Concentrations Of Fluoranthene Research Articles

A baseline assessment of contamination in the Sacramento deep water ship channel

The Sacramento Deep Water Ship Channel (SDWSC) in the San Francisco Estuary, which is an active commercial port, is critical habitat for pelagic fish species including delta smelt (Hypomesus transpacificus), longfin smelt (Spirinchus thaleichthys), and Sacramento perch (Archoplites interruptus). Pelagic organism decline has been attributed to covarying factors such as manipulation of habitat, introduction of invasive species, decrease in food production, and contaminant exposure. Quantification of bioavailable toxicant loads in the SDWSC is limited despite previous surveys that have detected elevated contaminant concentrations in the sediments. Therefore, the focus of the present study was to characterize the bioavailability of the contaminants in the SDWSC from six sites along the channel. At each site, organochlorine pesticides (OCPs), pyrethroid insecticides, polyaromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) were quantified in sediment, zooplankton, and suspended solids. In addition, Tenax extraction was used to measure the bioaccessible fraction of sediment-associated contaminants freely dissolved in the water. Bioaccessible contaminants in the sediment provided an uptake route for these stressors into invertebrates and fish with bioaccessible OCPs being found at all sites, particularly 4,4′-dichlorodiphenyldichloroethylene (DDE). Bifenthrin was the only pyrethroid detected in the chosen matrices and it was found at concentrations below levels of concern. Bioaccessible PAHs were found at all sites, with highest detections for phenanthrene and pyrene. No PCBs were detected in sediments, but were detected in both suspended solids and zooplankton. Contaminant concentrations overall were significantly higher in suspended solids, followed by zooplankton and sediments. The highest sediment concentrations of DDE, fluoranthene, pyrene, and dibenzo[a,h]anthracene exceeded sediment quality benchmarks indicating potential risk to sediment-dwelling species. Finally, elevated contaminant levels were found in both suspended solids and zooplankton, suggesting additional risk to pelagic species in the SDWSC.

AQUA-GAPS/MONET-Derived Concentrations and Trends of PAHs and Polycyclic Musks across Global Waters.

Polycyclic aromatic hydrocarbons (PAHs), released from petrogenic, pyrogenic or diagenetic sources (degradation of wood materials), are of global concern due to their adverse effects, and potential for long-range transport. While dissolved PAHs have been frequently reported in the literature, there has been no consistent approach of sampling across water bodies. Passive samplers from the AQUA/GAPS-MONET initiative were deployed at 46 sites (28 marine and 18 freshwater), and analyzed for 28 PAHs and six polycyclic musks (PCMs) centrally. Freely dissolved PAH concentrations were dominated by phenanthrene (mean concentration 1500 pg L-1; median 530 pg L-1) and other low molecular weight compounds. Greatest concentrations of phenanthrene, fluoranthene, and pyrene were typically from the same sites, mostly in Europe and North America. Of the PCMs, only galaxolide (72% of samples) and tonalide (61%) were regularly detected, and were significantly cross-correlated. Benchmarking of PAHs relative to penta- and hexachlorobenzene confirmed that the most remote sites (Arctic, Antarctic, and mountain lakes) displayed below average PAH concentrations. Concentrations of 11 of 28 PAHs, galaxolide and tonalide were positively correlated (P < 0.05) with population density within a radius of 5 km of the sampling site. Characteristic PAH ratios gave conflicting results, likely reflecting multiple PAH sources and postemission changes.

Purification, characterization and three-dimensional structure prediction of multicopper oxidase Laccases from Trichoderma lixii FLU1 and Talaromyces pinophilus FLU12

