Polycyclic Aromatic Hydrocarbons In Surface Water Research Articles

Fate of polycyclic aromatic hydrocarbons from the North Pacific to the Arctic: Field measurements and fugacity model simulation

Polycyclic aromatic hydrocarbons (PAHs) have accumulated ubiquitously inArctic environments, where re-volatilization of certain organic pollutants as a result of climate change has been observed. To investigate the fate of semivolatile organic compounds in the Arctic, dissolved PAHs in the surface seawaters from the temperate Pacific Ocean to the Arctic Ocean, as well as a water column in the Arctic Ocean, were collected during the 4th Chinese National Arctic Research Expedition in summer 2010. The total concentrations of seven dissolved PAHs in surface water ranged from 1.0 to 5.1 ng L−1, decreasing with increasing latitude. The vertical profile of PAHs in the Arctic Ocean was generally characteristic of surface enrichment and depth depletion, which emphasized the role of vertical water stratification and particle settling processes. A level III fugacity model was developed in the Bering Sea under steady state assumption. Model results quantitatively simulated the transfer processes and fate of PAHs in the air and water compartments, and highlighted a summer air-to-sea flux of PAHs in the Bering Sea, which meant that the ocean served as a sink for PAHs, at least in summer. Acenaphthylene and acenaphthene reached equilibrium in air-water diffusive exchange, and any perturbation, such as a rise in temperature, might lead to disequilibrium and remobilize these compounds from their Arctic reservoirs.

New protocol based on high-volume sampling followed by DLLME-GC-IT/MS for determining PAHs at ultra-trace levels in surface water samples

Polycyclic Aromatic Hydrocarbons (PAHs), ubiquitous compounds coming from incomplete combustion processes, are very toxic species and can cause serious effects on the human health. At authors' knowledge, studies on PAHs levels in surface waters are scarce: the main problem regards the analytical implications due to analyzing such compounds at very low levels. This paper would like to present a new extraction protocol based on Dispersive Liquid-Liquid MicroExtraction (DLLME) procedure followed by GC-IT/MS for simultaneous determination of nine PAHs in surface water. Iso-octane is used as extraction solvent whereas no dispersive solvent is involved. An important issue regarded the procedure to obtain the emulsion without dispersive solvent but using ultrasounds; the other important novelty of this method of extraction regards the enrichment factors, that were demonstrated to be significantly high (up to 100,000). Methodological parameters such as the volume of surface water sample, the extraction solvent and relative volume, the time required for breaking emulsion and the salting-out effect have been investigated. Under the optimum experimental conditions (1L-volume of surface water sample, 300μL of isooctane as extraction solvent, 2min-ultrasound for the emulsion and 10minutes-agitation for breaking the emulsion, nitrogen stream for concentrating up to 10μL, analysis by GC-IT/MS) the method provides very good correlation coefficients (R2>0.99) in the range investigated, LODs and LOQs able to analyze such compounds in any water matrix (0.001–0.009pgμL−1 and 0.003–0.022pgμL−1, respectively), recoveries ranging 97–108%, inter- and intra-day precisions below 6.0% and 8.2%, respectively, for all PAHs. A comparison with other methods reported in literature demonstrates the reliability of such easy, cost-effective and reproducible methods. Finally, applications to nine different water samples are reported and discussed.

Seasonal Pollution Characteristics and Source Identification of Polycyclic Aromatic Hydrocarbons and Organochlorine Pesticides in Surface Water of Baiyangdian Lake

