Baseline PAHs, N-PAHs and 210Pb in Segment Samples from Bodo Creek: Comparison with Bonny Estuary, Niger Delta

Anyanwu, Ihuoma N.; Sikoki, Francis D.; Semple, K. T.

Baseline PAHs, N-PAHs and 210Pb in Segment Samples from Bodo Creek: Comparison with Bonny Estuary, Niger Delta

2021

Anyanwu, Ihuoma N. | Sikoki, Francis D. | Semple, K. T. (Kirk T.)

Polycyclic aromatic hydrocarbons (PAHs), the nitrogen-containing analogues (N-PAHs) and lead 210 (²¹⁰Pb) were measured in 2-cm interval core segments from Bodo Creek to evaluate impact of oil pollution in the waterbody. PAHs and N-PAHs were measured by gas chromatography analysis with mass spectrometry detection, and ²¹⁰Pb activity concentration was determined by alpha spectrometry measurement. Data shows that ƩPAHs and ƩN-PAHs ranged from 12,774.3–18,470.2 µg/kg and 524.0–672.2 µg/kg, respectively. Concentrations were found to increase with increase in depth (cm). Petrogenic PAHs predominated the surface sediment (with elevated levels of 2,3,6-trimethyl-naphthalene, phenanthrene and 1-methyl-phenanthrene), while pyrogenic-PAHs dominated the deeper segments (with high levels of pyrene, benzo[a]anthracene, chrysene and benzo[k]fluoranthene). For N-PAHs, benzo[h]quinoline, 4,7-phenanthroline and benzo[a]acridine recorded high values. Chemicals comparison with values measured from Bonny Estuary revealed greater PAHs contamination in the estuary, while N-PAHs recorded elevated values in the creek. ²¹⁰Pb activity concentration in the creek showed relatively low activity compared to the estuary, and similar distribution with the aromatic hydrocarbons. The measured hydrocarbons were high and exceeded the Canadian sediment quality guidelines. However, there are concerns over toxic ratios > 70% and radioactivity (EPR-D-values) > 3 – 4.E ± 01 Bq measured in the polluted creek. This gives insight on the level of radioactivity, PAHs, N-PAHs and PAHs toxic ratios in Bodo creek which would be useful in future remediation studies and/or monitoring the ability of sediments to recover under natural conditions.

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