Occurrence of polycyclic aromatic hydrocarbons in the estuarine sediments of the Taihu Lake and their associated toxic effects on aquatic organisms

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous toxic organic pollutants in the natural environment that are strongly associated with socioeconomic activities. Exploring the distribution, sources, and ecological toxicity of PAHs is essential to abate their pollution and biological risks. The 16 priority PAHs in different lakeside city estuarine sediments in the northern Taihu Lake in China were determined using gas chromatography-mass spectrometry. Results showed that total concentrations...     

Composition,distribution and sources of polycyclic aromatic hydrocarbons in sediments of the western harbour of alexandria,egypt

Aim and Background  Little data are available on the levels of polycyclic aromatic hydrocarbons (PAHs) in the sediments of the Mediterranean Sea Coast of Egypt in general and the Alexandria coastal zone in particular. It was therefore deemed necessary to set up a monitoring programme to determine the current concentrations of PAHs in bottom sediments, and to identify any area where high concentrations of these potential hazardous contaminants were present in the Western Harbour of Alexandria. Methods  The composition, distribution and the source of PAHs in surficial sediments of the harbour were investigated. To document the spatial PAH input, surficial sediment samples from 23 locations throughout the harbour were analysed. as]Results and Discussion The total PAH load determined in the surficial sediment samples ranged from 8 to 131150 ng g¹ dry wt, generally with most of the samples having total concentrations of PAHs greater than 5000 ng g¹ dry weight. The highest concentration of total PAHs was recorded in sediments of the inner harbour. Ratio values of specific compounds such as phenanthrene to anthracene, fluoranthrene to pyrene, methyl-phen-anthrene to phenanthrene, methyl-dibenzothiophenes to dibenzothiophenes, alkylated to non-alkylated and high molecular weight to low molecular weight PAH, were calculated to evaluate the possible source of PAH contamination in the harbour sediments. Conclusions  Two main sources of PAH in the study area have been found: pyrolytic and petrogenic. Interferences of rather petrogenic and pyrolytic PAH contaminations were noticed for most samples. The dominant sources of PAH appear to be the combustion processes through run-off, industrial and sewage discharges, and atmospheric input. The concentrations of PAHs were generally above levels expected to cause adverse biological effects. Recommendations and outlook  Information from this study and any other relevant studies should be useful in designing future strategies for environmental protection and management of the harbour.     

Trace elements and polycyclic aromatic hydrocarbons in road gully sediments from different land uses,Hong Kong

Purpose

This study investigated the concentrations of cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), zinc (Zn), and polycyclic aromatic hydrocarbons (PAHs) in sediments collected from gully pots for road drainage in Hong Kong. The presence and intensity of anthropogenic contamination of road gully sediments were assessed. Identifications of potential sources of trace elements and PAHs were performed to help understand the situation for future control of pollution to the land and aquatic environments.

Materials and methods

Gully sediment samples were collected from gully pots of 18 roads that are potentially exposed to different pollution sources in Hong Kong. The selection of roads considered different road features, adjacent land uses, and traffic volumes. Composite samples were collected for the analysis of trace elements (Cd, Cr, Cu, Pb, Ni, and Zn) and PAHs by an accredited environmental testing laboratory. Geo-accumulation index (I_geo), contamination factor (C_f), modified degree of contamination (mC_d), ecological risk factor (Er), and pollution load index (PLI) were used to assess the level of ecological risk of trace element contamination. Positive matrix factorization (PMF) and PAH diagnostic ratios were applied to identify the sources of trace elements and PAHs.

Results and discussion

Elevated trace element concentrations were commonly found in gully sediments. The concentrations of Zn (267–3700 mg kg^?1) were the highest compared to the other trace elements. Noticeable high concentrations of Cu (27–1020 mg kg^?1), Pb (21–332 mg kg^?1), and Cr (14–439 mg kg^?1) were found in all samples. The PAH contents were moderate to high (0.6 to 24.7 mg kg^?1). Commercial/industrial emissions and road features that cause frequent acceleration-deceleration and turning events showed important influences on the contaminant levels. Strong correlations between the concentrations of Cd, Cr, Pb, and Zn were identified, implying that these trace elements are likely from common sources. The contamination assessment indices reflect significant sediment pollution. The ecological risk ranges from the considerable/moderate-risk class to over the high-risk class.

