Transport of polycyclic aromatic hydrocarbons and pesticides during snowmelt within an urban watershed

During snowmelt events in urban watersheds large amounts of organic contaminants are mobilized, potentially affecting the quality of surface and groundwater resources. The transport of polycyclic aromatic hydrocarbons (PAHs) and two pesticides in the highly urbanized Highland Creek watershed within the city of Toronto, Canada, was investigated by sampling river water during two snowmelt periods. The dissolved and the particulate fractions were separately extracted and analyzed. While during normal flow conditions levels of the sum of nine PAHs including phenanthrene, anthracene, fluoranthene, pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno(1,2,3-c,d)pyrene, and benzo(ghi)perylene ranged between 18 and 45 ng/L, concentrations at the onset of melting varied from 550 to 4500 ng/L. Considering enhanced stream discharge rates during snowmelt the contaminant flux in the river increased by three orders of magnitude. The intensity of the melt event largely determined the extent of the PAH concentration increase in the river. The relatively water soluble pesticides chlorothalonil and lindane (γ-HCH) also tended to appear early during melting. Their enrichment in river water may be influenced by the thickness of the snow pack at the onset of melting, and the mode of melt water ablation from the snow pack to the stream, i.e. whether it occurs by overland or sub-surface flow.     

Determination of Polycyclic Carbohydrates in Atmospheric Water by the Method of Chromatography

Isomers of benzoperene were studied. Calculated values of hydrophobicity of their molecules were analyzed. The search for optimal conditions of extraction removal from atmospheric water of isomers of benzopyrene and chromatographic separation of benzo(e)pyrene and benzo(a)pyrene in atmospheric water (snow) was made. The concentration of benzo(e)pyrene and benzo(a)pyrene in atmospheric water (snow) polluted by polycyclic aromatic hydrocarbons (benzo(a)anthracene, benzo(b)fluoranthene, chrysene) was determined.     

Biological half-lives of eight polycyclic aromatic hydrocarbons (PAHs) in rainbow trout (Salmo gairdneri)

Adult rainbow trout were exposed to a single oral dose containing a mixture of eight PAHs, and fish were sampled at intervals between 5–48 days after exposure. Regression analyses on whole fish indicate levels declined significantly in four of the compounds monitored. Their biological half-lives were estimated as 9 days for phenanthrene, 7 days for fluorene and anthracene and 6 days for fluoranthene. No reliable estimates could be derived for benzo[a]pyrene, benz[a]anthracene, chrysene or pyrene because of low or nondetectable concentrations at the first sample interval although it could be suggested that their half-lives would be less than several days. The data also suggested that these PAHs are poorly absorbed by trout.     

Polycyclic aromatic hydrocarbons in remote mountain lake waters

Polycyclic aromatic hydrocarbons (PAH), including alkylated and sulfur derivatives, were identified and measured in the waters from three European remote mountain lakes during both ice-free and ice covered periods. The measured concentrations were in the same order in all three lakes (700-1100 pg/l). The PAH patterns in both dissolved and particulate water phases were dominated by the low molecular weight compounds (i.e. phenanthrene, fluoranthene and pyrene) in Lakes Redó (Pyrenees) and Gossenk?lle (Alps). In contrast, the high molecular weight (HMW) compounds (i.e. chrysene+triphenylene, benzofluoranthenes, benzo[e]pyrene) were very significant in lake Ovre Ne?dalsvatn (Caledonian). These HMW PAH correspond to mixtures originating from high temperature combustion processes which have been photodegraded during long range atmospheric transport and parallel the PAH mixtures encountered in the underlying lake sediments. In contrast, dissolved PAH exhibit temperature dependence with higher concentrations found at water temperatures below 6-7 degrees C reflecting higher condensation from the atmospheric gas phase reservoir.     