Broad-spectrum biocatalysts enzymes, Laccases, have been implicated in the complete degradation of harmful pollutants into less-toxic compounds. In this study, two extracellularly produced Laccases were purified to homogeneity from two different Ascomycetes spp. Trichoderma lixii FLU1 (TlFLU1) and Talaromyces pinophilus FLU12 (TpFLU12). The purified enzymes are monomeric units, with a molecular mass of 44 kDa and 68.7 kDa for TlFLU1 and TpFLU12, respectively, on SDS-PAGE and zymogram. It reveals distinct properties beyond classic protein absorption at 270–280 nm, with TlFLU1's peak at 270 nm aligning with this typical range of type II Cu site (white Laccase), while TpFLU12's unique 600 nm peak signifies a type I Cu2+ site (blue Laccase), highlighting the diverse spectral fingerprints within the Laccase family. The Km and kcat values revealed that ABTS is the most suitable substrate as compared to 2,6-dimethoxyphenol, caffeic acid and guaiacol for both Laccases. The bioinformatics analysis revealed critical His, Ile, and Arg residues for copper binding at active sites, deviating from the traditional two His and a Cys motif in some Laccases. The predicted biological functions of the Laccases include oxidation–reduction, lignin metabolism, cellular metal ion homeostasis, phenylpropanoid catabolism, aromatic compound metabolism, cellulose metabolism, and biological adhesion. Additionally, investigation of degradation of polycyclic aromatic hydrocarbons (PAHs) by purified Laccases show significant reductions in residual concentrations of fluoranthene and anthracene after a 96-h incubation period. TlFLU1 Laccase achieved 39.0% and 44.9% transformation of fluoranthene and anthracene, respectively, while TpFLU12 Laccase achieved 47.2% and 50.0% transformation, respectively. The enzyme structure–function relationship study provided insights into the catalytic mechanism of these Laccases for possible biotechnological and industrial applications.

Numerical simulation of soot and NO formation in DME/gasoline laminar co-flow diffusion flames

Dimethyl ether (DME) is regarded as a promising alternative fuel to reduce greenhouse gases and soot emission. However, the application of DME in actual engines is difficult because of its low calorific value and viscosity. DME is commonly utilized as a supplementary component in traditional fuels to enhance their combustion efficiency and emission performance. This study investigated the effect of DME blending on the soot and NO formation in laminar diffusion gasoline flames. The results showed that the peak soot volume fraction (SVF) reduced by 12.3 %, while the peak temperature increased by 19.2 K and the peak concentration of NO increased by 18.2 % when the blending ratio of DME increased from 0 % to 15 %. The primary reason for the reduction in the soot inception rate was the decrease in benzo(ghi)fluoranthene (BGHIF) concentration. The formation of BGHIF was controlled by the C6H5CH3 → A1 → A1-→A1C2H → A2R5 → A2 → A2-→BGHIF pathways. The decrease of initial soot particles led to a reduction in Hydrogen Abstraction Carbon Addition (HACA) surface growth rate. The increase in A4 concentration was due to the increase in the concentration of C4H2 in the reaction A2R5 + C4H2 = A4. Therefore, more benzo[a]pyrene (BAPYR) was formed through A4 + C4H2 = BAPYR, promoted the process of soot condensation. The increase in OH concentration promoted the oxidation of OH, and the decrease in soot inhibited the oxidation of O2. The majority of NO was primarily produced through the NO thermal pathway in the DME/gasoline flame, and N + OH = NO + H was the main reaction to form NO. The increase of O, H and OH radicals caused the increase in NO concentration.

Fluoranthene biotreatment using prominent freshwater microalgae: physiological responses of microalgae and artificial neural network modeling of the bioremoval process

Due to the intensified industrial activities and other anthropogenic actions, contamination of polycyclic aromatic hydrocarbons (PAHs) has been growing at an alarming rate, turning in to a serious environmental concern. Bioremediation, as an eco-friendly and sustainable removal technology, can be used by organisms to reduce the resulting contaminations. In the present study, the ability of Tetradesmus obliquus to remove of fluoranthene (FLA) was evaluated. It was confirmed that FLA removal efficiency was managed by various environmental parameters and pH was found to be one of the most important influencial factors. The reusability of the algae in long-term repetitive operations confirmed the occurrence of biodegradation along with other natural attenuation and 10 intermediate compounds were identified in the FLA biodegradation pathway by GC-MS. As a result of physiological assays, induced antioxidant enzymes activities and augmentation of phenol and flavonoids contents, after the treatment of the microalgae by a high concentration of FLA, confirmed the ability of the microalgae to upregulate its antioxidant defense system in response to the toxic effects of FLA. An artificial neural network (ANN) model was then developed to predict FLA biodegradation efficiency and the appropriate predictive performance of ANN was confirmed by comparing the experimental FLA removal efficiency with its predicted amounts (R2 = 0.99).

