Detection of Polynuclear aromatic hydrocarbons in mud skippers (<i>Gobiformes oxudecidae</i>) from Jones Creek, Delta State, Southern Nigeria

Abstract

The measurement of polynuclear aromatic hydrocarbons (PAHs) was conducted with respect to Gobiformes oxudecidae (mudskipper) specimens collected from Jones creek, Delta State. They were analyzed for 16 priority PAHs spanning through a total duration of eighteen months which adequately captured both wet and dry seasons. The ΣPAHs varied from 0.000 to 0.106 mg/kg for mud skipper samples within the aforesaid duration of the research. The most dominant PAH observed were chrysene and benzo(a)anthracene with amounts of 0.106 ± 0.095 mg/kg and 0.042 ± 0.030 mg/kg. The most abundant PAH in terms of its detection is chrysene accounting for 20.63% of the 16 PAHs while the least was dibenzo(a,h) anthracene with relative abundance of 0.37%. The individual component ratio revealed that refining operations, domestic and industrial discharges and possible storm run-off could likely be the source of contamination. The total amounts of PAHs in the rainy season were comparatively higher than values obtained in the dry season. Distribution patterns revealed that PAHs possessing 3 and 4 rings were dominant which confirmed the pyrogenic source of the detected PAH. The dominance of the low molecular weight PAHs across the sampling stations was indicative of their bioavailability for uptake by biota. Diagnostic ratio among others employed included phenanthrene/anthracene and benzo(a)anthracene/chrysene. Calculation based on these ratios to determine the PAHs emission origins suggested pyrolytic origin of the sediment associated PAHs coupled with a pyrolytic or pyrogenic source of PAHs present in the mudskipper specimens.