounds were the most abundant pollutants in the air collected at all the sampling sites.     

Einschätzung der Konzentrationsprofile polyzyklischer aromatischer Kohlenwasserstoffe (PAK) in Böden des Biosphärenreservates Spreewald

To work out background values, the information of concentration profiles of PAHs in soils of uncontaminated territories is indispensable. This investigation shows PAH concentrations of different soil samples like agricultural soils, grassland, forest and litter from the biosphere reserve in Spreewald, Germany. The mean values of the soil samples are about 460 μg Σ-PAK/kg d.m. A top value of 7.2 mg Σ-PAK/kg d.m. shows a sample of a flooded grassland area. The relation of the concentrations in the litter, forest, grassland and agricultural soil samples is about 5∶3∶2∶1. Compared to the other samples, the litter samples contain a higher amount of low molecular PAHs. Increasing distance to the former power plants Lübbenau and Vetschau (brown coal) lead to decreasing PAH contents in the soil samples of forests from 2190.9 after 4 km to 294.8 Σ-PAK/kg d.m. after 16 km. In comparison to results obtained in Nordrhein-Westfalen and Bayern, the PAH measurements indicate Spreewald to be an uncontaminated and rural area.     

Enrichment and transfer of polycyclic aromatic hydrocarbons (PAHs) through dust aerosol generation from soil to the air

● Compositional patterns of PAHs in dust aerosol vary from soil during dust generation. ● The EF of PAH in dust aerosol is affected by soil texture and soil PAH concentration. ● The sizes of dust aerosol play an important role in the enrichment of HMW-PAHs. Polycyclic aromatic hydrocarbons (PAHs) are major organic pollutants in soil. It is known that they are released to the atmosphere by wind via dust aerosol generation. However, it remains unclear how these pollutants are transferred through the air/soil interface. In this study, dust aerosols were generated in the laboratory using soils (sandy loam and loam) with various physicochemical properties. The PAH concentrations of these soils and their generated dust aerosol were measured, showing that the enrichment factors (EFs) of PAHs were affected by soil texture, PAH contamination level, molecular weight of PAH species and aerosol sizes. The PAHs with higher EFs (6.24–123.35 in dust PM_2.5; 7.02–47.65 in dust PM₁₀) usually had high molecular weights with more than four aromatic rings. In addition, the positive correlation between EFs of PAHs and the total OC_aerosol content of dust aerosol in different particle sizes was also statistically significant (r = 0.440, P < 0.05). This work provides insights into the relationship between atmospheric PAHs and the contaminated soils and the transfer process of PAHs through the soil-air interface.     

北京市某废弃焦化厂不同车间土壤中多环芳烃（PAHs）的分布特征及风险评价

以北京市某废弃焦化厂为研究对象,系统采集了6个车间0～4m深的26个土壤样本,利用GC/MS检测了U.S.EPA优控的16种多环芳烃(PAHs)的含量,分析了PAHs在焦化厂不同车间表层土壤的污染状况和深层土壤中的垂直分布特征并对土壤污染风险进行了评估.结果表明,1)该废弃焦化厂不同车间表层土壤(0～20cm)总PAHs(∑PAHs)的残留量介于672.8～144814.3ng·g-1之间;污染程度排序为:回收车间>老粗苯车间>焦油车间>炼焦车间>水处理车间>制气车间.2)该厂未受扰动的土壤样品显示PAHs主要聚集在表层土壤,并随着土壤深度的增加而迅速减少;其他样点由于土壤扰动,∑PAHs含量最大值出现在第三层土壤(80～180cm);该厂4m深底层土壤仍有高浓度PAHs,∑PAHs含量最高值出现在炼焦车间,达12953.1ng·g-1.3)焦化厂土壤PAHs污染主要集中在3环和4环的PAHs单体上,分别占到污染总量的51.3%和31.7%.4)根据Maliszewska-Kordybach的PAHs总量标准及加拿大土壤PAHs单体治理标准,该厂回收、老粗苯、焦油和炼焦车间表层和深层土壤PAHs含量均达到重污染水平,并对其周围土地带来较大风险,需要治理.     

