东莞市夏季大气颗粒物中的多环芳烃及硝基多环芳烃

以东莞市2011年夏季不同区域的大气颗粒物为研究对象,定性定量分析了其中多环芳烃(PAHs)及硝基多环芳烃(NPAHs)的浓度、组成.采用特征比值法分析了PAHs及NPAHs的来源,并通过PEFs毒性评价法评价了颗粒物中多环芳烃及硝基多环芳烃的BaP等效毒性,估算出个体致癌指数.结果表明东莞市颗粒物上16种多环芳烃总含量在12.60—193.95 ng·m-3范围内,6种硝基多环芳烃的总含量在5.88—62.79 ng·m-3,隧道环境中多环芳烃及硝基多环芳烃的浓度最高.除隧道环境中颗粒物的等效毒性及个体致癌指数超标外,东莞市颗粒物上PAHs及NPAHs对人体均不构成严重威胁.     

半透膜被动采样装置(SPMDs)对PAHs 和壬基酚类的静态富集

半透膜采样装置(SPMDs)是一种被动采样装置,它能模拟有机污染物穿过生物膜从水相到生物有机相的分配平衡过程,使得结果能显示出污染物的生物可利用性。它能对环境中有机污染物进行长时间连续监测,所得的是污染物被SPMD富集后的时间权重浓度。本实验测定了温度为18℃时标准SPMD对7种PAHs和3种NPnEO(n=0～2)的静态富集过程,通过测定污染物达到平衡时在SPMD内的浓度和在水相中浓度的比值,求解了各自的SPMD/水分配平衡常数KSPMD。表明了有机污染物在SPMD和水相之间达到分配平衡所需要的时间是随着其Kow值的增高而逐渐增长的,还与其各自的分子极性有关,并且几种达到富集平衡的PAHs在SPMD内的浓度也是随着其Kow值的增高而逐渐变大。比较KSPMD的理论值和实测值可以发现,对于PAHs而言,其实测值都高于理论值,而NPnEO都是实测值低于其理论值。但是KSPMD实测值和理论值随污染物Kow值变化的趋势相同。     

Analysis of polycyclic aromatic hydrocarbons by sensitized room temperature phosphorescence

Direct and selective simultaneous determination of several polycyclic aromatic hydrocarbons by sensitized room temperature phosphorescence in sodium dodecylsulphate micellar solutions was studied. This approach improved, for example, the selectivity factor in determining pyrene in the presence of fluoranthene by a factor of 350, and determined benz[a]anthracene and anthracene in the presence of pyrene with the selectivity factors as high as 200–220. Triphaflavine and acridine orange as triplet energy donors, thallium (I) nitrate as a heavy atom, and sodium sulphite were used as scavengers of oxygen. A comparative study of linear concentration ranges, detection limits and selectivity factors is presented here for pyrene, benz[a]anthracene and anthracene determination by fluorescence, phosphorescence and sensitized phosphorescence. Electronic Publication     

Photochemical reaction of nitro-polycyclic aromatic hydrocarbons: effect by solvent and structure

Photochemical degradation of 1-nitropyrene, 2-nitrofluorene, 2,7-dinitrofluorene, 6-nitrochrysene, 3-nitrofluoranthene, 5-nitroacenaphthene, and 9-nitroanthracene was examined in CHCl₃, CH₂Cl₂, DMF, DMF/H₂O (80/20), CH₃CN, or CH₃CN/H₂O (80/20). The degradation mostly follows the first order kinetics; but a few follow second order kinetics or undergo self-catalysis. The photodegradation rates follow the order: CHCl₃ > CH₂Cl₂ > DMF > DMF/H₂O > CH₃CN > CH₃CN/H₂O. DMF is an exceptional solvent because three of the seven compounds undergo self-catalytic reaction. 9-Nitroanthracene, which has a perpendicular nitro group, is the fastest, while the more compact 1-nitropyrene and 3-nitrofluoranthene are the slowest degrading compounds.     

