Characterisation of Polycyclic Aromatic Hydrocarbons in Mangrove Sediments of Ifiekporo Creek, Warri South Local Government Area, Delta State, Nigeria.

Abstract

The occurrence and level of polycyclic aromatic hydrocarbons (PAHs) in the mangrove sediment of the Ifiekporo community in Warri South Local Government Area of Delta State were assessed in this study. A total of 10 sediment samples were collected from 10 sites along the Ifiekporo Creek. The extraction of PAHs from the sediment samples was achieved using the PAHs Analytical Test Method (USEPA 8270). This method measures individual concentrations of extractable PAHs in samples. The aliphatic and poly-aromatic hydrocarbons were quantified within C11-C22. The basic GC parameters for the analysis of polyaromatic hydrocarbons were analyzed using the Gas Chromatograph-Mass Selective Detector (GC-MSD). The individual PAH concentration in mangrove sediment samples varies from Not Detected (ND) to 3.47 µg/kg. The PAHs concentration of 3.47 µg/kg was highest in sampling point 5 across the sampling points. The PAH source apportionment employing isomeric ratios and multivariate statistics indicated both pyrogenic and petrogenic source inputs in sediment samples. The PAHs homologous distribution sequence for sediment is 3-ring > 2-ring > 1-ring > 6-ring. The sediment samples are mostly dominated by LMW PAHs. The result of the ecological risk assessment in the study area indicates that there is low ecological risk associated with PAH exposures in sediment. These results provide data on the concentrations and compositional patterns of PAHs, which is useful in understanding the effects, sources, fate, and transport of PAHs in sediment in the study area, as well as providing relevant information for environmental quality management and forensic studies.