Spatial and temporal distribution of polycyclic aromatic hydrocarbons (PAHs) in sediments from Daya Bay, South China

The spatial and temporal distribution of polycyclic aromatic hydrocarbons (PAHs) has been investigated in Daya Bay, China. The total concentration of the 16 USEPA priority PAHs in surface sediments ranged from 42.5 to 158.2 ng/g dry weight with a mean concentration of 126.2 ng/g. The spatial distribution of PAHs was site-specific and combustion processes were the main source of PAHs in the surface sediments. Total 16 priority PAH concentration in the cores 8 and 10 ranged from 77.4 to 305.7 ng/g and from 118.1 to 319.9 ng/g respectively. The variation of the 16 PAH concentrations in both cores followed the economic development in China very well and was also influenced by input pathways. Some of the PAHs were petrogenic in core 8 while pyrolytic source was dominant in core 10. In addition, pyrolytic PAHs in both cores were mainly from the coal and/or grass and wood combustion.     

A novel approach for characterization of polycyclic aromatic hydrocarbon (PAH) pollution patterns in sediments from Guanabara Bay, Rio de Janeiro, Brazil

A novel multivariate method based on principal component analysis of pre-processed sections of chromatograms is used to characterize the complex PAH pollution patterns in sediments from Guanabara Bay, Brazil. Five distinct sources of 3- to 6-ring PAHs could be revealed. The harbour is the most contaminated site in the bay, its plume stretches in a South West to North East direction and the chemical profile indicates mainly pyrogenic sources mixed with a fraction of high-molecular-weight petrogenic PAHs. Rio São João de Meriti is the second largest source of PAHs, and introduces mainly a fraction of low-molecular-weight petrogenic PAHs from the western region of Rio de Janeiro. The sites close to the ruptured pipeline at the Duque de Caxias Refinery show a distinctive pollution pattern indicating a heavy petroleum fraction. The method also led to the identification of new potential indicator ratios also involving coeluting peaks (e.g., triphenylene and chrysene).     

Enrichment of polycyclic aromatic hydrocarbons (PAHs) in mariculture sediments of Hong Kong

Surface and core sediments collected from six fish farms in Hong Kong and from reference sites were investigated for the enrichment and sources of polycyclic aromatic hydrocarbons (PAHs). Moderately high ∑PAH₁₆ levels (123-947 ng g⁻¹, mean: 450 ng g⁻¹) were found in the surface aquaculture sediments. In comparison with the sediments from the reference sites, the average enrichment percentage of total organic carbon (TOC) and PAHs in surface sediments were 21.4 and 43.8%, respectively, and in the core sediments, 24.6 and 73.7%, respectively. Mathematical source apportionment analyses (i.e. isomer ratios, hierarchical cluster analysis, principal components analysis with multiple linear regression analysis) suggested a higher percentage of petrogenic sources in aquaculture sediments. The fish feeds might be the main source of the enriched PAHs in the aquaculture sediments. To our knowledge, this is the first study showing that PAHs in aquaculture sediments could be attributed to human aquaculture activities.     

Assessment of honey contamination with polycyclic aromatic hydrocarbons

The aim of this study was to assess honey contamination by polycyclic aromatic hydrocarbons. Six species of honey were examined, as well as rape blossom and soil from villages P?czerzyno and Przybys?aw in West Pomerania, Poland. The instrumental analysis was performed using a HP 6890 gas chromatograph coupled to a HP 5973 mass spectrometer with selected ion monitoring (SIM). Quantification was done by gas chromatography-mass spectrometry (GC-MS) using perdeuterated internal standards. Both soil samples showed high levels of all 23 PAHs, whereas honey contained mostly non-carcinogenic PAHs of low molecular weight. The most contaminated honey from P?czerzyno contained 0.24 μg kg-1 benzo[a]pyrene. Moreover, despite low contamination of honey, a positive correlation was found between PAH content in honey, blossom and soil.     