Uptake,metabolism and discharge of polycyclic aromatic hydrocarbons by marine fish

The uptake, metabolism and discharge of two polycyclic aromatic hydrocarbons, ¹⁴C-naphthalene and ³H-3,4-benzopyrene, were studied in 3 species of marine fish (mudsucker or sand goby, Gillichthys mirabilis; sculpin, Oligocottus maculosus; sand dab, Citharichthys stigmaeus). The path of hydrocarbons through the fish included entrance through the gills, metabolism by the liver, transfer of hydrocarbons and their metabolites to the bile, and, finally, excretion. The gall bladder was a major storage site of labeled hydrocarbons and their metabolites. The major product of ²H-3,4-benzypyrene metabolism was tentatively identified as 7,8-dihydro-7,8-dihydroxybenzopyrene. The ¹⁴C-naphthalene was metabolized to 1,2-dihydro-1,2-dihydroxynaphthalene after 24 h exposure. The urine appeared to the major avenne for discharge of labeled hydrocarbon from the body. Our laboratory results indicated that certain polycyelic aromatic hydrocarbons were rapidly taken up from seawater by the above fish, but detoxification mechanisms existed for efficient removal of these compounds from their body tissues.     

Accumulation and release of petroleum-derived aromatic hydrocarbons by four species of marine animals

Survival of Ctenodiscus crispatus during exposure to hypoxia (P _{O 2}<3 mm Hg) at 5°C is greater than that of any echinoderm reported in the literature, the LT₅₀ being 248 h; this is reduced to 236 h in the presence of hydrogen sulfide. Unlike Asterias vulgaris and A. forbesi, both of which lose the tube foot response to tactile stimulation long before death from hypoxia occurs, C. crispatus remains responsive until death. The extension of the highly protrusible epiproctal cone, which occurs in 75% of the mud stars simultaneously exposed to hypoxia and H₂S, serves to maintain burrow contact with the overlying water. The rate of oxygen consumption remains constant down to an ambient oxygen partial pressure of 10 to 25 mm Hg, becoming more oxygen-dependent after prior exposure of the asteroids to hypoxia. C. crispatus exhibits a clear oxygen-debt phenomenon as well as a compensatory reduction in the residual P _{O 2} (oxygen partial pressure at which oxygen consumption ceases) from 2.4 to 0.2 mm Hg after hypoxic exposure.     

Ecotoxicity of polycyclic aromatic hydrocarbons, aromatic amines, and nitroarenes through molecular properties

Air, marine, and terrestrial pollution are continuously critical issues to be solved in environmental sciences. Particularly with the recent disaster in the Mexico Gulf and the risk of oil spills from the continuous offshore drilling activities in the North Sea, ecotoxicological profiling requires great attention. Fjord ecosystems are particularly neglected marine ecosystems, which require better surveillance and ecotoxicological profiling. In this context, this study focuses on exploring three potential indicators for aquatic stress [polycyclic aromatic hydrocarbons (PAHs), aromatic amines (AAs), and nitroarenes (NAs)] by the study of their molecular and sub-molecular properties. The results show that the aromatic amine, 4-aminobiphenyl, gains a particularly reactive electronic potential, which can be summarized as a large change in LUMO+2 and HOMO?1 electron orbitals upon metabolic activation in the organism. This change in orbitals increases the overall electrostatic energy of the molecule, inducing a high affinity for DNA-adduct formation. Electronic analysis on nitroarenes shows in addition why 1,6-dinitropyrene is more stable than 1,8-dinitropyrene, and how the electrons favor nitrenium activation on the 6th and 8th carbon. Further analysis shows also that PAHs have a present correlation with hormonal similarity, and that their resemblance to estrogen can be correlated to mutagenicity, contributing to increased ecotoxicity. The electronic analysis of these three types of fossil pollutants shows how their toxicity is exerted from the electronic level and which structural features that determine the level of reactivity and toxicity. The summation of the background and electronic properties of these molecular toxins elucidates that PAHs, aromatic amines, and nitroarenes are all of equal importance as stress indicators for fjord systems, with particular emphasis on PAHs, which also exert hormonal structural similarities as a probable base of their carcinogenic mechanisms.     

