Abstract

<p>River waters and sediments of the marine ecological systems are habitats to diverse species and biodiversity for their position and complexities as major recipient of pollutants from natural and anthropogenic sources. Polycyclic Aromatic Hydrocarbons (PAHs) account for the abiotic synthesis of materials resulting in carbon-based pollutions in the natural environment at elevated concentrations. These ecotoxic stressors are oftentimes bequeathed as legacies with increasing potencies and reactivity in surface waters and bottom sediments of the marine environment. Crude oil spills from hydrocarbon exploration and illicit artisanal refineries have become major cause of marine ecological pollutions affecting aquatic life and humans in the Niger Delta. Descriptive and comparative statistics designs were adopted in this study to evaluate the environmental and public health implications of seasonal (dry and wet/rainy) levels of marine ecological bioavailability and characteristics of PAHs in the waters and bottom sediments of the contiguous saline differentiated coastal deltaic Lower Orashi and Sombriero River Systems, Rivers State, Nigeria; to determine the extent of PAHs pollution. The study area was segmented into 10 sites, where water and sediment samples were collected into decontaminated plastic bottles and zip lock bags, sealed and appropriately labeled sample stations-wise, stored in ice-parks cooler for preservation of their oxidation states. Standard laboratory methods were adopted for analysis of physico-chemical parameters. Inductively Coupled Plasma Mass Spectrometer (ICP-MS) was used for the sequencing/speciation of PAHs. The study findings show that 15 of 16 IARC priority PAHs exceeded the WHO/USEPA tolerant values (TLV) in the study media except Fluorine. Significant variation exists in the PAHs among the surface waters and sediments at p&lt;0.05. This shows that the marine media are contaminated with PAHs, hence unsuitable for pelagic and benthic aquatic demersals/species, thus, predisposing the riparian population to possible health risks associated with PAHs exposure. Articulation of efficient and sustainable multi-stakeholder environmental decontamination/remediation and mitigation of the study area and Niger Delta urgently recommended.</p>