Polycyclic Aromatic Hydrocarbons (PAHs) Pollution in Agricultural Soil in Tianjin,China

Representative soil samples (n = 60) collected from suburban agricultural land in Tianjin were analyzed to determine 16 PAHs in this study. Accelerated solvent extraction, GPC (Gel Permeation Chromatography), and SPE (Solid Phase Extraction) clean-up procedures were employed for PAH preparation prior to analysis with gas chromatography–mass spectrometry. The concentrations of the total PAHs (T-PAHs) ranged from 228.6 ng/g to 14722.1 ng/g with the mean value of 613.1 ng/g. Bap concentrations in many sites exceeded the suggested standards. Spatial variation of PAHs in soil was illustrated; the pollution status and comparison to other cities were also investigated. Severe PAH soil pollution was observed in some sites near urban areas. Higher PAH concentrations were detected at the downwind side of the urban areas, indicating the influence of human activities. Two indicative ratios (Fl/(Fl+Pyr, Baa/(Baa+Chr)) and principal component analysis were used to identify the possible sources of PAHs. These suggested that coal combustion was still the most important source of PAHs in Tianjin, which coincided well with the previous studies. These data can be further used to assess the health risk associated with soils polluted by PAHs and can help local government find proper ways to reduce PAHs’ pollution in soils.     

Polycyclic Aromatic Hydrocarbons (PAHs) in Surface Sediments of Lake Manzala,Egypt

This investigation represents the first extensive study of the spatial distribution, sources, and potential effects of polycyclic aromatic hydrocarbons (PAHs) in sediments from Lake Manzala, the largest of Egypt's Mediterranean coastal lakes. The concentrations of PAHs (Σ39 components) ranged from 246 to 9910 ng g^?1 dry wt., the highest values corresponding to urban hotspots with high anthropogenic input coming from wastewater discharges and combustion activities and decreasing offshore. The levels of PAHs were significantly lower compared to values reported in several coastal/estuarine areas (e.g., in Spain, Italy, USA, and Egypt) receiving substantial anthropogenic inputs from urban and industrial activities. Source ratios indicated that the PAHs were mainly from petrogenic sources in near-shore urban hotspots, with higher contributions of pyrolytic sources in coastal and offshore areas which are little influenced by human activities. Sediment quality guidelines (SQGs) showed that except at one station heavily impacted by sewage discharge, the total and individual PAH concentrations were below effect range low (ERL) concentrations that are not likely to adversely affect benthic biota.     

微生物降解多环芳烃的研究进展

多环芳烃(PAHs)是具有严重危害的环境污染物质。介绍PAHs的降解菌,降解机理和PAHs的生物修复方面的研究进展。土壤中PAHs的生物修复被认为是解决污染的有效方法,目前,菲的生物降解途径已经比较清楚,但对结构更为复杂的多环芳烃研究较少。文章还对消除环境中多环芳烃的相关生物技术提出展望。     

藻类对多环芳香烃(PAHs)的富集和代谢

概述了藻类对PAHs的富集和代谢的研究进展。环境中多环芳香烃(PAHs)的污染能导致严重的健康问题,利用生物特别是微生物去除污染环境中的PAHs是一项新的技术。藻类对PAHs的富集与有机污染物的类型、藻类的种类及藻类的生物量有关,活细胞和死细胞对PAHs均有富集能力。还阐述了PAHs在真菌、细菌和藻类体内代谢的途径以及代谢过程中起关键作用的酶,PAHs在藻类中的代谢途径和细菌及真菌都不同,谷胱甘肽转移酶(GST)在藻类代谢PAH过程中起重要作用,但细胞色素P450酶所起的作用则不详。     

Biodegradation of Polycyclic Aromatic Hydrocarbons (PAHs) by Trichoderma reesei FS10-C and Effect of Bioaugmentation on an Aged PAH-Contaminated Soil