Heavy metal contamination in surface sediments of Yangtze River intertidal zone: An assessment from different indexes

Surface sediments (0-5 cm) from 59 stations within the Yangtze River intertidal zone (YRIZ) were sampled for metal contamination analysis in April and August 2005. The concentrations ranged (in mg kg⁻¹ dry weight): Al, 40,803-97,213; Fe, 20,538-49,627; Cd, 0.12-0.75; Cr, 36.9-173; Cu, 6.87-49.7; Mn, 413-1,112; Ni, 17.6-48.0; Pb, 18.3-44.1; and Zn, 47.6-154; respectively. Among the 59 sampling stations, enrichment factors (EF) indicate enrichment of Cd (52 stations), Cr (54 stations), Cu (5 stations), Ni (26 stations), Pb (5 stations) and Zn (5 stations). Geoaccumulation indexes (I_geo) also suggest individual metal contamination in localized areas. This study indicates that Cd, Cr and Ni enrichment in the YRIZ sediment is widespread whereas Cu, Mn, Pb and Zn enrichment is localized or nonexistent. Factor and cluster analyses indicate that Cd is associated with total organic carbon whereas Cu, Cr, Ni, Pb and Zn have a close association with Mn.     

Polycyclic aromatic hydrocarbons and their hydroxylated metabolites in fish bile and sediments from coastal waters of Colombia

Sediments and fish bile collected from the Atlantic coastal waters of Colombia were analyzed for 16 parent polycyclic aromatic hydrocarbons (PAHs), and 23 hydroxylated PAHs (OH-PAHs), respectively. Sediments contained overall mean SigmaPAH concentrations of 2090, 234 and 170 ng/g, dry wt, for Cartagena Bay, Caimanera Marsh, and Totumo Marsh, respectively. The mean concentration of the summed OH-PAHs in fish bile was 1250, 180 and 64.1 ng/g bile wt for Cartagena Bay, Caimanera Marsh, and Totumo Marsh, respectively. The results suggest that Cartagena Bay is heavily polluted by PAHs, and that exposure to high concentrations of PAHs together with other factors could contribute to the decreased health of fish living in this ecosystem. This is one of the first studies to describe the analysis of 23 individual OH-PAHs in fish bile, using authentic standards.     

Polycyclic aromatic hydrocarbon (PAH) contamination of surface sediments and oysters from the inter-tidal areas of Dar es Salaam, Tanzania

Surface sediment and oyster samples from the inter-tidal areas of Dar es Salaam were analyzed for 23 polycyclic aromatic hydrocarbons (PAHs) including the 16 compounds prioritized by US-EPA using GC/MS. The total concentration of PAHs in the sediment ranged from 78 to 25,000 ng/g dry weight, while oyster concentrations ranged from 170 to 650 ng/g dry weight. Hazards due to sediment contamination were assessed using Equilibrium Partitioning Sediment Benchmarks and Threshold Effect Levels. Diagnostic indices and principle component analysis were used to identify possible sources. Interestingly, no correlation between sediment and oyster concentrations at the same sites was found. This is supported by completely different contamination patterns, suggesting different sources for both matrices. Hazard assessment revealed possible effects at six out of eight sites on the benthic communities and oyster populations. The contribution of PAH intake via oyster consumption to carcinogenic risks in humans seems to be low.     

Source diagnostics of polycyclic aromatic hydrocarbons in urban road runoff, dust, rain and canopy throughfall

Diagnostic ratios and multivariate analysis were utilized to apportion polycyclic aromatic hydrocarbon (PAH) sources for road runoff, road dust, rain and canopy throughfall based on samples collected in an urban area of Beijing, China. Three sampling sites representing vehicle lane, bicycle lane and branch road were selected. For road runoff and road dust, vehicular emission and coal combustion were identified as major sources, and the source contributions varied among the sampling sites. For rain, three principal components were apportioned representing coal/oil combustion (54%), vehicular emission (34%) and coking (12%). For canopy throughfall, vehicular emission (56%), coal combustion (30%) and oil combustion (14%) were identified as major sources. Overall, the PAH's source for road runoff mainly reflected that for road dust. Despite site-specific sources, the findings at the study area provided a general picture of PAHs sources for the road runoff system in urban area of Beijing.     

