Polycyclic Aromatic Hydrocarbons in Soil and Vegetation of Niger Delta, Nigeria: Ecological Risk Assessment

Okoye, Esther Amaka; Ezejiofor, Anthonet N.; Nwaogazie, Ify L.; Frazzoli, Chiara; Orisakwe, Orish E.

doi:https://doi.org/10.1155/2023/8036893

Journal of Toxicology

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Abstract Introduction Materials and Methods Results and Discussion Conclusion Data Availability Additional Points Conflicts of Interest Authors’ Contributions Acknowledgments References Copyright Related Articles

Research Article | Open Access

Volume 2023 | Article ID 8036893 | https://doi.org/10.1155/2023/8036893

Polycyclic Aromatic Hydrocarbons in Soil and Vegetation of Niger Delta, Nigeria: Ecological Risk Assessment

Esther Amaka Okoye,¹Anthonet N. Ezejiofor,^2,3Ify L. Nwaogazie,¹Chiara Frazzoli,⁴and Orish E. Orisakwe^2,3

Academic Editor: Mohd. Salman

Received17 Nov 2021

Revised15 Aug 2022

Accepted13 Jun 2023

Published20 Jul 2023

Abstract

The Niger Delta, Nigeria, is noted for crude oil exploration. Whereas there seems to be a handful of data on soil polycyclic aromatic hydrocarbon (PAH) levels in this area, there is a paucity of studies that have evaluated soil and vegetation PAHs simultaneously. The present study has addressed this information gap. Fresh Panicum maximum (Jacq) (guinea grass), Pennisetum purpureum Schumach (elephant grass), Zea mays (L.) (maize), and soil samples were collected in triplicate from Choba, Khana, Trans-Amadi, Eleme, Uyo, and Yenagoa. PAHs determination was carried out using GC-MS. The percentage composition of the molecular weight distribution of PAHs, the molecular ratio of selected PAHs for identification of possible sources, and the isomeric ratio and total index of soil were evaluated. Pennisetum purpureum Schumach (elephant grass) from Uyo has the highest (10.0 mg·kg⁻¹) PAH while Panicum maximum (Jacq) (guinea grass) has the highest PAH (32.5 mg·kg⁻¹ from Khana. Zea mays (L.) (maize) from Uyo (46.04%), Pennisetum purpureum Schumach (elephant grass) from Trans-Amadi (47.7%), guinea grass from Eleme (49.2%), and elephant grass from Choba (39.9%) contained the highest percentage of high molecular weight (HMW) PAHs. Soil samples from Yenagoa (53.5%) and Khana (55.3%) showed the highest percentage of HMW PAHs. The total index ranged 0.27–12.4 in Uyo, 0.29–8.69 in Choba, 0.02–10.1 in Khana, 0.01–5.53 in Yenagoa, 0.21–9.52 in Eleme, and 0.13–8.96 in Trans-Amadi. The presence of HMW PAHs and molecular diagnostic ratios suggest PAH pollution from pyrogenic and petrogenic sources. Some soils in the Niger Delta show RQ_(NCs) values higher than 800 and require remediation to forestall ecohealth consequences.

1. Introduction

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous and persistent organic pollutants consisting of two or more fused rings [1–3]. Their structural stability, semivolatility, and hydrophobicity make them ubiquitous in the environment [4–7]. PAHs have been implicated in diverse toxicities including mutagenicity, teratogenicity, neurotoxicity, genotoxicity, and carcinogenicity in humans [8–12]. Given these public health concerns, 16 PAHs have been recommended for the priority control list by the United States Environmental Protection Agency (USEPA) due to their carcinogenicity, neurotoxicity, and genotoxicity [9]. Furthermore, PAHs are known to migrate and transform among different environmental matrices, including those interfacing food chains, thus affecting both animal and human health [13].

The environmental persistence and public health importance of PAHs in recent years have attracted global attention [14–16]. The principal sources of PAHs in different environmental matrices (soil, water, atmosphere, and food) are natural sources and anthropogenic processes including diverse industrial activities, especially those involving incomplete combustion of coal. Similarly, crude oil and petroleum manufacturing process also produce significant amounts of PAHs [17–19].

Although the uptake of PAH by leaves is mainly by gaseous deposition [20], some reports have demonstrated that leaves can accumulate PAHs from contaminated soils through their roots [21–23]. Nevertheless, Su and Zhu [24] suggested that the PAHs transported from roots to shoots may be negligible, with other researchers affirming that atmospheric PAHs are dominant contributors to the total PAHs in leaves [25, 26].

Long periods of crude oil exploitation in many countries have led to complex contamination by petroleum hydrocarbons and PAHs in many cities. For instance, some studies from China have reported an average content of 16 PAHs (∑₁₆ PAHs) of 1840 μg/kg in Daqing street dust [27]. All in all, it is known that the pollution effects of PAHs on ecological land in oil- producing cities and surrounding communities have great significance on urban ecological security and environmental health [28, 29]. The Niger Delta area of Nigeria is one of the major crude oil-exploring regions in the world with inundated cases of oil spills, aerial deposition of organic by-products originating from flared gases and massive environmental degradation by both inorganic and organic pollutants like PAHs [10]. Some researchers have reported concentrations and compositional patterns of PAHs that can be employed in understanding the effects, sources, fate, and transport of PAHs in soils, as well as environmental quality management in the Niger Delta, Nigeria [30, 31]. PAHs strongly accumulate in the food chain and are subsequently transferred to humans, thereby posing a threat to human health [32, 33]. Some skeletal surveys of PAHs in agricultural soils have been carried out in Niger Delta [34–36]. Some of these surveys suggest that some agricultural soils in the Niger Delta, Nigeria, suffer from PAH pollution due mainly to point source pollution. Surface and underground water are polluted with PAHs in Nigeria [37, 38]. PAHs can transfer from soil to borehole water [39]. Although some studies have reported soil and vegetation PAH contamination, information remains sparse on PAH contamination of both soils and vegetation from the same location [40]. Understanding of the spatial distribution of PAHs in agricultural topsoil is critical for environmental management and the safety of agricultural produce.

As recently discussed [41], the One Health strategy, including environmental health and food safety, can help risk assessors and risk managers in prioritising actions for the prevention and mitigation of PAH pollution and its spread and accumulation. In the present study, we evaluated the whole ecological risk of PAHs in soil and vegetation samples from farmlands in six major cities of Niger Delta, Nigeria.

2. Materials and Methods

2.1. Study Area

The Niger Delta, Nigeria, is the third largest mangrove forest and the second largest delta in the world. It falls within the central coastlands of southern Nigeria [10]. The Niger Delta area is well known for crude oil exploration and environmental pollution. According to Okoye et al. [10], the black to greyish brown and dark grey soils are acidic with slight to moderate electrical conductivity and high organic carbon content.