Transmembrane transport of polycyclic aromatic hydrocarbons by bacteria and functional regulation of membrane proteins

• Explaintheadsorption, uptake and transmembrane transport of PAHs by bacteria. • Analyze functional regulation of membrane proteins inthe transmembrane transport. • Proteomics technology such as iTRAQ labeling was used to access expressed proteins. • Single cell analysis technology wereused to study the morphological structure. In recent years, increasing research has been conducted on transmembrane transport processes and the mechanisms behind the microbial breakdown of polycyclic aromatic hydrocarbons (PAHs), including the role of membrane proteins in transmembrane transport and the mode of transmission. This article explains the adsorption, uptake and transmembrane transport of PAHs by bacteria, the regulation of membrane protein function during the transmembrane transport. There are three different regulation mechanisms for uptake, depending on the state and size of the oil droplets relative to the size of the microbial cells, which are (i) direct adhesion, (ii) emulsification and pseudosolubilization, and (iii) interfacial uptake. Furthermore, two main transmembrane transport modes are introduced, which are (i) active transport and (ii) passive uptake and active efflux mechanism. Meanwhile, introduce the proteomics and single cell analysis technology used to address these areas of research, such as Isobaric tags for relative and absolute quantitation (iTRAQ) technology and Nano Secondary ion mass spectrometry (Nano-SIMS). Additionally, analyze the changes in morphology and structure and the characteristics of microbial cell membranes in the process of transmembrane transport. Finally, recognize the microscopic mechanism of PAHs biodegradation in terms of cell and membrane proteins are of great theoretical and practical significance for understanding the factors that influence the efficient degradation of PAHs contaminants in soil and for remediating the PAHs contamination in this area with biotechnology.     

杭州市郊区表层土壤中的多环芳烃

采集了杭州市郊区表层土壤中多环芳烃样品,用内标法和色谱-质谱技术对多环芳烃化合物进行定量分析.美国环保总署推荐优先控制的16种多环芳烃均被检出,多环芳烃单体的质量浓度在1.49～87.43 ng·g-1之间;其中萘、芴、苊等低分子量芳烃的质量浓度相对较低; 、茚并[1,2,3-cd]芘、苯并[ghi]苝等高分子量芳烃的质量浓度相对较高,苯并[ghi]苝的质量浓度最高.16种多环芳烃的质量总浓度超过荷兰政府规定无污染土壤PAHs值的10～40倍;与国内外其他地区相比较,多环芳烃污染处于中等水平.多环芳烃Ant/(Phe+Ant)、BaA/(Chr+BaA)、Flua/(Pyr+Flua)等参数表明,多环芳烃主要来源于燃烧源,且以机动车尾气为主;BeP/(BeP+BaP)比值偏高,可能与土壤中的多环芳烃主要来源于大气沉降有关.     

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.     

土壤与沉积物对多环芳烃类有机物的吸附作用

吸附作用是疏水性有机物在土壤和沉积物环境中的重要迁移转化行为之一。多环芳烃是环境中一种重要的疏水性有机污染物。文章着重阐述了多环芳烃类有机物在土壤和沉积物中有机质和粘土矿物吸附机理，指出土壤、沉积物有机质的结构异质性是导致非线形吸附的重要原因；分析了影响多环芳烃吸附过程的诸多因素，并提出该研究领域存在的问题以及今后发展的方向。     

环境中的氧化多环芳烃综述

氧化多环芳烃(OPAHs)是芳环上具有至少一个羰基氧(C=O)的PAH衍生物,广泛存在于环境中.氧化多环芳烃主要通过含碳燃料的燃烧和PAHs的转化释放到环境中,且其较稳定难降解,因此OPAHs被称为生物和化学降解的"末端产物".目前,在多种动物组织样本中都可检测出OPAHs,并发现OPAHs可能比亲代PAHs具有更强的毒性.本文阐述了OPAHs的理化性质、来源、测定方法、环境分布、转运和转化、(生态)毒理学效应及其毒性作用机制,并对今后的研究方向进行了展望,进而为该类化合物的环境污染及生态风险评估提供相应参考.     

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.     