Conclusions

The collected gully sediments are identified as highly contaminated and need to be isolated from the environment upon final disposal. Through the comprehensive analysis of the collected data, this study provides a detailed insight into the contaminant levels of road gully sediments and potential sources of contamination. Disposal of gully sediments and potential impacts due to release of contaminants into the downstream aquatic environment during rainstorm events should receive attention and need further investigation.

     

Extraction of polycyclic aromatic hydrocarbons from spiked soil

A homogenization method was evaluated for extracting polycyclic aromatic hydrocarbons (PAHs) from soils. Fifteen PAHs were spiked and recovered from 2 soils at concentrations ranging from 1 to 1000 micrograms/g, using the homogenization method and a Soxhlet extraction method. Each extraction method performed well in removing the 15 PAHs from both soils over a broad range of concentrations. In general, Soxhlet extraction yielded slightly but significantly (P less than 0.05) higher recoveries than did the homogenization method. The homogenization method, however, was easy to use, and the extraction step turnaround time was less than 15 min/sample. The method should be suitable for other applications requiring the extraction of hydrophobic organic compounds from soils.     

湛江市区不同利用类型土壤的PAHs污染特征和来源

首次对湛江市表层土壤PAHs污染进行研究,并根据利用类型对其进行分类讨论。虽然湛江市的环境质量在全国名列前茅,但研究显示随着重化工业的快速发展,湛江市土壤已受到一定程度的PAHs污染,∑PAHs的平均含量达491.1ng.g-1,低于珠三角的发达城市,而高于中等城市,特别是某些工业区污染严重,超过荷兰相关标准;与其它城市一样,湛江市土壤PAHs的组分构成以4环和5环为主,占∑PAHs的65.1%。∑PAHs的变化趋势为旧厂址>市区工业区>交通>郊区工业区>休闲>农业,市区>郊区;3环组分比重随市中心距离的增大而增加,4环和5环则相反,6环差异较小。农业和郊区工业高比重的3环组分可能与市区石油源PAHs的大气输送有关。已搬迁工厂高含量∑PAHs表明PAHs在土壤的积累影响是长期的,而休闲区178.7 ng.g-1的∑PAHs则表明解决PAHs的污染问题必须解决污染源问题。利用4种PAHs比值判断湛江市土壤PAHs的来源主要是石油源、石化燃烧和煤、柴等生物燃烧源的混合源,与湛江市社会经济情况相符。     

Degradation of selected polycyclic aromatic hydrocarbons in coastal sediments: Importance of microbes and polychaete worms

Rates of degradation of polycyclic aromatic hydrocarbons (PAH) were examined after addition of crude oil enriched with anthracene, fluoranthene, benz(a)anthracene, and benzo(a)pyrene to coastal sediments in a laboratory (20°) flowing seawater system. Three types of sediment (fine sand, medium sand, and marsh sediment) with and without the benthic polychaete worm, Capitella capitata, were used. After extraction from the sediment, PAH concentrations were measured by liquid chromatography with fluorescent detection. Microbial degradation was studied by incubating sediments with radioactive PAH and measuring subsequent production of ¹⁴C0₂. Concentrations of the four PAH decreased significantly with time in fine and medium sized sands. PAH levels also decreased in marsh sediment but trends were not significant (P < 0.05). C. capitata stimulated PAH degradation. Microbial degradation was more rapid in upper surfaces than in lower layers of the sediments.     

Determination of polycyclic aromatic hydrocarbons in fumes from fried chicken legs

The amount and variety of polycyclic aromatic hydrocarbons (PAHs) in fumes during frying of chicken legs in edible oils were determined using a modified smoke collection device and a GC-MS technique. Chicken legs were fried in soybean oil, canola oil, or sunflower oil at 163 degrees C for 1-4 h. Results showed that most smoke (99%) was collected in the condensation apparatus, whereas the rest (1%) was adsorbed onto adsorption wool. A large proportion of PAHs in the smoke were detected in adsorption wool, whereas a small portion was found in the condensation apparatus. Canola oil generated the largest content (500.9 g for a frying time of 4 h) of smoke, followed by soybean oil, and sunflower oil. A similar trend was observed for PAH formation in fumes, with the exception that soybean oil produced a higher level than canola oil.     