ABSTRACT?The co-metabolism of benzo[a]pyrene (B[a]P) and the capacity of the fungus Trichoderma reesei FS10-C to bioremediate an aged polycyclic aromatic hydrocarbon (PAH)-contaminated soil were investigated. The fungal isolate removed about 54% of B[a]P (20 mg L^?1) after 12 days of incubation with glucose (10 g L^?1) supplementation as a co-metabolic substrate. Bioaugmented microcosms showed a 25% decrease in total PAH concentrations in soil after 28 days, and the degradation percentages of 3-, 4-, and 5(+6)-ring PAHs were 36%, 35%, and 25%, respectively. In addition, bioaugmented microcosms exhibited higher dehydrogenase (DHA) and fluorescein diacetate hydrolysis (FDAH) activities and increased average well-color development (AWCD), Shannon-Weaver index (H), and Simpson index (D) significantly. Principal component analysis (PCA) also distinguished clear differentiation between treatments, indicating that bioaugmentation restored the microbiological function of the PAH-contaminated soil. The results suggest that bioaugmentation by T. reesei FS10-C might be a promising bioremediation strategy for aged PAH-contaminated soils.     

Bioremediation of Polycyclic Aromatic Hydrocarbons in Creosote-Contaminated Soil by Peniophora incarnata KUC8836

ABSTRACT Polycyclic aromatic hydrocarbons (PAHs) are present in products made from creosote, coal tar, and asphalt. When wood pile treated with creosote is placed in soil, PAHs can contaminate it. Creosote has been used for wood preservation in the past and is composed of approximately 85% PAHs and 15% phenolic compounds. PAHs cause harmful effects to humans and the environment because of their carcinogenic and mutagenic properties. White rot fungi can degrade not only lignin, but also recalcitrant organic compounds such as PAHs. Among numerous white rot fungi used in previous studies, four species were selected to degrade PAHs in a liquid medium. From this evaluation of the degradation of PAHs by the four fungal isolates, two species were ultimately selected for the highest rates of removal. Following 2 weeks of incubation with Peniophora incarnata KUC8836, the degradation rates of phenanthrene, fluoranthene, and pyrene were 86.5%, 77.4%, and 82.6%, respectively. Mycoaciella bispora KUC8201 showed the highest degradation rate for anthracene (61.8%). Hence, bioremediation of creosote-contaminated soil with an initial concentration of 229.49 mg kg^?1 PAHs was carried out using the two selected fungi because they could simultaneously degrade 13 more PAHs than the comparison species. More importantly, isolates of P. incarnata KUC8836 were discovered as powerful degraders of PAHs by producing laccase and manganese-dependent peroxidase (MnP), with 1.7- and 1.1-fold higher than the comparison species, respectively. Therefore, the white rot fungus may be proposed for the removal of PAHs and xenobiotic compounds in contaminated environments.     

Probabilistic Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Produced Water

The produced water extracted during oil and gas production includes formation water, injected water, small volumes of condensed water, and any chemical added during the oil/water separation process. Produced water contains both organic and inorganic constituents, and several studies have been conducted in the past to assess their risk. The toxicity and persistence of polycyclic aromatic hydrocarbons (PAHs) in produced water is of particular environmental concern, but there are very few studies on human health risk assessment from PAHs of produced water. This article summarizes the results of a conservative human health risk assessment approach for PAHs in produced water discharges to the marine environment. Due to the absence of available toxicity data for PAHs, the cancer slope factors were determined by using the relative potency factors (RPF) and Toxicity Equivalency Factors (TEF). Using the concentration distribution factors, the maximum cancer risks to humans were predicted in the range of 4.07 × 10^?7 to 2.95 × 10^?6. The 95th-percentile values show that the risks are well within the acceptable limits.     