The quantum of polycyclic aromatic hydrocarbon in &lt;em&gt;Pyxicephalus edulis&lt;/em&gt; and sediments in Oluwa river, Igbekebo area, Ondo state, Nigeria

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds composed of two or more fused aromatic rings. PAHs can be found in a variety of foods and beverages, including drinking water, vegetables, fruits, cereals, oils, seafood, and meats. The current study investigated the pollution levels of the quantum of polycyclic aromatic hydrocarbon in Pyxicephalus edulis and river sediments. Twenty-five sediment samples and male and female specimens of Pyxicephalus edulis were collected from Oluwa River near Igbekebo, Ondo State Nigeria. The sediment samples were then dried in the open air for three days while the identified frog species were dried separately for 6 hours at 105°C before being powdered. The physicochemical parameters of sediment samples examined using standard physical and chemical analytical techniques and polycyclic aromatic hydrocarbons in frog and sediment samples were examined using gas chromatographyflame ionization analysis (GC-FID). The toxicity equivalent(TEQ) values of PAHs in sediment samples were determined by comparing the findings of this study to the Sediment Quality Guideline (SQG) with effects range from viz., low (ERL), median(ERM) and threshold-effects level (TEL)/probable-effects level (PEL) to assess the toxicity of PAHs to aquatic organisms living in sediments. Male frogs had significantly higher concentrations of Acenaphthylene, Phenanthrene, Anthracene, Pyrene, and total PAHs than females, and lower concentrations of Naphthalene, Acenaphthylene, Fluorene, and Fluoranthene. BaAnt, Benzo(b) fluoranthene, Benzo(k)fluoranthrene, Benzo(a)pyrene, Indeno(1,2,3-cd) pyrene, Dibenz(a,h)anthracene, Benzo(g,h,i)perylene were reported only among males. The cause of this variation is unknown, but it could be due to differences in the genetic make-up of male and female frogs.

The multifaceted effects of fluoranthene and polystyrene on the taxonomic composition and associated functional traits of marine meiofauna, by using single and mixture applications

The current experiment measured the multifaceted effects of polystyrene and fluoranthene, acting alone or in a mixture on marine meiofauna, but with a special focus on nematodes' morphological and functional traits. The results showed changes in the abundances for all tested concentrations of both compounds. The nematode communities exposed to the highest concentrations of fluoranthene (30 ng.g−1 Dry Weight (DW)) and polystyrene (100 mg.kg−1 DW) alone or in a mixture, were significantly less diverse compared to control and were associated with significant changes in the percentage of taxonomic composition and feeding-guilds. The most sensitive taxa to fluoranthene comprised epistratum feeders, whereas the nematodes mostly affected by polystyrene were omnivores-carnivores. A new functional tool, the Index of Sensitivity (IOS), proved to be reliable in depicting the changes that occurred in the taxonomic and functional features of the nematofauna.

Air pollution prevention in central China: Effects on particulate-bound PAHs from 2010 to 2018