Studies on polycyclic aromatic hydrocarbons in two sediment cores from the huaxi reservoir,china: Assessment of levels,sources, and ecological risk

This study investigated the levels, sources and ecological risks of 16 polycyclic aromatic hydrocarbons (PAHs) in two sediment cores that were collected along the Huaxi Reservoir. The spatial distributions and residue levels of the 16 priority PAHs in the sediments from the Huaxi Reservoir were analyzed for their potential ecological risk, source apportionment and contribution to the total PAH residue. The concentration level of the total PAHs (TPAHs) was in the range 1805 ng·g^?1 to 20023 ng·g^?1 based on dry weight, and the content of PAHs in the Huaxi Reservoir exhibited a gradual upward trend. The PAH congener ratios fluoranthene/(fluoranthene + pyrene) and indeno[1, 2, 3-cd]pyrene/(indeno[1, 2, 3-cd]pyrene + benzo[g, h, i]perylene) were used to identify the source. The main source of the low molecular weight PAHs was wood and coal combustion, whereas the high molecular weight PAHs were primarily from petroleum combustion sources. The results of an ecological risk assessment demonstrated that ACE poses a potential ecological risk, while FLU, NAP, ANT, BaP, DBA, PHEN and PYR can have serious ecological risks.     

Characterization of extractable and non-extractable polycyclic aromatic hydrocarbons in soils and sediments from the Pearl River Delta, China

Formation of bound residues of pollutants in soils and sediments is an important process to control the fate of pollutants in the environment. The most of bound residue is not solvent extractable. In this paper, we measured both extractable and non-extractable polycyclic aromatic hydrocarbons (PAHs) in different organic matter fractions of samples from the Pearl River Delta, China. Non-extractable PAHs concentration was 234.45-1424.57 μg/kg and accounted for 33.78-57.44% of total PAHs. 2-3 Ring PAHs were the dominant species and differed in concentration substantially between the samples. The atomic ratio of PAHs over organic-C in the fractions ordered as solvent soluble organic matter > humin > humic acids, matching the content of aliphatic moieties in the fractions of organic matter. The ratio of extractable and non-extractable PAHs may relate to the aging process of PAHs in soil and sediment.     

Concentrations, sources and spatial distribution of polycyclic aromatic hydrocarbons in soils from Beijing, Tianjin and surrounding areas, North China

The concentrations, profiles, sources and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) were determined in 40 surface soil samples collected from Beijing, Tianjin and surrounding areas, North China in 2007, and all sampling sites were far from industrial areas, roadsides and other pollution sources, and across a range of soil types in remote, rural villages and urban areas. The total concentrations of 16 PAHs ranged from 31.6 to 1475.0 ng/g, with an arithmetic average of 336.4 ng/g. The highest PAH concentrations were measured in urban soils, followed by rural village soils and soils from remote locations. The remote-rural village-urban PAH concentration gradient was related to population density, gross domestic product (GDP), long-range atmospheric transport and different types of land use. In addition, the PAH concentration was well correlated with the total organic carbon (TOC) concentration of the soil. The PAH profile suggested that coal combustion and biomass burning were primary PAH sources.     

Impact of soil organic matter on the distribution of polycyclic aromatic hydrocarbons (PAHs) in soils

The knowledge on the distribution of hydrophobic organic contaminants in soils can provide better understanding for their fate in the environment. In the present study, the n-butanol extraction and humic fractionation were applied to investigate the impact of SOM on the distribution of polycyclic aromatic hydrocarbons (PAHs). The results indicated that 80.5%-94.8% of the target PAHs could be extracted by n-butanol and 63.1%-94.6% of PAHs were associated with fulvic acid (FA). Concentrations of un-extracted PAHs increased significantly with the increasing soil organic matter (SOM), however, such an association was absent for the extractable fractions. The results suggested that the sequestration played a critical role in the accumulation of PAHs in soils. SOM also retarded the diffusion of PAHs into the humin fractions. It implied that sequestration in SOM was critical for PAH distribution in soils, while the properties of PAH compounds also had great influences.     

