Individual Polycyclic Aromatic Hydrocarbons Research Articles

Screening Risk Assessment of Agricultural Areas under a High Level of Anthropopressure Based on Chemical Indexes and VIS-NIR Spectroscopy.

Intensive anthropogenic activity may result in uncontrolled release of various pollutants that ultimately accumulate in soils and may adversely affect ecosystems and human health. Hazard screening, prioritisation and subsequent risk assessment are usually performed on a chemical-by-chemical basis and need expensive and time-consuming methods. Therefore, there is a need to look for fast and reliable methods of risk assessment and contamination prediction in soils. One promising technique in this regard is visible and near infrared (VIS-NIR) spectroscopy. The aim of the study was to evaluate potential environmental risk in soils subjected to high level of anthropopressure using VIS-NIR spectroscopy and to calculate several risk indexes for both individual polycyclic aromatic hydrocarbons (PAHs) and their mixture. Results showed that regarding 16PAH concentration, 78% of soil samples were contaminated. Risk assessment using the most conservative approach based on hazard quotients (HQ) for 10 individual PAHs allowed to conclude that 62% of the study area needs further action. Application of concentration addition or response addition models for 16PAHs mixture gave a more realistic assessment and indicates unacceptable risk in 23% and 55% of soils according to toxic units (TUm) and toxic pressure (TPm) approach. Toxic equivalency quotients (TEQ) were below the safe limit for human health protection in 88% of samples from study region. We present here the first attempt at predicting risk indexes using VIS-NIR spectroscopy. The best results were obtained with binary models. The accuracy of binary model can be ordered as follows: TPm (71.6%) < HI (85.1%) < TUm (87.9%) and TEQ (94.6%). Both chemical indexes and VIS-NIR can be successfully applied for first-tier risk assessment.

Competitive Adsorption of Polycyclic Aromatic Hydrocarbons to Carbon Nanotubes and the Impact on Bioavailability to Fathead Minnow (Pimephales promelas)

Recent studies investigating the influence of carbon nanotubes (CNTs) on the bioavailability of organic contaminants have mostly focused on single-solute systems; however, a more likely scenario in the natural environment is a multisolute system where chemical interactions at the surface of the CNT may alter the bioavailability of these chemicals. In the present study bisolute adsorption isotherms of pairs of chemically similar polycyclic aromatic hydrocarbons (PAHs) by multiwalled carbon nanotubes (MWCNTs) were established, in conjunction with quantifying the bioavailability of the 2 competing MWCNT-adsorbed PAHs to Pimephales promelas using bile analysis by high-performance liquid chromatography with fluorescence detection. The results showed that whereas adsorption and bioavailability of chemically similar PAHs (anthracene and phenanthrene, and fluoranthene and pyrene) were the same in a single-solute system, in bisolute systems, PAHs that could better align or flex with the MWCNT surface due to morphological characteristics would outcompete the more rigid or planar PAHs. The bioavailability of individual PAHs in bisolute solutions increased by as much as 50% compared with single-solute solutions. However, the relationship between adsorption (i.e., Kd ) and concentration of PAH in the fish bile was similar in single and bisolute systems. This finding indicates that competitive interactions at the surface of MWCNTs influence bioavailability by way of altering adsorption affinity in a moderately predictable manner. Environ Toxicol Chem 2020;39:1702-1711. © 2020 SETAC.

Mechanism of biochar as a biostimulation strategy to remove polycyclic aromatic hydrocarbons from heavily contaminated soil in a coking plant

Twelve types of biochars were applied in a heavily contaminated soil from a coking plant to gain insights into the mechanism responsible for the microbial response to the addition of different biochar types into soil and biodegradation removal of polycyclic aromatic hydrocarbons (PAHs). The biochars primarily influenced the bacterial community at the genus level, while they strongly affected the fungal community not only at the genus level but also at the class and phylum levels. Principal component analysis (PCA) indicated that the inorganic minerals in biochars played a key role in stimulating microbial abundance (bacteria) and diversity (bacteria and fungi) in soil from the coking plant, and significantly negative correlations between the residual concentrations of PAHs in biochar-treated soils and the ash contents in biochars (generally, p < 0.05 for PAHs with 3–6 rings) were observed. These findings further suggested a positive effect of the inorganic minerals of biochars on stimulating changes in microorganisms, which could contribute to the biodegradation of PAHs in soil from the coking plant. Generally, the addition of biochars to the soils increased the biodegradation percentages of individual PAHs by 3.0–60.3% compared to those of the control. Among these biochars, rice straw-derived biochar pyrolyzed at 600 °C (RS6) effectively degraded PAHs from soil, with increasing biodegradation percentages of individual PAHs from 40.00% to 58.84%. This result was likely attributed to that the substantially specific Acidobacteria-related genera in RS6-treated soil were detected, which contributed to the effective biodegradation of PAHs. Accordingly, biochars pyrolyzed at a relatively high heating temperature with rice straw feedstock containing relatively high mineral nutrients are recommended for application to heavily PAH-contaminated soils.