Seasonal variations of 17 polycyclic aromatic hydrocarbons(PAHs) and 15 persistent organochlorine pesticides(OCPs) were analyzed during spring and summer in surface water from 12 sampling sites of Baiyangdian lake to elucidate their seasonal pollution characteristics and sources. The results showed that total concentrations of PAHs in surface water of Baiyangdian lake ranged from 35.38 to 88.06 ng·L-1(46.57 ng·L-1 in average) in spring and 25.64 to 301.41 ng·L-1(76.23 ng·L-1 in average) in summer, respectively, and total concentrations of OCPs ranged from 0.69 to 4.50 ng·L-1(1.77 ng·L-1 in average) in spring and 0.11 to 3.20 ng·L-1(0.90 ng·L-1 in average) in summer, respectively. Seasonal pollution characteristics of PAHs in surface water during two different seasons showed that the total concentration of PAHs was much higher in summer than in spring at three sampling sites of Baiyangdian lake including Qiantang, Guancheng and Anxin bridge, and the level of PAHs in spring was much higher than that in summer at the other nine sites. While seasonal pollution characteristics of OCPs showed that the total concentration of OCPs was much higher in summer than in spring in samples of Guancheng sites, and the level of OCPs in spring was slightly higher than that in summer in the rest of samples. From the perspective of spatial and temporal variations in the composition patterns of PAHs and OCPs in surface water of Baiyangdian lake, PAHs were predominated by 3-ring PAHs with 45.92% and 61.36%(52.60% in average) of total PAHs in spring, while in summer Nap was the chief component of 2-ring PAHs in three sampling sites including Qiantang, Guancheng and Anxin bridge with 84.91%, 91.04% and 78.10% of the total, respectively, and 3-ring PAHs were primary pollutants in the other nine sites with 37.14% to 53.90%(48.94% in average) of the total. Residues of HCHs and DDTs were detected in different degrees and β-HCH was the main pollutant at all sampling sites with 29.94% and 100%(59.87% in average) of total HCHs in spring, while β-HCH was the predominant compounds at five sampling sites with 57.55% and 80.23%(61.98% in average) in summer and α-HCHs and δ-HCH were abundant at other sampling sites. Source analysis based on isomer ratios indicated that the main source of PAHs in Baiyangdian lake originated from combustion sources, and additional sources for several sampling sites could be petroleum processes. Ratios of HCH isomers and DDT congeners confirmed that environmental historical residues and long range atmospheric transport were the major sources of OCPs contamination in the study area. Compared with the water quality standard of China and other countries or organizations, concentrations of PAHs and OCPs in surface water of Baiyangdian lake did not exceed the target values of the standard. However, the concentrations of α-HCH and p,p'-DDD in Anxin bridge and Quantou sites exceeded the limit of human health ambient water quality criteria developed by EPA, which reflected that α-HCH and p,p'-DDD would have a potential hazards risk to the residents from Baiyangdian district.

Study of Kinetics Mechanism of PAHs Photodegradation in Solution

As a typical group of persistent organic pollutants, polycyclic aromatic hydrocarbons (PAHs) are widely distributed and persistent in ecological environment via environmental media (e.g. air, soil, water, suspended solids, organisms, etc.), causing great damage to organisms. Its fate and transportation from surface water to aquifers has attracted more and more attention. As PAHs in surface water or in topsoil will undergo photochemical reactions, a self-designed cylindrical photodegradation reactor has been designed to study the photodegradation of PAHs in aqueous solutions in this study. The results have shown that PAHs degrade rapidly under the lighting conditions. Pseudo-first-order kinetics was observed for degradation of fluorene (FLU), phenanthrene (PHE) and pyrene (PYR), as indicated by linear relations between ln (C0/Ct) and time. The reaction kinetics constants of FLU, PHE and PYR were 0.031, 0.045, 0.017 min-1 respectively, and the photolysis half-lives of PAHs are only several minutes (FLU, 4.17min; PHE, 3.79min; PYR 4.77min). Their photolysis rates following the decreasing order PHE > FLU > PYR is due to their different absorption spectrum and peak values under the UV-light.