LAS对土壤中多环芳烃吸附行为的影响

研究了阴离子表面活性剂十二烷基苯磺酸钠（LAS）对PAHs在士壤中吸附行为的影响。结果表明，LAS改变了PAHs在土水体系中的吸附／解吸平衡，吸附态LAS可提高土壤对PAHs的吸附，而溶解态LAS则增加了PAHs的表观溶解度，这2种作用的综合结果改变了PAHs在土水体系中的吸附系数。凶此，文中用表观吸附系数来描述PAHs在土壤-水-LAS体系中的综合吸附行为。     

LAS对土壤中多环芳烃吸附行为的影响

研究了阴离子表面活性剂十二烷基苯磺酸钠(LAS)对PAHs在土壤中吸附行为的影响.结果表明,LAS改变了PAHs在土水体系中的吸附/解吸平衡,吸附态LAS可提高土壤对PAHs的吸附,而溶解态LAS则增加了PAHs的表观溶解度,这2种作用的综合结果改变了PAHs在土水体系中的吸附系数.因此,文中用表观吸附系数来描述PAHs在土壤-水-LAS体系中的综合吸附行为.     

Oxygen-containing polycyclic aromatic hydrocarbons (OPAHs) in urban soils of Bratislava, Slovakia: patterns, relation to PAHs and vertical distribution

We determined concentrations, sources, and vertical distribution of OPAHs and PAHs in soils of Bratislava. The ∑14 OPAHs concentrations in surface soil horizons ranged 88-2692 ng g⁻¹ and those of ∑34 PAHs 842-244,870 ng g⁻¹. The concentrations of the ∑9 carbonyl-OPAHs (r = 0.92, p = 0.0001) and the ∑5 hydroxyl-OPAHs (r = 0.73, p = 0.01) correlated significantly with ∑34 PAHs concentrations indicating the close association of OPAHs with parent-PAHs. OPAHs were quantitatively dominated by 9-fluorenone, 9,10-anthraquinone, 1-indanone and benzo[a]anthracene-7,12-dione. At several sites, individual carbonyl-OPAHs had higher concentrations than parent PAHs. The concentration ratios of several OPAHs to their parent-PAHs and contribution of the more soluble OPAHs (1-indanone and 9-fluorenone) to ∑14 OPAHs concentrations increased with soil depth suggesting that OPAHs were faster vertically transported in the study soils by leaching than PAHs which was supported by the correlation of subsoil:surface soil ratios of OPAH concentrations at several sites with K_OW.     

Influence of physical factors on polycyclic aromatic hydrocarbons (PAHs) content in vegetable oils

The aim of this study was to test the hypothesis about physical factors causing a significant decrease of polycyclic aromatic hydrocarbon (PAH) compounds in foodstuffs. For this purpose, extraction of 16 PAHs (prioritised by EPA) from selected foodstuffs (rapeseed oil and sunflower oil) was carried out. The changes in PAH content in oils exposed to selected physical factors (UV radiation, temperature and time) were observed. Oils under study were exposed to two types of UV radiation: direct and indirect (through a glass plate). In both experiments, a reduction of 16 PAHs in oils was recorded but in the latter a PAH reduction was not as high. In another experiment, the temperature of oils was raised to 40, 100 and 200°C. As a result, the content of PAHs has decreased significantly. In both cases, exposure to UV radiation and high temperature resulted in the reduction of PAHs, it was strongly correlated with the duration of experiments. The results showed relatively low contamination of oil with PAHs. Only for rapeseed oil, the level of said contamination was substantially higher than laid down limits.     