2.2. Sampling and Sample Treatment

2.2.1. Detailed Sampling Locations (GPS)

Soil and fresh plant (guinea grass, elephant grass, and maize) samples were sampled in Choba-4°53′16.6″N 6°54′31.3″E, Khana-4°39′36.0″N 7°22′39.4″E, Trans-Amadi-4°48′53″N 7°2′14″E, Eleme-4°47′24.2″N 7°07′47.6″E, Uyo-5°01′59.0″N 7°56′15.8″E, and Yenegoa-4°55′29″N 6°15′51″E in the Niger Delta. Figure 1 shows the sampling sites. The sampling, done in triplicate, was carried out during the period of mass flowering of plants, specifically in January 2018. Soil samples were sampled from 0 to 5 cm depth as the most root-inhabited soil layer according to the US EPA Method 610 (U.S. EPA, 1977). The sampled soil was cleaned of plant residues and other inclusions, ground in a porcelain mortar, and passed through a sieve with a hole diameter of 1 mm. Plants were dried and ground up to a hole diameter of 1 mm for analytical analysis.

2.3. Analytical Determinations

2.3.1. Information on LOD, LOQ, and Calibration (QA/QC)

Analyses of PAHs were done using gas chromatography (6890 series and 6890 plus) equipped with a dual detector (FID-ECD), dual column, TriPlus AS autosampler with helium carrier gas, and a quadrupole mass spectrometer (Agilent 5975 MSD) based on the US EPA method 8100. This analytical procedure has been described previously [42–45]. Briefly, the extraction of PAHs from the samples was done with a sonicator (ultrasonic bath, Elmsonic S40H) in accordance with US SW-846 Method 3550. Two grams of either soil or plant samples were extracted with a 50 : 50 mixture of acetone and methylene chloride (analytical grade), spiked with 1 ml of PAH internal standard, and shaken thoroughly for proper mixing before being placed in an ultrasonic bath. Thereafter, 2.00 μl of each sample extracts were injected into the GC port set at column conditions: HP-5cross-linked PH-ME siloxane, length of 30 m, I.D: 0.25 mm, thickness of 1 μm with helium carrier gas set in the spitless, constant flow mode with a 1.2 ml/min flow rate. Other GC and MS operating setups were done according to the instrument’s method of development as specified in the operating instruction manual. Identification and quantification of individual PAHs were based on an internal calibration standard containing known concentrations of the 16 PAHs [43–45]. The specificity of the 16 PAHs sought in the samples was confirmed by the presence of transition ions (quantifier and qualifier) as shown by their retention times which corresponded to those of their respective standards. The measured peak area ratios of precursor to quantifier ions were in close agreement with those of the standards. The 16 PAHs analyzed were the following: napthalene (Nap) CAS No. 91-20-3, acenaphthylene (Acy) CAS No. 208-96-8, acenapthene (Ace) CAS No. 83-32-9, fluorene (Flu) CAS No. 86-73-7, phenanthrene (Phe) CAS No. 85-01-8, anthracene (Ant) CAS No. 120-12-7, fluoranthene (Flt) CAS No. 206-44-0, pyrene (Pyr) CAS No. 129-00-0, benzo[a]anthracene (BaA) CAS No. 56-55-3, chrysene (Cry) CAS No. 218-01-9, benzo[b]fluoranthene (BbF) CAS No. 205-99-2, benzo[k]fluoranthene (BkF) CAS No. 207-08-9, benzo[a]pyrene (BaP) CAS No. 50-32-8, dibenzo[ah]anthracene (DahA) CAS No. 53-70-3, benzo[ghi]perylene (BghiP) CAS No. 191-24-2, and indeno[1,2,3-cd]pyrene (Ind) CAS No. 193-39-5. The CAS No. is a unique identification number assigned by the Chemical Abstracts Service (CAS), US, to every chemical substance described in the open scientific literature.

The detection limit (LOD) is estimated as three times the background noise (IUPAC criterion). The blank samples remained always below the quantification limit (LOQ). Table S1 shows the reproducibility relative standard deviation (RSDr; n = 6), repeatability relative standard deviation (RSDr; n = 6), recoveries, linear range, LOQ, LOD, and coefficient of estimation (r²).

2.4. Data Analysis

SPSS version 17.0 software (SPSS Inc., USA) was used to perform all statistical analyses. The data were analyzed to test for the significance of observed differences in the PAH content by using analysis of variance (ANOVA), while the Tukey test was used to establish if the observed differences in the mean content of PAHs from the different cities were significant.

The sources of the soil PAHs from different cities were evaluated by using PAH isomeric ratios.

The risk quotient in ecological risk assessment is defined as the level of risk produced by a particular PAH and is estimated from the risk quotient (RQ), as shown in the following equation:where C_PAHs is the concentration of certain PAHs in the soil and C_QV is the corresponding quality value concentration for these PAHs in the soil. Cao et al. [46] model was adopted in order to obtain the quality value concentrations in the present study.

The negligible concentrations (NCs) and the maximum permissible concentrations (MPCs) of PAHs are two quality values employed here with corresponding risk quotients, RQ_NCs and RQ_MPCs, respectively, computed fromwhere C_QV(NCs) is the quality value of the NCs and C_QV(MPCs) is the quality value of the MPCs of the PAHs in the soil.

The risk caused by a combination of all 16 PAHs can be appraised by calculating RQ∑PAHs_(NCs) and RQ∑PAHs_(MPCs) in which the values of RQ_NCs and RQ_MPCs of the individual PAHs that are not less than one are summed, as shown as follows:where .where .

The RQ denotes as follows: RQ_NCs <1.0 indicates that the individual PAH compounds are probably of negligible concern, while RQ_MPCs ≥ 1 suggests severe contamination by the individual PAH compound that requires remediation. RQ_NCs ≥ 1.0 and RQ_MPCs <1 indicate moderate risk posed by a single PAH compound that might require some control and remediation. However, and imply moderate risk 1. and indicate that the PAHs constitute a moderate risk 2; and show a high risk of the ∑16 PAHs in the ecosystem.

3. Results and Discussion

3.1. Level of PAHs

Table 1 shows the levels of PAHs in soil and elephant grass, maize, and guinea grass samples from Uyo, Choba, Khana, Yenagoa, Eleme, and Trans-Amadi. Guinea grass from Khana had the highest level of total PAH 32.5, whereas elephant grass from Uyo had the highest level of PAH 10.0. Maize samples from Yenagoa showed the highest level of PAH (9.73). Soil samples from Uyo had the highest soil total PAH (8.80).

3.2. Source Apportionment

Figures 2 and 3 show the PAHs content in elephant grass 2(a), maize 2(b), and guinea grass 2(c) from different locations in the Niger Delta and the abundance of individual PAHs in elephant grass 3(a), maize 3(b), and guinea grass 3(c) from Choba, Eleme, Khana, Trans-Amadi, Uyo, and Yenagoa in the Niger Delta, respectively.