Polycyclic aromatic hydrocarbons in the Yellow River estuary: Levels, sources and toxic potency assessment

This paper presents a systematic but preliminary study on the levels, sources and risk of exposure to polycyclic aromatic hydrocarbons (PAHs) in the Yellow River estuary by examining 16 priority PAHs listed by the U.S. EPA in four main environmental media (soil, surface water, groundwater and sediment). The concentration of individual PAHs in each medium in the study area was compared with the reported PAH values in China and abroad and to related environmental quality standards. The pollution levels of PAHs were found to be moderate in the soil and sediment, and low in the surface water and groundwater. Wood, coal combustion and petroleum inputs are the main PAH sources in soil and sediment, while petroleum inputs and petroleum combustion are the main PAH sources in surface water and groundwater. This indicates that PAH input caused by the high-speed inflow of external water over a long time has made a definite contribution to the occurrence of PAHs in surface water and groundwater in the study area. Furthermore, the mean value of the sum of the Excess Lifetime Cancer Risk (∑ELCR) exposure to PAHs in all media exceeded the generally acceptable risk level of 1.0E−06 recommended by the USEPA for carcinogenic chemicals, and the relative proportion contributed by DBA to the ∑ELCR was the greatest.

Diverse toxicological risks of PAHs in surface water with an impounding level of 175m in the Three Gorges Reservoir Area, China.

The impounding level of 175m for the Three Gorges Reservoir (TGR) is of vital importance for efficient flood control, power generation and convenient navigation in China. However, little is known about the spatial distribution and toxicological risks of major pollutants in the Three Gorges Reservoir Area (TGRA) at that stage. The aim of this study is to probe the ubiquitous polycyclic aromatic hydrocarbons (PAHs) contamination and toxicological impacts in the surface water of the TGRA at the highest water impoundment level of 175m. Our results showed that the ƩPAHs levels ranged from 83 to 1631ng/L in the upper reaches, 354 to 1159ng/L in the middle reaches, and 23 to 747ng/L in the lower reaches of the TGRA. Source apportionment of PAHs indicated that coal combustion, industrial emissions, heavy traffic, agriculture and shipping activities were the primary sources. Compositional pattern highlighted >85% dominancy of low molecular weight (LMW) PAHs in the reservoir. Risk assessment based on risk quotients (RQs) implied moderate to high ecological risks: the upper reaches>the middle reaches>the lower reaches. However, gene expression profiles portrayed contrary scenario because of the presence of relatively higher footprints of high molecular weight (HMW) PAHs in the middle and the lower reaches, which was confirmed by Cox hazard proportional model. Moreover, the transgenic zebrafish Tg(cyp1a:gfp) induced by PAHs also expressed stronger fluorescent signals in the middle and lower reaches. Taken together, different approaches were employed to firstly reveal the real status of ecological toxicity of PAHs and explore the underlying mechanisms at the highest impounding level of 175m in the TGRA.

Characterization and Risk Assessment of Polycyclic Aromatic Hydrocarbons in Surface Water from Liaohe River, Northeast China

ABSTRACTIn this study, the characteristics, probable source, and potential carcinogenic risk of 16 polycyclic aromatic hydrocarbons (PAHs) in surface water of the Liaohe River were investigated. Twelve sampling points were selected, and water samples were collected in both dry and flood periods of 2011. Sample analysis indicated that the concentration of total PAHs varied from 840.50 ng/L to 4274.73 ng/L in the flood period, and from 387.76 ng/L to 1997.83 ng/L in the dry period. The representative PAHs in the flood period were benz[a]anthracene (Baa), naphthalene (Nap), and chrysene (Chr), whereas Phenanthrene (Phe), fluoranthene (Flu), and pyrene (Pyr) were the representative PAHs in the dry period. The compositional pattern of PAHs indicated that four-ring PAHs were predominant in the flood period, whereas three-ring and four-ring PAHs dominated in the dry period. The different PAH congener ratios indicated that PAHs in surface water of the Liaohe River mainly originated from a mixed source in the flood period, and from combustion in the dry period. Based on the methods of Incremental Lifetime Cancer Risk (ILCR) and the benzo[a]pyrene toxic equivalent (TEQ), the potential cancer risk was quantitatively assessed, and the results suggested that there was a potential cancer risk in surface water of the Liaohe River and more attentions must be paid to the PAHs contamination. The cancer risk in the teenager group was the most, followed by the children group, adult group, and infant group, and toddler group was the least.