Long-term trends in particulate-bound polycyclic aromatic hydrocarbon (PAH) concentrations in air in Zhengzhou (a severely polluted city in central China) between 2010 and 2018 were studied to assess the effectiveness of an air pollution prevention and control action plan (APPCAP) implemented in 2013. The PM2.5, sum of 16 PAHs (Σ16 PAHs), benzo[a]pyrene (BaP), and BaP toxic equivalent concentrations were high before 2013 but 41%, 77%, 77%, and 78% lower, respectively, after the APPCAP. The maximum daily Σ16 PAHs concentration between 2014 and 2018 was 338 ng/m3, 65% lower than the maximum of 961 ng/m3 between 2010 and 2013. The ratio between the Σ16 PAHs concentrations in winter and summer decreased over time and was 8.0 in 2011 and 1.5 in 2017. The most abundant PAH was benzo[b]fluoranthene, for which the 9-year mean concentration was 14 ± 21 ng/m3 (15% of the Σ16 PAHs concentration). The mean benzo[b]fluoranthene concentration decreased from 28 ± 27 ng/m3 before to 5 ± 4 ng/m3 after the APPCAP (an 83% decrease). The mean daily BaP concentrations were 0.1–62.8 ng/m3, and >56% exceeded the daily standard limit of 2.5 ng/m3 for air. The BaP concentration decreased from 10 ± 8 ng/m3 before to 2 ± 2 ng/m3 after the APPCAP (a 77% decrease). Diagnostic ratios and positive matrix factorization model results indicated that coal combustion and vehicle exhausts were important sources of PAHs throughout the study period, contributing >70% of the Σ16 PAHs concentrations. The APPCAP increased the relative contribution of vehicle exhausts from 29% to 35% but decreased the Σ16 PAHs concentration attributed to vehicle exhausts from 48 to 12 ng/m3. The PAH concentration attributed to vehicle exhausts decreased by 79% even though vehicle numbers strongly increased, indicating that pollution caused by vehicles was controlled well. The relative contribution of coal combustion remained stable but the PAH concentration attributed to coal combustion decreased from 68 ng/m3 before to 13 ng/m3 after the APPCAP. Vehicles made dominant contributions to the incremental lifetime cancer risk (ILCRs) before and after the APPCAP even though the APPCAP decreased the ILCRs by 78%. Coal combustion was the dominant source of PAHs but contributed only 12–15% of the ILCRs. The APPCAP decreased PAH emissions and changed the contributions of different sources of PAHs, and thus strongly affected the overall toxicity of PAHs to humans.

Efficiency and mechanism on photocatalytic degradation of fluoranthene in soil by Z-scheme g-C3N4/α-Fe2O3 photocatalyst under simulated sunlight.

Polycyclic aromatic hydrocarbons (PAHs) in soil have potential harm on human health. However, remediation of PAH-contaminated soils through photocatalytic technology remains a challenge. Therefore, the photocatalyst g-C3N4/α-Fe2O3 was synthesized and applied to photocatalytic degradation of fluoranthene in soil. The physicochemical properties of g-C3N4/α-Fe2O3 and various degradation parameters, such as catalyst dosage, the ratio of water/soil, and initial pH, were investigated in detail. In soil slurry reaction system (water/soil=10:1, w/w), the optimal degradation efficiency on fluoranthene was 88.7% after simulated sunlight irradiation for 12 h (contaminated soil=2 g, initial fluoranthene concentration=36 mg/kg, catalyst dosage=5%, and pH=6.8), and the photocatalytic degradation followed pseudo-first-order kinetics. The degradation efficiency of g-C3N4/α-Fe2O3 was higher compared with P25. Degradation mechanism analysis showed that •O2- and h+ are the main active species in photocatalytic degradation process of fluoranthene by g-C3N4/α-Fe2O3. Coupling g-C3N4 and α-Fe2O3 enhances the interfacial charge transport capacity via Z-scheme charge transfer route and inhibits the recombination of photogenerated electrons and holes of g-C3N4 and α-Fe2O3, then significantly improves the production of active species and photocatalytic activity. Results showed that photocatalytic treatment of soil by g-C3N4/α-Fe2O3 is an effective strategy for remediation of soils contaminated by PAHs.

Effects of dietary fluoranthene on tissue-specific responses of carboxylesterases, acetylcholinesterase and heat shock protein 70 in two forest lepidopteran species

In this study, responses of carboxylesterases, acetylcholinesterase, and stress protein Hsp70 were examined in the midgut and midgut tissue, and brain of fifth instar larvae of Lymantria dispar L. and Euproctis chrysorrhoea L. following chronic exposure to dietary fluoranthene. Specific carboxylesterase activity increased significantly in the midgut tissue of E. chrysorrhoea larvae treated with a lower fluoranthene concentration. The specific patterns of isoforms expression, recorded in larvae of both species, enable efficient carboxylesterase activity as a significant part of defense mechanisms. Increased Hsp70 concentration in the brain of L. dispar larvae points to a response to the proteotoxic effects of a lower fluoranthene concentration. Decreased Hsp70 in the brain of E. chrysorrhoea larvae in both treated groups can suggest induction of other mechanisms of defense. The results indicate the importance of the examined parameters in larvae of both species exposed to the pollutant, as well as their potential as biomarkers.