高效液相色谱法测定"北京烤鸭"中多环芳烃含量的研究

建立了高效液相色谱法同时检测烤鸭中16种多环芳烃的方法。经过索氏提取、皂化、液-液分配、柱层析等步骤将样品中的多环芳烃提取、净化、浓缩,采用带紫外检测器的高效液相色谱法直接检测。该方法测定出的多环芳烃浓度与其色谱峰面积的线性良好(0.9831(?) r(?)0.9997),主要多环芳烃的加标回收率在54.6%-139.8%之间。     

Source Analysis and Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Paddy Soils

Polycyclic aromatic hydrocarbons (PAHs) are typically persistent organic pollutants with hypertoxicity and widespreading, attracting increasing attention in recent years. Six paddy land sites soils irrigated from different rivers in the Nansi Lake area of Shandong Province, China, were studied to analyze and assess the source and risk of PAHs.Analysis revealed total PAHs (TPAHs) concentrations in topsoil ranging from 57.49 to 2046.47 μg kg^?1, meanwhile, Weishan County (WS) was highly contaminated primarily from coal combustion based on the Nemerow composite index and geochemical indices.Canonical correspondence analysis (CCA) suggested that bacterial species were affected by pH, TPAHs, and soil organic matter (SOM), while covariables analysis confirmed that most effects of PAHs on bacterial diversity were attributed to the PAHs effect alone rather than the combined effects of PAHs and soil properties. The average daily human exposure (ADE) in children was approximately 2 times higher than that in adults, and the exposure paths values followed a decreasing order, oral intake > skin contact > inhalation. Furthermore, the WS site and another rice test field (TF) presented potential cancer risks and required further investigation. Therefore, the study has important theoretical significance for the control of PAHs pollution in this field, providing a scientific basis for health assessment.     

Polycyclic Aromatic Hydrocarbons in Road-Deposited Sediments and Roadside Soil in Tijuana,Mexico

Road-deposited sediment and roadside soil in the urban area of the city of Tijuana were collected and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs). The ΣPAH concentration for road-deposited sediment (RDS) ranged between 460 and 2027 µg/kg with an average of 933 µg/kg. The ΣPAH concentration in roadside soil was lower than in RDS, with a range between 54 and 1863 µg/kg and a mean value of 308 µg/kg. The diagnostic ratios showed that the PAHs originated mostly from pyrogenic sources such as gasoline and diesel combustion. The results show that PAH concentration in RDS and roadside soils is low when compared with other published studies. The low PAH levels found in this study are possibly related to differences in climate, urban features, and anthropogenic activities conducted in the studied areas. The toxicity equivalent concentrations (TEQ) of PAH calculated were also low in comparison with other studies. This is probably due to the lower concentration of total PAHs and the highly toxic high-molecular-weight PAHs.     

好氧细菌对多环芳烃降解机制的研究进展

多环芳烃(PAHs)是指两个或两个以上的苯环以线性排列、弯接或簇聚方式构成的一类碳氢化合物.这类化合物广泛分布于环境中,具有潜在的致畸性、致癌性和遗传毒性.在自然环境中,好氧细菌对PAHs的生物降解是一种很重要的方式,凸显其在清除环境PAHs污染物中具有广阔的应用前景.在过去二十多年中,科学家们已经从基因水平上对好氧细菌降解PAHs的机制进行了深入的研究,其中包括PAHs降解基因的多样性、与PAHs降解有关的基因以及细菌群体PAHs遗传适应机制等.在此,就好氧细菌对多环芳烃降解机制的研究进展进行了综述和讨论.     