Occurrence and probabilistic risk assessment of PAHs in water and sediment samples of the Diep River, South Africa

This study investigated the levels of polycyclic aromatic hydrocarbons (PAHs) in water and sediment samples of the Diep River freshwater system of Western Cape Province, South Africa. A solid-phase extraction - gas chromatography - flame ionisation detection (SPE-GC-FID) method was utilised to simultaneously determine the 16 United States Environmental Protection Agency (US EPA) listed priority PAHs in water and sediment samples. The seasonal averages of individual PAH detected at the studied sites, ranged between not detected (Nd) and 72.38 ± 9.58 μg/L in water samples and between Nd and 16.65 ± 2.63 μg/g in the corresponding sediment samples. The levels of PAHs measured in water and sediment samples were subjected to probabilistic risk assessment to predict the possibility of regulatory values being exceeded. The average percentage exceedence of 63.26 was obtained for PAHs in water samples of the Diep River, while the corresponding average percentage exceedence obtained for sediment sample was 63.71. Sufficient exposure of humans and aquatic organisms to the exceedance levels obtained, would cause adverse health effect.

Carcinogenic organic content of particulate matter at urban locations with different pollution sources

Polycyclic aromatic hydrocarbons (PAHs) are compounds known for their adverse effects on human health. Many of them are proven carcinogens, especially those with 5 and 6 aromatic rings, which under normal tropospheric conditions are found in the particle-phase. Benzo(a)pyrene (BaP) is often measured as their general representative. Sarajevo, the capital of Bosnia and Herzegovina, is among the European cities with the poorest air quality. However, in Sarajevo PAHs are neither routinely measured within the air quality monitoring network nor have been a subject of extended, continuous field studies during the most polluted cold periods of the year. The capital of Croatia, Zagreb, is located approximately 300 km air distance north-west from Sarajevo. PAH mass concentrations in Zagreb have been measured continuously since 1994 within air quality monitoring networks. During winter 2017/2018, the SAFICA project (Sarajevo Canton Winter Field Campaign 2018) was carried out in order to characterize the chemical composition of organic and inorganic aerosol in the Sarajevo Canton. This paper presents the results of PAH measurements in the cities of Sarajevo and Zagreb at one urban location per city. Daily (24 h), continuous samples of PM10 (particulate matter with aerodynamic diameters ≤10 μm) were collected during heating season, from December 27, 2017 to February 27, 2018. Mass concentrations of eleven particle-phase PAHs in Sarajevo and Zagreb from filter samples collected during the same period were compared. The average BaP ambient mass concentrations in Sarajevo and Zagreb were 6.93 ng m−3 and 3.11 ng m−3, respectively. The contribution of BaP to the total PAH mass concentration was similar at both locations (11%). However, much higher contributions of particle-phase fluoranthene and pyrene were found in Sarajevo. Contributions of individual PAH, diagnostic ratios and factor analysis indicate that combustion of gasoline and diesel from vehicle traffic are a potential source of PAHs at both locations, as well as combustion of other liquid fossil fuels (petroleum and fuel oil). Wood burning was occasionally indicated as a PAH emission source in Zagreb, while in Sarajevo the contribution of PAHs from wood and coal combustion was more evident. Calculated value for total carcinogenic potency (TCP) of PAHs, which was estimated using toxic equivalence factors from the literature, in PM10 samples collected in Sarajevo was more than twice higher than in Zagreb (10.6 ng m−3 and 4.7 ng m−3, respectively). BaP had the highest contribution to the TCP at both locations (69 and 67%).

