Pinus nigra and Pinus pinaster needles as passive samplers of polycyclic aromatic hydrocarbons

Nine polycyclic aromatic hydrocarbons (PAHs) were analysed in pine needles of different ages (from 6 to 30 months) collected from two species, Pinus nigra and Pinus pinaster, in seven sites located along a transect from a suburban to a rural area of Genoa (Italy). In all sites and for both species, concentrations of more volatile PAHs (phenanthrene, anthracene, fluoranthene, pyrene) were higher than those for other less volatile PAHs, which are preferentially sorbed to airborne particulates (benzo[a]anthracene, chrysene, benzofluoranthenes, benzo[a]pyrene). Concentrations of total PAHs found in P. nigra in the rural sites were, on the average, 2.3 times higher than those in P. pinaster growing nearby. In both pine species, concentrations of volatile PAHs increased according to needle age. Annual trends of other PAHs were more variable, with a general decrease in older needles. P. pinaster needles are shown to be more reliable passive samplers, since they are more resistant to plant diseases, and considerable variation in PAH concentration was observed in P. nigra needles with moulds and fungi.     

Polycyclic aromatic hydrocarbons in the surface soils from outskirts of Beijing, China

Surface soils from the outskirts of Beijing were analyzed for 16 priority polycyclic aromatic hydrocarbons (PAHs) using gas chromatography and mass spectrometry (GC-MS). The distribution map of total PAHs content was obtained as a contour plot. The concentration range of 16 PAHs varied by over two orders of magnitude from 0.016 microg g-1 in rural to 3.884 microg g-1 in suburban soils with the relatively standard deviation of 70.5%, showing large differences in the extent of PAHs pollution at the various sampling sites. It was notable that the concentration of BaP was 0.005-0.270 microg g-1 with a mean of 0.055 microg g-1. In general, the distribution of PAHs centered on the high molecular weight PAHs known to be carcinogenic. The 4-6 ring PAHs represented about 66% in rural samples and 70% in suburban soils of the total PAHs found. There was relatively good relationship among most of the individual PAHs and the compounds of Pyr, BaA, Flu, BbF, BaP, Chr and Ph gave strong correlation (r>0.8) with the sum of PAHs. The selected marked compounds, a principal component analysis (PCA) and special PAHs compound ratios (Ph/An vs Flu/Pyr; summation operator COMB/ summation operator EPA-PAHs) suggest the pyrogenic origins, especially traffic exhausts, are the dominant sources of PAHs in Beijing outskirts soils.     

Assessment of air pollution in Nagasaki City: determination of polycyclic aromatic hydrocarbons and their nitrated derivatives, and some metals

Air pollutants such as polycyclic aromatic hydrocarbons (PAHs), their nitrated derivatives (NPAHs), and some metals on airborne particles in Nagasaki city, Japan were determined over a period of 12 months by high-performance liquid chromatography with chemiluminescence, fluorescence and flameless atomic absorption spectrometry. The average concentrations (range) were 18.24 (4.07-41.54) ng/m3 for total PAHs, 0.91 (0.23-4.10) pg/m3 for NPAHs, 7.95 (1.71-16.31) ng/m3 for Pb, 11.56 (3.35-24.96) ng/m3 for Mn and 3.79 (0.97-14.71) ng/m3 for Ni (n = 136). The toxic equivalency factors adjusted concentration of total PAHs determined in Nagasaki city area was 2.33 ng/m3. Concentrations of total PAHs and NPAHs in winter were higher than those in summer. In a weekly variations study, total PAHs and NPAHs concentrations, as well as traffic volume showed a similar tendency with all values higher during weekdays and lower at the weekend. The correlation coefficients between total PAHs or NPAHs and traffic volume were 0.781 and 0.818, respectively. These results suggested that one of the main sources for NPAHs and PAHs in a city area might be motor vehicles.     