Occurrence and risk assessment of polycyclic aromatic hydrocarbons in the Hanjiang River Basin and the Danjiangkou Reservoir, China

ABSTRACTThis study was conducted to investigate the occurrence, distribution, and source of 16 polycyclic aromatic hydrocarbons (PAHs) in the Hanjiang River Basin and the Danjiangkou (DJK) Reservoir. The concentrations of total PAHs in surface water, sediments, and bank soils ranged from 9.42 to 137.94 ng/l, 86.23 to 2514.93 ng/g, and 133.17 to 671.93 ng/g dry weight, respectively. The composition pattern of PAHs showed that 3-ring PAHs were dominated in all of the samples, while the proportion of high molecular weight PAHs (5- to 6-ring PAHs) in sediments and bank soil samples was almost three times higher than water. The source apportionment analysis showed that most of the PAHs in water were derived from sources of petroleum and combustion, while combustion was the predominant source of PAHs in sediments and bank soils. The methods based on toxic equivalency factors, risk quotient, and incremental lifetime cancer risk were used to assess the ecosystem risk and potential health risk of PAHs. The risk assessments showed that PAHs in the DJK Reservoir were out of potential health risk, but the ecological risk for majority of 16 PAHs was in the moderate level.

Distribution characteristics and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in the Liao River drainage basin, northeast China.

The Liao River drainage basin, which is one of China's seven major rivers basins, is located in northeast China. This region is characterized by important industrial bases including steel factories and oil and chemical plants, all of which have the potential to contribute pollutants to the drainage basin. In this study, 16 polycyclic aromatic hydrocarbons (PAHs) in water and suspended particulate matter (SPM) in the major rivers of the Liao River drainage basin were identified and quantified by gas chromatography mass spectrometry (GC/MS). The total PAH concentrations ranged from 0.4 to 76.5μg/g (dry weight) in SPM and 32.6 to 108ng/L in surface water, respectively. Low-ring PAHs (including two- and three-ring PAHs) were dominant in all PAH samples, and the level of low-ring PAHs in surface water was higher than that in SPM. The proportion of two-ring PAHs was the highest, accounting for an average of 68.2% of the total PAHs in surface water, while the level of three-ring PAHs was the highest in SPM, with an average of 66.3%. When compared with other river systems, the concentrations of PAHs in the Liao River drainage basin were lower. Identification of the emission sources based on diagnostic ratios suggested petroleum and fossil fuel combustion were important contribution to PAHs in the study area.

Assessment on the Health Risk of Low-Molecular-Weight Polycyclic Aromatic Hydrocarbons (PAHs) in Surface Water of Lake Baiyangdian

Low-molecular-weight (LMW) PAHs in surface water of Lake Baiyangdian were determined to assess the potential health risk when using as drinking water for children and adults. The concentration of LMW PAHs in surface water were in the range of 77.26-760.16 ng L-1. Compared with similar results reported around the world, the level of LMW PAHs in this study was in the mid-range. The analysis of health risk indicated that risks from LMW PAHs in most part of the lake would not be risky to human health according to the acceptable risk level, while carcinogenic effects caused by LMW PAHs might occur if drinking water from Nanliuzhuang (NLZ), Shaochedian (SCD) and Laowangdian (LWD). Risks of LMW PAHs for children were apparently much higher than those caused by LMWs PAHs for adults.

Persistent toxic substances in surface water of Todos Os Santos Bay, Brazil

Persistent toxic substances (PTSs) such as polycyclic aromatic hydrocarbons (PAHs) are of great concern due to their persistence, bioaccumulation and toxic effects. In this work, 14 PAHs included in the US Environmental Protection Agency’s (EPA) priority pollutant list were analysed using gas chromatography–mass spectrometry (GC–MS). Surface water sampling was undertaken in Todos os Santos Bay, northern Brazil. Total PAH concentrations varied from 0.0029 to 0.1079 ng/L in surface waters (main rivers, tributaries, etc.) with mean value of 0.0344 ng/L. Such concentrations can be taken as background values for the studied region and show that PAHs are within or lower than levels reported in certain other areas. The PAH profiles were dominated by high molecular weight PAHs (four- and five-ring components) in surface water samples. It indicated that PAHs in surface water have its origin from oil or sewage contamination (petrogenic input). The collected data, based on indices among phenanthrene versus anthracene, showed that petrogenic input was predominant at almost all the stations investigated. Principal component analysis (PCA), using a correlation matrix, revealed the latent relationships among all the surface water stations investigated and confirmed our analytical results.