Long-term willows phytoremediation treatment of soil contaminated by fly ash polycyclic aromatic hydrocarbons from straw combustion

A three-year experiment was conducted to investigate willows of Salix × smithiana Willd. (S. smithiana) phytoremediation of soil contaminated by polycyclic aromatic hydrocarbons (PAHs) derived by fly ash from biomass combustion. The total removal of ash PAHs in phytoremediation treatment was 50.9% after three consecutive years while the ash PAHs were decreased in natural attenuated soil by 9.9% in the end of the experiment. The ash and spiked PAHs with low and medium molecular weight were susceptible to be removed in higher rates than high molecular weight PAHs. Lower bioconcentration factors of individual PAHs were observed in willow shoots than in roots. The estimated relative direct removal of PAHs by S. smithiana in phytoremediation was significantly lower than 1% suggesting that the contribution of S. smithiana to take up PAHs from soil was negligible and the degradation of PAHs occurred mainly in soil. Phytoremediation using S. smithiana could be seen as a feasible and environmentally friendly approach of arable soils impacted by a PAH contaminated biomass fly ash.

Nonionic and anionic surfactant-washing of polycyclic aromatic hydrocarbons in estuarine sediments around an industrial harbor in southern Taiwan

Various surfactants, such as nonionic Triton X-100 and Simple Green™ (SG), and anionic sodium dodecylsulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS) were utilized to remove polycyclic aromatic hydrocarbons (PAHs) from heavily contaminated harbor sediments dredged from Kaohsiung Harbor in Taiwan. Desorption/re-sorption equilibrium, kinetics, and washability of PAHs using the selected surfactant were evaluated under different critical micelle concentrations (CMC). Experimental results revealed that the desorption rate of high molecular weight PAHs was greater than those of low molecular weight PAHs, and the anionic SDS was relatively effective in the removal of total PAHs (>50%) compared to the other surfactants. The correlation between the effectiveness of the surfactant washing processes and the physicochemical properties of individual PAH was statistically analyzed. The resulting data suggested that hydrophobic factors (Kow, Koc and Sw) affected PAH treatability more than the reactivity of PAH (electron affinity and ionization potential). Since the adsorption of anionic surfactant altered the hydrophobicity of organic matter in the sediment, PAHs preferred transferring from the sediment to the hydrophobic core of micelles in aqueous solution. Nevertheless, the nonionic surfactant enhanced the PAH partition in the aqueous phase, thus increasing the micellar solubilization of PAH.

Polycyclic aromatic hydrocarbons in bottom sediments of an inner-city lake in the zone of discharge of surface runoff

The study determined the content of polycyclic aromatic hydrocarbons (PAHs) in the bottom sediments of an inner-city Sredny Kaban Lake (Kazan, Russia) in the places of the organized release of untreated surface stormwater runoff within the catchment of the city. The content of 15 PAHs included in the priority list of PAHs for environmental research in the Russian Federation and in other countries was experimentally studied. The average content of the total PAHs studied (333.4 μg/kg) in the bottom sediments of the lake indicates a low degree of pollution. The analysis of the ratio of the content of individual PAHs reveals the main sources of their entry: fuel combustion (vehicles) and oil pollution of the surface water. Benzo(g,h,i)perylene and Benz(a)pyrene represent the largest contribution to the hazard coefficient of all studied PAHs for bottom sediments of the studied water body. Bottom sediments are composed mainly of particles with a size of 1–100 μm; the contribution of particles with a size of 0.1–1 μm was estimated to be up to 1%.

Classroom Dust-Bound Polycyclic Aromatic Hydrocarbons in Jeddah Primary Schools, Saudi Arabia: Level, Characteristics and Health Risk Assessment.