Comparing 10- and 28-Day Sediment Toxicity and Bioaccumulation of Fluoranthene in Hyalella azteca Using Passive Sampling Techniques.

Understanding the changes in the temporal and spatial concentrations of chemical substances in sediment toxicity tests facilitates interpretation of their toxicity and accumulation in benthic organisms because benthic organisms are affected by chemicals via multiple exposure pathways. However, such investigations using chronic sediment toxicity tests have rarely been performed. To examine the concentration profiles of a hydrophobic organic chemical using chronic spiked-sediment toxicity tests, we performed 28-day sediment toxicity tests of fluoranthene with a freshwater amphipod, Hyalella azteca, using a semi-flow-through system and compared the results with those of 10-day tests. In these experiments, we measured various types of fluoranthene concentrations over the test periods: total dissolved (Cdiss ) and freely dissolved (Cfree ) concentrations in overlying water and porewater as well as sediment concentrations. We also examined which concentration correlated with the amphipod bioconcentration factor (BCF). We found that both overlying water and porewater Cfree did not differ significantly on days 10 and 28. Sediment concentrations remained almost stable for 28 days, whereas Cdiss in overlying water varied temporally. These results suggest that the 28-day test provides almost constant concentrations of fluoranthene, particularly in porewater, even in a semi-flow-through system. In addition, the comparison of BCF of fluoranthene on day 10 in the present study with that obtained from water-only tests reported in the literature suggested that Cfree in pore water was the most representative indicator of bioaccumulation in H. azteca. Our findings support the possible use of a water-exchange system in chronic spiked-sediment toxicity tests of hydrophobic organic chemicals. However, further studies using sediments and chemicals with different properties are warranted to generalize the findings of the present study. Environ Toxicol Chem 2022;41:2679-2687. © 2022 SETAC.

Monitoring of PAHs (Fluoranthene and Benzo(a)Anthracene) in Ambient Air of Ghaziabad Area of National Capital Region and Control of Air Pollution by Triveni Wood

The main objective of this paper is to analyze the impacts of Fluoranthene and Benzo (a) Anthracene PAHs pollutants on the health of peoples residing in Ghaziabad area of National Capital Region. This paper gives some relevant reactions of Triveni wood in Yagya process for control of air pollution. Practical work was carried for a duration of approx. 2 years. Sampling of Fluoranthene and Benzo (a) Anthracene PAHs was carried on every fortnight and data was collected. The present study is very useful to regulatory authorities and administration to understand problems of air pollution in the concerning areas and helpful in prevention of Air Pollution. In Ghaziabad City, the sampling locations were selected based on land used pattern, i.e., residential area, commercial and industrial area during four seasons viz. summer, Monsoon, Post monsoon and Winter. Fluoranthene and Benzo (a) Anthracene level and their variation were observed during these seasons. The result of concentration of Fluoranthene and Benzo (a) Anthracene is minimum in Govindpuram residential area of Ghaziabad and maximum concentration observed in Sahibabad industrial area, which shown in Figure 1 (Results and Discussion) in year Jan 2016–Dec 2017. The conclusion of this study is that the concentration of Benzo(a)anthracene (110.1 ng/m3) found greater than Fluoranthene (98.8 ng/m3) in all sites.