Characterization and source apportionment of polycyclic aromatic hydrocarbons in the ambient air (Tehran,Iran)

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the urban atmosphere and the atmospheric pollutants to be identified as the most suspected carcinogens. In early measurements of urban PAH concentrations in Tehran area, the correlation between concentrations of different species indicated that automobiles were the predominant source of emission of PAHs in this city. From the diagnostic ratios, the results indicated that PAHs in the ambient air in Tehran originate primarily from diesel and gasoline engines, but contribution of the related diesel emission is apparently higher, or dominant, at the sampling sites and therefore considered as the major emission of PAHs in the ambient air.     

珠江水体表层沉积物中PAHs的含量与来源研究

沿珠江白鹅潭水域及大学城官州河流域设立6个采样点,利用沉积物捕获器收集沉积物。参照美国EPA8000系列方法及质量保证和质量控制,对各采样点表层沉积物中16种多环芳烃（polycyclic aromatic hydrocarbons,PAHs）进行分析,以阐明珠江广州河段表层沉积物中PAHs的含量和分布特征,并结合特征化合物指数对其来源作初步探讨。珠江广州河段表层沉积物中PAHs总量介于4 787.5～8 665 ng·g^-1,平均值为7 078 ng·g^-1,黄沙码头河涌出口沉积物中总量为最高（8 665 ng·g^-1）,芳村码头为最低（4 787.5 ng·g^-1）。16种多环芳烃中菲、荧蒽、芘含量较高,分别占PAHs总量的16.11%、14.47%和17.77%。特征化合物荧蒽/202比值均小于0.5,茚并[1,2,3-cd]芘/276比值均大于0.2,表明珠江广州段表层沉积物中PAHs主要来源于化石燃料的不完全燃烧。     

Source apportionment of polycyclic aromatic hydrocarbons in Lake Baikal water and adjacent air layer

The composition of polycyclic aromatic hydrocarbons (PAHs) in Lake Baikal water and adjacent air layer and PAH emission composition profiles of possible sources were investigated. Analysis of emission composition data showed that the source profiles could not be grouped by fuel type or pyrogenic/petrogenic origin. Because of the similarity of source PAH profiles, the drawing of 3D mixing diagrams was the only way to check whether some of the potential PAH sources were the true sources. The mixing diagrams showed that the sources of air pollution were paper mills and wood burning and that the sources of water pollution were coal-fired and oil-fired boilers. The common source for both air and water was only oil and petroleum products. To determine the locations of PAH sources, their contributions to air and water pollution were calculated and mapped. Based on the results, air and water were polluted from both local and regional sources. The location of the zone influenced by a particular source was conditioned by physical properties of source emission, direction of air/water flows that transfer PAHs and temperature differences between mixing air/water flows.     

Investigation on sampling artifacts of particle associated PAHs using ozone denuder systems

Polycyclic aromatic hydrocarbons （PAHs） are complex organic compounds which are identified as significant carcinogenic to human health. PAHs （mainly in particle phase） are susceptible to atmospheric oxidant gases, especially ozone, nitrogen oxides （NOx）, hydroxyl radical （OH）, and could be degraded on filters during sampling process, leading to an underestimation of ambient PAH concentrations. The goal of this work was to investigate particle associated PAHs sampling artifacts caused by ozone in summer of Beijing. Comparative sampling systems were operated simultaneously during the whole campaign, one with activated carbon ozone denuder, the other being set as conventional sampling system. Activated carbon denuder was testified to be highly efficient to eliminate ozone from air stream. In general, nine particle-bound PAHs observed from conventional sampler were all lower than those from ozone denuder system. The total PAHs （particle phase） concentration was averagely underestimated by 35.9% in conventional sampling procedure. Benzo[a]pyrene （BaP） had the highest percentage of mass loss. founded to have influences Ambient temperature was on PAHs sampling artifacts. High temperature can increase loss of particle associated PAHs during sampling.     