Spatial distribution and seasonal variation of polycyclic aromatic hydrocarbons (PAHs) contaminations in surface water from the Hun River, Northeast China

The objectives of this study were to investigate the levels, dispersion patterns, seasonal variation, and sources of 16 priority polycyclic aromatic hydrocarbons (16 EPA-PAHs) in the Hun River of Liaoning Province, China. Samples of surface water were collected from upstream to downstream locations, and also from the main tributaries of the Hun River in dry period, flood period, and level period, respectively. After appropriate preparation, all samples were analyzed for 16 EPA-PAHs. Total PAHs concentrations varied from 124.55 to 439.27 ng l(-1) in surface water in dry period, 1,615.75 to 5,270.04 ng l(-1) in flood period, and 2,247.42 to 7,767.9 ng l(-1) in level period. The 16 EPA-PAHs concentrations were significantly increased in the order of level period > flood period > dry period. The composition pattern of PAHs in surface water was dominated by low molecular weight PAHs, in particular two- to three-ring PAHs. In addition, two-ring PAH accounted for 39.33 to 88.27 % of the total PAHs in level period. Low molecular weight PAHs predomination together with higher levels of PAHs in flood and level period suggested a relatively recent local source of PAHs. Special PAHs ratios such as phenanthrene/anthracene and fluoranthene/pyrene indicated that under dry weather season conditions, the PAHs found in surface water were primarily from petrogenic source, while under wet weather season conditions they were from mixed source of both petrogenic inputs and combustion sources. The comparison of PAHs contamination among different types of areas in China suggested that atmospheric depositions might be the most important approaches of PAHs into water system. Although the Hun River exists low PAHs ecological risk now, potential toxic effects will be existed in the future especially in flood and level period.

Distribution of Fecal Sterols, Nonylphenol, and Polycyclic Aromatic Hydrocarbons in Surface Water from Masan Bay, Korea

Fecal sterols, nonylphenolic compounds (NPs), and polycyclic aromatic hydrocarbons (PAHs) were determined in surface water from Masan Bay and its adjacent rivers in February 2005. Concentrations of coporstanol (Cop), an indicator of fecal pollution, in surface water ranged from <10 to 13,853 ng/L, and concentrations of nonylphenol, the most toxic of the NPs, ranged from 10.2 to 481 ng/L, and concentrations of PAHs ranged from 8.61 to 223 ng/L. The concentrations of the compounds measured in this study were lower than or comparable to those at other locations in Korea and other countries. The contamination of Cop and PAHs in surface water was associated with the discharge from rivers passing through cities and/or industrial complexes. The NP contamination was associated with wastewater treatment plant (WWTP) effluents through outfalls as well as riverine discharge. Compared to ecotoxicological values, the concentrations of NPs from rivers, the mouths of rivers, and WWTP outfall areas exceeded guidelines, suggesting that hot spot areas may pose a potential risk to sensitive species.

Distribution and sources of polycyclic aromatic hydrocarbons in the aquatic environment: a multivariate analysis

Fourteen polycyclic aromatic hydrocarbons (PAHs) included in the US Environmental Protection Agency's (EPA) priority pollutant list were analyzed using gas chromatography-mass spectrometry (GC--MS). Surface water sampling was undertaken in the Paraguaçu Estuary (Bahia), northern Brazil. Total PAH concentrations varied from 0.0029 to 0.1079 ng/L in the surface waters (main rivers, tributaries) with a mean value of 0.0344 ng/L. Such concentrations can be taken as background values for the studied region. The PAH profiles were dominated by low molecular weight PAHs (two- and three-ring components) in surface water samples. It indicated that PAHs in surface water may have its origin from oil or sewage contamination (petrogenic input). The collected data showed that petrogenic input was predominant at almost all the stations investigated. To discriminate pattern differences and similarities among the samples, a principal component analysis (PCA) was performed using a correlation matrix. PCA revealed the latent relationships among all the surface water from the investigated stations.