The levels of different PAH content in elephant grass, maize, guinea grass, and soil samples, respectively, from Choba, Eleme, Khana, Trans-Amadi, Uyo, and Yenagoa in the Niger Delta, Nigeria, are provided in Figures 2–5. Figure 2(a) shows that elephant grass from Uyo had the highest number and content of PAHs whereas Khana had the least number of PAHs and the highest content of BaA (4.22 mg·kg⁻¹). The highest content of benzo[a]anthracene (BaA) in elephant grass and dibenzo[ah]anthracene (DahA) content in guinea grass seen in Khana may be an indication of the severity of PAH pollution, and its impact on ecohealth should be further investigated.

Figure 2(b) shows that the maize from Yenagoa and Eleme had a higher content of different PAHs than Khana which contained a fewer number of PAHs with BaA being the highest. The lowest levels of PAHs were seen in guinea grass 2C from Yenagoa, Eleme, Choba, Trans-Amadi, and Uyo. Guinea grass from Khana, Niger Delta, contain all the PAHs and highest levels of Acy (11.9 mg·kg⁻¹) and BaP (11.1 mg·kg⁻¹) in comparison to other locations in this study (Figure 2(c)).

The PAHs content in soil samples from different locations in the Niger Delta, and the abundance of individual PAHs in soil samples from different locations in the Niger Delta are shown in Figures 4 and 5, respectively. According to Figures 4 and 5, Khana had the least number of PAHs and the highest concentration of B(k)F and Flt in comparison to other locations. The soil sample from Uyo had the highest number and concentration of PAHs.

A comparison of the total soil PAH levels (mean and ranges) from different countries and present study is shown in Table 2.

The PAH concentrations of agricultural soils from Choba, Eleme, Khana, Trans-Amadi, Uyo, and Yenagoa, Niger Delta, were 7417, 6787, 6325, 7972, 8799, and 7394 μg·kg⁻¹, respectively. These PAH levels were higher than most of the soil PAH levels from other countries [61, 69, 70].

Figure 6 shows the total PAHs for the different samples from different locations in the Niger Delta of which Uyo has the highest (10.016 mg·kg⁻¹) in elephant grass and Khana has the highest PAH (32.508 mg·kg⁻¹) in guinea grass and the least in all the other samples. Vegetal levels (2.698 maize-32.508 mg·kg⁻¹ elephant grass) of PAHs were higher than soil sample levels (6.325–8.799 mg·kg⁻¹).

Based on the number of rings or molecular structure, the priority PAHs are classified as follows: low molecular weight (LMW) PAHs, i.e., Naph, Acy, Acen, Flu, Phen, and Anth (containing two and three rings), medium molecular weight (MMW) PAHs, i.e., Flan, Pyr, Chry, and BaA (with four rings), and high molecular weight (HMW) PAHs, i.e., BbF, BkF, BaP, IP, DBahA, and BghiP (with five and six rings) [71]. The percentage composition and molecular weight distribution of PAHs in vegetation, i.e., elephant grass, maize, and guinea grass and soils from Uyo, Choba, Khana, Yenagoa, Eleme, and Trans-Amadi in the Niger Delta, Nigeria, are shown in Table 3 and Figure 7. PAHs were grouped in three classes of LMW, MMW, and HMW. Maize from Uyo (46.0%), elephant grass from Trans-Amadi (47.9%), guinea grass from Eleme (49.2%), and elephant grass from Choba (39.9%) contained the highest percentage of HMW PAHs. Soil samples from Yenagoa (53.5%) show the highest percentage of HMW PAHs. Figure 7 shows the different distribution of PAHs according to their molecular weight: for Uyo, maize has more HMW while in guinea grass, elephant grass, and soil samples, LMW was more abundant. For Choba, samples of elephant grass and maize contain more HMW while guinea grass and soil samples have more LMW. For Khana, elephant grass and maize have more MMW PAH and HMW PAH in soil samples. The same trend follows in Yenagoa, Eleme, and Trans-Amadi with HMW in soil samples, guinea grass, and elephant grass, respectively.

The existence of different homologs of PAHs (PAHs with a number of aromatic rings) and PAHs with different molecular weights in the environment suggests their likely origin or sources [72–77].

Although there were higher levels of HMW PAHs in plant/vegetation samples in some cities in the present study, the fairly appreciable presence of 4-ring PAHs and 3-ring PAHs (Table 3 and Figure 7) is indicative of mixed pyrogenic sources. The LMW and MMW PAHs are known to exist both in the vapor and particulate phases [77] and usually reside within the locality of the origin or source. The observation from an additive standpoint that 3-4-rings PAHs predominated in this study suggests localized mixed sources coupled with atmospheric transport [40, 70].

PAHs with less than 4 aromatic rings (LMW PAHs) are typified by grass and industrial oil, wood combustion, and petroleum products (Liu et al. 2017), whereas PAHs with more than 4 aromatic rings (HMW PAHs) signify pyrogenic activities at high temperature including coal combustion and vehicular emissions [78]. The higher levels of HMW PAHs in maize from Uyo, elephant grass from Trans-Amadi, guinea grass from Eleme, elephant grass from Choba, and soil samples from Yenagoa and Khana may implicate vehicular traffic.

Since HMW PAHs tend to reside in closer proximity to emission sources and LMW PAHs are carried to areas far from the emission sources [40, 70], the homolog pattern of PAHs in this study with different molecular weights may be characterized by local combustion sources in addition to atmospheric transported depositions [77, 79].

In addition to using different homologs of PAHs (PAHs with the same number of aromatic rings) and PAHs with different molecular weights, molecular diagnostic ratios of selected PAHs concentrations, including Fle/(Fle + Pyr), Ant/(Ant + Phe), Flt/(Flt + Pyr) in PAH identification, BaA/(BaA + Cry), BbF/BkF, BaP/BghiP, BaP/(BaP + Cry), and Ind/(Ind + BghiP) were also employed as inferential tools in the characterization of possible sources of PAHs from plant and soils samples from Uyo, Choba, Khana, Yenagoa, Eleme, and Trans-Amadi (Table 4). The average ratio of PAHs in plants and soil suggested diverse pyrogenic sources of PAHs emission, such as Fle/(Fle + Pyr) (0.60 (0.59–0.97)) for petrol and diesel [72, 80], Ant/(Ant + Phe) (0.88 (0.61–0.70)) for petroleum and biomass combustions [81], Flt/(Flt + Pyr) (0.45 (0.77–1.67)) for biomass, coal combustion (39), BaA/(BaA + Cry) (0.27 (0.32–1.17)) for petrogenic and combustion of petroleum and biomass [80], BbF/BkF (1.16 (1.27−1.09)) for diesel engine and vehicular emissions [82], BaP/BghiP (0.76 (1.49–1.94)) for vehicular emissions and coal combustions [83], BaP/(BaP + Cry) (0.009 (0.01–0.86)) for gasoline [84], and Ind/(Ind + BghiP) (0.45 (1.30–2.91)) for petrogenic and petroleum combustions (Table 4). Molecular diagnostic ratio analysis suggests disparate combustion activities including petrol, diesel, gasoline, biomass, and coal combustions and vehicular emissions, as the principal sources. Petrogenic sources are also related to automobile workshops and accidental spillage.