Removal of high concentrations of polycyclic aromatic hydrocarbons from contaminated soil by biodiesel

Solubilizing experiments were carried out to evaluate the ability of biodiesel to remove polycyclic aromatic hydrocarbons (PAHs) from highly contaminated manufactured gas plant (MGP) and PAHs spiked soils with hydroxypropyl-β-cyclodextrin (HPCD) and tween 80 as comparisons. Biodiesel displayed the highest solubilities of phenanthrene (420.7 mg·L^-1), pyrene (541.0 mg·L^-1), and benzo(a)pyrene (436.3 mg·L^-1). These corresponded to several fold increases relative to 10% HPCD and tween 80. Biodiesel showed a good efficiency for PAH removal from the spiked and MGP soils for both low molecular weight and high molecular weight PAHs at high concentrations. Biodiesel was the best agent for PAH removal from the spiked soils as compared with HPCD and tween 80; as over 77.9% of individual PAH were removed by biodiesel. Tween 80 also showed comparable capability with biodiesel for PAH solubilization at a concentration of 10% for the spiked soils. Biodiesel solubilized a wider range of PAHs as compared to HPCD and tween 80 for the MPG soils. At PAH concentrations of 229.6 and 996.9 mg·kg^-1, biodiesel showed obvious advantage over the 10% HPCD and tween 80, because it removed higher than 80% of total PAH. In this study, a significant difference between PAH removals from the spiked and field MGP soils was observed; PAH removals from the MGP soil by HPCD and tween 80 were much lower than those from the spiked soil. These results demonstrate that the potential for utilizing biodiesel for remediation of highly PAH-contaminated soil has been established.     

Urban fractionation of polycyclic aromatic hydrocarbons from Dalian soils

This report evidences the fractionation of polycyclic aromatic hydrocarbons (PAHs) from urban to rural areas, and a higher contribution of coal and wood combustion in rural areas. PAHs are persistent semi-volatile organic pollutants in the environment. PAHs originate from the incompleted combustion of fossil fuel and biomass. Cities are usually considered as primary sources of PAHs. Due to different types and loads of fuel consumption in various functional areas of a city, the levels and composition profiles of PAHs are expected to be different. We, therefore, studied the mechanisms ruling PAH distributions in soils from a major Chinese city. Seventeen soil samples were collected in urban traffic areas, residential and park areas, suburban areas and rural areas of Dalian, northeastern China. PAHs were analyzed using a high-performance liquid chromatography. The composition profiles and seasonal variation of PAHs were investigated. Results show that the proportions of low-weight molecular PAHs to total PAHs increased with urban-suburban-rural gradient. This trend is explained by the “urban fractionation” of PAHs. Furthermore, the spring/autumn ratios of PAH concentrations were higher than 1. Specifically, the spring/autumn ratio was 1.79 for two ring PAHs, 1.42 for three ring PAHs, and lower than 1.20 for five and six ring PAHs. The spring/autumn ratios of phenanthrene were higher than 1 and increased with increasing distance from the urban areas. The results imply that the contribution of coal and wood combustion PAHs increases with the urban-suburban-rural gradient.     

Sources of polycyclic aromatic hydrocarbons (PAHs) in sediments of the Biobio River in south central Chile

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the environment; there are concerns about them due to their toxic properties. Human activities could significantly contribute to the total PAH burden in river sediments. In this work, we document the analysis of PAHs in sediments taken in the middle stretch of the Biobio River in south central Chile. This river is a principal system, draining more than 24,000 km² and subjected to a diverse variety of human-made stressors (pulp mill and urban effluents, agricultural drainage systems, etc). During 2003, several sediment samples were taken in more than 45 sampling sites located in the river’s middle stretch. Due to the granulometric characteristics (mainly sandy sediments), only 17 samples were analyzed, taking into consideration the presence of a fine section within the sediment sample. Using HPLC with fluorescence detection, 15 EPA priority PAHs and perylene were analyzed. The composition of PAHs in the sediment samples is rather similar between sites and levels averaged 104 ± 78 ng g⁻¹ d.w. The highest levels were detected downstream from an industrial discharge. A good correlation was observed between PAH levels and organic carbon content in the tested sediments; however, concentrations above 134 ng g⁻¹ d.w. did not indicate correlation. The samples PAH ratios (Flu/Pyr and Chr/B(a)A) reveal a strong pyrolytic PAH pattern in the sediments tested, supporting evidence indicating that PAHs come mainly from pyrolytic sources. This result contrasts with previous records that have shown a natural influence in the upper basin and a petrogenic pattern near the mouth.     