Binding of polycyclic aromatic hydrocarbons by humic acids formed during composting

Binding of two model polycyclic aromatic hydrocarbons (PAHs), phenanthrene and pyrene, by humic acids (HAs) isolated from an organic substrate at different stages of composting and a soil was investigated using a batch fluorescence quenching method and the modified Freundlich model. With respect to soil HA, the organic substrate HA fractions were characterized by larger binding affinities for both phenanthrene and pyrene. Further, isotherm deviation from linearity was larger for soil HA than for organic substrate HAs, indicating a larger heterogeneity of binding sites in the former. The composting process decreased the binding affinity and increased the heterogeneity of binding sites of HAs. The changes undergone by the HA fraction during composting may be expected to contribute to facilitate microbial accessibility to PAHs. The results obtained also suggest that bioremediation of PAH-contaminated soils with matured compost, rather than with fresh organic amendments, may result in faster and more effective cleanup.     

Enhanced degradation of polycyclic aromatic hydrocarbons by biodegradation combined with a modified Fenton reaction

A study has been conducted to enhance degradation of a mixture of polycyclic aromatic hydrocarbons (PAHs) by combining biodegradation with hydrogen peroxide oxidation in a former manufactured gas plant (MGP) soil. An active bacterial consortium enriched from the MGP surface soil (0-2 m) biodegraded more than 90% of PAHs including 2-, 3-, and 4-ring hydrocarbons in a model soil. The consortium was also able to transform about 50% of 4- and 5-ring hydrocarbons in the MGP soil. As a chemical oxidant, Fenton's reagent (H2O2 + Fe2+) was very efficient in the destruction of a mixture of PAHs (i.e., naphthalene (NAP), fluorene (FLU), phenanthrene (PHE), anthracene (ANT), pyrene (PYR), chrysene (CHR), and benzo(a)pyrene (BaP)) in the model soil; noticeably, 84.5% and 96.7% of initial PYR and BaP were degraded, respectively. In the MGP soil, the same treatment destroyed more than 80% of 2- and 3-ring hydrocarbons and 20-40% of 4- and 5-ring compounds. However, the low pH requirement (pH 2-3) for optimum Fenton reaction made the process incompatible with biological treatment and posed potential hazards to the soil ecosystem where the reagent was used. In order to overcome such limitation, a modified Fenton-type reaction was performed at near neutral pH by using ferric ions and chelating agents such as catechol and gallic acid. By the combined treatment of the modified Fenton reaction and biodegradation, more than 98% of 2- or 3-ring hydrocarbons and between 70% and 85% of 4- or 5-ring compounds were degraded in the MGP soil, while maintaining its pH about 6-6.5.     

Aquatic predicted no-effect concentration for three polycyclic aromatic hydrocarbons and probabilistic ecological risk assessment in Liaodong Bay of the Bohai Sea, China

Predicted no-effect concentration (PNEC) is often used in ecological risk assessment to determine low-risk concentrations for chemicals. In the present study, native marine species were selected for toxicity testing. The PNECs for three polycyclic aromatic hydrocarbons (PAHs), specifically phenanthrene (Phe), pyrene (Pyr), and benzo[a]pyrene (BaP), were derived from chronic and acute toxicity data with log-normal statistical methods. The achieved PNECs for Phe, Pyr, and BaP were 2.33, 1.09, and 0.011 μg/L, respectively. In Jinzhou Bay and the Shuangtaizi River Estuary of Liaodong Bay in the Bohai Sea, China, the surface water concentrations of the three PAHs were analyzed by gas chromatography–mass spectrometry. Based on two probabilistic ecological risk assessment (PERA) methods, namely probabilistic risk quotient and joint probability curve, the potential risk of Phe, Pyr, and BaP in Jinzhou Bay and Shuangtaizi River Estuary was assessed. The same order of ecological risk (BaP > Phe > Pyr) was found by both models. Our study considered regional characteristics of marine biota during the calculation of PNECs, and the PERA methods provided probabilities of potential ecological risks of chemicals. Within the study area, further research on BaP is required due to its high potential ecological risk.     