Data concerning polycyclic aromatic hydrocarbons (PAHs) in Jeddah’s schools, Saudi Arabia, and their implications for health risks to children, is scarce. Classroom air conditioner filter dusts were collected from primary schools in urban, suburban and residential areas of Jeddah. This study aimed to assess the characteristics of classroom-dust-bound PAHs and the health risks to children of PAH exposure. Average PAH concentrations were higher in urban schools than suburban and residential schools. Benzo (b)fluoranthene (BbF), benzo(ghi)perylene (BGP), chrysene (CRY) and Dibenz[a,h]anthracene (DBA) at urban and suburban schools and BbF, BGP, fluoranthene (FLT) and indeno (1, 2, 3, −cd)pyrene (IND) at residential schools were the dominant compounds in classroom dust. PAHs with five aromatic rings were the most abundant at all schools. The relative contribution of the individual PAH compounds to total PAH concentrations in the classroom dusts of schools indicate that the study areas do share a common source, vehicle emissions. Based on diagnostic ratios of PAHs, they are emitted from local pyrogenic sources, and traffic is the significant PAH source, with more significant contributions from gasoline-fueled than from diesel cars. Based on benzo[a]pyrene equivalent (BaPequi) calculations, total carcinogenic activity (TCA) for total PAHs represent 21.59% (urban schools), 20.99% (suburban schools), and 18.88% (residential schools) of total PAH concentrations. DBA and BaP were the most dominant compounds contributing to the TCA, suggesting the importance of BaP and DBA as surrogate compounds for PAHs in this schools. Based on incremental lifetime cancer risk (ILCingestion, ILCRinhalation, ILCRdermal) and total lifetime cancer risk (TLCR)) calculations, the order of cancer risk was: urban schools > suburban schools > residential schools. Both ingestion and dermal contact are major contributors to cancer risk. Among PAHs, DBA, BaP, BbF, benzo(a)anthracene (BaA), benzo(k)fluoranthene (BkF), and IND have the highest ILCR values at all schools. LCR and TLCR values at all schools were lower than 10−6, indicating virtual safety. DBA, BaP and BbF were the predominant contributors to cancer effects in all schools.

Background concentrations of polycyclic aromatic hydrocarbons (PAHs) in deep core sediments from the Norwegian Sea and the Barents Sea: A proposed update of the OSPAR Commission background values for these sea areas

Geochemical studies of 174 sediment cores collected by the MAREANO mapping program in Norwegian waters of the North Atlantic Ocean give new sets of values of background concentrations (BCs) for polycyclic aromatic hydrocarbons (PAHs) for the studied regions. The study is based on deep core sediment samples representing background levels of PAHs. The samples selected were only from the deeper parts of undisturbed sediment cores with low, stable concentrations of petrogenic and pyrogenic PAHs, with low variation for individual PAH compounds between the samples within the same core, and from below the parts of the cores dated with 210Pb to approximately the last 100–150 years. The results show that the main part of the studied area has BCs different from those previously established by OSPAR Commission (OSPAR) for the North-East Atlantic. Another area in central Barents Sea has a separate set of BCs of pyrogenic PAHs, apparently due to the influence from marginal ice zone mechanisms. A third area with its own set of BCs has been established for north-western Barents Sea off the coast of Svalbard, due to high natural contents of PAHs in this area. BCs for several PAHs not included in the present OSPAR list are also provided.

Variations of the composition of PAHs and the ratio of carbon and nitrogen in the soils of Batagaika thermoerosive carter in Northern Yakutia

Polycyclic aromatic hydrocarbons (PAHs) are the ubiquitous organic pollutants. They are formed as a result of incomplete oxidation of organic substance, for example, technogenic fuel combustion, heating system, wildfires, volcanism, and decomposition of organic residues. Special attention is given to pyrogenic factor of the formation of PAHs in soils. The subject of this research is PAHs in the soils of Batagaika thermoerosive carter in Northern Yakutia in Verkhoyansky Ulus in Yakutia. The author examines the peculiarities of two soil sections (indices B-VG-2019/1 and B-VG-2019/3). Both soils are post-pyrogenic and contain visible traces of a recent fire: embers are found in subsurface horizons of the examined sections, which indicate the recent fire. The following conclusion were formulated: 1) in soils, dicyclic PAHs account for 93%, while the proportions of tricyclic and tetracyclic compounds are roughly equivalent (4% and 3%, respectively); 2) the average values of individual PAHs in the upper (up to 30 cm) and lower (deeper than 30 cm) horizons differ. In the upper horizons, their total concentration is 27 ng/g, while in the lower horizons it is 14 ng/g; 3) in this case, the key biomarker of fires is naphthalene and its homologues. The absence of PAHs with considerable molecular weight most likely testifies to the relatively low fire intensity. The highest values of C/N ratio are noted in the bedding horizon: 10.89 and 3.31, and the lower soils are characterized with approximately 1, which is substantiated by the low content of carbon and nitrogen in the soil profile.