汕头经济特区土壤中优控多环芳烃的分布

运用气相色谱-质谱方法对汕头经济特区131个土样中的美国EPA优控多环芳烃(PAHs)进行定性、定量测定,讨论了PAHs的分布特征。结果表明,该区表层土壤中优控PAHs的总质量分数范围从22.1 ng/g到1256.9 ng/g之间,平均质量分数为(317.3210.2) ng/g。其分布随采样点的位置不同而有显著变化:工业区附近多环芳烃的质量分数最高,城市中心次之,郊区最低。大多数样点中?PAHs质量分数和单种PAH质量分数都呈现w(5~20 cm)> w(0~5 cm)>w(20~40 cm)>w(40~100 cm)的垂直分布规律。该区土壤PAHs以3环和4环化合物为主,单种PAH以萘、菲和苯并[b]萤蒽为主。     

An interval dynamic multimedia fugacity (IDMF) model for environmental fate of PAHs and their source apportionment in a typical oilfield,China

An interval dynamic multimedia fugacity (IDMF) model with a new validation criterion of interval average logarithmic residual error (IALRE) was developed in this study. The environmental fate of polycyclic aromatic hydrocarbons (PAHs) and their source apportionment in a typical oilfield of China were simulated from 1985 to 2010. The PAH concentrations predicted by the model were in agreement with the measured concentrations, which were indicated by the IALREs calculated at 0.41, 0.63, 0.52, and 0.58 for air, water, soil, and sediment, respectively. The multimedia concentrations of Σ16 PAHs were 29.55, 39.22, 31.98, and 26.69 times greater in 2010 than those in 1985, and were higher than any other year modelled. Additionally, 87.82% of PAHs remained in the soil in 2010. PAH source emission into the soil was the major modelled source, whereas PAH degradation in the air was the major modelled loss pathway; the dominant transfer process between the adjacent compartments was atmospheric deposition from air to soil. It was demonstrated that high-temperature combustion was the major source of PAHs in the air and soil, whereas biomass and coal combustion were attributed to water and sediment compartments. The IDMF model was effective in the dynamic source apportionment of PAHs.     

Polycyclic aromatic hydrocarbons in red mullet (Mullus bavbatus) and sediments from the Eastern Aegean Sea

The distribution of polycyclic aromatic hydrocarbons (PAHs) was investigated in red mullet (Mullus barbatus) and sediment samples in the eastern Aegean Sea. The data were collected during cruises in July and November 1994, in the framework of National Marine Measurement and Monitoring Programme in the Aegean Sea. PAHs were detected in the tissue of Mullus barbatus of different sex and size from nine sampling sites throughout the study area ranging from 0.03 to 0.46 ug/g (fresh weight). The observations show the high levels of PAHs were found in tissues of females. The average concentration of PAHs in Aegean Sea sediments ranged from 0.20 to 1.8 ug/g (dry weight). No significant correlation was observed between PAH and sedimentary organic carbon.     

PAHs in indoor dust samples in Shanghai’s universities: levels, sources and human exposure

Given the significant amount of time people spend indoors, the occurrence of polycyclic aromatic hydrocarbons (PAHs) in indoor dust and their potential risks are of great concern. In the present study, ten dust samples from lecture theatres and twelve samples from dining halls were collected from university campuses in Shanghai to investigate the PAH levels, possible sources and human exposure. The total concentrations of 18 PAHs ranged from 9.84 to 21.44?μg/g for dust samples from lecture theatres, and 9.63-44.13?μg/g for samples from dining halls. Total PAH concentrations in indoor dust samples showed a better correlation to black carbon compared to total organic carbon contents. PAHs in dining halls samples showed a similar distribution pattern with that of commercial kitchen air, which indicated that cooking activities could contribute most of the PAHs found in dining halls. Principal component analysis revealed both petrogenic and pyrogenic sources. The potential health risk for PAHs was assessed in terms of BaP equivalent carcinogenic power and estimated daily intake (EDI). Relatively high EDI values compared to other studies suggested that PAHs posed a potential threat to human health in indoor environments at Shanghai's universities.