Assessment Level of Polycyclic Aromatic Hydrocarbons in Soil Groundwater around Yenagoa and Environs, Southern Nigeria

ABSTRACT

The assessment of levels of Polycyclic Aromatic Hydrocarbons (PAHs) in groundwater and soils in Yenagoa and its environs, Southern Nigeria was carried out. A total of 10 samples each of soils and groundwater were collected and analysed using GC model: HP 6890 GC-FID, USA). Results indicates that average PAH values (concentrations in mg/l) for the groundwater in the area are: naphthalene (3.4036), acenapthylene (0.0845), acenapthene (0.0410), fluorine (9.0688), phenanthrene (4.4480), anthracene (0.9650), fluoranthene (0.5230), pyrene (10.0204), benz(a) anthracene (0.4920), chrysene (23.8938), benzo(b) fluoranthene (6.5118), benzo(k) fluoranthene (1.2597), indo(1,2,3-cd) pyrene (15.6872), dibenz(a,h) anthracene (26.8413). Standard Deviation (SD) for Water (PAH) as follows naphthalene ±4.57, acenapthylene ±0.13, acenapthene ±0.035, fluorine ±16.66, phenanthrene ±5.064, anthracene ±1.247, fluoranthene ±0.348, pyrene ±8.177, benz(a) anthracene ±0.376, chrysene ±25.36, benzo(b) fluoranthene ±15.208, benzo(k) fluoranthene ±1.152, indo(1,2,3-cd) pyrene ±10.828, dibenz(a,h) anthracene ±10.228. The mean concentrations of these PAHs in soils (mg/kg) in the area of the study are as follows: 6.148±18.21, 1.26,±2.659, 70±27.00, 2.56±6.10, 8.18±23.97, 1.87±4.89, 12.92±36.30, 422.58±1267.77, 157.99±491.41, 125.80±376.34, 218.03±1127.72, 67.65±256.79, 757.20±1609.17 and 4592.8±1286.13 respectively. The findings shows that PAHs concentrations are generally higher than the World Health Organization (WHO) recommended limits for both soil and water within the study area. The fairly strong correlation between the selected PAH ratios in the soil & groundwater (except for the B(a)A/Chr) clearly suggest common contamination pathways for both soil & groundwater in the area. The study also suggests the urgent need for hydrocarbon waste

management control in the area.

Keywords — Polycyclic, Aromatic, Hydrocarbon, Contamination, Soil and Groundwater