PM10-bound polycyclic aromatic hydrocarbons (PAHs) in the Greater Area of Athens, Greece

Polycyclic aromatic hydrocarbons (PAHs) associated to ambient PM10 were determined at four sites within the Greater Athens Area (GAA), Greece, during the period May 2001-June 2002. Daily average PM10 samples were collected using reference samplers installed in two urban locations (Maroussi, MAR and Aristotelous, ARI), a mixed urban-industrial location (Elefsina, ELE), and a background location (Thracomacedones, THR). Spatial and temporal variation of ambient PAH levels and possible relationships with conventional air pollutants and meteorological parameters were investigated. Moreover, source identification was attempted using diagnostic ratios. The PAH concentrations observed in this study, even in downtown Athens, were towards the lowest end of the range of values reported for other European urban locations. The mean concentration of the well known carcinogen B[alpha]Py was at all four sites below the proposed value of 1 ng m-3 (annual average assessment threshold). Automobile traffic was identified as the major PAH source in the GAA exhibiting greatest contribution in the urban sites.     

Polycyclic aromatic hydrocarbons in the ambient air of suburban and industrial regions of central Taiwan

The concentrations of gas-phase and particle-bound polycyclic aromatic hydrocarbons (PAHs) were measured simultaneously at an industrial area (Taichung Industrial Park) and a suburban area (Tunghai University Campus) in Taichung, Taiwan. Twenty-four hours samplings for two consecutive days were performed between August and December 2002 at both sampling sites. Ambient air particle-bound PAHs were collected on quartz filters and gas-phase PAHs were collected on glass cartridges using a PUF Sampler, respectively. Both types of samples were extracted with a DCM/n-hexane mixture (50/50, v/v) for 24 h, then the extracts were subjected to gas chromatography-mass spectrometric (GC-MS) analysis. Total PAHs concentrations at the Taichung Industrial Park (TIP) sampling site and the Tunghai University Campus (THUC) sampling site were found to be 1232.3+/-963.6 and 609.8+/-356.3 ng/m(3), respectively. Stationary combustion processes were mainly responsible for PAHs sources at the TIP sampling site, while traffic vehicle exhaust was the largest contributor for PAHs sources at the THUC sampling site.     

Characterizations of particle-bound trace metals and polycyclic aromatic hydrocarbons (PAHs) within Tibetan tents of south Tibetan Plateau, China

INTRODUCTION: Exposure to trace metals and polycyclic aromatic hydrocarbons (PAHs) adsorbed on particulates is of a serious health concern. Levels of some trace metals in total suspended particulate and 13 PAHs of fine particulate matter were measured from nomadic tents in the southern Tibetan Plateau in summer 2010. RESULTS AND DISCUSSION: The indoor air within the tents was seriously polluted, mainly due to yak dung combustion. Average trace metal concentrations were much higher (range of indoor/outdoor ratio 61-291) than those of the outdoor air. Additionally, enrichment factors of most trace metals of indoor air were similar to those of outdoor air, indicating outdoor air quality of the studied area was possibly influenced by pollutants emitted from local tents. Mean concentrations of total PAHs and BaP within tents was 5372.45 and 364.79 ng/m(3), hundred times higher than that of outdoor air of the Tibetan Plateau. Three- and four-ring PAHs were the predominant components. The diagnostic ratio of BaA/(BaA + Chr) was 0.33. Since Tibetan women typically spend longer time within the tents, they were exposed to PAHs (BaP exposure = 1.81 μg/m(3)) about two times of other family members. Among all the PAHs, Bap contributed the most (82.6%) of the total carcinogenicity. Similarly, the excess lifetime cancer risk for women and other family members were 2.75 × 10(-4) and 1.27 × 10(-4), respectively, indicating Tibetan herdsmen, especially women who are in charge of most house chores were at risk for adverse health effects.     