Flow injection solid-phase extraction using multi-walled carbon nanotubes packed micro-column for the determination of polycyclic aromatic hydrocarbons in water by gas chromatography–mass spectrometry

A flow injection solid-phase extraction preconcentration system using a multi-walled carbon nanotubes (MWCNTs) packed micro-column was developed for the determination of 16 polycyclic aromatic hydrocarbons (PAHs) in water by gas chromatography–mass spectrometry (GC–MS). The preconcentration of PAHs on the MWCNTs was carried out based on the adsorption retention of analytes by on-line introducing the sample into the micro-column system. Methanol was introduced to elute the retained analytes for GC–MS analysis using selected ion monitoring (SIM) mode. Important influence factors were studied in detail, such as sample acidity, sample flow rate, eluent flow rate and volume, dimensions of MWCNTs and amounts of packing material. Limits of detection of 16 PAHs for an extraction of 50 mL water sample were in the range of 0.001–0.15 μg L −1, and the precisions (RSD) were in the range of 4–14%. The optimized method was successfully applied to the determination of 16 PAHs in surface waters, with recoveries in the range of 72–93% for real spiked sample.

Significance of Indirect Deposition on Wintertime PAH Concentrations in an Urban Northern California Creek

To investigate the main inputs and sources of polycyclic aromatic hydrocarbons (PAHs) into surface water, stream and precipitation samples were collected along an urban tributary to the Sacramento River, California. Dissolved, particulate, and colloid-bound PAHs were monitored four times between October 2004 and March 2005. The total PAH concentrations ranged from 192 to 3784 ng/L in surface water and from 77 to 236 ng/L in precipitation. Naphthalene, phenanthrene, pyrene, and benzo[g,h,i]perylene were the most abundant compounds in both rain and surface water. Surface water had truly dissolved PAH concentrations between 18 and 48 ng/L and precipitation had similar values (15-66 ng/L). PAHs larger than four rings were seldom found in the dissolved phase. Colloid-associated PAHs accounted for 4-25% of the total PAHs in rain, while they contributed only 0.1-6% to the total surface water PAHs. Indirect deposition (i.e., washoff of atmospheric particles previously deposited to land) of PAHs into surface water is likely a more significant input pathway for total PAHs than direct dry or wet deposition during the wet season in California's Mediterranean climate. During the sampling period, there was not an obvious seasonal variation in dissolved PAH concentrations of surface water despite an enormous wintertime increase in the total aqueous concentrations. Particulate matter carried by stormwater runoff was the major source of PAHs in surface water in the early rainy season; this material likely represents a combination of indirect atmospheric inputs and other non-atmospheric anthropogenic inputs (e.g., oil leaks and spills). Selected PAH ratios indicate that observed PAHs in rainwater came from pyrogenic sources and those in surface water had more complicated and variable origins.

Polycyclic aromatic hydrocarbons (PAHs) in surface waters of Ráckevei-Soroksári Danube Branch, Hungary

Concentrations of polycyclic aromatic hydrocarbons (PAHs) in the surface waters of Ráckevei-Soroksári Danube (RSD) branch, Hungary were determined at ten sites during eight sampling events from October 2002–April 2004. Low and medium molecular weight PAHs (2–4 rings) varied from a few ng/L to hundreds of ng/L while high molecular weight PAHs (5–6 rings) were present at much lower concentrations (< 0.5–31 ng/L). Generally, concentrations of most of the individual PAHs were not significantly different (p > 0.05) during the different seasons. Concentrations of anthracene, fluoranthene, and pyrene were significantly lower (p < 0.005) in the winter month whereas concentrations of benzo(a) anthracene, chrysne, and benzo(b)fluoranthene were significantly lower (p < 0.05) in the fall season. Possible causes of such distribution in the surface waters of RSD include nature of the inputs of organic matter and different systems of winds or rains of the seasons. Of the total PAHs, the 2–3-ring PAHs contributed to about 78% while 4–6-ring PAHs accounted for 22%. This suggests that the incomplete combustion of fossil hydrocarbons may be the predomainate source of PAHs in surface water of RSD. Seasonally, petroleum and heavy fuel combustion were main sources of PAHs in summer and winter seasons, respectively. However, both sources contribute to PAHs in the spring season. The levels of PAHs in our study were compared with other regions of the world. Concentrations of PAHs in our study were higher than most of the surface waters of Europe, North America, and Australia, but similar to some parts of European and Asian regions.