The isomeric ratios, namely, Flt/(Flt + Pyr), Ant/(Ant + Phen), Phen/Ant, LMW/HMW, BaA/(BaA + Chry), and IndP/(IndP + BghiP), and the total index of soil from Uyo, Choba, Khana, Yenagoa, Eleme, and Trans-Amadi, Niger Delta, Nigeria, are shown in Table 5. Furthermore, total indexes [85–87] defined as the sum of single indices (aforementioned parameters previously discussed), respectively, were calculated and normalized for the limit value (low temperature sources–high temperature sources) [80].

Usually, PAHs associated with combustion or high-temperature processes possess a total index that is greater than 4, whereas PAHs originating from petroleum products or low-temperature processes have a total index that is less than 4. In the present study, the total index ranged 0.27–12.4 in Uyo, 0.29–8.67 in Choba, 0.00–10.1 in Khana, 0.01–5.53 in Yenagoa, 0.21–9.52 in Eleme, and 0.13–8.96 in Trans-Amadi. All the sampling locations had total index values greater than 4. It can therefore be inferred from the total index values that PAHs emanated from low- and high-temperature combustion processes. These observations seem to be in agreement with previous results from Warri [46].

3.3. Ecological Risk Assessment

Table 6 shows the RQ_(NCs) and RQ∑PAHs_(NCs) and RQ_(MPCs) and RQ∑PAHs_(MPCs) for the 16 priority PAHs in soils from Uyo, Choba, Khana, Yenagoa, Eleme, and Trans-Amadi, Niger Delta, Nigeria. RQ∑PAHs_(NCs) values less than 800 are indicative of low ecological risk of PAHs while RQ∑PAHs_(NCs) higher than 800 connote higher ecological risk of PAHs. Although some soil samples from the various sampling locations had RQ_(NCs) values greater than 800 in the present study, preponderance of the samples showed RQ_(NCs) values less than 800 which is suggestive of a low ecological risk of PAHs in these soils. Some previous studies in Nigeria have reported similar RQ_(NCs) values less than 800 [88]. The RQ∑PAHs_(MPCs) values were greater than 1 except for soil samples from Khana. In this study, Nap, Acy, Ace, Flu, Ant, Flt, and Pyr were the major causes of the ecological risk of PAHs in soils from Uyo, Choba, Yenagoa, Eleme, and Trans-Amadi, Niger Delta, Nigeria. The ecosystem risk of PAHs in soils from Khana was majorly, whereas due to Flt, Phe contributed less to the ecosystem risk of PAHs in soils from Uyo. Similarly, Ant contributed less to the ecosystem risk of PAHs in soils from Choba, Yenagoa, Eleme, and Trans-Amadi, Niger Delta, Nigeria.

4. Conclusion

Nap, Acy, Ace, Flu, Ant, Flt, and Pyr were the major causes of the ecological risk due to PAHs in soils from Uyo, Choba, Yenagoa, Eleme, and Trans-Amadi in the Niger Delta, Nigeria. The ecological risk assessment of PAHs derived from isomeric ratios suggested that the PAHs in soils and vegetation samples from Choba, Yenagoa, Eleme, and Trans-Amadi emanated from pyrogenic processes including traffic emissions, fossil fuels, and biomass combustion as well as petrogenic sources such as occasional spills of liquid petroleum fuels and discharges from automobile workshops.

From the risk quotient standpoint, some soil samples from the Niger Delta had RQ_(NCs) values greater than 800, thus indicating that soil may require remediation to forestall ecohealth consequences.

Data Availability

The data used to support the findings of this study are included within the article.

Additional Points

Highlights. (i) There is a widespread PAH pollution in the Niger Delta, Nigeria, (ii) Nap, Acy, Ace, Flu, Ant, Flt, and Pyr pose major ecological risk of PAHs in soils, (iii) PAHs from the Niger Delta emanated from pyrogenic processes and petrogenic sources, and (iv) some soil in the Niger Delta may require remediation.

Conflicts of Interest

The authors declare that there are no conflicts of interest.

Authors’ Contributions

EAO contributed to sampling and bench work. ANE and ILN contributed to manuscript writing and performed supervision. CF contributed to manuscript writing and to sourcing of fund. OEO conceptualised the study, performed supervision, and wrote the manuscript.

Acknowledgments

The study was partly funded under the subproject ‘Farm animals as sentinel for environmental health and food safety in Nigeria’ of the research project ‘The role of soil in the burden of noncommunicable diseases in Africa, from farm to lifestyle’ granted by the University of Tuscia, Viterbo, Italy, to the pan-African NGO NOODLES (Nutrition & food safety and wholesomeness-Prevention, education and research, www.noodlesonlus.org) (2017–2019). Esther Amaka Okoye received tuition waiver from World Bank.