Steroid Hormones Protect against Fluoranthene Ethoxyresorufin-O-Deethylase (EROD) Activity Inhibition

The physiological conditions of an organism may influence its ability to cope with environmental stressors, such as contaminants. Biotransformation and the endocrine system interact with each other to promote animal’s fitness. However, little is known regarding the interaction between hormones and response to pollutants such as polycyclic aromatic hydrocarbons (PAHs). In this in vitro study, we aimed to increase the knowledge regarding the effects of steroid hormones on ethoxyresorufin-O-deethylase (EROD) activity inhibited by contaminants. The effects on in vivo induced EROD activity of Anguilla anguilla were assessed by conducting single and combined exposures to fluoranthene (FL) and to physiological levels of two major steroid hormones (cortisol and 17ß-estradiol). Hepatic microsome exposure to the lowest concentrations of FL (0.1 and 0.3 µM), as well as to cortisol and 17ß-estradiol (E2), led to significant EROD activity induction. However, the highest tested concentrations of FL (0.9 and 2.7 µM) significantly inhibited this enzymatic activity. When microsomes were simultaneously exposed to 0.9 µM FL and one of the hormones, both cortisol and E2 were able to decrease the inhibitory effects, with the former completely reverting EROD activity inhibition. These findings support the idea that cortisol and E2 can help prevent the inhibitory effects of PAHs over biotransformation enzymes, highlighting the physiological relevance of these hormones.

Identification of a novel CYP4V gene in the polychaete Perinereis aibuhitensis: transcriptional comparison with a CYP4B gene exposed to PAHs.

Polychaete worms can biotransform polycyclic aromatic hydrocarbons (PAHs) in environments, and the cytochrome P450 (CYP) enzyme plays an important role in this process. Herein, a novel cytochrome P450 gene was identified and characterized from the polychaete worm Perinereis aibuhitensis. The full-length cDNA, which is named CYP4V82, is 1709bp encoding a protein of 509 amino acids and has high similarity to CYP4V. The expression levels of CYP4V82 and CYP4BB4 (a CYP gene identified from P. aibuhitensis in a previous study, Chen et al. Mar Pollut Bull 64:1782-1788, 2012) exposure to various concentrations of benzo[a]pyrene (B[a]P) (0.5, 2, 4, and 8μg/L) and same mass concentrations of fluoranthene (Flu, 3.2μg/L), phenanthrene (Phe, 2.9μg/L), B[a]P (4.0μg/L) were detected to identify the function of the CYP4 family in P. aibuhitensis. Compared with CYP4BB4, CYP4V82 mRNA was minimally expressed on day 7 but highly sensitive on day 14. Notably, the expression levels of CYP4V82 and CYP4BB4 were relatively different in short-term responses to PAHs with different benzene rings of the same concentration. The expression of CYP4V82 in the B[a]P group was the highest, while that of CYP4BB4 in the Phe group was relatively higher than the two other groups. These findings suggest that PAHs are associated with the induction of CYP4V82 and CYP4BB4 expressions in P. aibuhitensis, which may have different efficiencies in the detoxification of PAHs.

Polycyclic Aromatic Hydrocarbons (PAHs) and Heavy Metal content of Abattoir Wastewater in Bayelsa and Rivers States