HPLC determination of polycyclic aromatic hydrocarbons (PAHs) in the littoral urban sewage area of cortiou (Marseille,France)

A selective method for determining polycyclic aromatic hydrocarbons (PAHs) in sediments using solid‐phase extraction and RP‐HPLC with fluorescence and UV detection is described. The complete analytical method is used to surface sediments from the creek of Cortiou (France). Sewage from the urban area of Marseille is delivered to the creek. PAH levels in sediments (µg/g) range between 2.251 µg/g (for the benzo(a)anthracene) and 相似文献   

Influence of algal and bacterial particulate organic matter on benzo[a]pyrene bioaccumulation in Daphnia magna

In order to better asses the influence of organic matter on the bioavailability of hydrophobic organic contaminants, the effect of algae and POM of bacterial origin on the bioaccumulation of benzo[a]pyrene in Daphnia magna was evaluated. The bioaccumulation was monitored with increasing concentrations of particulate organic matter (POM) and dissolved organic matter (DOM). In all experiments, the presence of POM greatly reduced the bioaccumulation of benzo[a]pyrene. The reduction was more pronounced in the presence of algae, for which we observed a 99%-reduction effect in the presence of 6 x10 (5) cell/mL (equivalent to 5.3 mg C/L). The bioaccumulation of benzo[a]pyrene was decreased by 49% by organic matter of bacterial origin at 4.7 mg C/L. Assuming that benzo[a]pyrene was partitioned between water, DOM and POM and supposing that D. magna accumulated free benzo[a]pyrene via respiration and POM-bond benzo[a]pyrene via ingestion, bioaccumulation data allowed to estimate the dietary uptake rate of benzo[a]pyrene as well as partitioning coefficients K(POC) and K(DOC). Despite the ingestion of contaminated particles, we could not observe any dietary uptake of benzo[a]pyrene in daphnids. We verified, as usually supposed, that the bioaccumulation of benzo[a]pyrene to D. magna occurs mainly via direct contact. Very high partitioning coefficients (log K(POC) between 5.2 and 6.2) were estimated. This study pointed out the great influence of biogenic organic matter on the fate and the bioavailability of benzo[a]pyrene in aquatic ecosystems.     

Accelerated biodegradation of pyrene and benzo[a]pyrene in the Phragmites australis rhizosphere by bacteria-root exudate interactions

We investigated the biodegradation of pyrene and benzo[a]pyrene in Phragmites australis rhizosphere sediment. We collected P. australis plants, rhizosphere sediments, and unvegetated sediments from natural aquatic sites and conducted degradation experiments using sediments spiked with pyrene or benzo[a]pyrene. Accelerated removal of pyrene and benzo[a]pyrene was observed in P. australis rhizosphere sediments with plants, whereas both compounds persisted in unvegetated sediments without plants and in autoclaved rhizosphere sediments with sterilized plants, suggesting that the accelerated removal resulted largely from biodegradation by rhizosphere bacteria. Initial densities of pyrene-utilizing bacteria were substantially higher in the rhizosphere than in unvegetated sediments, but benzo[a]pyrene-utilizing bacteria were not detected in rhizosphere sediments. Mycobacterium gilvum strains isolated from rhizosphere sediments utilized pyrene aerobically as a sole carbon source and were able to degrade benzo[a]pyrene when induced with pyrene. Phragmites australis root exudates containing phenolic compounds supported growth as a carbon source for the one Mycobacterium strain tested, and induced benzo[a]pyrene-degrading activity of the strain. The stimulatory effect on benzo[a]pyrene biodegradation and the amounts of phenolic compounds in root exudates increased when P. australis was exposed to pyrene. Our results show that Mycobacterium-root exudate interactions can accelerate biodegradation of pyrene and benzo[a]pyrene in P. australis rhizosphere sediments.     

Biomimetic accumulation of PAHs from soils by triolein-embedded cellulose acetate membranes (TECAMs) to estimate their bioavailability

A new passive sampling device (PSD), a triolein-embedded cellulose acetate membrane (TECAM), was used to biomimetically accumulate naphthalene, phenanthrene, pyrene and benzo[a]pyrene from ten spiked soils and a soil spiked with different concentrations of these polycyclic aromatic hydrocarbons (PAHs). TECAM exposure conditions were optimized. The quantities of PAHs accumulated by TECAMs were positively and linearly related to their concentrations in the soil. PAHs accumulated by TECAMs were negatively related to soil organic matter (SOM) and positively related to the dissolved organic carbon (DOC) according to the results obtained from ten spiked soils. Aging time (1-150 days) had a significant effect on accumulation of PAHs by TECAMs. A good linear relationship (R2=0.970-0.993) was observed between TECAM-accumulated PAHs and PAHs accumulated by earthworms (Eisenia andrei). The data indicate that TECAM represents a useful surrogate to estimate the bioavailability of PAHs and perhaps other hydrophobic organic contaminants (HOCs) in soils.     