Polycyclic Aromatic Hydrocarbons in Sediments: An Overview of Risk-Related Issues

This series of articles address site-specific issues associated with evaluating exposure and toxicity of polycyclic aromatic hydrocarbons (PAHs) in sediments. These include factors that influence the opportunity to come into contact with PAHs in sediments (bioaccessibility) and those that affect the potential for transfer from sediment to ecological and human receptors (bioavailability). Although organic carbon is viewed as an important matrix for sorbing PAHs, studies have shown that there are various forms of carbon, some of which are highly sorptive. These latter forms vary on a site-specific basis and including this form of carbon in the assessment can reduce the uncertainty associated with estimating exposure. Other site-specific factors associated with water clarity, depth, and light penetration can result in enhanced toxicity of PAHs as a result of photoactivation. Chemical analyses of sediments increasingly include the alkylated PAH compounds. Although analyses of this suite of PAH compounds is being conducted to support ecological assessments and forensic analyses, there is little guidance on how to interpret the alkylated PAHs with respect to human health risks. An approach for accomplishing this is suggested.     

好氧细菌对多环芳烃降解机制的研究进展

多环芳烃(PAHs)是指两个或两个以上的苯环以线性排列、弯接或簇聚方式构成的一类碳氢化合物。这类化合物广泛分布于环境中, 具有潜在的致畸性、致癌性和遗传毒性。在自然环境中, 好氧细菌对PAHs的生物降解是一种很重要的方式, 凸显其在清除环境PAHs污染物中具有广阔的应用前景。在过去二十多年中, 科学家们已经从基因水平上对好氧细菌降解PAHs的机制进行了深入的研究, 其中包括PAHs降解基因的多样性、与PAHs降解有关的基因以及细菌群体PAHs遗传适应机制等。在此, 就好氧细菌对多环芳烃降解机制的研究进展进行了综述和讨论。     

Polycyclic Aromatic Hydrocarbon (PAH) Contamination in the Urban Topsoils of Shenyang,China

Polycyclic aromatic hydrocarbons (PAHs) in the surface urban soils of Shenyang in Northeastern China were investigated. The total concentration of the PAHs ranged from 0.09 to 8.35 mg kg^?1, with an average value of 1.51 ± 1.64 mg kg^?1. 3–5-ring PAHs accounted for 90% of total PAHs. The functional areas, such as the industrial regions (4.95 mg kg^?1) and main roads (1.56 mg kg^?1), as well as the administrative divisions, including the districts of Shenhe (1.49 mg kg^?1), Heping (2.08 mg kg^?1), and Tiexi (2.14 mg kg^?1), were heavily polluted by PAHs. The diagnostic ratios and principal component analysis (PCA) for PAHs indicate that the pollutants probably originated primarily from coal combustion and petroleum sources. The Nemerow composite index, used to assess environmental quality, shows that the soil samples were heavily polluted with PAHs, and although 52.8% of the soil sampling sites were safe, 47.2% of the soil sampling sites registered different grades of PAH pollution. The PAH contamination in Shenyang emphasizes the need for controlling fossil fuel combustion and traffic exhaust.     

城市污泥和化肥对水稻土种植的通菜中多环芳烃(PAHs)的影响

在水稻土上施用城市污泥和化肥盆栽通菜,应用GC／MS联机检测技术对通菜中17种多环芳烃化合物进行了分析。结果表明,各处理通菜中的∑PAHs含量在0．414-5.404mg/kg之间,依次是佛山污泥＋化肥＞广州污泥＋化肥＞化肥＞广州污泥＞佛山污泥＞空白,致癌性PAHs化合物的总含量（∑PAHscarc)在0.068-0.944mg/kg之间,绝大部分化合物在通菜中的含量大于在根系中的含量,与空白对照相比,施用城市污泥和化肥均使通菜中的∑PAHs含量明显提高,各处理通菜中的PAHs都只是以一种或几种化合物为主,主要是3,4个苯环的化合物,显示不同的分布特征,。     