Polycyclic aromatic hydrocarbons in rainwater and surface waters of Lake Maggiore, a subalpine lake in Northern Italy

Fourteen polycyclic aromatic hydrocarbons (PAHs) were measured in surface waters and precipitation inputs to Lake Maggiore, a subalpine lake in Northern Italy, from July 2003 to January 2004. Particulate and dissolved phases in surface water and rain samples were determined. Analyses of PAHs were performed using XAD-2 resin to isolate the dissolved PAHs and subsequent extraction by accelerated solvent extraction (ASE). Both the dissolved and particulate phase PAH patterns in surface water and rainwater samples were dominated by the low molecular weight compounds (e.g., phenanthrene, fluoranthene and pyrene). More than 85% of PAHs in surface waters and 72% of PAHs in rainwater were associated to the dissolved phase. The ΣPAH concentrations in surface waters (particulate and dissolved phases) were 0.584 ± 0.033 ng l −1, 2.9 ± 0.312 ng l −1 and in rainwater (particulate and dissolved phases) 27.5 ± 2 ng l −1, 75.4 ± 9 ng l −1, respectively. Temporal variability of PAH concentrations in rain and surface water samples were observed, with higher concentrations in November and December, coinciding with the largest precipitation amounts. The comparison of PAH signatures in rainwater and surface waters seems to indicate that wet deposition (2.5–41 μg m −2 month −1) is the main source of PAH contamination into surface waters of Lake Maggiore.

Distributions of polycyclic aromatic hydrocarbons in surface waters, sediments and soils of Hangzhou City, China

Ten polycyclic aromatic hydrocarbons (PAHs) were simultaneously measured in 17 surface water samples and 11 sediments of four water bodies, and 3 soils near the water-body bank in Hangzhou, China in December 2002. It was observed that the sum of PAHs concentrations ranged from 0.989 to 9.663μg/L in surface waters, from 132.7 to 7343ng/g dry weight in sediments, and from 59.71 to 615.8ng/g dry weight in soils. The composition pattern of PAHs by ring size in water, sediment and soil were surveyed. Three-ring PAHs were dominated in surface waters and soils, meanwhile sediments were mostly dominated by four-ring PAHs. Furthermore, PAHs apparent distribution coefficients (Kd) and solid foc-normalized Kd (e.g. Koc= Kd / foc) were calculated. The relationship between logKoc and logKow of PAHs for field data on sediments and predicted values were compared. The sources of PAHs in different water bodies were evaluated by comparison of Koc values in sediments of the river downstream with that in soils. Hangzhou section of the Great Canal was heavily polluted by PAHs released from industrial wastewater in the past and now PAHs in sediment may serve as sources of PAHs in surface water. PAHs in Qiantang River were contributed from soil runoff. Municipal road runoff was mostly contributed to West Lake PAHs.

Polycyclic aromatic hydrocarbons in the bulk precipitation and surface waters of Northern Greece

Bulk (wet and dry) precipitation and surface water sampling was undertaken in the main plain of central Macedonia in Northern Greece. Fourteen polycyclic aromatic hydrocarbons (PAHs) included in the US EPA's priority pollutant list were analysed. The concentrations determined in bulk precipitation were in general within the range of values worldwide reported. Concentrations were highest in the cold months. Deposition fluxes of PAHs were of the same order of magnitude as reported data. The greatest values were found when high concentrations of PAHs in precipitation coincided with large precipitation amounts. The concentrations of PAHs in surface waters (main rivers, tributaries, ditches, etc) were in general lower than those in bulk precipitation, and among the lowest reported for European rivers, excepting Np and Ph. Bulk deposition and domestic effluents are suggested as being the main PAH sources into surface waters.