Edu Inam^{1, 2,}, Gerald G. Inoh³, Nnanake-Abasi O. Offiong^{1, 2}, Bassey B. Etim⁴

The coastal region of Nigeria has witnessed intense anthropogenic activities that have overtime necessitated several environmental monitoring campaigns to ascertain impacts and proffer remedial solutions. In the present study, standard analytical protocols were employed to assess the physicochemical parameters, trace metals and polycyclic aromatic hydrocarbons (PAHs) levels of ground and surface water used for drinking purposes in Okoroette community in Nigeria. The results obtained show that investigated parameters varied widely and were generally higher in the surface water samples collected during the dry season. The levels of most of the physicochemical parameters recorded were acceptable when compared with Nigerian Standards for Drinking Water Quality (NSDWQ) except for turbidity and dissolved oxygen. In both ground and surface waters, the following trace metals exceeded the NSDWQ permissible limits: Pb, Cd, Fe, and Mn. The total mean level of PAHs (> 1.0 mg/l) in both ground and surface water samples exceeded the acceptable level when compared with the NSDWQ guideline value of 0.007 mg/l. The health risk assessment applied on trace metal levels reveal that there is significant potential toxic risk to exposed individuals as calculated hazard indexes (HI) were greater than one. Results from Water Quality Indices (WQI) modelling reveal that the water sources in the community were generally categorised as poor quality or unfit for drinking purposes. Chemometric characterisation of the water quality indicators revealed that some of the contaminants may be of geogenic, anthropogenic organic in origin. The study reveals that drinking water sources in Okoroette community are not suitable for consumption and domestic use therefore treatment is highly and urgently recommended to safeguard public health.

water quality, health risk assessment, trace metals, PAHs, chemometrics, modelling