Rhizosphere-enhanced biosurfactant action on slowly desorbing PAHs in contaminated soil

We studied how sunflower plants affect rhamnolipid biosurfactant mobilization of slowly desorbing fractions of polycyclic aromatic hydrocarbons (PAHs) in soil from a creosote-contaminated site. Desorption kinetics of 13 individual PAHs revealed that the soil contained initially up to 50% slowly desorbing fractions. A rhamnolipid biosurfactant was applied to the soil at the completion of the sunflower cycle (75 days in greenhouse conditions). After this period, the PAHs that remained in the soil were mainly present in a slowly desorbing form as a result of the efficient biodegradation of fast-desorbing PAHs by native microbial populations. The rhamnolipid enhanced the bioavailable fraction of the remaining PAHs by up to 30%, as evidenced by a standardized desorption extraction with Tenax, but the enhancement occurred with only planted soils. The enhanced bioavailability did not decrease residual PAH concentrations under greenhouse conditions, possibly due to ecophysiological limitations in the biodegradation process that were independent of the bioavailability. However, biodegradation was enhanced during slurry treatment of greenhouse planted soils that received the biosurfactant. The addition of rhamnolipids caused a dramatic shift in the soil bacterial community structure, which was magnified in the presence of sunflower plants. The stimulated groups were identified as fast-growing and catabolically versatile bacteria. This new rhizosphere microbial biomass possibly interacted with the biosurfactant to facilitate intra-aggregate diffusion of PAHs, thus enhancing the kinetics of slow desorption. Our results show that the usually limited biosurfactant efficiency with contaminated field soils can be significantly enhanced by integrating the sunflower ontogenetic cycle into the bioremediation design.

Bisphenol A (BPA) and polycyclic aromatic hydrocarbons (PAHs) in the surface sediment and bivalves from Hormozgan Province coastline in the Northern Persian Gulf: A focus on source apportionment

This study investigates Polycyclic Aromatic Hydrocarbons (PAHs) and Bisphenol-A (BPA) pollution in coastal sediments and bivalves of Hormozgan Province coastline. The results indicated that the BPA concentration in some bivalves reached up to 340.16 ng g−1. The mean BPA concentration in the sediment samples was also 787.01 ng g−1. The ∑PAHs content in sediments ranged from 14.54 to 85.00 ng g−1, while values for bivalves ranged from 5.37 to 16.40 ng g−1. Individual PAH concentrations in sediments exceeded those in bivalves for which only LMW PAHs were detected. A combination of techniques including Self-Organizing Maps (SOM), Positive Matrix Factorization (PMF), and Cluster Analysis (CA) were applied and both petrogenic and pyrogenic sources were identified. The risk of PAHs in the sediments was relatively low according to the sediment quality guidelines. The health risk indices suggest that exposure to PAHs through bivalve consumption does not impose harmful health effects upon consumers.

Occurrence of PAHs in water samples of the Diep River, South Africa

Occurrence of polycyclic aromatic hydrocarbons (PAHs) in freshwater may aggravate the water crisis currently being experienced in the Western Cape Province of South Africa. However, there is dearth of data on the levels of PAHs, which is necessary for effective assessment of water quality as well as remediation strategies. This study therefore assessed levels of PAHs in the Diep River freshwater system of Western Cape Province, South Africa. A liquid-liquid extraction solid-phase extraction gas chromatography flame ionisation detection (LLE-SPE-GC-FID) method was developed to simultaneously determine the 16 United States Environmental Protection Agency (USEPA) listed priority PAHs in water samples. The SPE-GC-FID method allowed an acceptable linearity (R2 &gt; 0.999) within the calibration range of 1 to 50 µg/mL. Instrument detection limits ranged between 0.02 and 0.04 µg/mL and instrument quantification limits between 0.06 and 0.13 µg/mL. Recovery study results were also acceptable (83.69–96.44%) except for naphthalene, which had recovery of 60.05% in spiked water matrix. The seasonal averages of individual PAH detected at the studied sites ranged between not detected (nd) and 72.38 ± 9.58 µg/L in water samples.

Field analysis of PAHs in surface sediments of the Pearl River Estuary and their environmental impacts.