Characterization and distribution of polycyclic aromatic hydrocarbon contaminations in surface sediment and water from Gao-ping River, Taiwan

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in water and sediment samples collected from 12 locations in Gao-ping River, Taiwan were analyzed. Molecular ratios and principal component analysis (PCA) were used to characterize the possible pollution sources. Concentrations of total 16 PAHs (SigmaPAHs) in water samples ranged from below method detection limits (相似文献   

Partitioning and desorption behavior of polycyclic aromatic hydrocarbons from disparate sources

Contaminated sediments pose a unique challenge for risk assessment or remediation because the overlying water column may transport contaminants offsite or to ecological receptors. This research compares the behavior of polycyclic aromatic hydrocarbons (PAHs) on marine sediments from two sites. The first site was affected by shipping activities and the second was impacted by a creosote seep. Organic carbon:water partitioning coefficients (Koc values) were measured with three solutions. Desorption was measured using Tenax beads. PAHs from the ship channel had lower Koc values than those from the creosote facility. For example, the average logKoc value of ship channel pyrene was significantly lower than that of creosote facility pyrene (4.39 +/- 0.35 and 5.29 +/- 0.09, respectively, when tested in 5 mM calcium chloride). These results were consistent with the greater desorption of pyrene, phenanthrene and benzo(a)pyrene from the ship channel than from the creosote facility sediments. Organic compound desorption from sediments can be considered to be a two-stage process, with a labile fraction that desorbs quickly and a refractory fraction that desorbs much more slowly. In both sediments, more than 75% of the benzo(a)pyrene was found to have partitioned into the refractory phase. The amounts of phenanthrene and pyrene that partitioned into the refractory phase were lower. Linear correlations of logKoc with log(CR/CL) (where CR and CL are the fractions of the compound in the refractory and labile phases, respectively, at time zero) showed that partitioning measurements made with the US EPA's Toxicity Characteristic Leaching Procedure fluid (US EPA, 1996) most closely matched predictions of desorption behavior. The data imply that with a larger data set, it may be possible to relate simple partitioning measurements to desorption behavior. Partitioning measurements were used to predict water concentrations. Despite having higher concentrations of carcinogenic PAHs [cPAHs, the seven PAHs categorized by the US EPA (2004) as class B2 carcinogens], creosote facility sediments were predicted to produce lower aqueous concentrations of cPAHs. These results indicate that both sediment and contaminant characteristics will impact contaminant release from sediments.     

Determination of polycyclic aromatic hydrocarbons in sediments and mussels from Saudafjord, W. Norway, by glass capillary gas chromatography.

Polycyclic aromatic hydrocarbons (PAH) have been determined, by glass capillary gas chromatography, in two species of bivalves (Mytilus edulis and Modiolus modiolus) and sediments of Saudafjorden, Norway. The PAH observed are derived from waste effluents from a ferro alloy smelter. Up to 34 PAH compounds were identified, including some reported to be carcinogenic. The concentrations decreased rapidly with distance from the source and with sediment depth, but could be traced more than 15 km from the source. Relative abundance of various PAH did not change significantly in the mussels collected from the head to the mouth of the fjord. In the sediments, however, phenanthrene increased from minor importance to dominance towards the mouth, whereas the relative content of anthracene and benzo [a]pyrene decreased. The results are compared with observations from other marine localities and discussed in relation to transport processes, biodegradation and chemical transformation in the sediments.     