Availability of polycyclic aromatic hydrocarbons in aging soils

Purpose  

The soil contamination by hydrophobic organic contaminants (HOCs), such as polycyclic aromatic hydrocarbons (PAHs), poses great threats to human health and ecological security and attracts worldwide concerns. The total HOC concentrations overestimate its available fraction to the soil biota. Increased understanding of the availabilities of PAHs in soil environment will have considerable benefits for their risk assessment and be very instructive to food safety and remediation strategies in contaminated sites. However, the availability of PAHs in aging soils and particularly the correlations of the availabilities with their forms in soils have yet to be elucidated. In this work, the availabilities of PAHs in aging soils were evaluated using a sequential mild extraction technique.     

滇池沉积物铵态氮的时空变化特征研究

沉积物在湖泊氮、磷循环和水体富营养化过程中起着重要作用。本研究应用GPS定位技术,于2003年5月至2004年5月,对滇池海埂、斗南、罗家村、新街、昆阳等5个代表性样点沉积物铵态氮含量进行为期1 a的动态监测,全面分析了滇池不同区域、不同层次、不同时期沉积物铵态氮的动态变化特征。结果表明,滇池沉积物铵态氮平均含量为74.57 mg kg-1,全湖沉积物铵态氮平均含量年变化范围是45.55~170.1mg kg-1。沉积物铵态氮因季节变化其变化幅度很大,各区域沉积物铵态氮含量总体趋势夏季高、冬季低,但不同位点变化高峰和趋势不同。不同层次沉积物铵态氮含量变化随季节而变化,夏季为表层(0~5 cm)中层(5~10 cm)底层(10~20 cm),冬季为中层表层和底层。表层、中层、底层沉积物铵态氮含量的变化范围分别为18.71~172.9mg kg-1、29.55~192.2mg kg-1、19.93~123.8mg kg-1。各区域沉积物铵态氮平均含量以罗家村最高,斗南最低。沉积物铵态氮与水体铵态氮、水体pH呈显著正相关,与沉积物有效磷呈显著负相关,暗示了沉积物铵态氮是水体氮的源和库,并影响着沉积物中磷的释放。     

Sedimentary records of historical occurrence and sources of 21 organochlorine pesticides in Lake Taihu,China

Journal of Soils and Sediments - Sediments are natural archives to record the occurrence and sources of organochlorine pesticides (OCPs). Most previous studies on historical occurrence and sources...     

The history of airborne polycyclic aromatic hydrocarbons (PAH) and perylene as recorded in dated lake sediments

Polycyclic aromatic hydrocarbons (PAH) were analyzed in sediment cores from five small forest lakes in Finland. The catchments of the lakes were undisturbed (2 lakes) or only very slightly disturbed by human activity (3 lakes). None of the lakes had runoff delivery of PAH from their shores. Lead-210 dating of four lakes enabled the calculation of individual PAH fluxes over the past 100 to 150 yr. The sedimentary distribution of abiotic PAH in these lakes appears to be indicative of the development of combustion-generated energy production in Finland and adjacent countries. This development is reflected in an overall increase in sedimentary PAH since about 1850. After World War II the rate of accumulation of PAH continues to increase. The large variation between the PAH fluxes of different lakes indicates different trapping efficiencies and/or different preservation of the PAH compounds due to limnological differences between the lakes.     

Determination of monocyclic and polycyclic aromatic hydrocarbons in fish tissue

An analytical method is presented in which fish tissue is analyzed for neutral monocyclic and polycyclic aromatic hydrocarbons (AHs) and aromatic sulfur heterocycles (ASHs) by capillary column gas chromatography (CGC) with photoionization detection. The sample enrichment procedure includes saponification with aqueous KOH, acidification of the digestates, and extraction of the aromatic compounds into cyclopentane-dichloromethane. Adsorption chromatography on tandem segments of potassium silicate and silica gel removes 99% of the coextracted lipid. Final enrichment by gel permeation chromatography eliminates residual biogenic material and potentially interfering alkanes. Relatively volatile monoaromatics are included among the analytes by virtue of the efficiency of the complementary enrichment steps, the use of small quantities of only low-boiling solvents, and the selectivity of the detector. Most targeted compounds (AHs ranging in size from C3-alkylbenzenes through benzo[g,h,l]perylene and ASHs within the same size range) can be determined in 5 g (wet weight) samples of fish tissue at concentrations as low as 20 ng/g. Comparisons are made of recoveries of selected AHs under ordinary and gold fluorescent lighting conditions.     