References

F. Li, X. Zeng, J. Yang et al., “Contamination of polycyclic aromatic hydrocarbons (PAHs) in surface sediments and plants of mangrove swamps in Shenzhen, China,” Marine Pollution Bulletin, vol. 85, no. 2, pp. 590–596, 2014.
View at: Publisher Site | Google Scholar
S. Sushkova, T. Mi̇nki̇na, S. Tari̇gholi̇zadeh et al., “PAHs accumulation in soil-plant system of Phragmites australis Cav. in soil under long-term chemical contamination,” Eurasian Journal of Soil Science, vol. 9, no. 3, pp. 242–253, 2020.
View at: Publisher Site | Google Scholar
A. G. Fedorenko, N. Chernikova, T. Minkina et al., “Effects of benzo [a]pyrene toxicity on morphology and ultrastructure of Hordeum sativum,” Environmental Geochemistry and Health, vol. 43, no. 4, pp. 1551–1562, 2021.
View at: Publisher Site | Google Scholar
P. Gao, E. da Silva, L. Hou, N. D. Denslow, P. Xiang, and L. Q. Ma, “Human exposure to polycyclic aromatic hydrocarbons: metabolomics perspective,” Environment International, vol. 119, pp. 466–477, 2018.
View at: Publisher Site | Google Scholar
B. M. Sharma, L. Melymuk, G. K. Bharat et al., “Spatial gradients of polycyclic aromatic hydrocarbons (PAHs) in air, atmospheric deposition, and surface water of the Ganges River basin,” Science of the Total Environment, vol. 627, pp. 1495–1504, 2018.
View at: Publisher Site | Google Scholar
B. Soukarieh, K. El Hawari, M. El Husseini, H. Budzinski, and F. Jaber, “Impact of Lebanese practices in industry, agriculture and urbanization on soil toxicity. Evaluation of the Polycyclic Aromatic Hydrocarbons (PAHs) levels in soil,” Chemosphere, vol. 210, pp. 85–92, 2018.
View at: Publisher Site | Google Scholar
J. Yan, J. Liu, X. Shi, X. You, and Z. Cao, “Polycyclic aromatic hydrocarbons (PAHs) in water from three estuaries of China: distribution, seasonal variations and ecological risk assessment,” Marine Pollution Bulletin, vol. 109, no. 1, pp. 471–479, 2016.
View at: Publisher Site | Google Scholar
S. J. Varjani, E. Gnansounou, and A. Pandey, “Comprehensive review on toxicity of persistent organic pollutants from petroleum refinery waste and their degradation by microorganisms,” Chemosphere, vol. 188, pp. 280–291, 2017.
View at: Publisher Site | Google Scholar
M. Oliveira, K. Slezakova, C. Delerue-Matos, M. C. Pereira, and S. Morais, “Children environmental exposure to particulate matter and polycyclic aromatic hydrocarbons and biomonitoring in school environments: a review on indoor and outdoor exposure levels, major sources and health impacts,” Environment International, vol. 124, pp. 180–204, 2019.
View at: Publisher Site | Google Scholar
E. A. Okoye, B. Bocca, F. Ruggieri et al., “Concentrations of polycyclic aromatic hydrocarbons in samples of soil, feed and food collected in the Niger Delta region, Nigeria: a probabilistic human health risk assessment,” Environmental Research, vol. 202, Article ID 111619, 2021.
View at: Publisher Site | Google Scholar
K. Sun, Y. Song, F. He, M. Jing, J. Tang, and R. Liu, “A review of human and animals exposure to polycyclic aromatic hydrocarbons: health risk and adverse effects, photo-induced toxicity and regulating effect of microplastics,” The Science of the Total Environment, vol. 773, Article ID 145403, 2021.
View at: Publisher Site | Google Scholar
K. H. Kim, S. A. Jahan, E. Kabir, and R. J. Brown, “A review of airborne polycyclic aromatic hydrocarbons (PAHs) and their human health effects,” Environment International, vol. 60, pp. 71–80, 2013.
View at: Publisher Site | Google Scholar
G. Karaca and Y. Taşdemir, “Migration of PAHs in food industry sludge to the air during removal by UV and TiO2,” 2014, https://acikerisim.uludag.edu.tr/handle/11452/27729.
View at: Google Scholar
O. Alshaarawy, H. A. Elbaz, and M. E. Andrew, “The association of urinary polycyclic aromatic hydrocarbon biomarkers and cardiovascular disease in the US population,” Environment International, vol. 89-90, pp. 174–178, 2016.
View at: Publisher Site | Google Scholar
A. J. White, P. T. Bradshaw, A. H. Herring et al., “Exposure to multiple sources of polycyclic aromatic hydrocarbons and breast cancer incidence,” Environment International, vol. 89-90, pp. 185–192, 2016.
View at: Publisher Site | Google Scholar
C. Wang, S. Wu, S. Zhou, Y. Shi, and J. Song, “Characteristics and source identification of polycyclic aromatic hydrocarbons (PAHs) in urban soils: a review,” Pedosphere, vol. 27, no. 1, pp. 17–26, 2017.
View at: Publisher Site | Google Scholar
M. Jumpponen, H. Rönkkömäki, P. Pasanen, and J. Laitinen, “Occupational exposure to gases, polycyclic aromatic hydrocarbons and volatile organic compounds in biomass-fired power plants,” Chemosphere, vol. 90, no. 3, pp. 1289–1293, 2013.
View at: Publisher Site | Google Scholar
O. O. Okedeyi, M. M. Nindi, S. Dube, and O. R. Awofolu, “Distribution and potential sources of polycyclic aromatic hydrocarbons in soils around coal-fired power plants in South Africa,” Environmental Monitoring and Assessment, vol. 185, no. 3, pp. 2073–2082, 2013.
View at: Publisher Site | Google Scholar
H. I. Abdel-Shafy and M. S. Mansour, “A review on polycyclic aromatic hydrocarbons: source, environmental impact, effect on human health and remediation,” Egyptian journal of petroleum, vol. 25, no. 1, pp. 107–123, 2016.
View at: Publisher Site | Google Scholar
E. Wild, J. Dent, G. O. Thomas, and K. Jones, “Direct observation of organic contaminant uptake, storage, and metabolism within plant roots,” Environmental Science and Technology, vol. 39, no. 10, pp. 3695–3702, 2005.
View at: Publisher Site | Google Scholar
Z. Qamar, S. Khan, A. Khan, M. Aamir, J. Nawab, and M. Waqas, “Appraisement, source apportionment and health risk of polycyclic aromatic hydrocarbons (PAHs) in vehicle-wash wastewater, Pakistan,” Science of the Total Environment, vol. 605-606, pp. 106–113, 2017.
View at: Publisher Site | Google Scholar
Y. Zheng, Z. Lin, H. Li et al., “Assessing the polycyclic aromatic hydrocarbon (PAH) pollution of urban stormwater runoff: a dynamic modeling approach,” The Science of the Total Environment, vol. 481, pp. 554–563, 2014.
View at: Publisher Site | Google Scholar
L. Samsøe-Petersen, E. H. Larsen, P. B. Larsen, and P. Bruun, “Uptake of trace elements and PAHs by fruit and vegetables from contaminated soils,” Environmental Science and Technology, vol. 36, no. 14, pp. 3057–3063, 2002.
