Heavy Metal Concentrations in Water from fishing sites in Federal Capital Territory and Four Selected States in North Central Nigeria

Abstract

Water collected from fifteen active fishing sites in Niger, Kogi, Kwara, Benue states and the Federal Capital Territory (FCT) were analyzed for its physico-chemical properties (pH, temperature, conductivity, total hardness and dissolved oxygen). The heavy metal contents (Cu, Zn, Ni, Cr, Pb and Cd) of the water samples were determined using MP-AES. The results obtained show that the pH of the water collected from Aliara fishing site in Kwara State was higher (8.111) and significantly different (p<0.05) from the pH of the water collected from other fishing sites. The mean conductivity values of the water collected from the study area (110.667-115.111 μs/cm) showed significant differences (p<0.05) from each other. Also, the Cu content in the water collected from Jabi mechanic fishing site (1.046 mg/dm3) was higher and differed (p<0.05) from the Cu content in the rest samples. Generally, the Zn (0.016-0.863 mg/dm3), Ni (0.001-0.074 mg/dm3) and Cr (0.001-0.062 mg/dm3) in the water samples from the study area were lower than the WHO permissible limits. However, the Cd content in these water samples evaluated in this study (0.005-0.015 mg/dm3) was higher than the WHO recommended permissible limits. The Principal component analysis (PCA) showed the following sequence: Pb>Ni>Cd>Cu>Zn>Cr. High level of heavy metals in River waters could be toxic to aquatic life and invariably affect humans following consumption. Relevant governmental agencies should enlighten the fishing communities on the best way to discharge their waste.