Impact of polycyclic aromatic hydrocarbon emissions from medical waste incinerators on the urban atmosphere

In this study, polycyclic aromatic hydrocarbon (PAH) emissions from two batch-type medical waste incinerators (MWIs), one with a mechanical grate and the other with a fixed grate, both operated by a medical center, were assessed. Both MWIs shared the same air-pollution control devices (APCDs), with an electrostatic precipitator and a wet scrubber installed in series. Results show that when APCDs were used, total PAHs and total benzo[a]pyrene equivalent (total BaP(eq)) emission concentrations of both MWIs were reduced from 2220 to 1870 microg/m3 and 50 to 12.4 microg/m3, respectively. We used the Industrial Source Complex Short Term model (ISCST) to estimate the ground-level concentrations of the residential area and the traffic intersection located at the downwind side of the two MWIs. For the traffic intersection, we found both total PAHs and total BaP(eq) transported from MWIs to both studied areas were not significant. For the residential area, similar results were found when APCDs were used in MWIs. When APCDs were not included, we found that total PAHs transported from MWIs accounted for < 12%, but total BaP(eq) accounted for > 90%, of the on-site measured concentrations. These results suggest that the use of proper APCDs during incineration would significantly reduce the carcinogenic potencies associated with PAH emissions from MWIs to the residential area.     

降解菌对堆肥中多环芳烃降解作用的研究

通过在堆肥中加入经过驯化的降解菌这种土壤有机污染生物修复技术 ,对堆肥中多环芳烃的浓度变化进行监测 ,从而了解降解菌对堆肥中多环芳烃的降解作用。实验结果表明 ,降解菌的加入能明显地提高多环芳烃的降解率 ,本次实验中 ,菲、芴的去除率提高了 2 5 %左右 ,芘的去除率提高了约 4 5 %。     

Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments of rivers and an estuary in Shanghai, China

Concentrations, spatial distribution and sources of 17 polycyclic aromatic hydrocarbons (PAHs) and methylnaphthalene were investigated in surface sediments of rivers and an estuary in Shanghai, China. Total PAH concentrations, excluding perylene, ranged from 107 to 1707 ng/g-dw. Sedimentary PAH concentrations of the Huangpu River were higher than those of the Yangtze Estuary. The concentration of the Suzhou River was close to the average concentration of the Huangpu River. PAHs source analysis suggested that, in the Yangtze Estuary, PAHs at locations far away from cities were mainly from petrogenic sources. At other locations, both petrogenic and pyrogenic inputs were significant. In the Huangpu and Suzhou Rivers, pyrogenic input outweighed other sources. The pyrogenic PAHs in the upper reaches of the Huangpu River were mainly from the incomplete combustion of grass, wood and coal, and those in the middle and lower reaches were from vehicle and vessel exhaust.     

Assessing contamination of smoked sprats (Sprattus sprattus) with polycyclic aromatic hydrocarbons (PAHs) and changes in its level during storage in various types of packaging

The analysis of material used in this study demonstrated that the amount of polycyclic aromatic hydrocarbons (PAHs) in smoked sprats varies from the level below the lowest detection limit in muscles up to 9.99 µg kg^?1 of benzo[a]pyrene (BaP) in fish skin. Such a high level of PAHs in skin was reported only in one of six batches of sprats, while mean BaP level was at 1.69 µg kg^?1. Regardless such a high BaP level in skin, its concentration in muscles did not exceed the maximum acceptable level. The study objective was to assess to what extent packaging materials adsorb PAH compounds from food. Changes in the PAH levels were monitored in fish during their storage in packages made of various materials. The storage time was from 0 to 168 hours. The obtained results varied considerably, therefore their scatter did not allow to confirm unequivocally the preliminary hypothesis about the reduction of PAHs due to their migration to packaging material. However, analysis of the packaging used in this study demonstrated a significant increase in the level of total 16 PAHs. When high-density polyethylene (HDPE) packaging was analysed, a six-fold increase in the total 16 PAHs was observed comparing to the blank sample.