DNA damage by benzo[a]pyrene in the liver of mosquito fish Gambusia affinis

Exposure of Gambusia affinis to water containing different concentrations of benzo[a]pyrene (BaP) causes an increase in benzo[a]pyrene monooxygenase (BPMO) activity which reaches a maximum on the second day. Concomitantly, the DNA is altered in such a way that nuclease S1-sensitive sites (SSS) become measurable. The size distribution of liver DNA treated with nuclease S1 in control fish shows two populations of DNA by length, with means of 30 X 10(6) and 60 X 10(6) Daltons, respectively. In fish treated with 100 ppb BaP, the population with longer molecules of DNA disappears and shorter molecules increase in number. This may be explained in terms of the introduction of an additional 0.31-0.46 DNA nicks per control DNA molecule caused by metabolically activated BaP derivatives.     

Bioconcentration factor estimates of polycyclic aromatic hydrocarbons in grains of corn plants cultivated in soils treated with sewage sludge

This study presents a model to simulate the organic substance concentrations in corn grains assuming that the substances in soil solution are absorbed via the transpiration stream by plants growing in soils fertilized with sewage sludge (SS). The model was applied and validated using soil and corn grain samples from a long-term field experiment with six successive yearly applications of SS to the soil. The following polycyclic aromatic hydrocarbons (PAHs) were simulated and evaluated in soil and grain samples: acenaphthene, acenaphthylene, anthracene, benz(a)anthracene, benz(a)pyrene, benz(b)fluoranthene, benz(g,h,i)perylene, benz(k)fluoranthene, chrysene, dibenz(a,h)anthracene, fluoranthene, fluorene, indeno(1,2,3-c,d)pyrene, naphthalene, phenanthrene and pyrene. The PAH bioconcentration factors (BCF) in corn grains ranged from 1.57 to 10.97 L kg^− 1. Polycyclic aromatic hydrocarbons with low soil distribution coefficients and high values of transpiration stream concentration factors (TSCF) are more likely to be absorbed by corn plants and accumulated in grains. It was possible to estimate and observe that highly lipophilic PAH molecules (heavy PAHs) show lower accumulative potential in corn grains than the less lipophilic ones (light PAHs). Sewage sludges containing significant concentrations of light PAHs with two, three or four benzene rings should be avoided as fertilizers in alimentary field crops.     

The use of manures for detection and quantification of polycyclic aromatic hydrocarbons and 3-hydroxybenzo[a]pyrene in animal husbandry

PAHs from a polluted atmosphere are generally transferred to plants by particle-phase deposition on the waxy leaf cuticle or by uptake in the gas phase through stomata. Thus, they are also present in ingredients for animal feed. Generally, toxic substances are metabolized before or after absorption through the intestinal tract. This is the case of 3-hydroxybenzo[a]pyrene, which can be found free or in its glucuronide and/or sulphate conjugate forms. This article develops a procedure to monitor the carry-over of PAHs from feed to food of animal origin based on the analysis of animal manure. Eleven PAHs and 3-hydroxybenzo[a]pyrene were measured in four animal manures (cow, horse, rabbit and pig) by liquid chromatography with fluorescence detection. benzo[a]pyrene, benzo[b]fluoranthene and benzo[k]fluoranthene were found in all the selected samples, but their total levels were not alarming (benzo[a]pyrene equivalents (microg/kg)<3.1). 3-hydroxybenzo[a]pyrene was quantified in all the samples exempting rabbit manure. The highest total PAH levels were detected in cow manure (9.0 microg/kg), while the highest 3-OH-B[a]P level was determined in horse samples (13 microg/kg).     

Carcinogenic effects of some polycyclic aromatic hydrocarbons on the Japanese medaka and guppy in waterborne exposures