The source,composition and flux of polycyclic aromatic hydrocarbons in sediments of the river Derwent,Derbyshire, U.K.

To observe the rate of degradation of refuse and to assess the rate of pollution below a landfill, the concentration of total C, volatile content, COD, humified C, humic acids (HA) and fulvic acids (FA) in solid waste samples were analyzed. The samples were obtained by field drilling at increasing depths. The volatile content, organic C and COD decreased with the depth of the refuse and their variability was related to the decomposition processes of refuse. High coefficient of determination (r ²) values indicated a positive relationship between the results of total C, humified C, HA and FA. The concentration of organic substances in the soil below the landfill is lower than in the soil outside the landfill site.     

Distribution of polycyclic aromatic hydrocarbons in the soil-plant system

The content and composition of the polycyclic aromatic hydrocarbons (PAHs) in the conjugated systems of [arable soil]-[above-ground plant organs] in background (reference) and contaminated regions were studied. The coefficients of the biological uptake of PAHs by plants (K _bPAH) were determined for different PAH concentrations in the soil. Correlations of the PAH accumulation rate in plants with the physicochemical properties of the PAHs—the solubility, hydrophobicity, volatility, and chemical activity (polarizability and ionization potential)—were revealed. The high accuracy, sensitivity, and information value of the standardized parameters K _b were shown (with K _bPAH as an example) for the quantitative study of the accumulation mechanisms of substances by plants compared to the average arithmetic values of their concentrations in the plants.     

Assessment of polycyclic aromatic hydrocarbons in biochar and biochar-amended agricultural soil from Southern Spain

Journal of Soils and Sediments - The goal of this study was to determine if the application of four biochars produced from different feedstock leads to soil contamination with the 16 US...     

Liquid chromatographic determination of polycyclic aromatic hydrocarbons in fish and shellfish

A simple and accurate analytical method for determination of polycyclic aromatic hydrocarbons (PAHs) in fish and shellfish is presented, which is considered to be useful for routine analyses and for screening purposes. The procedure involves alkaline digestion, extraction with n-hexane, silica gel column chromatography, and liquid chromatographic (LC) determination with fluorometric detection. During development of the analytical method for determination of PAHs, it was found that benzo[a]pyrene, a representative PAH, was decomposed easily by the analytical procedure, and this tendency was investigated for the experimental conditions used. Benzo[a]pyrene was decomposed by the coexistence of alkaline conditions, light, and oxygen; by peroxides in aged ethyl ether; and by oxygen when absorbed on silica gel. Thus, to obtain good recoveries and precise analytical results, these decomposition conditions must be avoided. The following precautions are recommended: protection from light through all analytical steps; addition of Na2S to alkaline digestion mixture as an antioxidant; complete removal of peroxides from ethyl ether just before use; quick column chromatography on silica gel; and prevention of air from contact with adsorbent. When this simple method was applied to fish and shellfish samples, very good recoveries of PAHs from fortified fish samples were obtained, and no serious interferences were observed in fish and shellfish extracts.     

Formation of polycyclic aromatic hydrocarbons in northern and middle taiga soils

An integrated study of the qualitative and quantitative composition of polycyclic aromatic hydrocarbons (PAHs) in the atmospheric precipitation-soil-lysimetric water system was performed using high performance liquid chromatography. It was shown that the accumulation of low-molecular PAHs (phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, and chrysene) in soils is due to the transformation of organic matter and the regional transport and deposition of PAHs with atmospheric precipitation on the underlying surface. High-molecular polyarenes (benz[b]fluoranthene, benz[k]fluoranthene, benz[a]pyrene, dibenz[a,h]anthracene, benzo[ghi]perylene, and indeno[1,2,3-cd]pyrene) mainly result from the decomposition of soil organic matter.     

A review of atmospheric polycyclic aromatic hydrocarbons: Sources,fate and behavior

A review has been written to assess the sources, fate and behavior of polycyclic aromatic hydrocarbons (PAH) in the atmosphere. PAH are formed mainly by anthropogenic processes, especially the combustion of organic fuels. PAH concentration in air will reflect the location of source emitters, with high concentrations corresponding with urban and industrial areas. PAH are however ubiquitous contaminants of the environment having been detected in remote areas of the world. This is thought to be due to long term transport in the atmosphere. PAH can also be subjected to chemical and/ or photochemical change whilst resident in the atmosphere prior to their removal by either wet or dry deposition.