Bioremediation of polycyclic aromatic hydrocarbon-contaminated saline-alkaline soils of the former Lake Texcoco

Polycyclic aromatic hydrocarbons (PAHs) such as phenanthrene, anthracene and Benzo[a]pyrene (BaP) are toxic for the environment. Removing these components from soil is difficult as they are resistant to degradation and more so in soils with high pH and large salt concentrations as in soil of the former lake Texcoco, but stimulating soil micro-organisms growth by adding nutrients might accelerate soil restoration. Soil of Texcoco and an agricultural Acolman soil, which served as a control, were spiked with phenanthrene, anthracene and BaP, added with or without biosolid or inorganic fertilizer (N, P), and dynamics of PAHs, N and P were monitored in a 112-day incubation. Concentrations of phenanthrene did not change significantly in sterilized Acolman soil, but decreased 2-times in unsterilized soil and >25-times in soil amended with biosolid and NP. The concentration of phenanthrene in unsterilized soil of Texcoco was 1.3-times lower compared to the sterilized soil, 1.7-times in soil amended with NP and 2.9-times in soil amended with biosolid. In unsterilized Acolman soil, degradation of BaP was faster in soil amended with biosolid than in unamended soil and soil amended with NP. In unsterilized soil of Texcoco, degradation of BaP was similar in soil amended with biosolid and NP but faster than in the unamended soil. It was found that application of biosolid and NP increased degradation of phenanthrene, anthracene and BaP, but to a different degree in alkaline-saline soil of Texcoco compared to an agricultural Acolman soil.     

Absorption of polycyclic aromatic hydrocarbons to cellulose

Polycyclic aromatic hydrocarbons (PAHs) are widespread toxic chemicals. The environmental fate of these chemicals is in part controlled by sorption to (organic matter in) sediments and soils. One of the most abundant organic matter compounds on earth is cellulose. Remarkably, sorption of PAHs to cellulose has hardly been studied; only two reports on the binding of some low-molecular-weight PAHs exist in the literature. In this study, sorption of PAHs to cellulose was investigated in more detail, by measuring isotherms for a series of 13 PAHs, covering a wide hydrophobicity range. The results indicated that sorption of PAHs to cellulose is a linear partition process for all PAHs investigated (phenanthrene-indeno[1,2,3-cd]pyrene). The affinity of PAHs for cellulose appeared to be about 400 times lower than for octanol and even up to 300000 times lower than for black carbon or coal. Linked to the estimated yearly production of cellulose and black carbon, these results suggest that cellulose is probably not a major environmental sorption domain for PAHs.     

采油废水中多环芳烃的生态风险评价

先利用C-18固相萃取小柱富集大港油田港东联合处理站污水处理站的采油废水中16种多环芳烃(PAHs,即萘、苊烯、苊、芴、菲、蒽、荧蒽、芘、、苯并[a]蒽、苯并[b]荧蒽、苯并[k]荧蒽、苯并[a]芘、茚并[1,2,3-cd]芘、二苯并[a,h]蒽和苯并[g,h,i]苝),再用气相色谱/质谱(GC/MS)分析测定其浓度,以评价PAHs的去除率和生态风险。结果表明:(1)采油废水经处理后,COD、石油类去除率分别达到82.27%、91.06%;外排水COD、石油类达到《污水综合排放标准》(GB 8978—1996)一级标准要求,优于中国采油废水处理的一般水平。(2)采油废水主要以2、3环的PAHs为主,约占总量的93%以上。(3)苯并[a]芘超过《地表水环境质量标准》(GB 3838—2002)中限值。(4)处理前的采油废水中蒽、菲和苯并[a]芘具有一定的生态风险;处理后的外排水中萘、蒽、菲、荧蒽、苯并[a]芘的暴露浓度(PEC)/预测无效应浓度(PNEC)均小于1,目前尚未对环境造成威胁。但是8种PAHs(苊烯和苯并类PAHs除外)总和表现出较大的毒性,需要引起重视。     