In this paper, we review studies on the carcinogenic effects of two polycyclic aromatic hydrocarbons (PAHs), benzo(a)pyrene (BaP) and 7,12-dimethylbenz(a)anthracene (DMBA), on the Japanese medaka (Oryzias latipes) and the guppy (Poecilia reticulata). Exposure media were prepared by adding PAHs to water, with and without dimethylformamide (DMF) as a carrier, and passing this solution through various sized filters. The low exposure medium was a 0.45 micron filtrate without DMF that contained less than 5 micrograms L-1 PAH. The intermediate medium was a DMF-mediated 0.45 micron filtrate which contained 30-50 micrograms L-1 of PAH. The high medium was a DMF-mediated glass-fibre filtrate which contained 150-250 micrograms L-1 of PAH. Young fish specimens (6-10 d old) were given a 6 h exposure once weekly for 2 to 4 wk. Both BaP and DMBA induced hepatic neoplasms in the two species, with the medaka being more sensitive than the guppy, and DMBA being a stronger carcinogen than BaP. Liver neoplasms almost exclusively developed after exposure to BaP and the neoplasms were limited to the high concentration exposure, whereas DMBA caused a substantial number of extrahepatic neoplasms as well as hepatic ones, especially in the medaka. Furthermore, all three concentrations of DMBA induced hepatic neoplasms in the medaka and all but the low concentration induced neoplasms in the guppy. These studies demonstrate the carcinogenic effects of two waterborne PAHs on two small fish species following brief exposures to very low concentrations, and support the contention that environmental PAHs can contribute to the occurrence of cancer in wild fishes.     

Particle-associated polycyclic aromatic hydrocarbons in the atmospheric environment of Zonguldak, Turkey

Airborne fine (PM(2.5)) and coarse (PM(2.5-10)) particulate matter was collected from January to December in 2007 in Zonguldak, Turkey using dichotomous Partisol 2025 sampler. Fourteen selected polycyclic aromatic hydrocarbons (PAHs) in particulate matter were determined simultaneously by high-performance liquid chromatography with fluorescence detection (HPLC-FL) and seasonal distributions were examined. The source identification of PAHs in airborne particulates was performed by principal component analysis (PCA) in combination with diagnostic ratios. The predominant PAHs determined in PM(2.5) were pyrene, fluoranthene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene. The total concentrations of PAHs were up to 464.0 ng m(-3) in fine and 28.0 ng m(-3) in coarse fraction in winter, whereas in summer times were up to 22.9 and 3.0 ng m(-3) respectively. Approximately 93.3% of total PAHs concentration was determined in PM(2.5) in winter and 84.0% in summer. The concentration levels of PAHs fluctuate significantly within a year with higher means and peak concentrations in the winter compared to that of summer times. Higher benzo(a)pyrene-equivalent (BaPE) concentrations of PAHs were obtained for PM(2.5) especially in winter. The results obtained from PCA in combination with diagnostic ratios revealed that coal combustion and vehicle emissions were the major pollutant sources for both PM(2.5) and PM(2.5-10) associated PAHs in studied area. Two principal components for PM(2.5) and three for PM(2.5-10) were identified and these accounted for 89.4 and 85.2% of the total variance respectively. The emissions from coal combustion were estimated to be the main source of PAHs in the ambient air particulates with contributions of 80.8% of total variance for PM(2.5) and 53.8% for PM(2.5-10).     

Distribution of polycyclic aromatic hydrocarbons in snow of Mount Nanshan,Xinjiang

Polycyclic aromatic hydrocarbon (PAH) in snow samples collected from Mount Nanshan (Xinjiang, China) was investigated for eight stations. Fourteen PAHs were detected in these samples. The total PAH concentration ranged from 70.15 ng/L to 155.67 ng/L, with an average of 113.02 ng/L. Human carcinogens, such as fluoranthene, chrysene, benzo(a)pyrene, dibenzo(a,h)anthracene, indeno(1,2,3‐cd)pyrene and benzo(ghi)perylene in snow were assessed based on risk quotient. Preliminary assessment showed that these PAHs posed a moderate risk. Component analysis showed that the PAHs found in the snow samples were mainly three‐ring PAHs, which comprised 34.51–90.81% of the total PAHs. Phenanthrene, fluorene and anthracene accounted for 35.08, 11.90 and 11.13% of the total PAHs, respectively. The ΣPAH content increased with the increasing altitude, and the highest concentration of 155.67 ng/L was observed in snow samples from the N7 station, which was located near the top of the mountain. This high PAH concentration in N7 was possibly due to more frequent human activities in the area and long‐distance transportation of PAHs. Isomer ratios were used to determine the possible sources of PAHs in the samples. The results indicate that coal and biomass combustion made a larger contribution than emissions from petroleum consumption. It is therefore of utmost importance to develop new fuels taking the place of coal and to achieve as complete as possible for the burning of carbon‐containing materials.     

