Distribution and the use of diagnostic ratios for source investigation in urban soils of the Yenagoa City, Bayelsa State, Nigeria

Yenagoa is a non-industrialized city. This work aims to investigate the distribution, content and source of the sixteen United State Environmental Protection Agency (USEPA) priority polycyclic aromatic hydrocarbons (PAHs) in urban soils of the Yenagoa, Bayelsa State, Nigeria. The PAH concentrations in the urban soil samples were performed using GC–MS method. The Swali market axis of the city had the highest concentration (∑PAHs). The burden of low molecular weight (LMW) PAHs follows a decreasing order: Phenanthrene > acenaphthene>cenaphthylene>naphthalene> anthracene>fluorine and while the burden of high molecular weight (HMW) PAHs follows the decreasing order: Pyrene> Dibenzo (a,h) anthracene > indeno [1,2,3-cd] pyrene (InP> Chrysene> Fluoranthene> Benzo(a)anthracene> Benzo(k)fluoranthene> Benzo(b)fluoranthene. PAH fingerprint ratios for determining both petrogenic and pyrogenic (pyrolytic) PAH accumulation was employed. The Ph/An ratio for the soil samples were 2.49, 3.47, 0.613, 1.59, 1.99 and 2.44 respectively. This may be indicative of pyrogenic (pyrolytic) origin. Ind(1,2,3-cd)P and DbahA were high in the soils, this may indicate a major concern for carcinogenic risk and demands an urgent attention from policy makers and the government.