Polycyclic aromatic hydrocarbons in the sediments of the South China Sea

Sixteen sediment samples, collected from the South China Sea, were analyzed for 11 parent polycyclic aromatic hydrocarbons (PAHs) using gas chromatography and gas chromatography-mass spectrometry. Total concentrations of the 11 PAHs studied in the sediments ranged from 24.7 to 275.4 ng/g with a mean of 145.9 ng/g dry sediment. PAH concentrations displayed a consistent distribution trend with the sediment organic carbon content. The linear regression analysis showed that the total concentration of PAHs in the sediment was significantly correlated to the sediment organic carbon content with a correlation coefficient of 0.735 (n=16). Special PAH compound ratios, such as phenanthrene/anthracene and fluoranthene/pyrene, were calculated to evaluate the relative importance of different origins. The collected data showed that pyrolytic input from anthropogenic combustion processes was predominant at almost all the stations investigated. Only one station, located in the proximity of oil wells, appeared to be contaminated predominantly by petrogenic input. Three anthropogenic PAHs, i.e. pyrene, benzo[a]pyrene and benzo[e]pyrene, exhibited similar distribution patterns in the studied area, implying that these compounds possess identical sources. However, perylene did not entirely follow the distribution trend of the three PAHs, suggesting that the sediment perylene probably derived from other sources such as in situ biogenic origins. Dibenzothiophene, a sulfur heterocyclic aromatic compound, was also measured in this study.     

Biomonitoring seasonal variation of urban air polycyclic aromatic hydrocarbons (PAHs) using Ficus benghalensis leaves

Temporal and seasonal variations of polycyclic aromatic hydrocarbons (PAHs) concentrations in leaves of Ficus benghalensis were investigated in Varanasi city (India). Leaf samples were collected from six sites from urban area of Varanasi and from a control site. PAH extraction was done by sonication in dichloromethane-acetone and quantification by GC-MS. In January total leaf PAHs concentrations at all the urban sites were twice higher as compared to other season's viz. summer and rainy. In contrast, at the control site leaf PAHs concentrations showed lower values than urban sites. The maximum concentrations of total PAHs in winter were due to the medium molecular weight PAHs which increases with respect to both low and high molecular weight PAHs. The temporal variation of medium molecular weight PAHs was similar both at the urban and remote sites. These results support biomonitoring ability of Ficus benghalensis leaves to temporal variations in PAHs contamination.     

Emission inventory and sources of polycyclic aromatic hydrocarbons in the atmosphere at a suburban area in Taiwan

The application of a chemical mass balance air pollution model to ambient measurements of polycyclic aromatic hydrocarbons (PAHs) is presented. Sixteen air samples were collected at seven sites in a suburban area in Taiwan and analyzed for the concentration of 21 compounds between July 2001 and September 2001. Each ambient sample was evaluated for the PAH contribution from six sources (heavy oil combustion, natural gas combustion, coal combustion, diesel combustion, vehicles and municipal solid waste incinerator). Average predictions agree well with the emission inventory. By this method, the average contributions are 49%, 14%, 22%, 12%, and 2% from vehicles, heavy oil combustion, natural gas combustion, coal combustion and diesel combustion at these seven receptors. By far, vehicles are the major PAH emission sources and municipal solid waste incinerator is a minor contributor. The calculated result of particulate PAHs is compared with that of total (gaseous and particulate) PAHs. The estimate based on total PAHs is better than the estimate based on particulate PAHs only. Contributions of eight low reactive PAHs for the same emission sources and receptors were calculated. Atmospheric reactivity seems not a problem for source apportionment in this study.     

Analysis of nitrated polynuclear aromatic hydrocarbons

A derivatization-gas chromatography/electron capture detector (GC/ECD) method has been developed for the measurement of trace nitrated polynuclear aromatic hydrocarbons (NPAHs) in air. The method involves first the derivatization of parent nitro-PAHs to their corresponding fluorinated derivatives, followed by GC/ECD analysis. The sensitivity of the method is an order of magnitude higher than those of direct GC/ECD analysis of NPAHs themselves. The method is simple and robust and thus ideally suited for the routine monitoring of NPAHs in air samples. The sensitivity and reproducibility of GC/negative ion chemical ionization MS (NICIMS) for the measurement of NPAHs after derivatization has been evaluated. The method has sensitivity comparable to GC/ECD, but is less reproducible in quantification. The method is therefore suitable for method validation and NPAHs peak confirmation rather than routine operations.     

