scholarly journals Toxicity and Risks Assessment of Polycyclic Aromatic Hydrocarbons in River Bed Sediments of an Artisanal Crude Oil Refining Area in the Niger Delta, Nigeria

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3295
Author(s):  
Ibigoni C. Howard ◽  
Kingsley E. Okpara ◽  
Kuaanan Techato
Keyword(s):  
Molecular Weight ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Crude Oil ◽  
Aromatic Hydrocarbons ◽  
Niger Delta ◽  
Oil Refining ◽  
Diagnostic Ratios ◽  
Bed Sediments ◽  
River Bed ◽  
Polycyclic Aromatic

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants that possess serious risks to human health and the environment. Forty riverbed sediments samples were collected in mangrove river bed sediments where artisanal refining of crude oil takes place in the Niger Delta of Nigeria. The concentration, occurrence, distribution, toxicity and health risk of sixteen priority PAHs (16PAHs) were analysed in the samples. Apart from Nap, Acy, BkF, InP and DbE, all the other PAHs were present in all the sampled points of the studied area with BbF and BaA recording the highest mean values. The range and mean of the total PAHs (∑16PAHs) of this study are 23.461–89.886 mg/kg and 42.607 ± 14.30 mg/kg dry weight (dw), which is classified as heavily contaminated when compared to the European classification of PAHs pollution in soil (>1.0 mg/kg). The range of the effect range factors used to assess the risk of PAHs in an ecosystem (Effect rang-low (ER-L) and Effect range-median ER-M) of this study is from 0.953 to 8.80 mg/kg. PAHs below ER-L (4.0 mg/kg) indicate no toxic effect, but values above ER-M (44.79 mg/kg) indicate toxic effects to the sediments, its resources and, ultimately, the public that consumes the resources thereof; hence, the study area falls within the contaminated category. The occurrence of the high molecular weight (HMW) PAHs (73.4%) supersedes those of the lower molecular weight (LMW) PAHs (26.6%). The diagnostic ratios and principal component analysis suggest that the main contributors of PAHS into the sediments are the combustion of biomass, fossil fuel (crude oil) and pyrogenic sources. The toxic equivalent quotient (TEQ) and mutagenic equivalent quotient (MEQ) of PAHs ranged from 2.96 to 23.26 mgTEQ/kg dw and 4.47 to 23.52 mgMEQ/kg dw, and the total mean toxic equivalency quotient (∑TEQ) (15.12 ± 8.4 mg/kg) is also greater than the safe level of 0.6 mg/kg, which indicates high toxicity potency. The mean incremental lifetime cancer risks (ILCRs) of human exposure to PAHs shows that both adults TotalILCR adults (6.15 × 10−5) and children TotalILCR children (2.48 × 10−4) can be affected by dermal contact rather than ingestion and inhalation. Based on these findings, the appropriate regulatory bodies and other organs of government in the region should enforce outright stoppage of the activities of these illegal artisans who do not have control mechanisms for loss control at the site and carry out appropriate clean-up of the area.

scholarly journals Polycyclic Aromatic Hydrocarbons in PM2.5 and PM2.5–10 in Urumqi, China: Temporal Variations, Health Risk, and Sources

Atmosphere ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 412 ◽  
Author(s):  
Suwubinuer Rekefu ◽  
Dilinuer Talifu ◽  
Bo Gao ◽  
Yusan Turap ◽  
Mailikezhati Maihemuti ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Coal Combustion ◽  
Temporal Variations ◽  
Diagnostic Ratios ◽  
Positive Matrix ◽  
Increasing Trend ◽  
Polycyclic Aromatic ◽  
The Mean

