TITLE:
Sources of Polycyclic Aromatic Hydrocarbons (PAHs) in Groundwater and Associated Health Risks to the Population: A Case of the Continental Terminal (CT) Aquifer in South-Eastern Côte d’Ivoire
AUTHORS:
Koffi N’Da Florent Ayezou, Bernard Adiaffi, Brou Richmond Konan, Christelle Marlin, Aimé Koudou, Véronique Durand, Yéï Marie Solange Oga, Armandine Durand, Carine Kouadio, Elisabeth Gibert-Brunet, Éric Germain Kouakou
KEYWORDS:
Groundwater, Polycyclic Aromatic Hydrocarbons (PAHs), Continental Terminal, Sources, Health Risks, Abidjan, Western Africa Urban Area
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.14 No.9,
September
29,
2026
ABSTRACT: Polycyclic aromatic hydrocarbons (PAHs) are emerging contaminants of concern in groundwater of Côte d’Ivoire’s coastal zone, where rapid urbanisation and land-use changes have increased their release into the environment. This study investigated the occurrence, sources, and potential health risks of PAHs in groundwater from the unconfined Continental Terminal (CT) aquifer across the agricultural sectors of Dabou and Bonoua and the surrounding, urbanised sector of Abidjan. Concentrations of the 16 priority PAHs were analysed in 26 groundwater samples. Eight compounds were detected: fluorene (Flu), acenaphthylene (ACL), fluoranthene (FLR), pyrene (Pyr), benzo(b)fluoranthene [B(b)FL], benzo(a)pyrene [B(a)P], benzo(k)fluoranthene [B(k)FL], and indeno (1,2,3-cd)pyrene (InP). Total PAH concentrations ranged from 0.026 to 3.356 ng/L, with a predominance of low-molecular-weight PAHs, and remained well below the US EPA guideline value of 200 ng/L. Diagnostic ratio analysis revealed mixed petrogenic and pyrogenic origins, indicating contributions from petroleum-related activities and combustion processes. Human health risks were evaluated through ingestion and dermal exposure pathways. Non-carcinogenic hazard indices (HI) and carcinogenic risks (CR) for both children and adults were significantly below accepted safety thresholds (HI −4), suggesting negligible current health risks. Nevertheless, continuous monitoring is recommended because of the persistence, mobility, and documented toxicity of PAHs in groundwater resources in a highly dynamic unconfined aquifer under an equatorial climate.