Based on a monthly field survey in 2011 of the Pearl River Estuary, the dynamics of polycyclic aromatic hydrocarbons (PAHs) in surface sediments (depth < 5cm) were explored. The seasonal variations in PAH level and composition were investigated in this study, as well as their environmental behaviors, the role of particles, and source apportionment. The concentration of the sum of 16 priority PAHs (defined as ∑16PAHs) ranged from 0.32 to 1.10μg/g, while that of the sum of 62 PAHs (defined as ∑tPAHs) varied from 0.83 to 2.75μg/g. The levels of both the ∑16PAHs and ∑tPAHs peaked in February, although the minimum levels appeared in different months-December and August, respectively. The seasonal difference in the ∑tPAHs was significant (flood season, 7.69μg/g; dry season, 10.51μg/g). The 5-ring PAH compound (e.g., perylene) was the most abundant and was responsible for 35% of the total, which implied a terrestrial input source via the Pearl River. Sediment particles were predominantly composed of clayed sand, and sediment PAHs showed a greater tendency to be adsorbed onto the large-sized particles rather than the fine fractions. Total organic carbon (TOC) could considerably facilitate the sediment PAHs. Principal component analysis revealed that vehicle emission sources, petroleum sources, and combustion sources were the major anthropogenic contamination sources. The diagnostic ratios of various individual PAHs were also explored. These findings are particularly useful for understanding the geochemistry of organic pollutants in the complex estuarine environment.

Exposure to polycyclic aromatic hydrocarbons and risk for premature ovarian failure and reproductive hormones imbalance

Polycyclic aromatic hydrocarbons (PAHs) are a typical class of persistent organic pollutants that is ubiquitous worldwide. Previous animal studies suggested that PAHs had adverse effects on female reproduction. However, the human data regarding relationship of PAHs exposure with women reproductive health, such as ovarian dysfunction, are scarce. In this case-control study, the associations of serum levels of PAHs with the risk of premature ovarian failure (POF) and reproductive hormones in Chinese women were investigated, with recruiting 157 POF patients and 217 healthy women. The serum levels of 12 types of PAHs, as well as reproductive hormones, including follicle-stimulating hormone, luteinizing hormone and anti-mullerian hormone, were determined. In the logistic regression models, most individual PAH congeners showed significantly positive correlations with the risk of POF (p < 0.05), except for fluorine and pyrene. Benzo(a)pyrene (BaP), as the most carcinogenic PAH congener, was observed to be significantly positively associated with the risk of POF. After adjustment for age, body mass index, educational levels and household income, per one-unit increase in the log-transformed BaP concentration was significantly correlated with 2.191-fold increased risk of POF (OR = 2.191, 95%CI: 1.634–2.938, p < 0.05). To the best of our knowledge, this is the first study to report an association between internal exposure levels of PAHs and the increased risk of POF in women.

A Preliminary Study on Pollution of Polycyclic Aromatic Hydrocarbons in Soil around a Thermal Power Plant of Xi'an City

To understand the status and risk of polycyclic aromatic hydrocarbons (PAHs) pollution in industrial areas in China. The total of 4 surface soil samples were collected from a thermal power plant of Xi’an. The concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) were analyzed by high performance liquid chromatography (HPLC). In addition, the composition, source, pollution level and risk assessment of PAHs in surface soil of thermal power plant were studied. The results showed that the total concentrations of 16 PAHs ranged from 3.28 to 8.88 μg•g-1, with a mean of 5.52 μg•g-1. The concentration of 7 carcinogenic PAHs (Σ7CPAHs) ranged from 1.52 to 4.82 μg•g-1, with a mean of 2.60 μg•g-1. The ∑PAHs in around thermal power plant surface soils of Xi’an belonged to serious pollution level. The PAHs in present study were mainly composed of medium molecular weight PAHs and high molecular weight PAHs, which have strong three effects. The results of source analysis showed that the PAHs in surface soil were mainly originated from the combustion of fossil oil, coal, wood and other biomass. The results of ecological risks of PAHs in the surface soil showed that all samples were polluted generally. The potential ecological risk of PAHs belonged to the serious level in individual PAHs and samples. There are two samples value of TEQBap exceed the security value 0.600 μg•g-1. Therefore, the environment of industrial areas should be attention and controlled.

Sample preparation of soils and bottom sediments for gas chromatography–mass spectrometry determination of PAHS