View at: Publisher Site | Google Scholar
Y. H. Su and Y. G. Zhu, “Uptake of selected PAHs from contaminated soils by rice seedlings (Oryza sativa) and influence of rhizosphere on PAH distribution,” Environmental Pollution, vol. 155, no. 2, pp. 359–365, 2008.
View at: Publisher Site | Google Scholar
J. Jia, C. Bi, J. J. Zhang, and Z. Chen, “Atmospheric deposition and vegetable uptake of polycyclic aromatic hydrocarbons (PAHs) based on experimental and computational simulations,” Atmospheric Environment, vol. 204, pp. 135–141, 2019.
View at: Publisher Site | Google Scholar
J. Jia, C. Bi, X. Jin et al., “Uptake, translocation, and risk assessment of PAHs in contaminated soil-air-vegetable systems based on a field simulation experiment,” Environmental Pollution, vol. 271, Article ID 116361, 2021.
View at: Publisher Site | Google Scholar
N. N. Song, J. H. Ma, Y. Yu, Z. F. Yang, and Y. X. Li, “New observations on PAH pollution in old heavy industry cities in northeastern China,” Environmental Pollution, vol. 205, pp. 415–423, 2015.
View at: Publisher Site | Google Scholar
X. Li, R. Zheng, Q. Bu et al., “Comparison of PAH content, potential risk in vegetation, and bare soil near Daqing oil well and evaluating the effects of soil properties on PAHs,” Environmental Science and Pollution Research, vol. 26, no. 24, pp. 25071–25083, 2019.
View at: Publisher Site | Google Scholar
X. Cui, N. Ailijiang, Y. Mamitimin et al., “Pollution levels, sources and risk assessment of polycyclic aromatic hydrocarbons in farmland soil and crops near urumqi industrial park, xinjiang, China,” Stochastic Environmental Research and Risk Assessment, vol. 37, no. 1, pp. 361–374, 2023.
View at: Publisher Site | Google Scholar
E. E. Akporhonor, O. O. Emoyan, and P. O. Agbaire, “Concentrations, origin, and human health risk of polycyclic aromatic hydrocarbons in anthropogenic impacted soils of the Niger Delta, Nigeria,” Environmental Forensics, vol. 23, no. 1-2, pp. 127–140, 2021.
View at: Publisher Site | Google Scholar
Y. W. Qiu, G. Zhang, G. Q. Liu, L. L. Guo, X. D. Li, and O. Wai, “Polycyclic aromatic hydrocarbons (PAHs) in the water column and sediment core of Deep Bay, South China,” Estuarine, Coastal and Shelf Science, vol. 83, no. 1, pp. 60–66, 2009.
View at: Publisher Site | Google Scholar
L. Y. Liu, J. Z. Wang, G. L. Wei, Y. F. Guan, and E. Y. Zeng, “Polycyclic aromatic hydrocarbons (PAHs) in continental shelf sediment of China: implications for anthropogenic influences on coastal marine environment,” Environmental Pollution, vol. 167, pp. 155–162, 2012.
View at: Publisher Site | Google Scholar
Y. G. Gu, Q. Lin, T. T. Lu, C. L. Ke, R. X. Sun, and F. Y. Du, “Levels, composition profiles and sources of polycyclic aromatic hydrocarbons in surface sediments from Nan’ao Island, a representative mariculture base in South China,” Marine Pollution Bulletin, vol. 75, no. 1-2, pp. 310–316, 2013.
View at: Publisher Site | Google Scholar
J. K. Nduka and O. E. Orisakwe, “Water quality issues in the Niger delta of Nigeria: polyaromatic and straight chain hydrocarbons in some selected surface waters,” Water Quality, Exposure and Health, vol. 2, no. 2, pp. 65–74, 2010.
View at: Publisher Site | Google Scholar
K. Alagoa, J. Godwin, P. Daworiye, and B. Ipiteikumoh, “Evaluation of total petroleum hydrocarbon (TPH) in sediments and aquatic macrophytes in the river Nun, amasoma Axises, Niger Delta, Nigeria,” International Journal of Agriculture and Environmental Research, vol. 4, pp. 63–67, 2018.
View at: Google Scholar
A. E Ite, T. A Harry, C. O Obadimu, E. R Asuaiko, and I. J Inim, “Petroleum hydrocarbons contamination of surface water and groundwater in the Niger Delta region of Nigeria,” Journal of Environment Pollution and Human Health, vol. 6, no. 2, pp. 51–61, 2018.
View at: Publisher Site | Google Scholar
V. U. Okechukwu, D. O. Omokpariola, V. I. Onwukeme, E. N. Nweke, and P. L. Omokpariola, “Pollution investigation and risk assessment of polycyclic aromatic hydrocarbons in soil and water from selected dumpsite locations in rivers and Bayelsa State, Nigeria,” Environmental Analysis Health and Toxicology, vol. 36, no. 4, Article ID e2021023, 2021.
View at: Publisher Site | Google Scholar
C. T. Umeh, J. K. Nduka, D. O. Omokpariola et al., Ecological Pollution and Health Risk Monitoring Assessment of Polycyclic Aromatic Hydrocarbons and Heavy Metals in Enugu River, Southeastern Nigeria, Heliyon In press, Nigeria, 2022.
V. N. Okafor, D. O. Omokpariola, E. C. Igbokwe, C. M. Theodore, and N. G. Chukwu, “Determination and human health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in surface and ground waters from Ifite Ogwari, Anambra State, Nigeria,” International Journal of Environmental Analytical Chemistry, vol. 23, pp. 1–23, 2022.
View at: Publisher Site | Google Scholar
J. Wang, X. Zhang, W. Ling et al., “Contamination and health risk assessment of PAHs in soils and crops in industrial areas of the Yangtze River Delta region, China,” Chemosphere, vol. 168, pp. 976–987, 2017.
View at: Publisher Site | Google Scholar
G. J. Udom, C. Frazzoli, O. C. Ekhator, A. P. Onyena, B. Bocca, and O. E. Orisakwe, “Pervasiveness, bioaccumulation and subduing environmental health challenges posed by polycyclic aromatic hydrocarbons (PAHs): a systematic review to settle a one health strategy in Niger Delta, Nigeria,” Environmental Research, vol. 226, Article ID 115620, 2023.
View at: Publisher Site | Google Scholar
S. Igbiri, N. A. Udowelle, O. C. Ekhator, R. N. Asomugha, Z. N. Igweze, and O. E. Orisakwe, “Polycyclic aromatic hydrocarbons in edible mushrooms from Niger Delta, Nigeria: carcinogenic and non-carcinogenic health risk assessment,” Asian Pacific Journal of Cancer Prevention: Asian Pacific Journal of Cancer Prevention, vol. 18, no. 2, pp. 437–447, 2017.
View at: Publisher Site | Google Scholar
O. C. Ekhator, N. A. Udowelle, S. Igbiri, R. N. Asomugha, C. Frazzoli, and O. E. Orisakwe, “Street foods exacerbate effects of the environmental burden of polycyclic aromatic hydrocarbons (PAHs) in Nigeria,” Environmental Science and Pollution Research, vol. 25, no. 6, pp. 5529–5538, 2018.
View at: Publisher Site | Google Scholar