An appraisal of relative airborne sub-urban concentrations of polycyclic aromatic hydrocarbons monitored indoors and outdoors.

Particle-size distribution studies of polycyclic aromatic hydrocarbons in city and sub-urban atmospheres indicate that these compounds are associated with particles having MMD values of about 0.5 micrometer. Ambient airborne concentrations of pyrene, chrysene, benzo[a]pyrene, benzo[e]pyrene and coronene at suburban sites between 11 and 17 km from a city centre are shown to be approximately similar inside and outside detached residential houses. At all sites, monitored chrysene appears in highest concentration in the range 4-7 ng m-3, followed by benzo[a]pyrene and benzo[e]pyrene between 2-4 ng m-3, with coronene generally less than 1 ng m-3. By taking benzo[a]pyrene as a typical example of this class of compounds, these results indicate that the lungs of sub-urban populations will be exposed to about 34 ng of benzo[a]pyrene per day. This background amount is roughly equivalent to the exposure to this chemical experienced by the lung when one cigarette is smoked per day.     

Inhalation exposure of traffic police officers to polycyclic aromatic hydrocarbons (PAHs) during the winter in Beijing, China

This study concerns the use of personal samplers to evaluate the exposure of traffic police to polycyclic aromatic hydrocarbons (PAHs) during the winter of 2005 in Beijing. We measured the samples collected for gas and particulate phases PAHs with the same technique used for an earlier study during the summer of 2004, and evaluated exposure risk based on the calculated benzo(a)pyrene equivalent concentrations (BaP(eq)) of both summer and winter. The mean exposure concentrations of gaseous and particulate phase PAHs in the winter are 4300+/-2900 ng/m(3) and 750+/-1000 ng/m(3), respectively, significantly higher than those measured simultaneously at control sites and also considerably higher than the values measured during the summer. The exposure PAH profiles for police and the control subjects are similar with predominant naphthalene in gaseous phase and dominant fluoranthene, pyrene, anthracene and naphthalene in particulate phase. Large daily variations occur both in summer and winter, because of the changes in the weather conditions especially wind speed and relative humidity which tend to disperse and scavenge PAHs in air. In the winter, the average BaP(eq) value for traffic police is 82.1 ng/m(3), which is significantly higher than those for the control subjects and the national standard of 10 ng/m(3) for ambient air. Particulate phase PAHs contribute more than 90% of the total exposure risk in the winter. Annually, weighted-average probabilities of exceeding the national standard (10 ng/m(3)) are 69.3% and 20.6% for the police and the controls, respectively.     

Seasonal responses to diesel oil and subsequent recovery of the cytocgrome P-450 monooxygenase system in the common mussel,Mytilus edulis L., and the periwinkle,Littorina littorea L

Mussels and periwinkles under natural environmental conditions were exposed long-term (4–8 and 16–24 months, respectively) to environmentally realistic levels of, on average, 30 and 129 ppb diesel oil and then allowed to recover for 2–9 months in the absence of oil. With oil exposure, increases were seen in digestive gland microsomal cytochrome P-450 content and NADPH-cytochrome c reductase activity, and the changes in the latter were particularly consistent in periwinkles, showing a stepwise elevation with oil dosage at all times of the year. The changes were less consistent in mussels, with a dependence on season or reproductive condition being indicated. Fewer changes were seen in cytochrome b₅ content and the associated NADH-dependent reductase activities of the digestive gland microsomes of both molluscs. The microsomal parameters tended to be higher in female than male mussels, but the responses of the sexes to oil-exposure were not obviously different. With recovery the elevated microsomal parameters declined and the changes paralleled the depuration of polynuclear aromatic hydrocarbons from the tissues. Few changes were seen in benzo[a]pyrene hydroxylase activity. It is concluded that some of the observed enzyme changes, particularly in periwinkles, could have a potential for application in pollution monitoring, but that the in vivo function of these enzymes must first be elucidated.