PM2.5 and PM2.5–10 samples were simultaneously collected in Urumqi from January to December 2011, and 14 priority polycyclic aromatic hydrocarbons (PAHs) were determined. The mean concentrations of total PAHs in PM2.5 and PM2.5–10 were 20.90~844.22 ng m−3 and 19.65~176.5 ng m−3 respectively, with the highest in winter and the lowest in summer. Above 80% of PAHs were enriched in PM2.5, which showed remarkable seasonal variations compared to coarse particles. High molecular weight (HMW) PAHs were predominant in PM2.5 (46.61~85.13%), whereas the proportions of lower molecular weight (LMW) and HMW PAHs in PM2.5–10 showed a decreasing and an increasing trend, respectively, from spring to winter. The estimated concentrations of benzo[a]pyrene equivalent carcinogenic potency (BaPeq) in PM2.5 (10.49~84.52 ng m−3) were higher than that of in PM2.5–10 (1.15~13.33 ng m−3) except in summer. The estimated value of inhalation cancer risk in PM2.5 and PM2.5–10 were 1.63 × 10−4~7.35 × 10−3 and 9.94 × 10−5~1.16 × 10−3, respectively, far exceeding the health-based guideline level of 10−4. Diagnostic ratios and positive matrix factorization results demonstrated that PAHs in PM2.5 and PM2.5–10 were from similar sources, such as coal combustion, biomass burning, coking, and petroleum combustion, respectively. Coal combustion was the most important source for PAHs both in PM2.5 and PM2.5–10, accounting for 54.20% and 50.29%, respectively.

scholarly journals CYP63A2, a Catalytically Versatile Fungal P450 Monooxygenase Capable of Oxidizing Higher-Molecular-Weight Polycyclic Aromatic Hydrocarbons, Alkylphenols, and Alkanes

2013 ◽  
Vol 79 (8) ◽  
pp. 2692-2702 ◽  
Author(s):  
Khajamohiddin Syed ◽  
Aleksey Porollo ◽  
Ying Wai Lam ◽  
Paul E. Grimmett ◽  
Jagjit S. Yadav
Keyword(s):  
Molecular Weight ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Substrate Specificity ◽  
Crude Oil ◽  
Aromatic Hydrocarbons ◽  
Aliphatic Hydrocarbon ◽  
Ligand Docking ◽  
P450 Monooxygenase ◽  
Polycyclic Aromatic ◽  
Long Chain

ABSTRACTCytochrome P450 monooxygenases (P450s) are known to oxidize hydrocarbons, albeit with limited substrate specificity across classes of these compounds. Here we report a P450 monooxygenase (CYP63A2) from the model ligninolytic white rot fungusPhanerochaete chrysosporiumthat was found to possess a broad oxidizing capability toward structurally diverse hydrocarbons belonging to mutagenic/carcinogenic fused-ring higher-molecular-weight polycyclic aromatic hydrocarbons (HMW-PAHs), endocrine-disrupting long-chain alkylphenols (APs), and crude oil aliphatic hydrocarbonn-alkanes. A homology-based three-dimensional (3D) model revealed the presence of an extraordinarily large active-site cavity in CYP63A2 compared to the mammalian PAH-oxidizing (CYP3A4, CYP1A2, and CYP1B1) and bacterial aliphatic-hydrocarbon-oxidizing (CYP101D and CYP102A1) P450s. This structural feature in conjunction with ligand docking simulations suggested potential versatility of the enzyme. Experimental characterization using recombinantly expressed CYP63A2 revealed its ability to oxidize HMW-PAHs of various ring sizes, including 4 rings (pyrene and fluoranthene), 5 rings [benzo(a)pyrene], and 6 rings [benzo(ghi)perylene], with the highest enzymatic activity being toward the 5-ring PAH followed by the 4-ring and 6-ring PAHs, in that order. Recombinant CYP63A2 activity yielded monohydroxylated PAH metabolites. The enzyme was found to also act as an alkane ω-hydroxylase that oxidizedn-alkanes with various chain lengths (C9to C12and C15to C19), as well as alkyl side chains (C3to C9) in alkylphenols (APs). CYP63A2 showed preferential oxidation of long-chain APs and alkanes. To our knowledge, this is the first P450 identified from any of the biological kingdoms that possesses such broad substrate specificity toward structurally diverse xenobiotics (PAHs, APs, and alkanes), making it a potent enzyme biocatalyst candidate to handle mixed pollution (e.g., crude oil spills).

scholarly journals Temporal Distribution and Gas/Particle Partitioning of Polycyclic Aromatic Hydrocarbons (PAHs) in the Atmosphere of Strasbourg, France

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 337
Author(s):  
Supansa Chimjarn ◽  
Olivier Delhomme ◽  
Maurice Millet
Keyword(s):  
Molecular Weight ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Solid Phase ◽  
Large City ◽  
Ambient Air ◽  
Temporal Variations ◽  
Diagnostic Ratios ◽  
Particulate Phase ◽  
Polycyclic Aromatic