Determination of polycyclic aromatic hydrocarbons in roasted coffee

Polycyclic aromatic hydrocarbons (PAHs) are suspected to be carcinogenic and mutagenic. This study describes the presence of PAHs in light, medium and dark roasted coffee including instant and decaffeinated brands. Total PAHs concentration was related to the degree of roasting with light roasted coffee showing the least and dark roasted coffee showing the highest level. Both instant and decaffeinated coffee brand showed lower levels of PAHs. Naphthalene, acenaphthylene, pyrene and chrysene were the most abundant individual isomers. The concentrations ranged from 0 to 561 ng g^?1 for naphthalene, 0 to 512 ng g^?1 for acenaphthylene, 60 to 459 ng g^?1 for pyrene and 56 to 371 ng g^?1 for chrysene. Thus, roasting conditions should be controlled to avoid the formation of PAHs due to their suspected carcinogenic and mutagenic properties.     

Characteristic study of polycyclic aromatic hydrocarbons for fine and coarse particulates at Pastureland near Industrial Park sampling site of central Taiwan

The concentrations of ambient air polycyclic aromatic hydrocarbons were measured in a farm area (Tunghai University Pastureland) between August 2001 and April 2002 in central Taiwan, Taichung. Particle-bound polycyclic aromatic hydrocarbons (PAHs) were collected on quartz filters, the collected sample was extracted with a dichloromethane (DCM)/n-hexane mixture (50/50, v/v) for 24 h, and then the extracts were subjected to gas chromatography-mass spectrometric analysis. The PM2.5 (fine particulate) and PM2.5-10 (coarse particulate) total PAHs concentrations at the Tunghai University Pastureland sampling site were found to be 180.62 ngm(-3) and 164.98 ngm(-3), respectively. In general, the concentrations of polycyclic aromatic hydrocarbons were higher in spring and winter than those of summer and autumn for either PM2.5 or PM2.5-10 in Pastureland in central Taiwan. Moreover, coarse particulates are the dominant species during the dust storm season (March and April) in central Taiwan.     

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.     

Synergistic solubilization of polycyclic aromatic hydrocarbons by mixed anionic-nonionic surfactants

Water solubility enhancements of naphthalene (Naph), acenaphthylene (Acen), anthracene (An), phenanthrene (Phen) and pyrene (Py) by micellar solutions of single and mixed anionic-nonionic surfactants were measured and compared. Effects of typical inorganic ions, such as NH(4)(+), Na(+) and Mg(2+) coexisted with the organic pollutants (in soils) on water solubilities of polycyclic aromatic hydrocarbons (PAHs) in the presence of single and mixed surfactants were also investigated. Solubilities of PAHs in water are greatly enhanced in a linear fashion by each of Triton X-100 (TX100), Triton X-305 (TX305), Brij 35, and sodium dodecyl sulfate (SDS). Solubility enhancement efficiencies of surfactants above the critical micelle concentration (CMC) follow the order of TX100>Brij 35>TX305>SDS. PAHs are solubilized synergistically in mixed anionic-nonionic surfactant solutions, especially at low surfactant concentrations. The synergistic power of the mixed surfactants is SDS-TX305>SDS-Brij 35>SDS-TX100. Synergistic effect of a given mixed-surfactant solution on different PAHs also appears to be linearly related to the solute logK(ow). The noted synergism for the mixed surfactants is attributed to the formation of mixed micelles, the lower CMC of the mixed-surfactant solutions, and the increase of the solute's molar solubilization ratio or micellar partition coefficients (K(mc)) because of the lower polarity of the mixed micelles. Suitable quantity of inorganic cations can enhance the solubilization capacities of anionic-nonionic mixed surfactants, the effect being Mg(2+)>NH(4)(+)>Na(+). The water solubility of pyrene was slightly increased by anthracene and significantly increased by 1,2,3-TCB in the presence of SDS-Brij 35. Mixed surfactants may improve the performance of surfactant-enhanced remediation of soils and sediments by decreasing the applied surfactant level and thus the remediation cost.