O. E. Orisakwe, H. O. Mbagwu, P. Ukpai, and N. A. Udowelle, “Survey of polycyclic aromatic hydrocarbons and lead in Chinese teas sold in Nigeria: levels and health implications,” Roczniki Panstwowego Zakladu Higieny, vol. 66, no. 3, pp. 225–232, 2015a.
View at: Google Scholar
O. E. Orisakwe, Z. N. Igweze, K. O. Okolo, and N. A. Udowelle, “Human health hazards of poly aromatic hydrocarbons in Nigerian smokeless tobacco,” Toxicology Reports, vol. 2, no. 2, pp. 1019–1023, 2015b.
View at: Publisher Site | Google Scholar
Z. Cao, J. Liu, Y. Luan et al., “Distribution and ecosystem risk assessment of polycyclic aromatic hydrocarbons in the Luan River, China,” Ecotoxicology, vol. 19, no. 5, pp. 827–837, 2010.
View at: Publisher Site | Google Scholar
M. Krauss, W. Wilcke, and W. Zech, “Polycyclic aromatic hydrocarbons and polychlorinated biphenyls in forest soils: depth distribution as indicator of different fate,” Environmental Pollution, vol. 110, no. 1, pp. 79–88, 2000.
View at: Publisher Site | Google Scholar
T. D. Bucheli, F. Blum, A. Desaules, and O. Gustafsson, “Polycyclic aromatic hydrocarbons, black carbon, and molecular markers in soils of Switzerland,” Chemosphere, vol. 56, no. 11, pp. 1061–1076, 2004.
View at: Publisher Site | Google Scholar
J. J. Nam, B. H. Song, K. C. Eom, S. H. Lee, and A. Smith, “Distribution of polycyclic aromatic hydrocarbons in agricultural soils in South Korea,” Chemosphere, vol. 50, no. 10, pp. 1281–1289, 2003.
View at: Publisher Site | Google Scholar
R. Hao, H. F. Wan, Y. T. Song, H. Jiang, and S. L. Peng, “Polycyclic aromatic hydrocarbons in agricultural soils of the southern subtropics, China,” Pedosphere, vol. 17, no. 5, pp. 673–680, 2007.
View at: Publisher Site | Google Scholar
M. Krauss and W. Wilcke, “Polychlorinated naphthalenes in urban soils: analysis, concentrations, and relation to other persistent organic pollutants,” Environmental Pollution, vol. 122, no. 1, pp. 75–89, 2003.
View at: Publisher Site | Google Scholar
H. W. Mielke, G. D. Wang, C. R. Gonzales, B. Le, V. N. Quach, and P. W. Mielke, “PAH and metal mixtures in New Orleans soils and sediments,” The Science of the Total Environment, vol. 281, no. 1-3, pp. 217–227, 2001.
View at: Publisher Site | Google Scholar
S. Ray, P. S. Khillare, T. Agarwal, and V. Shridhar, “Assessment of PAHs in soil around the international airport in Delhi, India,” Journal of Hazardous Materials, vol. 156, no. 1-3, pp. 9–16, 2008.
View at: Publisher Site | Google Scholar
S. Baran, J. E. Bielinska, and P. Oleszczuk, “Enzymatic activity in an airfield soil polluted with polycyclic aromatic hydrocarbons,” Geoderma, vol. 118, no. 3-4, pp. 221–232, 2004.
View at: Publisher Site | Google Scholar
C. D. Stalikas, C. I. Chaidou, and G. A. Pilidis, “Enrichment of PAHs and heavy metals in soils in the vicinity of the lignite-fired power plants of West Macedonia (Greece),” The Science of the Total Environment, vol. 204, no. 2, pp. 135–146, 1997.
View at: Publisher Site | Google Scholar
P. Weiss, A. Riss, E. Gschmeidler, and H. Schentz, “Investigation of heavy metal, PAH, PCB patterns and PCDD/F profiles of soil samples from an industrialized urban area (Linz, Upper Austria) with multivariate statistical methods,” Chemosphere, vol. 29, no. 9-11, pp. 2223–2236, 1994.
View at: Publisher Site | Google Scholar
X. J. Wang, Y. Zheng, R. M. Liu, B. G. Li, J. Cao, and S. Tao, “Medium scale spatial structures of polycyclic aromatic hydrocarbons in the topsoil of Tianjin area,” Journal of Environmental Science and Health, Part B, vol. 38, no. 3, pp. 327–335, 2003.
View at: Publisher Site | Google Scholar
B. Škrbic´ and N. Miljevic´, “An evaluation of residues at an oil refinery site following fires,” Journal of Environmental Science and Health, Part A, vol. 37, no. 6, pp. 1029–1039, 2002.
View at: Publisher Site | Google Scholar
M. Trapido, “Polycyclic aromatic hydrocarbons in Estonian soil: contamination and profiles,” Environmental Pollution, vol. 105, no. 1, pp. 67–74, 1999.
View at: Publisher Site | Google Scholar
M. I. Bakker, B. Casado, J. W. Koerselman, J. Tolls, and C. Kolloffel, “Polycyclic aromatic hydrocarbons in soil and plant samples from the vicinity of an oil refinery,” The Science of the Total Environment, vol. 263, no. 1-3, pp. 91–100, 2000.
View at: Publisher Site | Google Scholar
R. Wang, G. Liu, C. L. Chou, J. Liu, and J. Zhang, “Environmental assessment of PAHs in soils around the anhui coal district, China,” Archives of Environmental Contamination and Toxicology, vol. 59, no. 1, pp. 62–70, 2010.
View at: Publisher Site | Google Scholar
H. Jiao, Q. Wang, N. Zhao, B. Jin, X. Zhuang, and Z. Bai, “Distributions and sources of polycyclic aromatic hydrocarbons (PAHs) in soils around a chemical plant in Shanxi, China,” International Journal of Environmental Research and Public Health, vol. 14, no. 10, p. 1198, 2017.
View at: Publisher Site | Google Scholar
E. J. Kim, S. D. Choi, and Y. S. Chang, “Levels and patterns of polycyclic aromatic hydrocarbons (PAHs) in soils after forest fires in South Korea (PAHs) in soils after forest fires in South Korea,” Environmental Science and Pollution Research, vol. 18, no. 9, pp. 1508–1517, 2011.
View at: Publisher Site | Google Scholar
K. Banger, G. S. Toor, T. Chirenje, and L. Ma, “Polycyclic aromatic hydrocarbons in urban soils of different land uses in Miami, Florida,” Soil and Sediment Contamination: International Journal, vol. 19, no. 2, pp. 231–243, 2010.
View at: Publisher Site | Google Scholar
O. S. Sojinu, O. O. Sonibare, and E. Y. Zeng, “Concentrations of polycyclic aromatic hydrocarbons in soils of a mangrove forest affected by forest fire,” Toxicological and Environmental Chemistry, vol. 93, no. 3, pp. 450–461, 2011.
View at: Publisher Site | Google Scholar
G. O. Tesi, C. M. A. Iwegbue, F. N. Emuh, and G. E. Nwajei, “Lagdo dam flood disaster of 2012: an assessment of the concentrations, sources, and risks of PAHs in floodplain soils of the lower reaches of river Niger, Nigeria,” Journal of Environmental Quality, vol. 45, no. 1, pp. 305–314, 2016.
View at: Publisher Site | Google Scholar
A. O. Abbas and W. Brack, “Polycyclic aromatic hydrocarbons in Niger Delta soil: contamination sources and profiles,” International journal of Environmental Science and Technology, vol. 2, no. 4, pp. 343–352, 2005.
View at: Publisher Site | Google Scholar