新型复合生物乳化剂的性质及其在多环芳烃降解中的作用

对一株能利用多种石油烃的Em1菌株产生的生物乳化剂 ,采用柱层析方法进行分离纯化 ,其表面活性组分存在于氯仿、甲醇、浓盐酸混合物 (V V V =5∶1∶0 0 1 )的洗脱液中 ,挥发洗脱溶剂即为纯化的生物乳化剂。该生物乳化剂可使蒸馏水的表面张力由 72mN m降至 30mN m ,其临界胶团浓度 (CMC)为 75mg L。它不含糖类、蛋白、中性脂、磷酸基团和α 氨基酸 ,采用红外光谱 (IR)、气质联用 (GC MS)和核磁共振 (NMR)测定其化学组成和结构 ,表明其主要由十六烷酸、脂肪醇类、酯类和脂肪酰胺类等组成 ,这些物质的协同作用是该生物乳化剂高表面活性的关键。该生物乳化剂可明显促进菌株对多环芳烃的降解作用 ,可将降解率提高 2 0 % ,其促进降解的机制主要是提高多环芳烃在水中的溶解度 ,平均可提高约 1 0倍的溶解度     

Formation of Carbon-Carbon Bonds in the Photochemical Alkylation of Polycyclic Aromatic Hydrocarbons

The reaction of polycyclic aromatic hydrocarbons (PAHs) withalkanes was examined in the presence of ultraviolet (UV) lightunder model prebiotic Earth and interstellar medium (ISM)conditions. We observed the formation of alkylated PAHs from avariety of PAHs and alkanes, which was caused by the absorptionof UV light by the PAH molecule. Photoalkylation occurred inPAHs and alkanes in solution, in thin films in contact withsimulated ocean water, and in matrices simulating ISMconditions. Photoalkylation occurred readily, with significantproduct yields within 5 h of irradiation. Because alkanes andPAHs are presumed to be part of the organic inventory in the ISMand on the early Earth, we propose that this photoalkylation reactionis a plausible pathway for the formation of carbon-carbon bondsin both these environments.     

Distribution,Levels, and Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Singed Cattle Hide

Human beings are exposed to polycyclic aromatic hydrocarbons (PAHs) from various occupational, environmental, and dietary sources. The study was carried out in the Cape Coast Metropolis of Ghana to assess the levels of PAHs in treated and untreated cattle hide and the associated health risks thereof. Treated cattle hide (wele) is one of the most well-patronized meat products in Ghana. A total of 90, treated (n = 36), untreated (n = 36), and control (n = 18) cattle hide samples were treated and analyzed using a gas chromatography flame ionization detection (GC/FID) technique. The total PAH concentration in the treated cattle hide ranged from 5.9 μg/kg naphthalene to 719.9 μg/kg benzo[b]fluoranthene. The total PAHs in untreated hide ranged from 57.6 μg/kg naphthalene to 19840.9 μg/kg benzo[b]fluoranthene. The amount of PAHs in the control hide, however, ranged from non-detectable for many of the PAHs to 0.5 μg/kg for fluorene. The carcinogenic risk value associated with the consumption of treated hide in children ranged between 1.0 × 10^?3 and 9.4 × 10^?3 whereas that of adults ranged between 1.9 × 10^?4 and 2.1 × 10^?5. This implies that the continuous consumption of heavily burnt cattle hide may not exempt the consumers from all the possible health cases associated with PAHs.     

Evaluation of the Soil Contamination of Tangier (Morocco) by the Determination of BTEX,PCBs, and PAHs

Benzene, toluene, ethylbenzene, and xylenes (BTEX), twelve polycyclic aromatic hydrocarbons (PAHs) and seven polychlorinated biphenyls (PCBs), were selected as pollutants to evaluate the contamination of soils in the urban and industrial areas of Tangier (Morocco). PAHs and PCBs were determined by gas chromatography-mass spectrometry (GC-MS) after a microwave-assisted extraction (MAE) and gel permeation chromatography (GPC) clean-up. BTEX were directly determined by head-space GC-MS. Results obtained in this study show the presence of high levels of BTEX and PAHs in the soil near the urban waste deposit. However, the analysis of pollutants in the other sampling sites provided comprehensive evidence that soils of Tangier city are not contaminated.