Polycyclic aromatic hydrocarbons (PAHs) are a class of compounds which have been known to be carcinogenic, teratogenic and mutagenic as well as act as pollutants of environmental objects. The determination of PAHs in complex matrices is difficult, and it is very important to use an efficient sample pretreatment technique. A sample preparation technique was developed involving extractive freezing-out and centrifugation of the samples for the determination of polycyclic aromatic hydrocarbons (PAHs) in soils and bottom sediments using gas chromatography – mass spectrometry (GC–MS). Sochi soils (The Imereti Lowlands), turf, sea bottom sediments (Azov Sea, The Temryuk Bay), river bottom sediment (Kurchansky estuary) and Caio Romano (Cuba) island sand were selected as the objects for the research. Soils and bottom sediments which contained no determined PAHs were used as model samples. The conditions of sample preparation have been optimized, and the extraction effects of acetonitrile with water on the PAHs recoveries have been investigated. It was found that for the determination of the compounds consisting from two to four fused aromatic rings such as naphthalene, 2-methylnaphthalene, acenaphthylene, biphenyl, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene, the extraction occurred when the extractive mixture contained 15% acetonitrile. The proposed method detection limits of individual compounds ranged from 0.83 to 0.92 µg/kg. The extractive mixture containing 50% acetonitrile was proposed for the determination of 20 PAHs such as naphthalene, 2-methylnaphthalene, acenaphthene, biphenyl, acenaphthylene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, triphenylene, benz[b]fluoranthene, benz[k]fluoranthene, benz[e]pyrene, benz[a]pyrene, indene[1,2,3–c,d]pyrene, dibenz[a,h]anthracene, benz[g,h,i]perylene. The extraction of PAHs in these conditions demonstrated the recoveries from 61% to 97%. As matter of fact, the lower recoveries of PAHs, that contained four or more fused aromatic rings, have been caused by the sorption in the cracks of the solid aqueous phase. The extraction, clear-up of extract and concentration were realized as one step of the sample pretreatment. As a result, the rapid and express technique of the sample preparation with combined GC-MS were proposed for the PAHs determination in soils and bottom sediments. This method’s limits of individual PAHs quantitation ranged from 1 to 5 µg/kg, and these were lower that the maximum permissible concentration.

Occurrence and potential health risks assessment of polycyclic aromatic hydrocarbons (PAHs) in different tissues of bivalves from Hainan Island, China

The levels of 16 PAHs were determined in the adductor, gills, gonads, hepatopancreas and mantles of the pearl oyster (Pinctada martensii) and the mussel (Perna viridis) collected from coasts of Li'an and Xincun Bays. The levels of ΣPAHs ranged from 597.1 to 2332 ng g−1 d w in the various tissues of bivalves. The pyrolytic source played an important role in the local coastal environment. Significantly higher levels of M-PAHs and H-PAHs were observed in Pinctada martensii than in Perna viridis. The ΣPAHs at different tissues showed the following order from high to low: mantles > hepatopancreas > gonads > gills > adductor. When levels of individual PAHs in the five bivalve tissues have been compared with each other, high correlations have been found (r2 = 0.793–0.975). A general trend was observed that log transformed BSAFs declined with increase of Kow values. The estimated amount of ΣPAHs via ingestion of oyster and mussel varied from 1.35 × 10−2-1.70 × 10−1 and 2.15 × 10−2-1.91 × 10−1 μg kg−1 body weight day−1, respectively. The THQs and CRs calculated for regular consumption of raw bivalves were in the acceptable ranges and may not pose health risk concerns. But for certain population with higher consumption rate for PAHs contaminated bivalves, cautions should be taken for their higher cancer risk.

Enrichment behavior of contemporary PAHs and legacy PCBs at the sea-surface microlayer in harbor water.

Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the sea-surface microlayer (SML) and sub-surface water (SSW) were analyzed in and around Kaohsiung Harbor. The results confirm SML enrichments for PAHs, but PCBs less significantly, since PAHs are still produced while PCBs had banned years ago. However, PCBs still leak to the environment from contaminated sites. The results showed the sources and transport of PAHs and PCBs were different, but both are enriched in the SML. Total particulate PAHs at most sites are below the toxicity thresholds, with a few individual PAHs between the effects range-low and effect range-median even higher than the effect range-median. Total particulate PCBs might cause occasionally adverse effects in sensitive species and pose a risk to the organisms. The particulate phase in the SML poses a higher risk to the marine ecosystem than in the SSW although not all organisms will make direct use of the microlayer. Principal component analysis (PCA) of PAHs indicated the important contribution of traffic engine emission in the particulate samples of the SML and SSW and revealed that probably the petroleum pollutants are a predominant source for the dissolved phase. Cluster analysis revealed that PAH-PCB patterns in the river and anchorage channels were different to those in the wetlands and open harbor. However, PCA of PCBs showed differences in the congener profiles for the two phases, with highly chlorinated PCBs more abundant in particles, while less chlorinated PCBs were more abundant in dissolved.