Evaluation of the Hydrocarbon Status at Ahoada Oil-spill-impacted Site in the Niger Delta

The amount and distribution of total hydrocarbons (total petroleum hydrocarbons – TPH and polycyclic aromatic hydrocarbons -PAHs) were evaluated following the oil spill at Olaikata-Edoha in Ahoada-East Local Government Area of Rivers State, Nigeria. Both TPH and PAHs were estimated using Gas Chromatography (GC). TPH recorded a hydrocarbon distribution from n-C8-n-C40, consisting of total aliphatic hydrocarbon content and the acyclic isoprenoid hydrocarbons (pristane, phytane). TPH was 3.743m mg/kg at the oil-spill-impacted site against a control reference of 42 mg/kg. PAH also showed a higher concentration of 39.53mg/kg in the contaminated soils, and 4.31mg/kg in the reference control soils. High TPH levels adversely impact soil structure by clogging soil pores, reducing water retention, and disrupting root growth. Such soils become unfit for agriculture as the plants face restricted nutrient and water access, ultimately leading to reduced crop yields. The higher-than-normal concentration of PAHs obtained indicates significant health and ecological risks due to their carcinogenic potential and persistence in the environment. The findings of this work highlight the urgency of remediation efforts to address the elevated PAH and TPH levels to mitigate long-term environmental damage. Remediation techniques such as bioremediation, which employs microbial communities to break down hydrocarbons, could be effective in this context. Phytoremediation, using plants to absorb or degrade hydrocarbons, may also be explored as a means to restore soil health over time.