The polycyclic aromatic hydrocarbons and heavy metals in wastewater generated from abattoir were analyzed. Wastewater samples were collected from four abattoirs in Yenagoa Local Government Area of Bayelsa State and an abattoir in Obio/Akpor Local Government Area of Rivers State, respectively using standard methods. The polycyclic aromatic hydrocarbons (PAHs) were determined using Gas chromatographic method, while the heavy metals were determined using spectrophotometer. Results showed that Acenaphthene, Acenaphthylene and Naphthalene recorded its highest value of 123.77µg/ml, 199.64µg/ml and 6.82µg/ml, respectively in wastewater samples from Opolo, while they were not detected in Rumuokoro samples (0.00µg/ml). Anthracene recorded the highest value in sample from Opolo (4.59 µg/ml) and the least value was in samples from Swale (0.00 µg/ml). Values of Benzo(a)pyrene recorded value of 0.86 µg/ml in Opolo sample. Chrysene value was 66.19µg/ml in Rumuokoro wastewater, 0.03µg/ml in Igbogene wastewater and 0.24 µg/ml in the control while the value was 0.00µg/ml in other abattoir locations. Benzo(b)flouranthene recorded the highest value of 38.79µg/ml at Igbogene and 1.93µg/ml in Tombia while other sampling location recorded 0.00µg/ml. Indenol(1,2,3cd) pyrene highest value of 4.38µg/kg was obtained at Igbogene, Swale, and the control, recorded zero value. Flourene was present in all the abattoir samples but with the highest concentration at Opolo (42.96µg/ml) and the least concentration in Swale (0.17µg/ml). The highest value of 2-methylnaphthalene recorded was 52.65µg/ml at Opolo which was followed by 11.2 µg/ml at Tombia while it was not detected in other locations (0.00µg/ml). Flouranthene recorded its highest concentration of 55.01µg/ml (Rumuokoro) and the least were 0.00µg/ml at Tombia. Rumuokoro and Igbogene had Benzo (k) fluoranthene concentrations of 14.90g/ml and 0.02g/ml, respectively, whereas other locations had zero. Except for Anthracene, Fluoranthene, Pyrene, Chrysene and Benzo(g,h,i)perylene, all the other PAHs were not detected in the control. The decreasing order of total PAHs in wastewater samples is as: Opolo &gt; Tombia &gt; Rumuokoro &gt; Igbogene &gt; Swale &gt; Control. Chromium (Cr) was detected in wastewater from all abattoir locations, while all other heavy metals were undetected. Results from this study shows that the abattoir wastewaters had high pollution strength and thus should be treated before being discharged into the environment. The presence of PAHs that are known carcinogens poses a serious threat to the health and well-being of humans.

Polycyclic aromatic hydrocarbons in grilled foods from Kermanshah province

ABSTRACT Grilling is one of the most traditional ways of cooking foods, especially meat, which can produce a number of carcinogenic compounds. This study was to identify the pattern of kebab consumption and its PAHs among a selection of the Iranian population. Kebab consumption pattern were assessed using a validated questionnaire. A sample of three types of popular kebabs, including Koobideh (minced meat), Barg (crushed meat pieces), and Juje (chopped chicken pieces), was collected from each restaurant and then transferred to a laboratory to measure PAHs. The median benzo[a]pyrene concentrations (7.85 μg/kg) and the sum of benzo[a]pyrene, chrysene, benzo[a]anthracene, and benzo[b]fluoranthene concentrations (15.74 μg/kg) were higher than the maximum level imposed by the Commission of the European Communities. A significant relationship between Barg kebab prepared with charcoal and the amounts of anthracene, benzo[a]anthracene, dibenzo[a,h]pyrene, and benzo[g,h,i]perylene was found. The highest PAHs produced in samples prepared with charcoal was dibenzo[a,h]pyrene.

Effects of fluoranthene on digestive enzymes activity and relative growth rate of larvae of lepidopteran species, Lymantria dispar L. and Euproctis chrysorrhoea L.

Fluoranthene is one of the most abundant polycyclic aromatic hydrocarbon pollutants in the environment and it may accumulate in plant leaves which are the main food source for phytophagous insect species. The aim of this study was to establish the effects of dietary fluoranthene on specific activities of digestive enzymes and expression of their isoforms in the midgut, and the relative growth rates of Lymantria dispar and Euproctis chrysorrhoea larvae. Exposure to fluoranthene led to significantly decreased trypsin activity in the midgut of larvae of both species. Leucine aminopeptidase activity decreased significantly in the midgut of L. dispar larvae exposed to the lower concentration of fluoranthene, but that enzyme activity showed the opposite trend in E. chrysorrhoea larvae. There was no pollutant induced changes in lipase activity in L. dispar, while elevated enzyme activity was recorded in the midgut of E. chrysorrhoea larvae exposed to the lower concentration of fluoranthene. Different patterns of expression of enzyme isoforms were noticed. Relative growth rates of both species significantly decreased in fluoranthene treated larvae. These responses indicate to the significance of relationships between physiological changes and fitness-related traits in L. dispar and E. chrysorrhoea larvae affected by pollutant, and contribute to understanding the mechanisms of their adjustment to stressful conditions.

