ABSTRACT
Sango-Ota is the industrial nerve centre of Ogun State in Nigeria. River Atuara is an urbanized river in this town. The aim of this study is to assess the quality of water in the river along its 13 km urbanized stretch within Owode – Ota and Gbenga quarters of Sango – Ota in Ogun State, Nigeria. A study of some physical and chemical analysis was carried out to determine the level of pollution in the river. Total Dissolved Solids, TDS, pH, Colour and Temperature measurements were obtained for nine locations on the 21 km river stretch. Laboratory analyses were carried out at 4 locations along the water course for the following parameters: pH, Conductivity, Turbidity, DO, BOD, COD, TDS, TSS. Others include Phosphate, Chloride, Nitrate, Sulphate, Cadmium, Lead, Iron, Copper, Zinc, and Nickel. Results indicate that the water quality reduces downstream of the urbanized stretch. Some of the level of heavy metals in the river calls for concern. At Owode, the lead content of 0.11 mg/L is too high compared to a maximum of 0.01 mg/l permissible, which can cause cancer. This can interfere with Vitamin D metabolism, and can affect mental development in infants. It is toxic to the central and peripheral nervous systems. Cadmium is below 0.002 which is just below the 0.003 mg/l permitted in Nigeria. Nickel content was 0.046 mg/l between Owode and Ewupe and this is above the maximum permissible level of 0.02 for Nigeria. This has the possibility of carcinogenic health impact. Owode and Ewupe have greater industrial impacts than the other two locations, Igboloye and Gbenga. The trends of each of the 21 parameters from the urbanized stretch of the river have been observed to follow a pattern that can be categorized as similar, mirrored, somersault and composite of mirrored and somersault. More studies were recommended in this direction as well as in determining the locations of factories and industries contributing to the pollution level around Ewupe and their effluent disposal programs will need to be ascertained.