Sampling of airborne polycyclic aromatic hydrocarbons with semipermeable membrane devices

Semipermeable membrane devices (SPMDs) are nowadays used as passive samplers of organic pollutants. The knowledge of the sampling rate values (R_S) of each substance trapped on membranes is necessary to calculate their average concentration. Here we calculate R_S values for 16 polycyclic aromatic hydrocarbons using the comparison of active sampling method results and the amounts sequestered by SPMDs at varying exposure times.Selected article from the Regional Symposium on Chemistry and Environment, Krusevac, Serbia, June 2003, organized by Dr. Branimir Jovancicevic.     

Concentrations of polycyclic aromatic hydrocarbons in soils of a mangrove forest affected by forest fire

Surface soils affected by forest fires from Igbanko mangrove forest in Nigeria were analyzed for 16 EPA priority polycyclic aromatic hydrocarbons (PAHs) using gas chromatography–mass spectrometry (GC–MS). The total PAHs concentrations in the soils ranged from 63 to 188?µg?kg^?1 dry weight (average: 108?µg?kg^?1). The three predominant PAHs in the soils were naphthalene (Na), fluoranthene (Flu), and benzo(b)fluoranthene (BbF). Compared to the control sample (19?µg?kg^?1), elevated PAHs concentrations were observed in the soils, an indication of some level of PAHs contamination. PAHs source diagnostic ratios of Flu/(Flu?+?Pyr) and Ant/(Ant?+?Phe) indicated that the PAHs have a pyrogenic origin which may have resulted from combustion of grass, wood, or coal. An assessment based on Canadian soil quality guidelines indicated that the studied locations do not pose any serious adverse risk on human health.     

深圳市室内大气多环芳烃的含量与组成

利用PUF大气被动采样技术,对深圳市室内大气多环芳烃(PAHs)进行了为期68周的连续观测.结果表明,深圳市室内大气PAHs主要以气态化合物为主,尤以菲的含量为最高.室内大气PAHs的含量范围为44.2395.4 ng·m-3,平均123.6 ng·m-3.不同场所的室内PAHs污染呈如下分布:ρ(工厂车间)>ρ(家居客厅)@ρ(办公环境),苯并[a]芘毒性质量浓度则为:ρ(工厂车间)>ρ(家居客厅)>ρ(办公环境).研究表明,工厂车间与家居办公环境中的PAHs来源不相尽同,认为办公环境中的PAHs污染主要来自户外的对流交换,而吸烟和厨房烹调是影响客厅PAHs含量的重要因素.总体来说,深圳地区室内大气PAHs污染较低,但工厂车间的PAHs污染及其健康危害值得关注.     

Application of probabilistic risk assessment at a coking plant site contaminated by polycyclic aromatic hydrocarbons

Application of Probabilistic Risk Assessment （PRA） and Deterministic Risk Assessment （DRA） at a coking plant site was compared. By DRA, Hazard Quotient （HQ） following exposure to Naphthalene （Nap） and Incremental Life Cancer Risk （ILCR） following exposure to Benzo（a）pyrene （Bap） were 1.87 and 2.12 × 104. PRA revealed valuable information regarding the possible distribution of risk, and risk estimates of DRA located at the 99.59th and 99.76th percentiles in the risk outputs of PRA, which indicated that DRA overestimated the risk. Cleanup levels corresponding acceptable HQ level of 1 and ILCR level of 104 were also calculated for both DRA and PRA. Nap and Bap cleanup levels were 192.85 and 0.14mg.kg-1 by DRA, which would result in only 0.25% and 0.06% of the exposed population to have a risk higher than the acceptable risk, according to the outputs of PRA. The application of PRA on cleanup levels derivation would lift the cleanup levels 1.9 times for Nap and 2.4 times for Bap than which derived by DRA. For this coking plant site, the remediation scale and cost will be reduced in a large portion once the method of PRA is used. Sensitivity analysis was done by calculating the contribution to variance for each exposure parameter and it was found that contaminant concentration in the soil （Cs）, exposure duration （ED）, total hours spent outdoor per day （ETout）, soil ingestion rate （IRs）, the air breathing rate （IRa） and bodyweight （BW） were the most important parameters for risk and cleanup levels calculations.