O. S. Sojinu, J. Z. Wang, O. O. Sonibare, and E. Y. Zeng, “Polycyclic aromatic hydrocarbons in sediments and soils from oil exploration areas of the Niger Delta, Nigeria,” Journal of Hazardous Materials, vol. 174, no. 1-3, pp. 641–647, 2010.
View at: Publisher Site | Google Scholar
C. M. Iwegbue, G. Obi, E. Aganbi, J. E. Ogala, O. O. Omo-Irabor, and B. S. Martincigh, “Concentrations and health risk assessment of polycyclic aromatic hydrocarbons in soils of an urban environment in the Niger Delta, Nigeria,” Toxicology and Environmental Health Sciences, vol. 8, no. 3, pp. 221–233, 2016.
View at: Publisher Site | Google Scholar
Z. Wang, X. Ma, G. Na, Z. Lin, Q. Ding, and Z. Yao, “Correlations between physicochemical properties of PAHs and their distribution in soil, moss and reindeer dung at Ny-A °lesund of the Arctic,” Environmental Pollution, vol. 157, no. 11, pp. 3132–3136, 2009.
View at: Publisher Site | Google Scholar
J. Xue, G. J. Liu, Z. Y. Niu et al., “Factors that influence the extraction of polycyclic aromatic hydrocarbons from coal,” Energy and Fuels, vol. 21, no. 2, pp. 881–890, 2007.
View at: Publisher Site | Google Scholar
B. Kumar, V. K. Verma, M. Mishra et al., “Assessment of persistent organic pollutants in soil and sediments from an urbanized flood plain area,” Environmental Geochemistry and Health, vol. 43, no. 9, pp. 3375–3392, 2021.
View at: Publisher Site | Google Scholar
B. Kumar, V. K. Verma, M. Mishra, S. Kumar, C. S. Sharma, and A. B. Akolkar, “Persistent organic pollutants in residential soils of North India and assessment of human health hazard and risks,” Toxicological and Environmental Chemistry, vol. 96, no. 2, pp. 255–272, 2014a.
View at: Publisher Site | Google Scholar
B. Kumar, V. K. Verma, S. Kumar, and C. S. Sharma, “Polycyclic aromatic hydrocarbons in residential soils from an Indian city near power plants area and assessment of health risk for human population,” Polycyclic Aromatic Compounds, vol. 34, no. 3, pp. 191–213, 2014b.
View at: Publisher Site | Google Scholar
B. Kumar, V. K. Verma, C. S. Sharma, and A. B. Akolkar, “Priority polycyclic aromatic hydrocarbons (PAHs): distribution, possible sources and toxicity equivalency in urban drains,” Polycyclic Aromatic Compounds, vol. 36, no. 4, pp. 342–363, 2015a.
View at: Publisher Site | Google Scholar
B. Kumar, V. K. Verma, J. Tyagi, C. S. Sharma, and A. B. Akolkar, “Health risk due to sixteen PAHs in residential street soils from industrial region, ghaziabad, Uttar Pradesh, India,” Journal of Environment Protection and Sustainable Development, vol. 1, no. 2, pp. 101–106, 2015b.
View at: Google Scholar
S. Ray, P. S. Khillare, and K. H. Kim, “Profiles, carcinogenic potencies, sources and association of black carbon and polycyclic aromatic hydrocarbons in size fractionated urban and forest soils of Delhi, India,” International Journal of Environmental Engineering and Management, vol. 4, no. 6, pp. 581–584, 2013.
View at: Google Scholar
L. C. Marr, T. W. Kirchstetter, R. A. Harley, A. H. Miguel, S. V. Hering, and S. K. Hammond, “Characterization of polycyclic aromatic hydrocarbons in motor vehicle fuels and exhaust emissions,” Environmental Science and Technology, vol. 33, no. 18, pp. 3091–3099, 1999.
View at: Publisher Site | Google Scholar
D. P. Singh, R. Gadi, and T. K. Mandal, “Levels, sources, and toxic potential of polycyclic aromatic hydrocarbons in urban soil of Delhi, India,” Human and Ecological Risk Assessment: An International Journal, vol. 18, no. 2, pp. 393–411, 2012.
View at: Publisher Site | Google Scholar
K. Ravindra, R. Sokhi, and R. Vangrieken, “Atmospheric polycyclic aromatic hydrocarbons: source attribution, emission factors and regulation,” Atmospheric Environment, vol. 42, no. 13, pp. 2895–2921, 2008.
View at: Publisher Site | Google Scholar
M. B. Yunker, R. W. Macdonald, R. Vingarzan, R. H. Mitchell, D. Goyette, and S. Sylvestre, “PAHs in the Fraser River basin: a critical appraisal of PAH ratios as indicators of PAH source and composition,” Organic Geochemistry, vol. 33, no. 4, pp. 489–515, 2002.
View at: Publisher Site | Google Scholar
R. M. Dickhut, E. A. Canuel, K. E. Gustafson et al., “Automotive sources of carcinogenic polycyclic aromatic hydrocarbons associated with particulate matter in the Chesapeake Bay Region,” Environmental Science and Technology, vol. 34, no. 21, pp. 4635–4640, 2000.
View at: Publisher Site | Google Scholar
M. F. Simcik, S. J. Eisenreich, and P. J. Lioy, “Source apportionment and source/sink relationships of PAHs in the coastal atmosphere of Chicago and Lake Michigan,” Atmospheric Environment, vol. 33, no. 30, pp. 5071–5079, 1999.
View at: Publisher Site | Google Scholar
N. R. Khalili, P. A. Scheff, and T. M. Holsen, “PAH source fingerprints for coke ovens, diesel and gasoline engines, highway tunnels, and wood combustion emissions,” Atmospheric Environment, vol. 29, no. 4, pp. 533–542, 1995.
View at: Publisher Site | Google Scholar
M. R. Mannino and S. Orecchio, “Polycyclic aromatic hydrocarbons (PAHs) in indoor dust matter of Palermo (Italy) area: extraction, GC–MS analysis, distribution and sources,” Atmospheric Environment, vol. 42, no. 8, pp. 1801–1817, 2008.
View at: Publisher Site | Google Scholar
S. Frenna, A. Mazzola, S. Orecchio, and N. Tuzzolino, “Comparison of different methods for extraction of polycyclic aromatic hydrocarbons (PAHs) from Sicilian (Italy) coastal area sediments,” Environmental Monitoring and Assessment, vol. 185, no. 7, pp. 5551–5562, 2013.
View at: Publisher Site | Google Scholar
S. Barreca, A. Mazzola, S. Orecchio, and N. Tuzzolino, “Polychlorinated biphenyls in sediments from Sicilian coastal area (Scoglitti) using automated soxhlet, GC-MS, and principal component analysis,” Polycyclic Aromatic Compounds, vol. 34, no. 3, pp. 237–262, 2014.
View at: Publisher Site | Google Scholar
M. J. Ehigbor, C. M. Iwegbue, O. I. Eguavoen, G. O. Tesi, and B. S. Martincigh, “Occurrence, sourcesand ecologicaland human health risks of polycyclic aromatic hydrocarbons in soils from some functional areas of the Nigerianmegacity, Lagos,” Environmental Geochemistry and Health, vol. 42, no. 9, pp. 2895–2923, 2020.
View at: Publisher Site | Google Scholar

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Copyright © 2023 Esther Amaka Okoye et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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