Evaluation of Polycyclic Aromatic Hydrocarbons of Some Groundwater Sources Within the Reclaimed Orji Auto Repair Workshops, OWERRI, IMO STATE, NIGERIA

The study determined the concentrations and assessed the risk of polycyclic aromatic hydrocarbons during wet and dry seasons of groundwater sources within the reclaimed Orji auto repair workshops, in Owerri, Nigeria. The amount of polycyclic aromatic hydrocarbons was determined in random samples from five locations within this vicinity using the liquid-liquid and soxhlet extraction procedures and gas chromatography in tandem with a flame ionization detector. A total of fourteen and twelve PAH congeners were detected for wet and dry seasons respectively with concentrations of total PAHs observed in water samples during wet season ranging from 0.0012mg/ml to 1.0352mg/ml, with Pyrene having the lowest concentration of 0.0012mg/ml and 1-2 Benzoanthracene having the highest concentration of 1.1143mg/ml, and from 0.0006mg/ml to 0.5839mg/ml for dry season with Fluorene having the lowest concentration and Flouranthene having the highest concentration. The ratios of low molecular weight polycyclic aromatic hydrocarbons to high molecular weight polycyclic aromatic hydrocarbons are less than 1 in all locations during the dry season but varied during the wet season indicating that the contamination was of pyrogenic and petrogenic sources which also highlights the significant contribution of rainfall in increasing the contamination, while diagnostic ratio of the data showed that the actions of craftsmen and artisans contribute significantly to the increased level of PAHs found in this vicinity. The carcinogenic potency major ecological concern because the cancer risks were above 1 x 10-6, indicating a higher risk of cancer and potential harm to the health of children and adults.