Expression profile of a novel glutathione S-transferase gene in the marine polychaete Perinereis aibuhitensis in short-term responses to phenanthrene, fluoranthene, and benzo[α]pyrene

Polychaete worms can eliminate polycyclic aromatic hydrocarbons (PAHs) in environments through a mechanism that increases their water solubility. This detoxification starts with cytochrome P450 enzymes (CYPs) and then with glutathione S-transferases (GSTs). Here, a novel GST gene was identified and characterized from the widespread polychaete Perinereis aibuhitensis. The full-length cDNA of GST is 1544 bp and encodes 256 amino acids, belonging to the omega class. Gene expression patterns in P. aibuhitensis showed that its transcriptional level was positively correlated with the concentration of benzo[α]pyrene (0.5, 2, 4, and 8 μg/L) exposure but was negatively correlated with a PAH benzene ring after it was exposed to the same mass concentrations of fluoranthene (3.2 μg/L), phenanthrene (2.9 μg/L), and benzo[α]pyrene (4.0 μg/L) during the 14-day experimentation. These findings indicate that omega GST may play an important role in the phase II detoxification of PAHs in polychaete worms, and the persistence and bioavailability of PAHs may depend on benzene rings.

Uptake and absorption of fluoranthene from spiked microplastics into the digestive gland tissues of blue mussels, Mytilus edulis L.

The present work intended to investigate the fate of contaminant-loaded microplastics if ingested by benthic filter feeder Mytilus edulis under laboratory conditions. In the course of a 7-day experiment the mussels were exposed to PVC microplastics in a size range ≤40 μm, in doses of 2000 particles L−1 (11.56 mg L−1). Particles were either virgin or loaded with one of four different nominal concentrations of the polycyclic aromatic hydrocarbon (PAH) fluoranthene (500, 125, 31.25 and 7.8125 μg g−1). Verification of fluoranthene concentrations on the particles provided evidence of the high absorptive capacity of PVC for this PAH, indicating that comparable particles may serve as considerable accumulation sites for high concentrations of hydrophobic contaminants in the aquatic environment. Analysis of digestive gland tissues via polarised light microscopy revealed the occurrence of particles and particle aggregates within stomach and intestines of all mussels treated with microplastics, thus making the xenobiotic bioavailable. Results of contaminant analysis in mussel tissues via equilibrium sampling point to a considerable capability of microplastics for the accumulation of hydrophobic contaminants from the environment and their potential to act as vehicles for the transport of theses contaminants into organismal tissues.

Polycyclic Aromatic Hydrocarbons in Surface Soil of China (2000-2020): Temporal and Spatial Distribution, Influencing Factors

With the rapid development of China's economy and society, the polycyclic aromatic hydrocarbon (PAH) pollution of surface soil has attracted increasing attention. Based on a systematic review, this study identified 166 relevant papers (published from 2000 to 2020) dealing with the contamination of 16 PAHs in the surface soil of China and summarized the pollution level, temporal, and spatial distribution influencing factors of PAHs with statistics, spatial interpolation analysis, and source analysis methods. The results showed that the surface soil of China has been polluted by human-caused PAHs, with a median concentration of 675.70 μg·kg-1. Although the overall condition is good, some sampling points have been seriously polluted. Among the monomers of PAHs, the concentrations of fluoranthene (Fla) and pyrene (Pyr) are high, while acenaphthylene (Acy) and acenaphthene (Ace) are relatively low. During the survey period, the concentration data of surface soil PAHs are generally within the moderate pollution levels of 313.10-1070.45 μg·kg-1, while the annual changes of PAHs do not show obvious fluctuations and are less affected by oil production and consumption. Statistics and spatial interpolation results show that PAH pollution in the surface soil of China has regional characteristics, where the concentration decreases in order from northwest, north, east, northeast, southwest, and south-central China. The pollution level in most provinces is "contaminated" or "weakly contaminated." From the source analysis results, PAH pollution in surface soils in most areas of China comes from the high-temperature combustion of fossil fuels such as petroleum, biomass, and coal. Heilongjiang and some northwestern regions (e.g., Xinjiang and Tibet) were mainly represented by oil source pollution. Such results could provide a reference for soil environmental management and PAH pollution control in China.