Gas and particulate phase ambient air concentrations of polycyclic aromatic hydrocarbons (Ʃ16PAHs) were determined in Strasbourg, a large city located in the Alsace region of northeastern France, from May 2018 to March 2020, to study the evolution of their temporal variations and their potential origins. The analysis of PAHs was performed using a global analytical method permitting the quantification of pesticides, PAHs, and polychlorobiphenyls (PCBs). Filters and Carbon doped silicon carbide NMC@SiC foams were extracted by accelerated solvent extraction (ASE) followed by a solid-phase extraction (SPE). Afterwards, extracts were analyzed using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Prior to analysis, a pre-concentration step based on solid-phase microextraction (SPME) was used with a polydimethylsiloxane (PDMS) 100 µm fiber. The average total (gas plus particulate) concentration of Ʃ16PAHs varied from 0.51 to 117.31 ng m−3 with a mean of 16.87 ng m−3, with higher concentrations in the cold season of more than 2.5-fold and 6-fold that in the warm season for the gas and particulate phases, respectively. Moreover, low molecular weight (LMW) (2-ring and 3-ring) and medium molecular weight (MMW) (4-ring) PAHs contribute dominantly to the gas phase, while the particulate phase is associated with MMW (4-ring) and high molecular weight (HMW) (5-ring and 6-ring) PAHs. Gas/particle partitioning coefficient (log Kp) was calculated, and values varied between −4.13 and −1.49. It can be seen that the log Kp increased with the molecular weight of the PAHs and that the log Kp is different between cold and warm seasons for HMW PAHs but not for LMW PAHs. Diagnostic ratios of PAHs, which were employed to estimate the primary source of PAHs in Strasbourg, indicate that fuel combustion and biomass/coal burning are the possible origins of PAHs in Strasbourg’s atmosphere.

scholarly journals Distribution and sources of polycyclic aromatic hydrocarbons in soils along the Shatt Al-Arab River Delta in southern Iraq

2019 ◽  
Vol 14 (No. 2) ◽  
pp. 84-93
Author(s):  
Hamid Al-Saad ◽  
Wisam Farid ◽  
Wasen Abdul-Ameer
Keyword(s):  
Molecular Weight ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Principal Component ◽  
Diagnostic Ratios ◽  
Industrial Emissions ◽  
Target Values ◽  
Polycyclic Aromatic ◽  
The Impact ◽  
Southern Iraq

The soil samples from 0–10 cm depth were collected from three areas (Center of Basrah – CB, Garmat Ali – GA, and Abu Al-Khasib – AK) located along the Shatt Al-Arab River (SR) delta in southern Iraq to estimate the distribution and sources of polycyclic aromatic hydrocarbons (PAHs). The PAH total concentrations in the soils decreased significantly from CB (72.16 ng/g dry weight (DW)), GA (36.48 ng/g DW), to AK (17.30 ng/g DW) gradually indicating the impact of pollution emissions on the distribution of PAHs in soils. The low (2 and 3 ring) and high (4, 5, and 6 ring) molecular weight PAHs accounted for 14%, 16%, 37%, 21%, and 12% respectively in CB soil, 24%, 31%, 29%, 7%, and 10% in GA soil and 40%, 29%, 17%, 8%, and 8% in AK soil. The high molecular weight PAHs predominated in CB soils and the low molecular weight PAHs dominated in GA and AK soils suggesting a difference in emission sources between the studied areas. The PAH diagnostic ratios and principal component analysis (PCA) indicated that PAHs in soils of the SR delta essentially originated from traffic and industrial emissions and biomass and grass/wood/coal combustion. The PAH atmospheric transport from CB area might impact the PAH distribution in the soils of AK area. The risk assessment of the soils has been performed. The total toxic equivalent concentrations (Bap<sub>teq</sub>) of PAHs in the examined areas did not exceed the Dutch target values suggesting that no carcinogenic risk for the SR delta soils was found.  

scholarly journals Evaluation of Polycyclic Aromatic Hydrocarbons and Total Petroleum Hydrocarbons Profiles in Some Nigerian Crude Oils

2019 ◽  
pp. 1-14
Author(s):  
N. Boisa ◽  
T. J. K. Ideriah ◽  
C. S. Okehie
Keyword(s):  
Molecular Weight ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Crude Oil ◽  
Aromatic Hydrocarbons ◽  
Petroleum Hydrocarbons ◽  
Total Petroleum Hydrocarbons ◽  
Crude Oils ◽  
Low Molecular Weight ◽  
Polycyclic Aromatic ◽  
Pahs Concentration

Aim: To evaluate the concentrations of Polycyclic Aromatic Hydrocarbons and Total Petroleum Hydrocarbons in some Nigerian crude oils. Study Design: Field and Laboratory-Experimental Design were used in this study. Place and Duration of Study: Crude oil samples were obtained from three locations (designated as Location 1, Location 2, and Location 3) in the Niger Delta, Nigeria. Methodology: The samples were subjected to liquid-liquid extraction using dichloromethane and analysed using GC-FID. Results: The results of the analyses of the crude oils gave polycyclic aromatic hydrocarbons (PAHs) concentrations of 2.6089 x 104 ppm representing 60.06% and total petroleum hydrocarbon (TPH) concentration of 4.3201 x 104 ppm at Location 1, PAHs concentration of 4.764 x 103 ppm (62.8%) and TPH recording a concentration of 7.583x 103 ppm at Location 2, while Location 3 had PAHs concentration of 9.93 x 102 ppm (30.66%) and TPH concentration of 3.239 x 103 ppm. The total concentrations of the high molecular weight PAHs were lower than those of the low molecular weight PAHs in the samples. Also the concentrations of the individual PAHs were higher in the low molecular weight PAHs. The mean PAHs concentrations of 2707.6 ppm (location 1), 551.5 ppm (location 2) and 90.7 ppm (location 3) are different. Conclusion: The observed  results show that all the sixteen polycyclic aromatic hydrocarbons listed as priority pollutants are present in the three crude oil samples with higher concentrations in the light crude oils than in the heavy crude oil and a strong correlation with the total petroleum hydrocarbon concentration. It was also observed that though the ratios of the low molecular weight PAHs to high molecular weight PAHs of the crude oils indicate petrogenic, the unique diagnostic ratios suggest pyrogenic input. There is therefore the need to develop a method of PAHs removal from PAHs contaminated water based on locally available and cheap materials.

scholarly journals Occurrence, Removal, and Mass Balance of Polycyclic Aromatic Hydrocarbons and Their Derivatives in Wastewater Treatment Plants in Northeast China

Toxics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 76
Author(s):  
Rashid Mohammed ◽  
Zi-Feng Zhang ◽  
Chao Jiang ◽  
Ying-Hua Hu ◽  
Li-Yan Liu ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Wastewater Treatment Plants ◽  
Principal Component ◽  
Diagnostic Ratios ◽  
Regression Methods ◽  
Polycyclic Aromatic ◽  
Meta Regression ◽  
Coal Composition

Polycyclic aromatic hydrocarbons (PAHs), 33 methylated PAHs (Me-PAHs), and 14 nitrated PAHs (NPAHs) were measured in wastewater treatment plants (WWTPs) to study the removal efficiency of these compounds through the WWTPs, as well as their source appointment and potential risk in the effluent. The concentrations of ∑PAHs, ∑Me-PAHs, and ∑NPAHs were 2.01–8.91, 23.0–102, and 6.21–171 µg/L in the influent, and 0.17–1.37, 0.06–0.41 and 0.01–2.41 µg/L in the effluent, respectively. Simple Treat 4.0 and meta-regression methods were applied to calculate the removal efficiencies (REs) for the 63 PAHs and their derivatives in 10 WWTPs and the results were compared with the monitoring data. Overall, the ranges of REs were 55.3–95.4% predicated by the Simple Treat and 47.5–97.7% by the meta-regression. The results by diagnostic ratios and principal component analysis PCA showed that “mixed source” biomass, coal composition, and petroleum could be recognized to either petrogenic or pyrogenic sources. The risk assessment of the effluent was also evaluated, indicating that seven carcinogenic PAHs, Benzo[a]pyrene, Dibenz[a,h]anthracene, and Benzo(a)anthracene were major contributors to the toxics equivalency concentrations (TEQs) in the effluent of WWTPs, to which attention should be paid.

Sign in / Sign up

Export Citation Format

Share Document